Fukushima Daiichi crisis – April 1 perspective

The Fukushima Daiichi nuclear crisis has moved off the front page of most newspapers, but a lot continues to happen, and the situation remains unresolved. Below I offer some personal perspectives on some of the things that have been widely reported over the last few days, and then I conclude with some official updates.

Disclaimer: What follows is my interpretation of the sparse and often confusing information being made available by TEPCO, NHK etc. Take or leave at your discretion.

Will the GE Advanced Boiling Water Reactor (a Gen III unit) be built at Fukushima Daiichi to replace units 1-4?

1. Plutonium detected in the soil around the plant. A few isotopes of plutonium (Pu) have been found in soil at various test sites at the FD plant. This has sent some folks on Twitter apoplectic. So where does it come from?

One theory, and quite a reasonable one, is that it is the global residual left over from the extensive atmospheric atomic weapons testing of the 1950s — 1970s. That would help explain the presence of Pu-238, for instance — an isotope not readily created in a power reactor.

Another thought is that there was a local source, either from volatilisation of sloughed material in the drying spent fuel ponds, or perhaps from the reactor cores (that was then carried away in minute traces via the vented steam). Being a heavy metal, however, the Pu would not mobilse readily and would deposit very locally. Remember, Pu is present in all spent fuel, via the U-238 –> Pu-239 transmutation pathway. All reactor fuel elements that have been fissioning will contain plutonium. It is not something peculiar to mixed-oxide (MOX) fuel (which was being used in FD unit 3), as some have implied — there has been a lot of nonsense written about this during the past few weeks.

In short, Pu is a metal, not a demon. Indeed, from my perspective on the Integral Fast Reactor technology, I see Pu as THE fuel of the future, and boldly predict that it will be looked back on, by some far distant civilisation, as among the most important elements humankind ever encountered. However, that’s for another post for another day. But if you want the full review now, please read Cohen.

2. Containment integrity and core damage. The story that hit the headlines was this

Richard T. Lahey, former chair of nuclear engineering at Rensellaer Polytechnic Institute, in Troy, N.Y., was quoted as saying that the evidence he had seen indicated that fuel melted through the pressure vessel of reactor No. 2 at some point after the crisis began. He told The Guardian:

“The indications we have, from the reactor to radiation readings and the materials they are seeing, suggest that the core has melted through the bottom of the pressure vessel in unit two, and at least some of it is down on the floor of the drywell.”

While I respect his personal opinion as an engineer with professional experience with GE BWRs, I really don’t think he’s correct– to me, as a logical analyst, it’s just not consistent with the recent data. The reactor pressure vessel (RPV) outlet temperature, RPV internal pressure, and drywell pressure readings, have all remained relatively stable over the last few days (see latest FEPC and JAIF reports at the foot of this blog entry). I can’t see that this could possibly have been the case if chunks of molten metal had burned a gaping hole through the 8″ thick steel vessel and then fizzed through the concrete floor to boot. It certainly didn’t happen at TMI-2 in 1979, and I don’t think that it happened at Fukushima unit 2 either. Lahey seems to think his theory is supported by the high radiation readings in the water trench adjacent to unit 2… however, I disagree, as I explain in point 3.

3. Trench water. I think World Nuclear News had done an excellent recap on this: Tsunami likely filled trenches. In short:

Analysis of the trenches at Fukushima Daiichi indicates they were probably flooded by the tsunami. Low radioactivity in one trench may result from capture of radionuclides from the air but high levels in another are unexplained…

…But while an answer appears close on the presence of the water, the levels of radioactivity remain unexplained. The trench at unit 2 is a serious concern due to radiation levels from surface measurement in excess of 1000 millisieverts per hour. Further sampling has not yet taken place due to this extraordinary level, and it is not clear if the dose rate is representative of the whole 6000 cubic metre body of water, although it does match the level in the basement of the turbine building. Unit 2 suffered suspected damage to its torus suppression chamber on the morning of 15 March.

The key to this riddle, I think, is the wetwell torus breech (which is likely to be a pinhole or crack) — there has clearly been damage to containment at unit 2, but NOT, I think, to the RPV. The radioactive water in the trench could also plausibly have come from cracked/burst piping or seals elsewhere in the containment/primary system (remembering that in a BWR, the cooling water/moderator also runs through the turbine directly, unlike in a PWR). But there is no reason to think that this water comes directly from the RPV or drywell (which is where the fuel would be if it had melted through the RPV). Indeed, I think the chances of a large steam explosion at this stage of events — more than two weeks out from the core damage event — is remote in the extreme, and even if this highly unlikely chain of events did occur, it would still not spread reactor fuel over a wide area, because most of the heavier material is very difficult to mobilise  and disperse (remembering that there is no burning graphite in this situation, unlike Chernobyl, and even in that accident most of the actinides stayed put).

The weird theories of Caldicott and her ilk, in which she fantasises about some ‘magical’ mechanism that is able to spread fine particulates of Pu across the landscape and into the lungs of millions of humans, and so (she outrageously claims) render the Japanese islands uninhabitable as a result, is simply beyond a joke (from many angles). Actually, it’s nothing short of appalling, grossly unscientific, hyper-alarmism.

4. Spent fuel ponds. These continue to get serious attention, with regular injections of water. They have likely been the primary source of the Cs-137 releases. The current TEPCO plan is to switch to fresh water injection ASAP. The pools in units 5 and 6 are now stable and both below 40C (see reports given at the end of this post), but there is still some concern of the pools in units 2, 3 and 4 especially. There was even a report that authorities are still considering entombing them in concrete. It’s possible, but I really don’t think that will happen because it may solve a few short-term problems, and create other longer-term site-management headaches (personal judgement).

5. Radation levels in the ocean. These continue to be elevated close to the plant, due presumably to site run-off and the flushing/settling of airborne particles, but drop away rapidly with distance as the isotopes are spread in the ocean waters, as expected. The I-131 has a short half life, and the longer-lived Cs-137 does not bioaccumulate like mercury (for instance). I thought John Bennetts, writing in response to another BNC commenter who had earlier objected vociferously to my rather bland statement about the ‘disperse and dilute’ principle, summed it up rather well:

Firstly, to demand that a reference be provided to support the notion that 500ml of water, when mixed with the waters of an ocean, actually dilutes! I am shocked! Indeed, once the dilution factor achieves 128, then all reported isotope concentrations will be below the reporting limit, i.e. of no interest to the regulatory authorities. So what’s there to worry about? At that point, your own concerns will become baseless. As per the table at the head of this thread, three limits have been exceeded and publicly reported.

With a half-life of 8 days, the offending isotope will naturally decay by a further factor of 128 in 7*8 = 56 days, after which time you can be doubly assured that no nasty exceedances remain. I have no doubt that assessment of the real world impacts will be reviewed and assessed and talked about for some time to come, but the fact remains, that once the waters have been diluted in the Pacific, there will be no cause for further alarm. There will be no ongoing public health threat and there will be no threat to the food chain.

The only threats after dilution will be those which arise due to incomplete dilution, e.g. possible uptake in molluscs of certain species, or in aquatic vegetation, and even these will dissipate rapidly with time. I am sure that there are many suitably qualified people who will be involved in ensuring that hypothetical secondary effects are assessed and monitored and that, where doubt exists, actions such as bans on fishing are put in place. You have added precisely nought to the process of rational assessment, review and response which will ensure that the community’s health will not be damaged through these releases.

6. Future of Fukushima Daiichi site. TEPCO have announced that units #1 to #4 will be decommissioned once the crisis is finally closed off. Hardly surprising. I said about 2 weeks ago that 1-3 were write-offs, and although unit 4 didn’t have a fuel loading during the accident, the secondary containment has been so badly damaged by the hydrogen fires and problems with the drying spent fuel ponds that it was inevitable that it’d also be curtains. World Nuclear News has more on that story here. The decomm period is likely to take 5-10 years, based on TMI-2 experience (TMI-1 is still running, incidentally), and perhaps longer given the serious problems they’ve had with multiple reactor units. The fate of the undamaged units 5 and 6, which are some 200 m distance from 1-4, remains unresolved. I suspect they’ll eventually be put back into operation, as Japan really needs their electricity, but probably not for 12+ months. From that WNN story, there is also now speculation about whether the slated Gen III units (GE advanced boiling water reactors, similar to those built at Kashiwazaki-Kariwa in the 1990s) will be built on the Fukushima Daiichi site the future:

Tepco had planned to construct two 1380 MWe Advanced Boiling Water Reactors at Fukushima Daiichi and the start of work on these was slated for 2012. This was a delayed date as a result of additional earthquake engineering flowing from what the company learnt during a July 2007 earthquake that hit similar reactors at Kashiwazaki Kariwa. Tepco contracted for 1600 MWe of new coal generation and 4500 MWe of gas to bridge the supply gap.

So, at least that’s clear. Once again, it’s nuclear, or it’s coal and gas.

7. Other useful unofficial posts. Charles Barton from Nuclear Green looks at the good, the bad and the ugly side of reporting on the Fukushima crisis. George Monbiot comments on The double standards of green anti-nuclear opponents (We must apply the same standards to all energy-generating technology as we do to nuclear power). Will Davis, a former U.S. navy reactor operator, has an interesting blog going here: Atomic Power Review, with some informed theories and speculation on what the FD data mean. Worth checking out.

8. Donations to BraveNewClimate. Many people have asked about this, in the comments and privately, and I thank them for their generosity. However, I’ve always maintained that I’d rather pay for the running of the site myself ,on principle. That is, I don’t want to be seen to profit from this venture in any way, because I do it for non-monetary reasons. Indeed, it’s fair to say that I get more than enough reward out of the work by having people read my posts and for them providing a wonderful stream of comments that really makes this blog alive (even if I don’t always agree with them!). That community input makes me feel rich indeed.

(Oh, and I don’t get any $$ from the Google Ads that run — this is how WordPress extracts their pound of flesh for their otherwise largely free [and excellent] hosting service — I just pay them for domain redirection etc.).

———————————

Okay, on to some (semi-) official stuff. The latest IAEA report is here (last updated on 30 March). NEI update status here. Some snips:

At the Fukushima Daiichi site, workers continued to inject fresh water into reactors 1, 2 and 3 to keep them cool, while at the same time dealing with water that has pooled in the basements of turbine buildings and in concrete trenches near the units. As available storage space in the reactors’ condensers is filled, Tokyo Electric Power Co. is looking to store the radioactive water in tanks that will be brought to the facility. TEPCO has switched to fresh water for spraying the spent fuel pools for reactors 1, 2, 3 and 4.

All the units at Daiichi are operating on off-site electric power and work continues to connect equipment. High radiation levels and wet equipment still hampers restoration of the plants’ original machinery.

Here is the latest JAIF status update, as of 2100 on 31 March 2011:

Here are links to the latest reports from the Japanese Nuclear and Industrial Safety Agency (NISA):

Conditions of Fukushima Dai-ichi Nuclear Power Station Unit 1-6(As of 14:00 30th, 2011)

Fukushima Di-ichi Nuclear Power Station Major Parameters of the Plant (As of 14:00, March 30th)

March 30th, 2011 Fukushima Dai-ichi Monitoring points

Finally, the most recent FEPC report:

  • Radiation Levels
    • At 8:51AM (JST) on March 31, it was announced that radioactive nuclide I-131 was detected from the seawater sampled near the seawater discharge point (south side) of Fukushima Daiichi Nuclear Station at 1:55PM on March 30. The level of concentration was approximately 4,385 times higher than the maximum permissible water concentration set by the government.
    • At 2:00PM on March 31, radiation level at main gate (approximately 3,281 feet from Unit 2 reactor building) of Fukushima Daiichi Nuclear Power Station: 157 micro Sv/hour.
    • At 2:00PM on March 31, radiation level at west gate (approximately 3,609 feet from Unit 2 reactor building) of Fukushima Daiichi Nuclear Power Station: 99.9 micro Sv/hour.
    • Measurement results of environmental radioactivity level around Fukushima Nuclear Power Station announced at 7:00PM on March 31 are shown in the attached PDF file. English version is available at:    http://www.mext.go.jp/english/radioactivity_level/detail/1304082.htm
    • For comparison, a human receives 2,400 micro Sv per year from natural radiation in the form of sunlight, radon, and other sources. One chest CT scan generates 6,900 micro Sv per scan.
  • Fukushima Daiichi Unit 1 reactor
    • At 8:00AM on March 31, pressure inside the reactor core: 0.329MPa.
    • At 8:00AM on March 31, water level inside the reactor core: 1.65 meters below the top of the fuel rods.
    • At 8:00AM on March 31, pressure inside the primary containment vessel: 0.21MPaabs.
    • At 8:00AM on March 31, the temperature of the reactor vessel measured at the water supply nozzle: 480.9 degrees Fahrenheit
    • At 9:20AM on March 31, transferring of the accumulated water at the trench (concrete tunnel which houses pipes and cables) outside the turbine building commenced, until 11:25AM. As a result, the water level at the trench was reduced from 0.14 meters to 1.14 meters below the top of the trench.
    • At 1:03PM on March 31, TEPCO began to shoot freshwater aimed at the spent fuel pool, with a specialized vehicle normally used for pumping concrete.
    • As of 3:00PM on March 31, the injection of freshwater into the reactor core continues.
    • As of 3:00PM on March 31, preparation to recover and transfer the accumulated water at the turbine building continues.
  • Fukushima Daiichi Unit 2 reactor
    • As of 3:00PM on March 29, the water level at the trench was 1.04 meters below the top of the trench.
    • At 8:00AM on March 31, the temperature of the spent fuel pool: 131 degrees Fahrenheit.
    • At 8:00AM on March 31, pressure inside the reactor core: -0.016MPa.
    • At 8:00AM on March 31, water level inside the reactor core: 1.5 meters below the top of the fuel rods.
    • At 8:00AM on March 31, pressure inside the primary containment vessel: 0.11MPaabs.
    • As of 3:00PM on March 31, the injection of freshwater into the reactor core continues.
    • As of 3:00PM on March 31, approximately 96 tons of water in total has been injected into the spent fuel storage pool.
    • As of 3:00PM on March 31, preparation to recover and transfer the accumulated water at the turbine building continues.
  • Fukushima Daiichi Unit 3 reactor
    • As of 3:00PM on March 29, the water level at the trench was 1.55 meters below the top of the trench.
    • At 9:40AM on March 31, pressure inside the reactor core: 0.016MPa.
    • At 9:40AM on March 31, water level inside the reactor core: 1.85 meters below the top of the fuel rods.
    • At 9:40AM on March 31, pressure inside the primary containment vessel: 0.1066MPaabs.
    • As of 3:00PM on March 31, the injection of freshwater into the reactor core continues.
    • As of 3:00PM on March 31, approximately 4,697 tons of water in total has been shot to the spent fuel storage pool.
    • As of 3:00PM on March 31, preparation to recover and transfer the accumulated water at the turbine building continues.
  • Fukushima Daiichi Unit 4 reactor
    • As of 3:00PM on March 31, approximately 1,098 tons of water in total has been shot to the spent fuel storage pool.
  • Fukushima Daiichi Unit 5 reactor
    • At 11:00AM on March 31, the temperature of the spent fuel pool: 86 degrees Fahrenheit.
  • Fukushima Daiichi Unit 6 reactor
    • At 11:00AM on March 31, the temperature of the spent fuel pool: 78.8 degrees Fahrenheit.
  • Fukushima Daiichi Common Spent Fuel Pool
    • At 8:20AM on March 30, the temperature of the spent fuel pool: 89.6 degrees Fahrenheit.
    • As of 3:00PM on March 31, approximately 130 tons of water in total has been injected to the spent fuel storage pool.

Our official sources are:

  • Office of The Prime Minister of Japan
  • Nuclear and Industrial Safety Agency (NISA)
  • Tokyo Electric Power Company (TEPCO) Press Releases
  • Ministry of Education, Culture, Sports, Science and Technology (MEXT)


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222 Comments

  1. … global residual left over from the extensive atmospheric atomic weapons testing of the 1950s — 1970s. That would help explain the presence of Pu-238, for instance …

    It is created by the (n, 2n) process on plutonium-239, so it accumulates and is one of the isotopes that prevents nuclear weapon seekers from being interested in power reactor plutonium.

    The (n, 2n) process can happen twice, and then you get plutonium-237, and this, if found, would be the isotope that would really nail down a local, recent origin for the plutonium they’re finding.

  2. Most of the problems seem to stem from:

    1. Public fear of the words “radiation” and “nuclear” rather than the reactors

    and

    2. From the fact that in a “face” culture like Japan’s no-one seems to want to accept any responsibility, in case they’re left holding the parcel when the music stops.

  3. “In short, Pu is a metal, not a demon”

    lol, I suppose you could look at anything like that. Mercury is only a metal, Arsenic is a Metalloid. Still would not like to have too much of that sort of thing sprinkled on my cornflakes. (Before you all start, I am not suggesting Plutonium will get on anyones cornflakes as I have no evidence)

    On the whole thanks. I do like your site as it is producing stimulating discussions.

  4. Good summary indeed

    Regarding point #2 :

    the pressure vessel of BWR (Fukushima) differs from the pressure vessel of PWR (TMI) in that the control rods raise from below instead of dropping from above. It means that there are a lot of holes at the bottom of the 8″ thick steel vessel, with seals potentially more fragile that the steel they cross. So some of the corium could get through this without necessarily destroying the temperature sensor at the bottom of the vessel. See Will Davis’s take on this http://atomicpowerreview.blogspot.com/2011/03/nisa-having-meeting-right-now.html?showComment=1301337725382#c5781536944638765117 .

    Regarding #6 :

    From a cold and rational standpoint, Fukushima may actually be the best site to build new NPP in Japan , not only using the 5 and 6 plants :
    – The “big one” has already happened, after a few years of aftershock, the area should be quite quiet.
    – It is likely that a zone of a few kilometers diameter is going to stay evacuated and TEPCO will have to indemnify anyway. At least they would get something for this money !

  5. Can someone explain the following? If they are pumping 130 lts/hr into reactor vessels, were is the output water going? Are they sending it to the sea and that can explain the radioactive isotopes found there? Because is like a great amount of water and should be difficult to find a place to store and clean it. What is the reactor vessel capacity (I mean, volume)?
    Thanks very much.
    Fernando.

  6. We need to start taking the lead in developing tsunami defense. Clearly the quake was, not to be glib, not the issue in terms of safety. In fact, if you look at all the total deaths, 90% of them seem to have come from the tsunami, not the quake, which despite the national reputation of Japan being dragged through the mud, was and IS the best prepared nation in the world for these sorts of quakes: Again, the quakes did relatively little damage.

    Now…we need to get the “industry” that has sea side plants around the Pacific to develop relatively ‘cheap’ tsunami defense against 10+ meter waves. This means massive, or higher than exists, break waters (jetties, walls, etc) set out in multiple layers around the entrances of these plants, especially around the intake structures.

    Secondly, the really expensive program, is to relocate those emergency generators and their fuel supplies to something akin to what Diablo Canyon has done in California: locate the full *up* over the plant to protect them, then, as the did at DCNPP, double reinforce the foundations and walls to prevent castrophic tank failure.

    David

  7. … radioactive nuclide I-131 was detected from the seawater … approximately 3,355 times higher than the maximum permissible water concentration set by the government

    Would that be a limit for potable water?

    What does this 3355-fold over the limit concentration amount to in terms of beta and gamma power per litre of this water?

  8. @Eric Moore: I guess I hed no difficulty understanding the “Pu is a metal, not a demon” phrase but I can also understand your puzzlement, because Barry doesn’t quote all the wild claims that are made about plutonium. They would require it to have supernatural properties to achieve even a fraction of the damage that anti-nuclear speakers attribute to it as a matter of course. In that world, plutonium can escape from any confinement, dissolve and precipitate at will, reverse entropy, kill people with a single atom, turn future generations into monsters and generally spell the end of lfe on the planet, if not the universe. In short, it would have to be a demon, not subject to physical laws.

    Caldicott is especially eloquent (in an obsessive [ad hom deleted] sorta way) on the subject.

  9. Pingback: Nuclear Power Poll – Your Opinion » The Green Forums - Sustainable energy, transport, architecture debate

  10. Eric Moore, of course plutonium and mercury are just metals. The important thing is to make sure they do not go into the environment at large scale. Coal plants have no problem emitting TONS of mercury, cadmium and arsenic per year per large plant. Plutonium oxides are not volatile which is why we see trivial amounts in the surroundings… these levels just aren’t anywhere near being dangerous, whereas the heavy metal emission of coal plants in NORMAL OPERATION is very damaging to health.

    I think Barry is right. Damage to fuel means fission products in the coolant water, then torus and/or some pipe damage leaks water into contaiment carriying said fission products… easy to get Sievert levels this way.

    There is water in the bottom of the reactor pressure vessels, the seawater and now freshwater that is injected. This means you cannot have a melt that goes through; any corium contacting water would be rapidly cooled and the water also cools the reactor pressure vessel bottom. It is a pan with water in it. You cannot burn a whole at the bottom of a pan when there is still water in it. IF there was damage to the control rod housing you would also see considerable water in the drywell, which isn’t detected. Like Barry says the pressure levels do not indicate any corium in the drywell bulb pit.

    Finally I would add that the drywell can be flooded which is just as easy as seawater injection the the reactor pressure vessel. If pressures and/or temps go too high the engineers will do this, if not necessary they won’t. Apparently they found it necessary to flood the drywell of unit 1, but not unit 2 and 3 according to the data so far (they use confusing words such as ‘to be confirmed’ which is annoying). Does anyone have a better

    As for perspective, so far zero radiation deaths and no lethal doses to workers yet. Clearly public safety is not at risk and worker safety is the only real concern. The worst are two workers that burned their legs in beta/alpha radiation water, however they are relieved from the hospital already. They do not face immediate risk but might have increased chances of skin cancer with local exposure up to 3 Sieverts (whole body dose under 0.2 Sievert). This is of course a serious situation for the two workers and I don’t mean to trivialise the risk of these poor workers but fossil fuels cause more than 100000 lung cancers a year and possibly over 1 million cancers total by linear no threshold model (but that model is silly). 6000 Chinese coal miners died in accidents last year (official figures are too low). This is not trivialising the situation, it is providing perspective. More perspective: so far no large dose rates in nearby land (all under 20 mrem/hour and dropping fast) and only small spikes of activity found in local areas (may require some soil remediation). So no evidence of ‘thousands not able to go back to their homes for decades’ as some anti-nukes have put it.

    Like David Mackay has said: “I’m not trying to be pro-nuclear – I’m just pro arithmetic”. Numbers are what is important in this situation. It is a shame the media is mostly innumerate, saying things like ‘plutonium found in soil’ but not mentioning the dose rate from standing on this soil or eating it. But perhaps its hardly surprising; if we look at dose rates per person for the public and dose rates from standing on nearby land, suddenly this crisis doesn’t look like apocolypse anymore. No sensation to be found there.

  11. Lahey’s qualifications

    Just a note to say who it is that Barry is disagreeing with.

    Lahey has been elected to the National Academy of Engineering, which is a part of the National Academy of Sciences in the US.

    He was Editor, Journal of Nuclear Engineering and Design (83-94). He was a member of the USNRC Containment Code Review Group (1977-1984). Lately, he was a member of the National Research Council panel that studied “The Safety and Security of Commercial Spent Fuel Storage” (2006), the ones who published on if a zirconium cladding fire could break out in a dry spent fuel pool and what the consequences might be.

    A tiny fraction of his published papers includes:

    “Modeling and Calculation of Corium/Concrete Interaction in a MARK-I Containment,” ANS Transactions, Vol. 61, 1990 (with H. Jia, S.J. Lee and M.Z. Podowski).

    “An Analysis of Chugging Loads in Containment Systems,” ANS Transactions , Vol. 62, 1990 (with P.M. Lahey and D.A. Drew).

    “The Analysis of S/RV Loads in Pressure Suppression Containment Systems,” ANS Transactions, Vol. 63, pp. 304-306, 1991 (with P.M. Lahey and D.A. Drew).

    “A Model of BWR Containment Thermal-Hydraulics under Severe Accident Conditions,” Proceedings of the 27th NHTC, Minneapolis, MN, July 28-31, 1991 (with S-W. Kim and M.Z. Podowski).

    “Multidimensional Effects During Corium Spreading in a MARK-I Containment,” Proceedings of the 28th NHTC, San Diego, CA, Aug. 9-12, 1992 (with S. Kasprzak, H. Jia, M.Z. Podowski and R. Lilquist).

    An Analysis of BWR/4 and BWR/5 Pressure Boundary Failure Modes During Core Meltdown and Its Impact on Mark-II Containment
    $304,667 2/1/84-1/31/86.

    There is a very long page listing all his experience qualifications, honors, and publications http://www.rpi.edu/~laheyr/laheyvita.html

  12. Caldicott

    I watched the Youtube video of the Caldicott vrs Monbiot debate hosted by Democracy Now.

    Barry up there actually understates what Caldicott is claiming.

    She is in high dudgeon now that there is the biggest spotlight on the nuclear issue since TMI and Chernobyl.

    After asserting that “1 million people” have already died as a result of Chernobyl, she stated that “people will continue to die for the rest of time”. Referring to Fukushima, she said there is “enough Plutonium in these reactors to kill EVERYONE ON EARTH”.

    It isn’t just the entire population of Japan she is worried about. This is “AN ABSOLUTE CATASTROPHE THE WORLD HAS NEVER SEEN”.

    According to her, it seems, there was no radiation anywhere in Europe until Chernobyl blew up. “40% of the European landmass is still radioactive”. Monbiot suggested that there were authorities who disagreed with her assessments. Caldicott: “There is NO DEBATE about this… in the medical community”.

    Caldicott: “You must listen to me…. I DON”T SAY THINGS THAT ARE INACCURATE…. Otherwise I would be deregistered. DOCTORS CAN’T LIE”.

    Its too bad. We’re all going to die. I guess there’s no point in finishing up that painting the kitchen project I’ve got going.

  13. Following Barry’s link to the IEEE Spectrum article, I wonder if that has been updated or if Barry is only quoting from the newspaper story about this.

    Barry dismisses (correctly) the notion that “chunks of molten metal had burned a gaping hole” — where does that come from? I’d like to see the first use of that claim tracked down. It’s nonsense. Someone’s exaggerating for effect. Who??

    And from reading the IEEE article, nobody claims that. The bottom of these reactor vessels is _full_of_holes_ — that’s how the control rods move in and out, through the bottom. It’s a plate full of openings with plugs and seals around each rod.

    The quotes at the IEEE article, at least as of right now, are far more nuanced than the paraphrase — and everyone seems to agree that some core material has leaked out, not a large-scale breach.

    From the IEEE article now:

    “Lahey thinks there’s a chance that the corium escaped through narrow channels formed by the control rods, which in this type of reactor go all the way to the bottom of the vessel. In that case, the corium could have been extruded through the channels, forming something with more surface area.
    …. If the corium has escaped through the control rod channels it’s more like trying to cool french fries.

    … We’ll check in with Lahey later as the situation develops.

    … Hidehiko Nishiyama, the deputy director general of the Nuclear Industry and Safety Agency (NISA), did not see evidence of a big breach of the pressure vessel, but acknowledged that its not completely contained. “When we look at the release of radioactive material up to now, while we do not believe there is any major breach either to the pressure vessel or the containment vessel, we are pretty sure there is some leakage” he told Boyd.
    —–

    So — “huge gaping hole” is bogus for the present situation. Hasn’t happened.

    On the other hand, “Cyril R” claims a safety level far beyond what the experts do. Read this:

    http://www2.jnes.go.jp/atom-db/en/trouble/individ/power/g/g20010706/index.html

    “This event is considered to be a common problem to BWRs which were constructed according to the same manufacturing process….”

    These specific reactor designs have had problems that — if they had not been fixed as of this quake and tsunami — could have caused the worst case melt-through (a boil-dry scenario); that’s a calculation from the heat produced vs. the quantity of water available in a worst case failure.

    That did NOT happen here.

    The company _did_ fix these problems with cracks in the bottle. See the pictures in that page. Work back up on the site to the list of problems and fixes:

    http://www2.jnes.go.jp/atom-db/en/trouble/individ/power.html

    Here’s Dai-ichi:

    http://www2.jnes.go.jp/atom-db/en/trouble/individ/power/f/f_power_index.html

    Lots of things found and fixed.
    Good thing, eh?

  14. Hank, on the problem discussed in your first link there: the shoud is a structure internal to the reactor pressure vessel. It is not a pressure vessel itself. Cracks in the shroud compromise its own structural integrity, and large-scale failure might well disrupt the working of the reactor, but would not constitute a path for radioisotope escape.

  15. The thing with plutonium toxicity; it’s not particularly dangerous unless respired or injected. Respirable particles are 5 micron or less; larger particles can’t get into alveoli and have short residency time in the lungs.

    For plutonium nitrate(very soluble in water) the gastrointestinal tract absorbs only ~10^-4. For fine particles of plutonium oxides it is ~10^-5.

    Plants show a similar level of discrimination against plutonium.

    Thus, inhalation is THE concern with plutonium(even after the plutonium-bearing dust has settled you should be more worried about it getting re-suspended than about drinking water), with drinking water being a very distant second and food completely irrelevant.

  16. The shroud cannot fail in a way which would compromise cooling during emergencies. It has to take its own weight which is trivial, it is a cilinder which is just sitting upright, it is not a pressure boundary (only slightly in normal operation with fast flow downwards, not in accidents decay heat cooling flows). There is no plausible way to deform the cilinder such that cooling the 0.2 percent decay heat can be inhibited.

  17. Regarding experts opinion, everyone can and does make mistakes. The Chairman of the US Nuclear Regulatory Committee said previously that the spent fuel pools were completely dry, which was proven very much false by sattelite imaging/sensing.

    Trust the evidence, trust the numbers.

  18. For someone without a science background, and many things at stake during this crisis, it is very easy to get lost amongst the many debates going on. For me, right now, its about making a choice, so my question is from a selfish perspective. Before the crisis, I had it all planned out to live in Tokyo for two years from April. Now I am concerned about the penetration of radioactive material in the food chain. Im considering cancelling my plans, since there has been evidence of contamination in some areas. Like I said, I get lost with all the different kinds of isotopes. All the doctor friends I have consulted back home (not radiology or oncology specialists) keep telling me to avoid going to Japan, but I’m not sure about their level of experteese in the subject, and wonder if they are not being carried away by the hysteria. It has probably been discussed before, so please re-direct me to the relevant discussion, but here is the question: given the information available at the moment, is it a health risk to spend two years in Japan from now?

  19. the evidence and numbers are not looking good.

    ground water has been strongly contaminated:

    “HIGH levels of radioactive iodine-131 that are 10,000 times the government safety standard have been found in groundwater below Japan’s stricken nuclear plant, its operator TEPCO says.

    The water sample, taken on Wednesday from 15 metres beneath reactor 1 at the Fukushima plant, tested at about 430 becquerels per cubic centimetre, a spokesman for Tokyo Electric Power Company said today.”

    http://www.heraldsun.com.au/news/breaking-news/radioactive-groundwater-below-nuclear-plant/story-e6frf7jx-1226031723826

  20. Hank, I for one wouldn’t agree that it is certain that anything has leaked out of the reactor vessel, in the sense of solids and high-temperature melts. The gas/vapour/smoke route of escape still seems more likely to me on the quality of releases to-date, which I think is achievable in principle through the venting mechanisms from the RPV, along with a breach of the wetwell torus.

    I would concede that there is a chance that Lahey is right, and some melt has extruded from the control rod channels. If so it would probably be rather reduced in fuel oxide compared to what remains in the RPV.

  21. sod, thanks for the good news. More iodine-131 staying safely under the plant is less getting airborne to cause problems.

    Incidentally, like the seawater measurements, the groundwater measurements are compared to drinking water standards. This is somewhat misleading; they would both fail on numerous other points to be safe for drinking.

  22. views of Bernard Cohen, LNT, and what scientific sources people should take to be the most credible

    Now that we are seeing the media blow radiation out of proportion, turning the spotlight on to types such as Caldicott etc., in reference to Fukushima, it is worth reading Cohen’s chapter How Dangerous is Radiation. http://www.phyast.pitt.edu/~blc/book/chapter5.html

    Cohen compares the credibility of, for example, the BEIR panels with the credibility of those such as Sternglas et. al, Caldicott, etc.

    People who dispute LNT as assessed by BEIR might want to consider what Cohen has to say about the National Academy of Sciences, the possibility that any panel created by the NAS could possibly be involved in a conspiracy to suppress the truth, or for that matter, be wrong, how solid the support is in the wider scientific community for NAS panels as opposed to the fringe views of a few scientists on any topic, etc.

    The next time you cite a study that appears, in your mind, to contradict what an NAS panel such as BEIR VII says, think about what Cohen has to say.

  23. When I examine the pressure readings, I see distinct differences between the way that reactors 1 – 3 are behaving.

    By design, the RPV is a pressure vessel within a secondary pressure vessel (the PCV and torus being the secondary pressure vessel). The RPV normally operates at ~70 atm but can withstand a lot higher pressure (up to 200 – 250 atm). The PCV/torus is designed for 4 atm. These numbers have been published numerous times in these threads.

    They are injecting water into the RPV to cool the core. As the injected water heats up, the pressure and temperature inside the RPV increase. They vent steam from the RPV to the PCV to reduce the pressure and allow them to inject more water. The stem vented to the PCV normally quenches and condenses and drains into the torus. The water in the torus is then cooled by heat exchangers.

    If you look at the published conditions you can see that #1 RPV is at ~5 atm gauge pressure and 150 deg C which is what one would expect for steam/water at 5 atm. The PCV is at ~2 atm absolute pressure. To me it appears that both the RPV and CPV are intact as they both hold pressure.

    With reactors #2 and #3 the RPVs and CPVs are both at atmospheric pressure which indicates to me that the RPV pressure boundry has been breached. As many have stated this does not mean that there is a gaping hole in the bottom of the RPV. But if the RPVs can’t hold pressure they are certainly leaking. Most likely through damaged packing glands for the control rods at the bottom of the RPV.

    Similarly for the CPVs: since they are not holding pressure they are breached.

  24. > it would probably be rather reduced in fuel oxide
    > compared to what remains in the RPV

    Why? Are you assuming fractionation and layering so a leak would be some oxide (heavier than anything else) at the bottom?

    References I see are to “corium” — a mixture of everything melted — as what’s expected to leak.

    I’m not able to tell who here is speaking from expert knowledge, who from amateur optimism, and who from some expert source — so some cite would be appreciated for the opinion.

    This page quotes “… two nuclear engineering experts, Andrew Kadak, from MIT, and Mitchell Farmer, a researcher at Argonne National Labs …” on the question: http://www.technologyreview.com/blog/energy/26524/

  25. Joffan, you’re right, that specific link is to internal (shroud) cracks. For more mentions of problems around connections to and penetrations of the pressure vessel, from the past history:

    http://www.google.com/search?q=site%3Awww2.jnes.go.jp+pressure+vessel+cracks

    Just saying, we have to remember the theory describes how the structure behaves when build; the actual condition after years of use and repairs will differ, and it’s hard to say how. Likely a repair will not be stronger than the original, though.

  26. @Hank Roberts On the contrary, repairs are often stronger than the original. This is fact in so many domains, that I’m surprised you would come to that conclusion.

  27. Hank, I am strictly an amateur. The information I was speculating on to reduce fuel content for extruded material was my recollection of the as-found condition of TMI damaged fuel. Having revisited the subject, I find that my recollection was wrong, and there is no special reason to expect lowered ratios of fuel in a melt compared to other core debris.

    And thanks for the link.

  28. > repairs … stronger than the original

    I was thinking specifically of repairs to nuclear reactors, from what I’ve read (and I’m an amateur, I’m just reading what I can find by looking).

    Here for example: a new laser welding technique

    http://infolib.hua.edu.vn/Fulltext/ChuyenDe2009/CD144/65.pdf

    As it says there, the laser method is tried because the standard welding method increases the susceptibility of the metal to corrosion (which in a reactor vessel would lower the strength).

    I’d be glad to see anything on this kind of repair that supports your belief.

  29. Thanks for the common sense articles, I am not at all involved in the nuclear industry and not pro nucleer except for Fussion reaction. What I do support is honest communication and feel the press and various pressure groups have taken advantage of the situation and mislead the public, causing needless tress, and whilst a very serious matter honest reporting is needed. Thanks again from somebody who appreciates common sense.

  30. @Hank Roberts – I am not an amateur when it comes to repairs on metals and composites. An improper repair is not what I was referring to. The wrong technique, or the wrong process is obviously not going to be serviceable; you wouldn’t try to patch a crack in a pressure vessel with chewing-gum.

    What I was contesting is your assertion that quote:“Likely a repair will not be stronger than the original” which is an unsupportable and invalid generalization.

    I cannot get your link to resolve, so I don’t know exactly what was written on the matter, but there are a host of processes, and craft techniques that can be used to prevent stress failure of weldments.

    Welds can be made with the addition of filler metal of the same composition as the base or can be made autogenously (without filler metal); controlled atmosphere, and heat control can be optimized to avoid improper recrystallization, microsegregation, and precipitation of secondary phases, all which cause susceptibility to corrosive attack. As well there are also many instances in which the weld exhibits corrosion resistance superior to that of the unwelded base metal.

    Thus any broad statements to the effect that a repair is necessarily weaker that the original is categorically wrong.

    BTW laser welding is hardly new – its been around for almost forty years

  31. > link
    Google found it, see if this finds it for you:

    JD Kima – 2001 – Repair welding of etched tubular components of nuclear power plant by Nd:YAG laser. Jae-Do Kima,*, Cheol-Jung Kimb, Chin-Man Chungb …
    infolib.hua.edu.vn/Fulltext/ChuyenDe2009/CD144/65.pdf

  32. I didn’t say a repair is “necessarily weaker” — I’m looking at the repair reports from the Japanese record and what I find about doing repair in that environment. Short answer: repairs aren’t necessarily as strong nor stronger; details and specifics matter; that’s my point, that making claims about how these plants ought to perform in theory shouldn’t preclude also looking at the actual reports of how they’ve done in practice. Knowing the sorts of failures of the penetrations through the bottom of the shield makes it possible to consider whether it’s possible such failures contribute to leaks. It’s a question of what’s possible, not what’s ideal.

    Try this too; again Google should find it for you.

    Corrosion in Nuclear Power Plants
    by VP Layer, Jan 16, 2002 … Two types of corrosion that can lead to premature failure in … it can be included in the planned repair work for the following year. … In these reactors the coolant water at the reactor core is strongly oxidising. …
    http://www.azom.com/Details.asp?ArticleID=1196

  33. Haha, sod, and he did what? drove around and left.

    Exactly what you think he could have done after breaking in to the site is left unsaid. However, this is probably because there is nothing he could have done to endanger anyone except himself.

    “This could have been an armed assault by a terrorist group”. And then they would be dead, because the armed guards would shoot them. But talking of terrorists, I see anti-nuclear fanatics are right onto it. – sending a letter bomb to a trade organisation in Switzerland. See upthread.

  34. confused by the fussion, on 1 April 2011 at 4:55 AM — By all means go to Japan. If you are going to live in the Tepco service area (Tokyo & envirnons) then the worst aspect will becoming accostomed to the rolling 3 hour power outages (but which are posted well in advance).

    The radiation hazard more than 30 km from Fukushima Dai-ichi is non-existenent; you would obtain a much higher dosage by living in Denver for those 2 years, not to speak of Leadville up the hill.

  35. As the reports of various radiation ventings/leaks/escapes mount up it is worth noting that radiation biophysicists are still unable to agree on risk (as at 2002).

    See for example;

    (2002) Kellerer, A. [Rad. and Env. Biophysics, 41(4) 307-316] indictes that “there is now conspicuous disagreement with current risk estimates”

    A central issue are newly published reduced estimates of the external dose to the Techa riverside population which imply substantially increased risk coefficients for solid cancer. Unless the new dosimetry system, TRDS-2000, has missed a major dose contribution, there is now conspicuous disagreement with current risk estimates. Unaccounted doses from atmospheric releases of fission products and from radiological screening of the Techa riverside population need to be explored, but underestimation of the short lived fission products released into the river appears to be a more critical factor. It is furthermore argued that even if TRDS-2000 were confirmed it would remain questionable whether risk estimates can be based on organ-specific doses when they are obtained in a population with a much higher bone-marrow exposure that may possibly have caused an ‘abscopal’ radiation effect.

  36. @Hank Roberts You wrote specifically that a repair was likely to be weaker, which means more often than not. This is just plain wrong. Most welded repairs are as strong, or stronger than the surrounding material, in almost all engineering cases. While an improper weld can cause trouble, this is not inherent to the process.

    Critical weldments can be tested nondestructively with eddy-current, ultrasound or x-rays and those that are licensed to weld in critical areas must continually supply test coupons at monthly or weekly intervals throughout their careers, or loose their endorsements.

    It is your generalization I am challenging, I am not asserting that a weld cannot fail, only that it is not likely to. The fact is that most welder repairs preform as designed, and are not likely to be a source of future failure, as your original statement implied

  37. I am here, 120 km (75 miles) from the nuclear mess.
    I have been watching all of the daily, and hourly where possible, monitoring of radiation levels.
    35-40 km NW, out of the evacuation zone, has had levels over 100µSv/h and has constantly been around 40-50µSv/h.

    How would you feel if you were getting a years dose of radiation in 1 hour? Or how about just 1 Xray an hour?

    This blog has repeatedly downplayed radiation levels and the contamination in general.

  38. Susanne posted a link at 4:34, with a disdainful sounding comment about American Media. Now I am not a fan of American Media at all, but I did click on the link and read the story. Here is the lead paragraph:

    Washington (CNN) — There is no health risk from consuming milk with extremely low levels of radiation, like those found in Washington state and California, experts said Thursday, echoing the U.S. Environmental Protection Agency.

    I can’t in truth call this particular article alarmist, perhaps quite the opposite.

    The link was:

    http://www.cnn.com/2011/HEALTH/03/31/radiation.us/index.html?hpt=Sbin#

  39. Pingback: Massive quake/tsunami in Japan - Page 20 - MBWorld.org Forums

  40. @Ernie Hamilton
    I was raising the issue some days ago already as an question.
    If there is no pressure in the PRV and in the containment, there must be some breach.
    And therefore we are really in trouble as radioactive material/steam will continue to escape (until the cracks are sealed).
    Especially the lost pressure of the PRV is a huge problem, as it questions the possibility to properly cool the core once the high pressure pumps can be ractivated. You need some pressure to be able to fully cover the core with water and to stop any steam escaping.
    Those firepumps currently used can’t be the permanent solution for the next years.

    Also the radioactive water found in the ground water underneath the basement raises the concern that there are cracks and structual damages to the concrete base of the building. This will not help to limit the emission of radioactivity…

  41. Latest TEPCO Washington update:

    Here are updates on March 31 at Fukushima Daiichi and Fukushima Daini NPS

    (1) Status of Fukushima Daiichi NPS as of March 31.
    (2) Detection of radioactive materials in the ground water at Fukushima Daiichi NPS
    (3) A campaign truck unlawfully entered the Fukushima-Daini NPS.
    (4) Photos at Fukushima Daiichi NPS: We have photos at Fukushima Daiichi NPS on the web. You may use these photos, but please put a note to indicate source as “Tokyo Electric Power Company”. http://www.tepco.co.jp/en/news/110311/index-e.html

    Contacts:
    TEPCO Washington Office :202-457-0790
    Kenji Matsuo, Director and General Manager
    Yuichi Nagano, Deputy General Manager,
    Masayuki Yamamoto, Manager, Nuclear Power Programs

    (1) Status of Fukushima-Daiichi NPS as of March 31
    ・ Units 1,2,3: Plan to transfer to the condenser (hotwell).
    ・ Unit 4: Under consideration.

    Underground floor of turbine building

    Condenser (hotwell)

    Condensate Water Tank

    【Unit 1】

    3/29 Suspend transfer to the condenser

    Full

    3/31 12:00~ Started water transfer to SP surge tank

    【Unit 2】

    Waiting for transfer to the condenser

    Full

    3/29~ Transfer to SP surge tank in progress

    【Unit 3】

    Waiting for transfer to the condenser

    Full

    3/31 8:37 Completed transfer to SP surge tank

    SP: Suppression Pool

    【Unit 1】 (Surface dose:0.4mSv/h)
    ・3/31 9:20~11:25 Water transfer to waste reserve tank at Rad Waste Treatment Facility, led water surface down 1m.
    【Unit 2】(Surface dose: over 1000mSv/h) : Water treatment measure under consideration
    【Unit 3】(Surface dose: N/A due to rubbles) : Water treatment measure under consideration
    【Unit 4】(Surface dose:0.5mSv/h) : Water treatment measure under consideration

    – Seawater
    【1-4u Water discharge Canal South 330m】
    ・Sample obtained at 13:55, 3/29 –> I-131: 130 Bq/cm3
    ・Sample obtained at 8:20, 3/30 –> I-131: 32 Bq/cm3
    ・Sample obtained at 13:55, 3/30 –> I-131: 180 Bq/cm3
    【5~6uWater discharge Canal North 30m】
    ・Sample obtained at 14:10, 3/29 –> I-131: 51 Bq/cm3
    ・Sample obtained at 8:40,3/30 –> I-131: 57 Bq/cm3
    ・Sample obtained at 14:15,3/30 –> I-131: 47 Bq/cm3

    – Other development
    3/30~ Started monitoring within a radius of 20km
    3/30 Conduct sampling survey of underground water

    – 3/31 Result
    【Unit 1】13:03~ Started fresh water injection by a concrete pump vehicle, then suspended injection.
    14:29~16:04 Resumed fresh water injection.
    – 3/31 Plan
    【Unit 3】Fresh water injection by a concrete pump vehicle.

    【Unit 1】Fresh water injection on going
    RPV Temperature 3/31 12:00〈Feed water nozzle〉246.1C 〈RPV Bottom〉126.1C
    【Unit 2】Fresh water injection on going
    RPV Temperature 3/31 12:00〈Feed water nozzle〉172.4C
    【Unit 3】Fresh water injection on going. No change.
    【Unit 4】N/A
    【Units 5/6】Cold Shutdown. No change.
    【Common Fuel Pool】 No change.

    【Units 1/2】3/31 Units 1/2 Common DC 125V Power Panel Access to Electricity
    【Units 3/4】3/30 Unit 3 DC 125V Power Panel(B) Access to Electricity. Battery charging
    【Units 1~6】Equipment integrity confirmation on going

    Postponed test dispersal of antiscattering agents due to bad condition by rain fall the day before.

    (2) Detection of radioactive materials in the ground water at Fukushima Daiichi NPS

    On March 28th, TEPCO received advice from Nuclear Safety Commission of Japan to conduct sampling survey of the water on the first basement of turbine building (= ground water) at Fukushima Daiichi NPS as well as to reinforce the sampling survey of seawater in order to secure safety and to monitor the leakage of the water on the basement into underground and/ or sea.
    On March 30th, TEPCO conducted nuclide analysis of radioactive materials, the sample of which was collected from the water on 1st basement (sub drain) of turbine building at Fukushima Daiichi NPS. Radioactive materials were detected as shown in the table bellow. TEPCO reported the result to Nuclear and Industry Safety Agency as well as to the government of Fukushima Prefecture on March 31.

    ・ Sub-drain is designed to drain groundwater in order to prevent the buildings from floating by the buoyancy of groundwater.
    ・ TEPCO is planning to constantly take samples, about once a week.
    ・ We have not found out any significant change (decrease) of the level of the water trapped in the turbine buildings (water puddle) but we will continuously monitor it. So far, no significant changes of the puddle level in the turbine buildings are confirmed.
    ・ We have not monitored the water level of the sub-drain because it is affected by the conditions of the groundwater. However, we have been monitoring the change of the water level of the turbine buildings and plumbing trench shafts.
    ・ We assume that the water containing radioactive materials has leaked into the underground by the precipitating water. It might have been caused by the sprayed water, besides the precipitation.

    (3) A campaign truck unlawfully entered the Fukushima-Daini NPS.

    A campaigner’s sound truck unlawfully entered the site through the west locked car gate around 1:08 pm on March 31. After driving around in the site, the car left through the same gate about 1:20 pm. TEPCO reported this event to the Fukushima Prefecture Police Department. We have shut the gate with TEPCO’s vehicles after the campaigner‘s vehicle left. The intruder was detained by the police and taken away to a decontamination facility.

  42. On items 1 – 7, this would be more credible if nearly every point wasn’t intended to deflate concerns raised in the media, and even contradict the tone of the coverage from IAEA: “Overall at the Fukushima Daiichi plant, the situation remains very serious.”

    IAEA also questions the validity of instrument readings, which are “still under investigation.” Given the multiple failures, dearth of information from TEPCO and other Japanese officials (3 weeks into this thing), and conflicting basis of several accounts … I’m likely to throw out the irrational extremes of any account (the rosy this will never leave the site boundaries assessments, and the sky is falling end of the world scenarios). IAEA reports sampling at 40 km distance from the power plants exceed their operational criteria for evacuation (a pretty startling discovery). Heck, in Pennsylvania today they even monitored I-131 readings at above EPA guidelines for rainwater.

    Regarding containment vessel integrity. We can rely on a single source, JAIF (or NISA), and say Reactor #2 has “damage and leakage suspected.” We can also look at others that report the same, and also raise concerns about Reactor #1 and #3 containment. We can look at the worst of cases, a breach of the pressure vessel in #2 suggested by Lahey, and repeat his caveats: “I hope I am wrong,” or that “it’s really hard to read the tea leaves” (which indicates a great deal of uncertainty). But it seems what we can’t do is rule out these statements (without a sufficient basis), look at faulty instrument readings, and say it’s all fine (and there is “no reason” to assume highly radioactive water has come from the RPV or drywell). There is a reason to suggest these things, we just don’t have very firm verification for it (and this is one of the larger issues that I see raised by this accident … the lack of transparency we have received so far from Japanese officials). And, I would add, the insufficiency of design criteria to meet the specific demands for this site, and inherent flaws of the Mark I containment design (which may or may not have been addressed at these particular plants with recommended retrofits).

  43. Pingback: Fukushima Daiichi Crisis: April 1 Perspective | marfdrat

  44. @Stephen, on 1 April 2011 at 10:34 AM said:

    Especially the lost pressure of the PRV is a huge problem, as it questions the possibility to properly cool the core once the high pressure pumps can be ractivated.

    I’m just a simple minded guy but maybe someone could explain why my thought process is wrong.

    The average refueling outage on an NPP is 37 days..that includes shutting down, cooling the core, opening the reactor, taking out the old fuel and replacing it with new.

    In order to take out the out fuel at some point the pressure has to be brought to 1 atmosphere.

    Why is the pressure in the core an issue?

    It seems to me that these reactors are going to be spent fuel pools for the next few years. Flooded with some sort of recirculating cooling pump.

  45. EL, on 1 April 2011 at 11:09 AM — Every natural disaster comes with some FUBAR with attendant lack of reliable information; Fukushima Dai-ichi has been remarkable in the rapid flow of fairly good information.

  46. Ok, Drudge has a headline up: “CHERNOBYL SOLUTION: WORLD’S LARGEST CONCRETE PUMP DISPATCHED TO JAPAN” linked to: http://chronicle.augusta.com/latest-news/2011-03-31/srs-concrete-pump-heading-japan-nuclear-site

    Which, no surprise, is giving a “site may be down” error message. I’m sure it’s being overwhelmed by people trying to go read the article.

    Wondering if anyone here has seen details, has a link, and if this is credible, and intended for concrete, not water? (after all, it is a concrete pumper that’s been doing the great job of spraying units so far).

  47. Ok, the site came up, here are the key bits:

    SRS concrete pump heading to Japan nuclear site
    By Rob Pavey Staff Writer
    Thursday, March 31, 2011 1:05 PM

    The world’s largest concrete pump, deployed at the construction site of the U.S. government’s $4.86 billion mixed oxide fuel plant at Savannah River Site, is being moved to Japan in a series of emergency measures to help stabilize the Fukushima reactors.

    The 190,000-pound pump, made by Germany-based Putzmeister has a 70-meter boom and can be controlled remotely, making it suitable for use in the unpredictable and highly radioactive environment of the doomed nuclear reactors in Japan, he said.

    “There are only three of these pumps in the world,…

    The pump was moved Wednesday from the construction site in Aiken County to a facility in Hanahan, S.C., for minor modifications, and will be trucked to Atlanta’s Hartsfield Airport, where it will be picked up by the world’s largest cargo plane, the Russian-made Antonov 225, which will fly it to Tokyo…. If all goes well, the pump will be en route to Japan sometime next week.

    …four smaller pumps made by the company are already at work at Fukushima pumping water onto the overheated reactors.

    Initially, the pump from Savannah River Site, and another 70-meter Putzmeister now at a construction site in California, will be used to pump water—and later will be used to move concrete.

    “Our understanding is, they are preparing to go to next phase and it will require a lot of concrete,” Ashmore said, noting that the 70-meter pump can move 210 cubic yards of concrete per hour.

    Putzmeister equipment was also used … to entomb the melted core of the reactor at Chernobyl.

    In addition …. a contractor in Vietnam has given up a 58-meter pump so it can be diverted to Japan, and two 62-meter pumps in Germany were loaded on Wednesday for transport to Tokyo….

  48. The Japan Times Online has published the following article which is just going to feed the hysteria. I notice that throughout this crisis Kyodo News appears to be one of the outlets that does this.
    MODERATOR
    Please supply link for full story. Quotes from a newspaper article are fine but you must supply the link.

    .

  49. ANL has a fact sheet on plutonium which includes the statement:

    The common myth that plutonium is the “deadliest substance known to man” is not supported by the scientific literature. It poses a hazard but is not as immediately harmful to health as many chemicals. For example, for inhalation – the exposure of highest risk – breathing in 5,000 respirable plutonium particles, about 3 microns each, is estimated to increase an individual’s risk of incurring a fatal cancer about 1% above the U.S. average “background” rate for all causes combined.”

    http://www.puzip.com/preview.php?key=Plutonium%20Its&url=http://www.globalsecurity.org/space/library/report/enviro/PlutoniumANLFactSheetOct2001.pdf

  50. Listening to NHK live TV, they’ve got video of the tsunami up against a cliff in one area (I didn’t catch where, I’m sorry!) such that it could be analysed. They’re saying it’s confirmed to have been over 20 meters high (65.6 ft). The area was a funnel shaped bay area, that interacted with the tsunami to amplify the height. So far it’s the highest confirmed location.

    They’re now saying that the seabed rose by as much as 5 meters in the focal zone of the earthquake (large area running along the area of the plate subduction I think – not just a line, but a long and wide area – on the TV screen it made a big rectangle with very rounded ‘corners,’ heck, something between a rectangle and oval). There was a video clip that was very short, but taken by a ship over the area when the quake occurred – it looked like there was a spurt of water high up into the air. Either that or it was disturbance on the water that made it seem that way when just catching a very brief clip.

    Barry, moderators, I’m sorry, I couldn’t decide if this belonged best here, or in the philo or tech open threads. Decided perhaps here because it is tech in nature and related to the size of the tsunami. I’m sorry if it’s the wrong place.
    MODERATOR
    Not easy to categorise I agree. Will leave it on today’s post. Please supply a link to the NHK live TV.

  51. Can I please get references for the following statement:
    “…the longer-lived Cs-137 does not bioaccumulate like mercury (for instance).”
    Lake Michigan study that I found was unconclusive from what I can tell. Just trying to decide whether I should invest in sushi futures or not. Thanks.

  52. “MODERATOR
    Please supply link for full story. Quotes from a newspaper article are fine but you must supply the link.”

    Sorry about that, Hit the post button too fast.
    Here is the link:

    http://search.japantimes.co.jp/cgi-bin/nn20110401a2.html

    Friday, April 1, 2011

    Hundreds of corpses believed irradiated, inaccessible
    Kyodo News
    Radiation is preventing the retrieval of hundreds of bodies from inside the 20-km evacuation zone around the Fukushima No. 1 nuclear power plant, police sources said Thursday.

    Based on initial reports after the March 11 catastrophe, the number of bodies is estimated at between a few hundred and 1,000, one of the sources said, adding that high radiation is now hampering full-scale searches.

    That view was supported by the Sunday find of high radiation levels on a body found in Okuma, Fukushima Prefecture, 5 km from the plant.

    The rescuers are now in a bind. Even if they retrieve the bodies, anyone who comes into contact with them risks being irradiated, too, whether they’re in the evacuation zone or not.

    And if the bodies are cremated, the smoke could spread radioactive materials as well, the sources said. Even burial poses a problem. When the bodies decompose, they might contaminate the soil with radioactive materials.

    Authorities are considering decontaminating and inspecting the bodies where they are found, but the sources said cleansing the decomposing bodies could damage them further.

  53. mpatmahoney, you are right, that sentence was rather loose — the Fukushima releases of cesium may well bioaccumulate in muscle and fat in some taxa (but not others — results in the literature have been mixed), but not in specific glands like the thyroid, and my point here was that it would not happen in the same way, or anywhere near the same concentrations, that mercury — a significant byproduct of coal-fired electricty — does.

  54. @ bks
    Edano also said this in the same article:

    “Edano was responding to statements by the International Atomic Energy Agency, which has “emphasized that the nuclear reactors won’t explode,” he said. Japan’s nuclear agency said there’s no possibility of uncontrolled chain reactions.”

    Let us not emphasisea worrying scenario without off-setting it with the better outcome.

    Read more: http://www.sfgate.com/cgi-bin/article.cgi?f=/g/a/2011/03/31/bloomberg1376-LIXG396K50YH01-6E85C18IU9EOCLTS7EMUKR96K3.DTL#ixzz1IFTdNsbo

  55. Geez,

    Where is a moderator when you need one?

    The weird theories of Caldicott and her ilk, in which she fantasises about some ‘magical’ mechanism that is able to spread fine particulates of Pu across the landscape and into the lungs of millions of humans, and so (she outrageously claims) render the Japanese islands uninhabitable as a result, is simply beyond a joke (from many angles). Actually, it’s nothing short of appalling, grossly unscientific, hyper-alarmism.

    Remember – Caldicott in 2006, predicted exactly the tsunami/earthquake/nuclear power station we see unravelling in front of your very eyes.

    When did BraveNewClimate consider the tsunami threat to shoreline nukes, real?

    You disagree with her – that does not give any cause for the ad-hom attack above.
    MODERATOR
    It is not a moderators job to edit posts by the host of the blog.
    If it had been I would have let the comment through.
    From the Latin -ad hominem literally means “to the man(person)”. In Aussie parlance “play the ball not the man”.
    I read this part of Barry’s post as a comment on Caldicott’s mis-understanding of the science (the ball) not on Caldicott herself (the man/person).

  56. Definitely nothing ad hominem about that paragraph.

    Saying “Helen Caldicott is an appalling, grossly unscientific, hyper-alarmist, and therefore she is wrong about the spread of Pu” would be an ad hominem.

    Saying “Helen Caldicott is wrong about the spread of Pu because it lacks any plausible mechanism, and therefore is spreading appalling, grossly unscientific, hyper-alarmism” is not an ad hominem at all.

  57. It is this abuse of expertise (or scientific opinions) in Oehmen’s text (for example) of which Karl Popper always warned about. In his lifetime he was pointing out the danger of a political dictatorship of the technocrats.

    Oehmen’s text is one of those attempts (if conscious or not) with the help of arguments, which have their origin in the engineering field, to disparage the fears of people in an ideological way

    in this case it does not even matter, if the technical argument is right or wrong. Important is the matter of fact that technical data and statements are used for the justification of an ideological point of view.
    MODERATOR
    This comment is in the wrong thread. It is not an up-date on the situation but a philosophical point. Please transfer your argument to the Fukushima Philosophical Open Thread. BNC policy is to delete off-topic comments after the initial wrong posting.Please check BNC Commenting Rules before posting.

  58. New Tsunami video, from THERMAL power plant on the coast ~25 km north of Fukushima Dai-ichi: http://www3.nhk.or.jp/daily/english/01_08.html

    Tsunami footage of Fukushima thermal plant posted

    Video footage of the March 11th tsunami, apparently taken by someone at a thermal power plant in Fukushima prefecture, has been posted on YouTube.

    The video was apparently taken from inside the Tohoku Electric Power Company’s Haramachi thermal plant in Minamisoma City.

    The video shows the crest of tsunami waves approaching from offshore, while emergency alarms ring in the building. The tsunami then reaches the grounds of the plant.

    The one-and-a-half minute video ends with a scene of workers running away.

    The plant caught fire on the day of the massive quake. Three days later, another fire broke out after leaked heavy oil ignited.

    The power plant is located about 25 kilometers north of the troubled Fukushima Daiichi nuclear power plant.

    Friday, April 01, 2011 05:09 +0900 (JST)

  59. mpatmahoney wrote:

    Can I please get references for the following statement:
“…the longer-lived Cs-137 does not bioaccumulate like mercury (for instance).”
Lake Michigan study that I found was unconclusive from what I can tell. Just trying to decide whether I should invest in sushi futures or not. Thanks.

    Can’t help you with that one. But I can provide a source that does detail bioaccumulation of Cesium isotopes in environment:

    http://www.cityu.edu.hk/ap/nru/pub_j27.pdf

  60. Barry Brook wrote:

    mpatmahoney, you are right, that sentence was rather loose — the Fukushima releases of cesium may well bioaccumulate in muscle and fat in some taxa (but not others — results in the literature have been mixed), but not in specific glands like the thyroid, and my point here was that it would not happen in the same way, or anywhere near the same concentrations, that mercury — a significant byproduct of coal-fired electricty — does.

    I don’t understand the fine point of this correction. Do we expect the pathways for cesium uptake and bioaccumulation to be the same as mercury? Are we measuring health impacts by raw concentration factors, regardless of the compound or it’s impact on human health?

  61. @Shelby, on 1 April 2011 at 11:35 PM said:

    The government and Tokyo Electric Power Co. are considering injecting nitrogen into containment vessels of the Fukushima Daiichi

    Injecting nitrogen is standard safety practice in many BWR’s.

    http://www.ansn-jp.org/jneslibrary/npp2.pdf

    following a loss of coolant accident, the temperature of fuel cladding could rise
    and hydrogen could be generated by a water-metal reaction, which could impair the
    containment integrity due to hydrogen gas combustion. In order to prevent such a case, BWR
    containments are kept inert with nitrogen gas

  62. Preliminary Assessment of Accident Sequences and Potential Atmospheric Radiation Releases

    http://isis-online.org/uploads/isis-reports/documents/Accident_Sequence_Fukushima_31March2011.pdf

    —-

    The authors match radiation readings with location of reading site and wind direction at the time of the reading. The data implies that many readings taken on site are not accurate because of the site location and wind direction, thus advertised on site radiation readings for the event not entirely accurate without including the location and wind direction.

    In addition, I now realize that the 13 neutron beams observed by Tepco, occur at roughly the same time as the 4 hydrogen explosions on March 13-16. This could support limited fuel/pond criticality during and immediately after the explosions. This also lines up on the time line with big radiation spikes.

  63. If I am not mistaken, in BWRs, nitrogen is used as ‘cover gas’ and as pressurizer gas upon startup and for the high pressure coolant injection systems.

    However, it may be that the drywell – the lightbulb containment around the reactor vessel – is not inerted during normal operation. The torus – the donut structure around the reactor – may also not be inerted and that might have caused the hydrogen explosion there? Anyone know exactly what parts are normally inerted and which parts are not, in older BWRs?

  64. > releases of cesium may well bioaccumulate in
    > muscle and fat in some taxa

    Barry, beware sounding evasive by using language appropriate to a science paper.

    Yes, all science can tell us is probability not certainty that anything happens, there is no certainty.

    Climate scientists — to ordinary readers — seem to be waffling with words like “may well” when they mean “damned sure” something happens.

    There’s nothing in the literature that suggests doubt that bioaccumulation of cesium happens, is there?

    http://scholar.google.com/scholar?q=cesium+bioaccumulation

  65. Also note, though there’s new work aplenty, most of the science on cesium-137 bioaccumulation is decades old and from the eastern US where the process has had time to work through generations of animals and up from plants to fish to birds and animals, e.g.

    http://www.springerlink.com/content/u28hg01255807301/

    A search for “K cogeners” may help, e.g. here’s a very old contamination problem with quite large current bioaccumulation values found, again in the US South:

    Plants as bio-monitors for Cs-137, Pu-238, Pu-239,240 and K-40 at the Savannah River Site
    Journal Article
    Eric Frank Caldwell, Martine C. Duff, Caitlin E. Ferguson and Daniel P. Coughlin
    J. Environ. Monit., 2011, Advance Article
    DOI: 10.1039/C0EM00610F, Paper

    http://pubs.rsc.org/en/Content/ArticleLanding/2011/EM/c0em00610f

    “The Savannah River Site was constructed in South Carolina to produce plutonium (Pu) in the 1950s. Discharges associated with these now-ceased operations have contaminated large areas within the site, particularly streams associated with reactor cooling basins. Evaluating the exposure risk of contamination to an ecosystem requires methodologies that can assess the bioavailability of contaminants. Plants, as primary producers, represent an important mode of transfer of contaminants from soils and sediments into the food chain. The objective of this study was to identify local area plants for their ability to act as bio-monitors of radionuclides. The concentrations of cesium-137 (137Cs), potassium-40 (40K), 238Pu and 239,240Pu in plants and their associated soils were determined using γ and α spectrometry….

    … Comparing 40K and 137C concentrations in each plant revealed an inverse relationship for these radioisotopes. Correlating 40K and 137Cs was most effective in identifying plants that have a high affinity for 137Cs uptake. The P. palustris and S. americanum proved to be particularly strong accumulators of all K congeners from the soil. Some species that were measured, warrant further investigation, are the carnivorous plant Utricularia inflata (bladderwort) and the emergent macrophyte Juncus effusus. For U. inflata, the levels of 137Cs, 238Pu, and 239,240Pu (which were 3922, 8399, and 803 Bq kg−1, respectively) in the leaves were extremely high. The highest 137Cs concentration from the study was measured in the J. effusus root (5721 Bq kg−1).”

  66. workers at the plant are sharing their dosimeter.

    The Kyodo news agency quoted the agency’s spokesman, Hidehiko Nishiyama, as saying that some workers have been found sharing dosimeters while doing the same job because many of the devices were destroyed in the March 11 disaster, adding that this trend is unsafe for the workers.

    http://www.dailyindia.com/show/432769.php

    [deleted personal opinion on actions/motives of others.Bordering on libel.]
    MODERATOR
    This almost got completely deleted on the grounds of deliberately distorting the facts.
    Cherry picking quotes in the hope that most won’t read the whole article is not good practice.

  67. Gack, I didn’t realize this apparently started with Barry’s first post.

    Barry, can you explain more clearly what you mean by writing “Cs-137 does not bioaccumulate like mercury” above?

    It sounds like you mean “does not bioaccumulate” — but that would be wrong.

    I am guessing what you mean is:

    “Cesium bioaccumulates like potassium, not like mercury or iodine or strontium — cesium is chemically similar to potassium.”

    Is that a clearer statement of what you meant?

  68. sod: there are defenders of nuclear power who don’t think labor exploitation exists and then there are defenders of nuclear power who are marxists. and many positions in between.

    Don’t lump together a technology with the social relations of production.

    The treatment of the workers, at least a couple of articles I have read (L.A. Times) seems pretty unconscionable.

    If they replace the lost nuclear power with coal and natural gas, I’m sure the labor relations will improve.

  69. Has anyone seen Lyman’s (UCS) comment about cesium 137 concentrations? He cites the March 30 IAEA update, referring to a very high upper limit of 3.7 megabq, but leaves out the range of 0.2-3.7 mbq and leaves out the point that the high number was found in a small area.

    The March 31 numbers are different, significantly so, but the regions being compared do not appear to be the same.

    Lyman’s point about evacuation seems right. But this use of numbers, citing the high number, seems highly unethical.

  70. > Gregory Myerson
    > has anyone seen Lyman’s … comment …?

    Why yes. You can find it with Google and read it for yourself. Paste your text into the Search field thus:

    http://www.google.com/search?q=Lyman’s+(UCS)+comment+about+cesium+137+concentrations

    Gregory Myerson writes
    > Lyman’s … use … seems highly unethical

    Uh, how would you believe this without reading what the man wrote?

    If you did read it, how could you possibly misread it so badly? You can look it up for yourself.

    He wrote:

    “Today, the daily update appears to show a significant upward trend in reported contamination levels. However, because it is not clear exactly where the measurements are being taken, one cannot do an apples-to-apples comparison.

    For instance, in its March 27 update the IAEA reports that the highest level of daily deposition of iodine-131 was measured on March 26 at 7,500 becquerels per square meter (Bq/sq. m) in Yamagata prefecture; for cesium-137, it was reported as 1,200 Bq/sq. m. (Actually, the statement does not make clear if these are daily rates or total cumulative deposition levels, although from the context it appears to be the former.)

    Compare these to the peak daily deposition rates reported in the March 26 update for measurements made on March 25. These were 480 Bq/sq. m for I-131 in Ibaraki and 110 Bq/sq. m for Cs-137 in Yamagata. But can these be compared? It would appear that the peak rate of Cs-137 daily deposition in Yamagata has increased by a factor of ten. But without knowing how comprehensive these surveys are, we don’t know if these represent actual increases or sampling discrepancies. …”

    How could you so badly misinterpret what he said? What source were you relying on for what you believed? Why did you consider it reliable?

    Why didn’t you look it up for yourself??

  71. Cyril R, on 2 April 2011 at 4:34 AM said:

    I’m not sure what you guys are talking about, but dose levels everywhere around Fukushima have been on a declining trend for over a week now:

    http://www.jaif.or.jp/english/news_images/pdf/ENGNEWS01_1301652988P.pdf

    Obviously the nuclides came with the steam relief as the cores were already damaged then, and then it stopped because decay heat dropped further and seawater cooling continued. The data explains this perfectly.

    —————–

    Cyril.

    that may be true as of late (lets hope it is)

    But the total radiation released in the first days and weeks now appears to be much higher than previously indicated by those who quoted various readings out of context with location and wind direction.

    Read…

    Preliminary Assessment of Accident Sequences and Potential Atmospheric Radiation Releases

    http://isis-online.org/uploads/isis-reports/documents/Accident_Sequence_Fukushima_31March2011.pdf

  72. Contrasting perspectives from Dr. John Price (former member of the Safety Policy Unit at the UK’s National Nuclear Corporation) and Laurence Williams (Professor of Nuclear Safety at England’s University of Central Lancashire and the former head nuclear regulator for the UK). And the Wall Street Journal thrown in for good measure.

    From ABC News: “Crews ‘facing 100-year battle’ at Fukushima” (April 01, 2010).

  73. Hank: I don’t think I misinterpreted anything. We’re talking about two different things.

    What I was referring to was a widely circulated UCS press release, concerning march 30 IAEA.

    here it is:

    The IAEA is reporting that measured soil concentrations of Cs-137 as far away as Iitate Village, 40 kilometers northwest of Fukushima-Dai-Ichi, correspond to deposition levels of up to 3.7 megabecquerels per square meter (MBq/sq. m). This is far higher than previous IAEA reports of values of Cs-137 deposition, and comparable to the total beta-gamma measurements reported previously by IAEA and mentioned on this blog.

    This should be compared with the deposition level that triggered compulsory relocation in the aftermath of the Chernobyl accident: the level set in 1990 by the Soviet Union was 1.48 MBq/sq. m.

    I think what may have happened is that in making the internet rounds, it was attributed to Lyman.

  74. Cyril: I read your graph earlier.

    Given the unevenness of distribution, the high cesium levels in that one location might be compatible with the graph. ?? what do you think?

    I was objecting to the press release’s misleading paraphrase of the IAEA report. I don’t see how anyone can justify the press release’s version of the report.

  75. “sod: there are defenders of nuclear power who don’t think labor exploitation exists and then there are defenders of nuclear power who are marxists. and many positions in between. ”

    i am not talking about social aspects of workers without the necessary equipment. i am talking about security aspects of having the wrong equipment.

    without running water, they can not decontaminate. they should not work under those conditions.

    without enough dosimeters, we simply do not know how high doses they accumulated. one dosimeter per group tells us nothing about individuals.

    ———————–

    [deleted personal opinion presented as fact. Please re-post with links/refs.]

  76. > Cyril R., on 1 April 2011 at 4:51 AM said:
    > The shroud cannot fail in a way which would
    > compromise cooling during emergencies

    A citation to the source for your belief would help, if you have a basis for believing this. If you have a source for believing it, why do you trust your source?

    Looking it up, I can’t support what you claim.

    I find much discussion, e.g.:

    http://www.osti.gov/energycitations/product.biblio.jsp?osti_id=561142

    “… Although assessments by the USNRC staff of the potential significance of this cracking have shown that core shroud cracking does not pose a high degree of risk in the short term, the staff concluded that the cracking was a safety concern for the long term because of the uncertainties associated with the behavior of core shrouds with complete 360{degrees} through-wall cracks under accident conditions and because it could eliminate a layer of defense-in-depth….”

    and

    http://www.inl.gov/technicalpublications/Documents/3314495.pdf.

    “… instances of core shroud cracking served to escalate attention as to the seriousness of the IGSCC problem in BWR reactor internals…. The primary emphasis has been placed on core shroud degradation, but common mode or cascading failure of other components could also have safety significance….
    “… consideration is given to potential cascading and common mode effects on system performance stemming from cracking of core shrouds and other BWR reactor internals components when subjected to design-basis and beyond-design-basis accident loading conditions such as seismic events….. It is recognized that other degradation mechanisms such as fatigue can act synergistically with IGSCC in that a crack which is initiated by IGSCC can propagate to failure from fatigue….

    But looking forward over time, looking up citing references, I can’t find the conclusion you state above that this is now known to be no problem. What’s your source for that?

  77. Rational Debate wrote:

    Listening to NHK live TV, they’ve got video of the tsunami up against a cliff in one area (I didn’t catch where, I’m sorry!) such that it could be analysed. They’re saying it’s confirmed to have been over 20 meters high (65.6 ft).

    Question for you RD. In light of this information, are you suggesting we should reconsider site design criteria for power plants located in coastal areas? Japan probably has dozens, and we (if you are in the US) have a few of our own. Should we be shutting down plants until they are retrofitted with sufficient defense in depth criteria to withstand probabilistic assessments at those specific sites? In 1929, The Grand Banks earthquake resulted in a 7 meter tsunami that swept the coast of Newfoundland (it was actually three successive waves that reached land 2.5 hours after the initial earthquake). What is the rational response to this information from someone who also appears to be a strong proponent of the industry?

  78. re post by: Cyril R, on 2 April 2011 at 4:34 AM said:

    I’m not sure what you guys are talking about, but dose levels everywhere around Fukushima have been on a declining trend for over a week now:….

    Hi Cyril,

    The link you provided is great, thanks! What they’re talking about is a different aspect of the big picture. The link you found is measuring the dose rate from pretty much everything – cloud ‘shine’ and direct exposure to the plume, ground ‘shine’ (dose rate from radiation deposited on the ground), and so on.

    In effect it’s from a piece of monitoring equipment that is measuring the ambient dose rate. Some degree of this dose rate may be coming from stuff that is passing you by, blown on the wind. That degree can be a lot, or a little, all depending on circumstances.

    A part of it, however, will be coming from ground shine. So you can measure just what isotopes have actually been deposited on the ground. Of course they’ll primarily report and look for the most concerning isotopes – ones that can get in the food chain, or that produce the most shine, etc. Depending on the surface, ground deposition is what is to some extent going to be there over time. Some of it may wind up picked up in the wind again and blown away, but much of it will stay – the surface type itself helps determine just how ‘fixed’ that contamination is or isn’t, in combination with wind, rain, etc.

    Anyhow, that’s what they’re talking about. Typically with the more likely accident scenarios, the dose rate being released from the plant will spike, and then taper off – the faster the better of course. There may be multiple spikes if there is periodic venting occurring – you see this most clearly right near the plant and various factors muddle it up a bit the further away you go.

    Usually under most hypothetical scenarios the initial spike will be the worst, and then it will taper off. All sorts of things can affect that for a particular location however, as I’m sure you’re already aware – changes in wind direction or precipitation especially. Even topography can have major effects, either concentrating or reducing the dose rate. These factors are expected, including the likelihood of some ‘hot spots.’

    Hot spots in this context doesn’t refer to the magnitude of either dose rate or deposition, so much as small relatively localized areas that because of a combination of the factors I’ve mentioned wind up with a notably higher dose rate or deposition amount than surrounding areas. We’re seeing what may be a prime example of this right now with the one small city to the NW of the plant that is outside of the exclusion zone.

    Anyhow, even as the dose rate tapers off as in the graphs you linked to, the total deposition is likely to continue increasing to some extent. It will do so as long as there is some plume passing by. The RATE of deposition will almost certainly be dropping, because it is a function of how much is in the plume and how much of that plume is passing thru – so the total amount on the ground would still be increasing even if at a slower and slower rate until there isn’t any plume passing by.

    Once it’s there all sorts of things then proceed to move it around… the already mentioned wind & precipitation, but also run off from any water, bioaccumulation, and so on. Even if contamination levels wind up high, there are often a number of things that can be done to decontaminate the area and make it safe again. You always hope that doesn’t wind up being necessary – as you can imagine trying to decon large areas can be pretty labor and $$ intensive. If it’s a city, just wiping down surfaces or washing them off can make a huge difference. If it’s ground, you may wind up removing the top inch or so of soil, that sort of thing.

    Anyhow, that’s the gist of it.

  79. rational debate:

    thanks for your post. It helped me a lot. I saw the distinction in the IAEA report between total and daily deposition but it wasn’t salient for me because I am not sufficiently familiar with the vocabulary. and these adjectives were not always employed, thus making the numbers a bit confusing to me.

  80. re post by: sod, on 2 April 2011 at 6:13 AM said:

    without running water, they can not decontaminate. they should not work under those conditions.

    without enough dosimeters, we simply do not know how high doses they accumulated. one dosimeter per group tells us nothing about individuals.

    Sod, why is it that you don’t bother noting that they’ve already corrected the situation and have dosimeters for everyone now?

    On the water front (pun intended): They don’t have running water as in infrastructure supplied tap water, regular water to sinks and so on. They DO have water for decontamination. Just because the infrastructure that normally provides running water to the plant isn’t working doesn’t mean that they don’t have water on site, portable decon units, tanks with sprayers, etc. Just one example, you know they’ve got fire trucks there full of clean water. Plus, you don’t even necessarily need running water of any sort for decon – sometimes just a wipe is more than enough. I think you are making more of and reading more into the water issue than is the case. Not having regular running taps and so on is very inconvenient – but it doesn’t have any bearing on ability to decontaminate.

    As to the dosimeter issue – I just saw that late last night/early this morning. It is very disconcerting. I would say ‘unexcusable’ except that wouldn’t necessarily be the case given the mass destruction in Japan. They apparently had over 5,000 dosimeters, and all but about 3xx were destroyed. IF they made prompt efforts to get all the dosimeters they could from other plants, including not only their own but any other ones, and from other sources, but weren’t able to get them for whatever reason (e.g., not a fault of theirs or lack of trying or something) then it wouldn’t be fair to slam them on this. Clearly they HAVE to try to keep these units from having worse problems. I have a hard time imagining that they wouldn’t be able to get more dosimeters however. But we don’t know any of the key pertinent details.

    Next, as to your statement “one dosimeter per group tells us nothing about individuals” That quite simply is NOT true. It all depends on the area, the dose rate, sources present in the immediate area, and the training those sharing a dosimeter were given. A single dosimeter used in a small group that is working in an area that has a fairly consistent dose rate gives quite good information about the group dose.

    Now don’t read into what I am saying. I am NOT saying that at Fukushima Dai-ichi this situation was ok. I am NOT saying that it’s ideal or anything like that. I am saying that if forced by circumstances, and done judiciously, you absolutely can get decent information about the dose each individual got.

    If management/staff responsible at F.Dai-ichi didn’t do everything possible to get more dosimeters, it is utterly inexcusable. If other plants or vendors were unwilling to loan/sell dosimeters to TEPCO when/if asked, it is utterly inexcusable. That still doesn’t mean that they can’t know the individual dose from shared dosimeters, however, if they were careful about how they did this.

    As usual, we don’t even begin to get enough data from these articles to know who should or shouldn’t be blamed. On the face of it, it sure doesn’t sound good tho.

    Meanwhile, for you to say this; “is there anything that they can do to the workers that will cause an outcry among the supporters of nuclear energy? no water, no dosimeter. this is criminal stuff!” is just unwarranted and inflammatory on several fronts.

  81. re post by: Gregory Meyerson, on 2 April 2011 at 7:53 AM

    You’re sure welcome Gregory! All of the exposure and contamination issues get really complicated – many many individual factors all of which are fairly straightforward and logical, but so many all interacting with each other that it becomes very complicated. Difficult to explain well in online posts – heck, entire books are written about it. :0) But trying to help folks who may not be familiar with some of these things with basic understanding of the big picture concepts where I can and as best I can with little time and unfortunately tossing things down in posts pretty quickly. Then any more detailed issues we can take to the technical open thread if they come up.

    Thanks for the feedback too, it’s nice to know that some of my posts have been useful.

  82. re post by: EL, on 2 April 2011 at 7:23 AM said:

    ….are you suggesting we should reconsider site design criteria for power plants located in coastal areas? …we (…in the US) have a few of our own. Should we be shutting down plants until they are retrofitted with sufficient defense in depth criteria to withstand probabilistic assessments at those specific sites? In 1929, The Grand Banks earthquake… What is the rational response to this information from someone who also appears to be a strong proponent of the industry?

    Hi El,

    I’m a strong proponent of facts, good science (there’s plenty out there that’s not), and logical thinking, and revising if new BETTER (more factual, accurate, etc) data becomes available.

    We really ought to take this one to the philosophical open thread. So I’ll post a response there in a little while, have some things I have to get done first. You may want to copy your post over there in the meantime.
    MODERATOR
    Well spotted RD. I would say philosophical too.:-)

  83. Interesting talks on Thursday at the University of Melbourne Department of Engineering, especially from Professor Iven Mareels – his estimates of the damage to the reactors is available online.

    [video src="http://www.eng.unimelb.edu.au/nuclear/FukushimaFactsFallout.mp4" /]

    Barry, you seem remarkably sanguine about the fuel assemblies, rejecting “in your personal judgement” the need to entomb them. Mareels is a lot more concerned, and I quote: “estimates of the likelihood of a meltdown and the size of it: number 1 around 70 per cent, number 2 around thirty per cent, number 3 probably completely” – download his talk and slides at

    [video src="http://www.eng.unimelb.edu.au/nuclear/FukushimaFactsFallout.mp4" /]

    [ad hom deleted]

  84. Trying to put in camera to trace leak:

    ‘Tokyo Electric Power Co. officials said they hope to place a camera in a maintenance tunnel to determine whether water is leaking from a joint of the trench, which could help to explain the troublesome spread of contaminated water around the plant.’

    Resin Spraying:
    ‘Crews also sprayed 2,000 liters (more than 500 gallons) of synthetic resin meant to bind radioactive particles to the site and prevent them from spreading, according to Tokyo Electric.’

    Concrete pumps to be used to pump water:
    ‘And huge concrete pumps described as the largest such machines in the world were being readied for delivery to the Fukushima plant as efforts continue to spray water onto the spent fuel pools and reactors at the plant to help keep the nuclear fuel cool. ‘

    Beef not contaminated:
    ‘Japan’s health ministry said Friday that it appeared an earlier report indicating there had been radioactive contamination of beef may have been wrong.

    The ministry said faulty testing may have led to the result, which indicated levels of radiation slightly in excess of those allowed by Japanese law. In a second round of tests, lab workers were unable to find any trace of radioactive cesium in the same cattle, according to the reports.
    Even if the report was accurate, the amount of radiation detected — 510 becquerels per kilogram — would expose a consumer who ate 95 pounds of beef in a year to 0.35 millisieverts of radiation, according to Nolan Hertel, a Georgia Tech nuclear engineering professor.
    Someone living in an industrialized nation is typically exposed to 3 millisieverts per year.
    Authorities had previously banned the sale and transport of numerous vegetables grown in the area after tests detected radiation.’

    Water in tunnels partly drained and no longer urgent:
    ‘Concerns also remained about other water that has shown high levels of radiation.
    This includes water in exposed maintenance tunnels leading into and out of the Nos. 1, 2, 3 and 4 reactor buildings, one of which earlier had radiation levels 100,000 above the norm.
    Authorities have been working in recent days to drain these tunnels, to prevent them from spilling over and sending tainted water into the ground. By Friday, an official with the Tokyo Electric Power Company — which operates the plant and heads the recovery effort — said water levels had dropped one or more meters, and that the issue was no longer urgent.’

    Groundwater radiation levels unclear. Probably not just from the air.
    ‘Early Friday, a Tokyo Electric official said that iodine-131 levels in ground water from a pipe near the No. 1 reactor had 10,000 times the standard limit. But the utility later backtracked, promising to get more clarity later.

    Edano addressed this confusion in a news conference later Friday, noting that a “constant amount of radiation” appeared to be getting into the groundwater while noting that further tests are forthcoming.

    “The numbers released … looked strange, and that led to the recalculation,” he said. “In either case, underground water seems to contain some level of radioactive substances, and this leads to an understanding that the … soil in the vicinity needs to be monitored closely.”

    All this contamination — both into the ground and, eventually, the sea — is the result of a leak or some other sort of ground seepage from one of the nuclear plant’s four most embattled reactors, a Tokyo Electric official said Thursday. The official noted that the high levels suggest the release of radiation into the atmosphere alone couldn’t be the lone source.’

    http://edition.cnn.com/2011/WORLD/asiapcf/04/01/japan.nuclear.reactors/index.html?hpt=T2

  85. @Peter Burnett:

    a couple of flaws I see on the surface of the UoMelbourse presentation:

    1) 9.0 earthquake was NOT within design limits…

    2) where do they get the information that the torus of unit 2 is damaged? seems to be at the crux of their argument that damage occurred on the bottom of the RPV..?

    the presentation clearly appears to be for educational purposes, seems to make some assumptions and “glosses over” intricate details for one reason or another…

  86. re to Rational Debate, on 2 April 2011 at 8:01 AM

    thanks for the answer.

    i know that they have enough dosimeters now. i strongly disagree with your assessment of group dosimeters being useful in the environment that they face there. ( we had a least one incident, with contaminated waters, in which the group got very different doses)

    one important point about the missing dosimeters are the claims about doses that workers received. we simply do not know it, when they didn t use dosimeters properly.

    ———————

    on the lack of running water:

    water was a scarce resource at the plant. we know that, because they didn t even have sufficient drinking water. (and multiple other small things)

    http://articles.latimes.com/2011/mar/29/world/la-fg-japan-workers-20110329

    i am a little surprised by the claim that running water isn t needed for decontamination. it is, even when things go fairly well, just to wash away accidential contamination during undressing. it is even more important in a potentially contaminated indoor area.(and of course i am speaking about water being delivered there, not about reconnection to official water pipes)

    ——————

    these aspects are very important, because obviously the work of these people did stop the accident from getting even worse. and whether people in the future will volunteer for a similar job (and that for our safety) depends on whether we do our best for those working there today.

    i simply can not understand, why you would send people there without full equipment (including a dosimeter, of course!!!)

    why they would sleep on the floor. (why they would sleep inside the compound at all?!?)

    why they don t work in shifts. why they don t have military NBC containers to support their work. …

  87. Barry Brook Wrote:

    The reactor pressure vessel (RPV) outlet temperature, RPV internal pressure, and drywell pressure readings, have all remained relatively stable over the last few days (see latest FEPC and JAIF reports at the foot of this blog entry).

    This doesn’t look very stable to me.

    From the data set provided here.

    RP: Reactor pressure
    D/W: Drywell pressure
    S/C: Suppression chamber (wet-well) pressure
    FNT: Feedwater nozzle temperature
    BHT: Bottom head temperature

  88. @David Martin: all japanese sleep on the floor. may appear strange, but it’s their habit (and a very conformable one, both for the back and for the space).
    and yes, hey work in shifts, otherwise it would be impossible to work no-stop for three weeks…

  89. Pingback: Top Posts — WordPress.com

  90. MODERATOR
    Please note that several comments, most of which were lodged overnight, are being held in the Pending/Moderation queue until Prof Brook returns some time today. Please be patient.

  91. @sod, on 2 April 2011 at 9:13 AM

    “i simply can not understand, why you would send people there without full equipment (including a dosimeter, of course!!!)”

    The same reason first response firemen sometimes have to run into a burning building to save lives, often without all the equipment and backup they would like.

    The conditions are such that they are very arguably still in “first response” mode.

    There is an underlying assumption that Tepco just doesn’t care because conditions aren’t ideal or maybe they are trying to save a few bucks by withholding food and water and sleeping mats, and saving gas on transport of off-duty workers to a safe shelter. There are no facts to prove that, just semi hysterical allegations based on snippets of information that may be unreliable and in any event is not taken in context of the utter devastation that surrounds that plant.

    Much of what you are claiming is based on a Fox News story, allegedly based on an anonymous (and therefore unverifiable) mother of a plant worker, speaking through an interpreter. That’s great infotainment but I wouldn’t condemn the operation based on that article.

    http://www.foxnews.com/world/2011/03/31/japans-nuclear-rescuers-inevitable-die-weeks/

    Fox News also reported today – on the air – that “blue lights” were seen at one or more reactors, claiming it as evidence of re-criticality. I did some googling and found only one private blog mentioning “blue lights” at the plant and it was obvious to me the report was not credible. Someone probably saw blue illumination lights, assuming it wasn’t made up out of whole cloth.

    Fox then put that clip on their web site. But I can’t link to it because for some strange reason I can’t find it now.

    I have no doubt doubt Fox dredged that blue light report out of that private blog, simply because it isn’t discussed anywhere else.

    At the very least I’d give that report on the workers condition a day or two to see if it “sticks”. [Ad hom deleted]
    Mods: feel free to edit my media directed ad-homs as you see fit. I just don’t know any better way to put it and I’m a Republican, and in this case ought to be sympathetic to Fox but I call em as I see em.

  92. Fukushima vs. TMI fuel melting

    There is a very informative (long) 4/1 update by KBMAN. Best to go straight over there to read as the discussion builds on premises that must be read in sequence.

    One summary point — because of the differences in BWR vs PWR fuel design, KBMAN speculates that Fukushima fuel melting has been much slower than TMI. That implies quite different activity by any corium dropping to the bottom of the RPV:

  93. @EL, on 2 April 2011 at 10:24 AM

    Thanks heaps for that dataset link for units 1, 2, 3. Just what I have been looking for.

    This doesn’t look very stable to me.

    What are you seeing that you don’t like?

  94. In the comments KBMAN explained clearly both the concentration of the source of contaminated water, and the encouraging fact that TEPCO can drain the basements while keeping up with the core cooling:

    Oh absolutely, there is some source of highly contaminated water. And considering that it was still that high despite dilution by the tsunami water means that the source is far more concentrated. This is the kind of symptom that causes me to suspect that significant amounts of fuel went into solution rather than melting.

    Another consideration regarding the incident at unit 3 is that the source water likely drained from the reactor building or turbine building into the basement where it met the backed up drain water from the trench. Given that the area was relatively dry the day before, the water they stepped in may not have had much dilution to that point in time. OTOH the 1 Sv/hr reading on the trench water at unit 2 is presumably after dilution.

    The whole point of the relative contributions was not to minimize the impact or importance of the leaks. But rather, it was to point out that the current rate of leakage does not prevent them from being able to get the basements drained while also maintaining cooling of the reactors. Sorry if this wasn’t more clear.

  95. I have been “off-line” for a couple of days and on returning find this TMI thread. No, not “Three Mile Island” but “Too Much Information”.

    Before I had a chance to skim this thread I saw the Fox News report with the “Blue Light” and also a ridiculous suggestion that there is a shortage of radiation monitors. I have tried protesting such rubbish from Fox News before only to be totally ignored.

    Blue light is what you find in pools of water contaminated with Beta emitters. This is called Cerenkov radiation.

    For blue light to be seen external to the building there would have to be criticality in a place where ionizing radiation could emerge with minimal shielding material to obstruct it. This requires several rather unlikely events:

    !. A prompt critical situation after control rods have been inserted.

    2. The breach of the pressure vessel.

    3. The breach of the main containment structure.

  96. After 2:40pm this afternoon, all comments have been in bold, rather than unbold. Any reason for this?

    I find it slightly less easy to read.
    MODERATOR
    I don’t know what is going on with this. Barry is not on the blog right now but I will ask him about it and see if we can correct it.

  97. @John Bennetts,

    Our much-overworked moderators have an unterminated paragraph tag in this comment “sod, on 2 April 2011 at 2:40 AM”

    That’s the result of the moderator extra efforts to remove the totally-unacceptable without completely deleting the comment.
    MODERATOR
    Thanks for that Steve. I had a sneaking suspicion it may have been my error. However, in the Comments Page that I’m working with everything looks normal.You did mention it before and I went back to look at the comment by “sod” but didn’t get what was wrong. I will see if I can fix it myself now.

  98. MODERATOR – IMPORTANT MESSAGE
    In future, comments will be deleted, if links are given, with accompanying quotes from articles etc., simply re-gurgitated, without critical feedback pertinent to the point being made by the commenter.Please be clear about your purpose for providing the link.

  99. TEPCO update 02.04.2011 10AM
    (only new information pasted here)
    Unit 2:
    At 5:05 pm on April 1st, the
    water injection was finished.

    ********

    *From 3:00 pm, April 1st, we started spraying inhibitor in order to
    prevent diffusion of radioactive materials. This attempt was conducted on
    a trial basis at the mountain side area of the common spent fuel pool in
    the range of 200m2. The spraying finished at 4:05 pm.

    *Monitoring posts (no.1 to no.8) which were installed around the site
    boundary have been restored. We will continue monitoring the measured
    value and make announcements on those values accordingly.

    http://www.tepco.co.jp/en/press/corp-com/release/11040201-e.html

  100. re post by: Barry Brook, on 2 April 2011 at 5:52 PM said:

    MODERATOR – IMPORTANT MESSAGE
    In future, comments will be deleted, if links are given, with accompanying quotes from articles etc., simply re-gurgitated, without critical feedback pertinent to the point being made by the commenter.Please be clear about your purpose for providing the link.

    Does this apply to simple plant status updates also? I thought that was in large part what this thread was for? I’m sorry, I’m a little confused on what prompted this note or just what it applies to?
    MODERATOR
    This is a new directive from Barry which, as I understand it, is meant to prevent folk giving a link, with just a selective, often cherry-picked quote from the article/blog, without commenting on that quote and their purpose for quoting it. I will no doubt have to check with him from time to time if lines seem blurred. It does not apply to plant up-dates.

  101. Oh shoot! Moderator, I’m sorry, apparently I missed my closing /blockquote at the end of quoting your message… I hope it doesn’t wind up propagating thru the thread like the missed /b did…
    MODERATOR
    Seems OK :-)

  102. Moderator:
    I had understood that the purpose of this thread was to provide updated information on the situation at the reactors rather than conducting extensive debate or argument and therefore have provided links to updates which did not seem to have appeared.
    This understanding seems to be incorrect as you are asking for argument, but with, I believe, supporting links.
    I would be grateful if you would clarify what you are looking for, and will of course be happy to comply with whatever your requirements are.
    MODERATOR
    I have asked Barry to give some more clarification. I don’t know whether he will be on the blog tonight, so this may not be answered straight away.

  103. Moderator:
    Perhaps I should clarify that the reason I had edited quotes from news-sources I linked was so as to avoid issues mentioned which were not directly relevant to the plant and their condition, and so as to provide topic summaries rather than for the purpose of in any way ‘cherry-picking’ data, save as that is inevitable from any effort to keep it relevant and within what I had understood was the purpose of these threads.

    I am therefore at a loss, and pending clarification of what is wanted will refrain from posting.
    MODERATOR
    See answer above.

  104. mpathmahoney;

    The commited dose factor for Cs-137 is 14 nSv/Bq ingested( 5.0E-02 rem/μCi, src: http://www.bnl.gov/bnlweb/PDF/00SER/c-app.pdf ).

    This estimate takes into account the absorption rate of Cs-137 by the GI tract and its biological half-life of 70 days(behaves much like sodium and potassium)

    E.g. if you eat 2.9 kg of sushi per year, and sushi has an activity of 500 bq/kg(the legal limit for sale of sea food in Japan), you will over time absorb a dose of 20 microsieverts.

  105. MODERATOR
    Would everybody please settle down and be patient. I have said the Barry is not available at the moment to clarify the new commenting rule. This is not a conspiracy to shut down comment but an attempt to keep the blog relevant and interesting/instructive. Sod and David Martin – I have put your last comments, regarding the new rule, in “Pending” as I can’t give you an answer and Barry will look at them immediately he logs on. In the meantime I suggest anyone who is unsure should hold off commenting, or post on the Open Threads which are specifically for opinions, ideas etc and where the commenting rules are more relaxed (except for ad homs, incivility and the like.)

    TECHNICAL OPEN THREAD
    Please restrict all discussion here to technical information, analysis, criticisms and questions on FD — no philosophising or excursions into whether nuclear power is ‘good’ or ‘bad’ or the implications of FD for the future of nuclear power (except for new technical developments, e.g. safety standards), etc. You may impart your deep wisdom on how the world should work on the Philosophical Open Thread.

    PHILOSOPHICAL OPEN THREAD
    Please keep all dialogue here to general and philosophical discussions on nuclear power, its benefits and limitations, its alternatives, history, media treatment of the FD accident, your views on how the world should work and why people should listen to you, etc., etc. Nothing technical please — leave that for the Technical Open Thread.

  106. David Martin, I think I understand what Barry is trying to do with this moderation rule, and I don’t think it was directed at your comments.

    Over many discussions here prior to the Fukushima incident, we sometimes get commenters, typically motivated idealogues, who support their various contentions with hyperlinks that, when followed and read with comprehension, simply do not bear on the point they are trying to make. The inference is that they themselves have not read or understood their references, or are blindly throwing in entries from some fact file they keep, or forwarding talking points from activist groups, etc.

    For an examples of this behaviour, see the many contributions from commenter “Machiavelli” in the Radiation thread, or search BNC for comments from “Webs and Weavers”, to name just two. We’ve seen this kind of behaviour here from the radiation alarmists, climate change denialists, proponents of various renewable energy technologies, and antinuclear activists.

    This behaviour is offensive because it is a simulacrum of engaged critical thinking. It apes the process of critical thinking by giving the appearance of providing substantiation, when it does nothing of the sort. It degrades the intellectual integrity of the discussion.

    So I can see why Barry is setting this moderation standard. I don’t know if I fully agree with it, because these commenters really do their case more harm than good. But there is no place for that kind of intellectual laziness in this forum.
    MODERATOR
    Thank you John for your input. I think you are probably “spot-on”.

  107. I’m not speaking for either side of the nuclear debate here, but I just wanted to point out something about the posting rules, which I see two posts from the bottom at this moment.

    If the “TECHNICAL OPEN THREAD” is limited to technical FD-only posts, and “PHILOSOPHICAL OPEN THREAD” is limited to any-subject, but non-technical posts, then there is no place here for technical non-FD posts, where technical rebuttal may be given on statements made about the general use of nuclear on the world stage. I have no rebuttal of my own to share in any of the threads, but I wanted to point this out, as it may have been an accidental statement.
    It occurs to me that the policy could be specifically tuned to achieve such an exclusion. If so, I understand that this is your site, and as such you are free to handle matters as you see fit. If however you seek to allow for technical rebuttal to the whole of the nuclear industry, for objectivity’s sake, perhaps some segregated allowance can be made for non-FD technical discussion.

    Your site is awesome, and I’ve learned a lot from it over the last few weeks. I appreciate your honesty, rigorous thought and info-mining.

    Take care,
    Joshua

    MODERATOR
    Joshua – I think you will find that, once the Fukushima crisis is less urgent, two simple Technical and Philosophical Open Thread will be established. In the meantime you should post non FD technical/philosophical points on the current OT’s.

  108. BARRY BROOK The commenting rules are not meant to be confusing, they’re meant to be logical. This is not a forum for cut-and-pasting slabs of text, with no other comment other than a link. Tell people why you think they should be interested in reading this, and what it means for this discussion. Otherwise, you’re not thinking and not contributing. Simple as that.

    I’ll add a new clause to the commenting rules:

    Citing literature and other sources: appropriate and interesting citations and links within comments are welcomed, but please DO NOT cite material that you have not yourself read, digested and understood. As a general rule, please introduce any and every link or reference with a short description of the material, your judgement on its quality, and the specific reason you are including it (i.e. how it is relevant to the discussion).

    Remember, we are moderating, but are not in the business of censoring criticism — we welcome well-presented critiques. The principal concern is working out how to conduct this debate in a civil and evidence-based manner, and do it well. We may reject some comments at our discretion, but will never misrepresent your comment. Comments that break “the rules” a little will generally be posted anyway, but probably with a note appended by the moderator and/or the offending part obviously expurgated. Those who have regularly broken the rules are on permanent moderation — most manage to live with this. Those who started their BNC commenting career by insulting me or others here, including threats, swearing etc. were instantly put on the ban list. They can find any number of swamps on the internet in which to lurk — I’m not interested in having them here.

  109. Question; Is reactor 3 the 800 pound gorilla? I’m reading JAIF and expert reports, namely on the RPV status, radioactive water, and the estimated fuel melt of reactor cores in 1 (70%) and 2 (30%), but there is less reporting on the status of reactor 3. We don’t have the same degree of updates on the core, RPV, or SPF of reactor 3. Mainly we have vague terms like damaged, or stable, Does this concern any of the experts here? Yes or no, please explain why?

  110. Steve Darden wrote:

    Thanks heaps for that dataset link for units 1, 2, 3. for.

    What are you seeing that you don’t like

    For Reactor #1, RP and D/W pressures seem to follow each other (as expected) until they no longer follow each other. RP rapidly goes down, and D/W pressure rapidly goes up. This indicates to me steam is not being managed through torus or condensate and feedwater lines very effectively, and there is likely a significant pipeline break in ECCS inside primary containment. What this means for on-going cooling and containment efforts remains to be seen. Further support for this is suggested here (around minute 9:30).

  111. http://www.nytimes.com/2011/04/03/science/03meltdown.html

    Details on how much is known (and how little is being told to the public) from an article about using forensics.

    “… Governments and companies now possess dozens of these independently developed computer programs, known in industry jargon as “safety codes.” Many of these institutions — including ones in Japan — are relying on forensic modeling to analyze the disaster at Fukushima Daiichi to plan for a range of activities, from evacuations to forecasting the likely outcome.

    “The codes got better and better” after the accident at Three Mile Island revealed the poor state of reactor assessment, said Michael W. Golay, a professor of nuclear science and engineering at the Massachusetts Institute of Technology.

    These portraits of the Japanese disaster tend to be proprietary and confidential, and in some cases secret. One reason the assessments are enormously sensitive for industry and government is the relative lack of precedent: The atomic age has seen the construction of nearly 600 civilian power plants, but according to the World Nuclear Association, only three have undergone serious accidents in which their fuel cores melted down.

    Now, as a result of the crisis in Japan, the atomic simulations suggest that the number of serious accidents has suddenly doubled, with three of the reactors at the Fukushima Daiichi complex in some stage of meltdown. Even so, the public authorities have sought to avoid grim technical details that might trigger alarm or even panic. ….”

    —-
    A few specifics given hint that far more could be told if the news folks go after it.

    Shorter: why bother blogging, we’re not going to have facts, we’re getting “reassurance” — blogging can only speculate without pretending we will know enough to say anything useful. Pretty dismal as a news story.

  112. @EL, on 3 April 2011 at 4:55 AM

    What this means for on-going cooling and containment efforts remains to be seen.

    Thanks, I see. Reminds me of patient peering at ECG, think are those good wiggles or bad wiggles? It’s not clear to the amateur which are the significant patterns.

    What is the source of the Unit 1 graph that you published with the raw data? Your own Excel I presume.

  113. “Hank Roberts, on 3 April 2011 at 7:17 AM said:
    Details on how much is known (and how little is being told to the public) from an article about using forensics….modeling”

    I would argue that the output of those models are not “known facts”, they are simply the speculations of the modelers, who fortunately have rarely had a chance to test their models.

    I can only imagine the hysteria that would be generated by the media, turning model *predictions* into certain facts and certain fates, and cherry picking model predictions.

  114. NR99: you can see for yourself what the “modelers” have said. It’s more an explanation of what they think the accident progression was in R1 to R4, instead of a prediction of hysterical situations.

    See Leo above at 7:46 AM

  115. What is the source of the Unit 1 graph that you published with the raw data? Your own Excel I presume.
    It’s not my own. It’s from the following thread (and the link to the data too … which is very useful). Is it worth asking why there is so little data for the first 8 hours of the accident (prior to venting). Definitely looks like a pretty hectic period in the control rooms for three different reactors.

  116. Sadly, the first two casualties have been announced.

    TOKYO — The operator of the stricken Fukushima Daiichi Nuclear Power Station said Sunday that two workers at the plant who had been missing for several days had been confirmed dead.

    The operator, Tokyo Electric Power Company, said the workers were found in the basement of the turbine building connected to the plant’s No. 4 reactor. The company did not say how the workers died. But various news media reports say the men lost blood and went into shock.

    “It pains me that these two young workers were trying to protect the power plant while being hit by the earthquake and tsunami,” Tokyo Electric’s chairman, Tsunehisa Katsumata, said in a statement, according to The Associated Press.

    http://www.nytimes.com/2011/04/04/world/asia/04japan.html

  117. Tokyo Electric Power Co. said Saturday that a cracked storage pit at the Fukushima No. 1 power plant was the source of a radioactive water leak contaminating the ocean and that it is attempting to fill it with concrete.
    According to the utility and the Nuclear and Industrial Safety Agency, the square, concrete-covered pit is situated near an intake used to pump seawater into reactor No. 2.
    Although the pit is small, it contains highly contaminated water with a radioactivity exceeding 1,000 millisieverts per hour that is leaking into the ocean from a 20-cm crack, Tepco said.
    The pit, which is 1.2 meters x 1.9 meters and 2 meters deep, is usually used to store cables. But it is also connected directly to the reactor building through a cable trench, raising the possibility that the source of the contaminated water is the reactor itself, a NISA official said.
    The cable trench is different from the pipe trench at No. 2, where water with the same level of radioactivity was discovered Monday. Although the two trenches are connected, no water has been found in the cable trench because it is at a higher elevation, the official said.
    How much water has leaked and for how long were not known as of Saturday afternoon.
    NISA spokesman Hidehiko Nishiyama said Tepco has been told to make sure there are no other leaks near reactor No. 2 and to strengthen is monitoring of seawater.

    http://search.japantimes.co.jp/cgi-bin/nn20110403a1.html

    There is a diagram of the location of the leak at the link.

    Of course this should actually be called the path of the leak, not the source, which presumably is some breach in the reactor or pipework.
    Blocking this will stop much or all of the drain to the sea though.

  118. @Leo Hansen, on 3 April 2011 at 11:54 AM said:

    “NR99: you can see for yourself what the “modelers” have said. It’s more an explanation of what they think the accident progression was in R1 to R4, instead of a prediction of hysterical situations.”

    I did *not* say that the modelers were predicting hysterical situations. I read the article; the predictions were along the lines of what has been discussed here since the early days of the event although the article implies the modelers very early predictions were more along the lines of what we know now than Barry’s early predictions, for example.

    Some models may have been very wrong. For example, the NRC Chairman’s announcement that SPF4 was bone dry and on fire has been shown, to the extent we understand things, to have been very wrong. I can only assume he was working from a model although he never disclosed the basis for his assertion (this discussed previously on the comments here in other threads).

    I suggested the *media* (not the modelers) would hype the various model predictions into “doomsday is here as a fact”.

  119. @NR99 I stand corrected, your comment was about the media, not about the modelers.

    BTW, I agree with you about models, having worked with them for years. We have a saying “All models are wrong, but some models are useful.”

    Your comment is I think especially true about climate models, climate modelers and the MSM: ” I would argue that the output of those models are not “known facts”, they are simply the speculations of the modelers, who fortunately have rarely had a chance to test their models.

    I can only imagine the hysteria that would be generated by the media, turning model *predictions* into certain facts and certain fates, and cherry picking model predictions.”

  120. Pingback: Thorium, a Safer Nuclear Alternative? « French News Online Newsroom

  121. > Blocking … the drain to the sea …

    Has anyone seen estimates of the volume of water that’s been going out via this path? It sounds like a lot did; the crack must date back to the earthquake (or earlier, and opened wide with the earthquake) so it may have served as a drain for a long time.

  122. IAEA: Unit 1 variable pressure; Unit 2 at atmospheric pressure; Unit 3 no pressure given.

    http://www.iaea.org/press/?p=1916#more-1916

    “… TEPCO announced on 2nd April that, following the detection of highly contaminated water leaking through a crack found in a pit near Unit 2, they had added 3 additional sampling points at 15km from Fukushima Daiichi and Fukushima Daiini….”

    [Can they locate and collect the water flowing out of the crack at the downstream end?]

    “In Unit 1 the indicated temperature at the feed water nozzle of the RPV is relatively stable at 259oC and at the bottom of RPV at 117oC. The RPV pressure indications are fluctuating and Drywell pressure is slightly decreasing. In Unit 2 the indicated temperature at the feed water nozzle of the RPV has decreased slightly from 161oC to 153oC. The temperature at the bottom of RPV was not reported. Indicated Drywell pressure remains at atmospheric pressure. The indicated temperature at the feed water nozzle of the RPV in Unit 3 is stable at 118oC and at the bottom of the RPV is about 92oC. The validity of the RPV temperature measurement at the feed water nozzle is still under investigation….”

  123. From the same IAEA report:

    “On 2 April, measurements were made at 7 locations at distances of 32 to 62 km, North and Northwest to the Fukushima nuclear power plant. The dose rates ranged from 0.6 to 4.5 microsievert per hour. At the same locations, results of beta-gamma contamination measurements ranged from 0.09 to 0.46 megabecquerel per square metre….”

    Anyone able to evaluate “beta-gamma … megabecquerel per square meter” numbers? Should that have a time associated with it as well as an area? Why are beta and gamma combined?

  124. An explanation of the terms (from a report on radioactivity left from some of the earliest research work done on radiation, by Rutherford)

    http://www.manchester.ac.uk/rutherfordreview/documents/ea-6-2009.pdf

    “… The rate at which spontaneous transformations occur in a given amount of a radioactive
    material (radioactive decay) is known as its activity. Activity is expressed in a unit called the Becquerel which has the symbol Bq, where 1 Bq is equal to one transformation per second. As for the unit of energy, multiples of the Bq are often used to describe the number of transformations that a radioactive material will undergo, with 1 million transformations being expressed as a mega-Becquerel (MBq)

    “Becquerel (Bq)
    The international (SI) unit for the number of nuclear disintegrations occurring per unit time, in a quantity of radioactive material. 1 Bq = 1 radioactive disintegration per second. This is an extremely small unit and levels are often prefixed with mega (106 Bq – MBq), giga (109 Bq – GBq) and tera (1012 Bq – TBq) particularly in the context of discharges of activity into the environment. Conversely, under normal circumstances, activity concentrations in environmental materials are generally low and so prefixes such as milli (10-3 Bq – mBq) and micro (10-6 Bq – μBq) are used…”

    This is part of a rather thorough academic explanation of the longterm exposures over the lifetime of the various decay chains from each source. I recommend it, from paging through several of the documents, as a likely good reference for explaining this. Many of the popular press explanations either ignore radioactive decay or else give the mistaken impression that one thing goes away without mentioning that some of the decay products are also radioactive with their own decay paths, so utterly fail to explain dosage over time. These papers get that clear.

    http://www.manchester.ac.uk/rutherfordreview/

  125. 2nd Attempt at blocking crack underway using expanding gel:

    ‘Workers on Sunday poured a chemical compound mixed with sawdust and newspaper into a crack at Japan’s Fukushima Daiichi nuclear power facility that’s been a conduit for highly radioactive water leaking into the Pacific Ocean, a utility company official said.
    This follows an unsuccessful attempt a day earlier to use concrete to plug the 2-meter-deep (6.5-foot-deep), concrete-lined basin, where authorities had found water gushing directly into the sea via a roughly 20-centimeter crack.
    Eighty bags of a water-gel mix made by the Tokyo-based IB Daiwa company will be used in the operation. Each one contains 100 grams of material that includes a special polymer. A Tokyo Electric official said the substance should expand to several thousand times its size as it sticks, ideally, to plug the leak.
    The cracked shaft sits behind the No. 2 reactor’s turbine building at the facility, which has been in constant crisis since the failure of cooling systems and numerous explosions in the wake of last month’s epic earthquake and tsunami.
    Fixing the problem quickly is critical because officials believe it is one source of alarmingly high levels of radiation spotted in seawater near the plant. ‘

    http://edition.cnn.com/2011/WORLD/asiapcf/04/03/japan.nuclear.reactors/index.html?hpt=T2

    The importance of this is presumably obvious.

  126. I have apparently been marked out for approval before posting although at no stage was I rude, and simply asked for clarification of what was wanted, which as I stated is fine by me whatever the requirements are providing I understand them.
    Since I have simply posted information which was not on the site already I am happy to continue to do so.
    I appreciate that moderation has been fraught, but should I find that the next update I attempt to post is singled out for moderation before posting I will assume that they are no longer wanted, and regrettably will no longer post to this blog.
    I wish all concerned all the best for the future.
    MODERATOR
    You have been put on the Pending list so that your incoming comments can be assessed for the new “Citing literature and other sources” commenting rule. You commented over-night Australian time so your comment has been held-up until Barry is on the blog. As Moderator I think your latest comment breaks the new rule but, as I am still getting used to it, I think we should await Barry’s decision.

  127. @Leo Hansen, on 3 April 2011 at 11:22 PM said:

    Another interesting example of models… for decades astronomers have been modeling the expected characteristics of other solar systems but until fairly recently no one had actually seen an exoplanet so the models were constructed totally “blind”, except for the one sample that was known – our solar system.

    Those models describe in great detail exactly how nebular material supposedly coagulates into a solar system. Some models even feature fancy computer graphics to illustrate the process in great detail.

    As I understand it, the preponderance of the models, if not all of them, suggested other solar systems would look very much like ours with gas giants at the outer areas of the solar system with smaller rocky planets closer to the star.

    In the last few years many exoplanets have been discovered and very recently some surprisingly small exoplanets have been discovered (something I find absolutely amazing).

    The common thread that has surfaced is that none of these solar systems look anything like ours :-). All the models are very, very wrong. The consensus conclusion, as I understand it, is that although the models are “based on hard science” and physics is physics, the models were all seriously biased by the one example we know.

    It would not be surprising that, months or a few years from now, after the cameras are finally lowered into these reactors and long term radiation studies are conducted, , all those forensic models will get some serious changes.

    This is nothing like TMI, which was a PWR that sustained a single LOCA event over a 12-14 hour period. In this case you have a BWR that has sustained various degrees of a LOCA (really a loss of power event) over several weeks. But unlike TMI, the onsite engineers likely understood very well what was happening at each stage, they just didn’t have the tools to control it.

    The current models are probably very biased toward the particulars of TMI since that is the only real life sample they have (of a major commercial reactor failure), not counting Chernobyl because the circumstances, engineering and equipment were so different and unlikely to be repeated.

    A stopped clock is right twice a day, every day. Any journalist can construct a story about highly accurate stopped clocks. He simply has to cherry pick his clocks and the time he measures them.

    Especially given the secrecy surrounding those models (per the article), we will never know how many of those models turned out wrong (and the results buried for good reason), based on what is known at this point in time or in the future. It’s easy to write a story about accurate models when you have the benefit of hind sight at some certain point in time, as we have now to some extent.

  128. NR99- Having had Geoff Marcy as a Professor (in Astrophysics post retirement) let me suggest that our current methods are skewed towards detecting giant plants circling close to stars. This is by the doppler shift method.

    As such,our current understanding of the distribution of plantetary systems is at thistime is crude. I agree that we should not have believed that our plantetary aranngement is typical.

  129. I have been wondering why it’s so far not been possible to get the reactor vessels full of water or to stay full (having just read that they’re getting ready to introduce pure nitrogen to reduce the risk of a hydrogen-oxygen reaction inside the vessel, makes me think there’s no expectation of being able to fill the space entirely with water and keep it full.

    Has anyone seen comments or information about this question anywhere?

  130. The pressure boundaries on PCVs #2 and #3 appear to leaking since they are running at atmospheric pressure. It was widely reported/speculated that #2 is leaking at or near the torus. Not sure where #3 is leaking. If they were to flood the PCV the static pressure head at the torus would be about 20 m = 4 atm which is the design pressure of the PCV. Maybe they can flood #1 since it holds pressure but unless they can repair the pressure boundary I doubt that they could flood #2 or #3.

  131. Leo, I understand very well that the exoplanet data is necessarily skewed towards large planets (but see below!).

    What broke the models, though, was the fact that many very large (presumably gas giant) planets are located very close to the stars, close enough to result in orbits in the order of a few days. The models all predicted that those gas giants must be very distant, like Jupiter and Saturn, with orbital periods measured in many years.

    If you take a look at this chart of Exoplanets:

    http://exoplanets.org/table/

    You see very massive planets – greater than 1 Jupiter mass – msin(i) – with very short orbital periods, some only a few days, placing them well inside the orbit of Mercury.

    You also see planets with as little as 0.02 Jupiter masses, which is only about 8x Earth’s mass. They are making great progress locating smaller planets- far greater than was expected only a few years ago.

    My main point, though, is that in general models work well when the outputs are well understood and well observed in the real world. They work progressively more poorly when the outputs are not well observed and understood.

    I suspect nuclear engineers know more about reactor behavior than astronomers know about exoplanets simply because they have blown a few up in the early years (this was discussed in a recent thread). And the physics may be simpler and more predictable- to some degree I do think the context holds, though, to some extenht. I’m not convinced climatologist modelers know much more, on a relative basis, than the astronomers, but that’s another discussion :-).
    MODERATOR
    Off-topic(as you say) – please move to Open Thread. Off-topic comments may be deleted as per BNC comment policy.

  132. David, I quite agree filling the air space with nitrogen makes sense. I don’t know if it’s a routine procedure delayed due to the earthquake (perhaps they didn’t have tanks of nitrogen on hand?) — or if it’s an unusual procedure entered into because they have concluded for whatever reason that they can’t get the containments to fill up anytime soon.

    My question is has anyone seen any clear answer to why they haven’t been able to get the containments to fill up, up to the level where they were normally expected to be? Different answers for each reactor, or a replicated failure?

  133. Hank Roberts, on 4 April 2011 at 12:09 PM — I have no idea how routine adding nitrogen might be, but I’ll opine it is not.

    I’ll also opine that #2 and #3 may have leaks. If so, those will need mending before the reactor container will hold water without incessant pumping.

  134. At this point the partial pressure of oxygen in the PCV should be approaching zero. The gas phase should be water only. Even if hydrogen is generated by oxidation of zircon by steam/water there will be no oxygen in the vessel to react with it. As long as any hydrogen is vented to the atmosphere outside of the rector building, it should not pose an explosion hazard.

    Additionally, introducing nitrogen would add another significant hazard, i.e. the possibility of oxygen depletion in the environment where workers are present.

  135. Ernie, David and Hank: It’s my understanding that the PCV are normally inerted with N2, so that H2 explosions are minimized.

    Although I doubt that zirconium-steam reactions are currently unlikely, radiolysis of water to produce both H2 and O2 is still taking place in the reactor. When the reactor PSV’s dump to the supression chamber, the H2 and O2 can build up over time in the PCV.

    Typically it takes (at least with HC’s) a min O2 of ~ 8-10% for an explosion to take place. Over-inerting with N2 to keep O2 low is a common practice in the petroleum and tanker business.

  136. I’ve been very grateful to this discussion the issues around the efforts to contain the reactors in Japan. The amounts of “highly contaminated water” reaching the ocean are receiving a lot of attention. Can anyone offer details of the risks this may actually pose, absent the expansive doom reverberating through the media?

  137. Question for anyone who actually knows the hardware: The IAEA says:

    “… In Unit 1 Fresh water has been continuously injected into the reactor pressure vessel through the feed-water line at an indicated flow rate of 6 m3/h using off-site power. In Unit 2 and Unit 3 fresh water is being injected continuously into the reactor pressure vessels through the fire extinguisher line indicated rates of 8 m3/h and 7 m3/h respectively …”

    and then says

    “In Unit 1 … The RPV pressure indications are fluctuating and Drywell pressure is slightly increasing. The reliability of RPV pressure indications is in question.
    In Unit 2 …. Indicated Drywell pressure remains at atmospheric pressure.
    In Unit 3 [no pressure given]”

    I’d think they would have a pressure gauge on the pumps putting water into the RPVs and could figure out the pressure against which they are pushing water into Unit 1, to evaluate the sensor; just stop the pump momentarily, close a valve and see how much the reactor is pushing back.

    Maybe not — if there’s a one-way valve in the system stopping backflow for example. That’s what I’m wondering. (I don’t expect to be told even if they do have them — I’m just wondering if it makes sense they’d have this info source, in addition to the pressure sensors originally installed that are dubious or dead.)

  138. Hank: A UCS file shows 2 isolation valves on the steam and 2 check valves on the main feedwater line (to prevent backflow). The two valves are 1 inside PCV and 1 outside.

    I’d expect that fire extinguisher line would also have 2 check valves, but I have never seen a fire extinguish line on any of the simple BWR dwgs.

    Re figuring out what pressure the reactor is at, one could back down the flow from the pumps and the indicated pressure at low flow would be the reactor pressure after adjusting for differences in height (static head)

  139. FEPC update, 4 April:

    • Radiation Levels
    o The level of concentration of radioactive nuclide I-131 (2.5 x 101 Bq/cm3) from the seawater sampled near the seawater discharge point of Fukushima Daiichi Nuclear Station at 1:50PM (JST) on April 3 was approximately 625 times higher than the maximum permissible water concentration (4.0 x 10-2 Bq/cm3) set by the government.
    o On April 4, TEPCO announced that it will discharge 10,000 tons of low level radioactive water stored at the Central Radioactive Waste Disposal Facility in order to accommodate higher level radioactive water. It will also discharge 1,500 tons of low level radioactive water which had accumulated at the sub-drain pits of Unit 5 and 6 in order to prevent important equipment of Unit 5 and 6 from being submerged. The original TEPCO press release is attached and also available at:

    http://www.tepco.co.jp/en/press/corp-com/release/11040404-e.html

    (At 9:30PM on April 4, NHK reported the discharge of water from the Central Radioactive Waste Facility has commenced around 7:00PM and from the sub-drain pits at 9:00PM.)
    o At 6:00PM on April 4, radiation level at main gate (approximately 3,281 feet from Unit 2 reactor building) of Fukushima Daiichi Nuclear Power Station: 118 micro Sv/hour.
    o At 6:00PM on April 4, radiation level at west gate (approximately 3,609 feet from Unit 2 reactor building) of Fukushima Daiichi Nuclear Power Station: 72.1 micro Sv/hour.
    o Measurement results of environmental radioactivity level around Fukushima Nuclear Power Station announced at 7:00PM on April 4 are shown in the attached PDF file. English version is available at: http://www.mext.go.jp/english/radioactivity_level/detail/1304082.htm
    o For comparison, a human receives 2,400 micro Sv per year from natural radiation in the form of sunlight, radon, and other sources. One chest CT scan generates 6,900 micro Sv per scan.
    • Fukushima Daiichi Unit 1 reactor
    o On April 2, lighting was restored at the part of the turbine building.
    o At 7:20AM on April 4, the temperature of the spent fuel pool by thermography measurement: 64.4 degrees Fahrenheit.
    o At 11:00AM on April 4, pressure inside the reactor core: 0.299MPa.
    o At 11:00AM on April 4, water level inside the reactor core: 1.65 meters below the top of the fuel rods.
    o At 11:00AM on April 4, pressure inside the primary containment vessel: 0.15MPaabs.
    o At 11:00AM on April 4, the temperature of the reactor vessel measured at the water supply nozzle: 469.0 degrees Fahrenheit.
    o As of 3:00PM on April 4, the injection of freshwater into the reactor core continues.
    o As of 7:00PM on April 4, preparation to recover and transfer the accumulated water at the turbine building continues.
    • Fukushima Daiichi Unit 2 reactor
    o On April 2, lighting was restored at the part of the turbine building.
    o On April 2, monitoring cameras were set at the trench outside the turbine building and at the basement floor of the turbine building to monitor the water levels.
    o At 9:30AM on April 2, the accumulated water was found in the pit (a vertical portion of an underground structure for housing electric cables) near the seawater intake and the radiation level of the water was over 1,000 milli Sv/hour. In addition, the water was observed entering the ocean from a crack (about 20cm = 7.9 inches) on the lateral surface of the pit.
    o At 4:25PM on April 2, concrete was injected into the pit in an attempt to stop the discharging of water. (injected again at 7:02PM)
    o At 1:47PM on April 3, polymer absorber, sawdust, and shredded newspapers were inserted in the pit in an attempt to stop the overflow of the discharge of water, until 2:30PM.
    o At 7:08AM on April 4, tracer (white colored bath agent) was inserted into the trench outside the turbine building to determine the route of the water leakage.
    o At 11:00AM on April 4, pressure inside the reactor core: -0.018MPa.
    o At 11:00AM on April 4, water level inside the reactor core: 1.5 meters below the top of the fuel rods.
    o At 11:00AM on April 4, pressure inside the primary containment vessel: 0.10MPaabs.
    o At 11:00AM on April 4, the temperature of the reactor vessel measured at the water supply nozzle: 282.2 degrees Fahrenheit.
    o At 11:00AM on April 4, the temperature of the spent fuel pool: 122 degrees Fahrenheit.
    o As of 3:00PM on April 4, the injection of freshwater into the reactor core continues.
    o As of 7:00PM on April 4, preparation to recover and transfer the accumulated water at the turbine building continues.
    • Fukushima Daiichi Unit 3 reactor
    o On April 2, lighting was restored at the part of the turbine building.
    o At 9:52PM on April 2, TEPCO began to shoot freshwater aimed at the spent fuel pool, with a specialized vehicle normally used for pumping concrete, until 12:54PM (approximately 75 tons in total).
    o At 7:20AM on April 4, the temperature of the spent fuel pool by thermography measurement: 134.6 degrees Fahrenheit.
    o At 9:30AM on April 4, pressure inside the reactor core: 0.005MPa.
    o At 9:30AM on April 4, water level inside the reactor core: 1.75 meters below the top of the fuel rods.
    o At 9:30AM on April 4, pressure inside the primary containment vessel: 0.1069MPaabs.
    o At 9:30AM on April 4, the temperature of the reactor vessel measured at the water supply nozzle: 194 degrees Fahrenheit. (This figure is under investigation.)
    o As of 3:00PM on April 4, the injection of freshwater into the reactor core continues.
    o At 5:03PM on April 4, TEPCO began to shoot freshwater aimed at the spent fuel pool, with a specialized vehicle normally used for pumping concrete.
    o As of 7:00PM on April 4, preparation to recover and transfer the accumulated water at the turbine building continues.
    o As of 7:00PM on April 4, approximately 4,908 tons of water in total has been shot into the spent fuel storage pool.
    • Fukushima Daiichi Unit 4 reactor
    o On April 2, lighting was restored at the part of the turbine building.
    o At 5:14PM on April 3, TEPCO began to shoot freshwater aimed at the spent fuel pool, with a specialized vehicle normally used for pumping concrete, until 10:16PM (approximately 180 tons in total).
    o At 7:20AM on April 4, the temperature of the spent fuel pool by thermography measurement: 86 degrees Fahrenheit.
    o As of 7:00PM on April 4, approximately 1,473.2 tons of water in total has been shot into the spent fuel storage pool.
    • Fukushima Daiichi Unit 5 reactor
    o At 2:00PM on April 4, the temperature of the spent fuel pool: 94.3 degrees Fahrenheit.
    • Fukushima Daiichi Unit 6 reactor
    o At 2:00PM on April 4, the temperature of the spent fuel pool: 70.7 degrees Fahrenheit.
    • Fukushima Daiichi Common Spent Fuel Pool
    o At 8:10AM on April 3, the temperature of the spent fuel pool: 89.6 degrees Fahrenheit.
    • Others
    o At 9:10AM on April 2, a US Military barge (No.2) carrying freshwater docked at the dedicated port at Fukushima Daiichi Nuclear Power Station, towed by a vessel of the Marine Self Defense Forces.
    o At 10:20AM on April 2, transferring freshwater from the US Military barge (No.1) to a filtrate tank resumed, until 4:40PM.
    o At 12:12PM on April 4, a US Military barge (No.2) carrying freshwater docked again at the dedicated port at Fukushima Daiichi Nuclear Power Station, after refilling the freshwater.

    Our official sources are:
    • Office of The Prime Minister of Japan
    • Nuclear and Industrial Safety Agency (NISA)
    • Tokyo Electric Power Company (TEPCO) Press Releases
    • Ministry of Education, Culture, Sports, Science and Technology (MEXT)

  140. TEPCO Washington Update, 5 April

    (1) Discharge of low level radioactive accumulated water in the Fukushima Daiichi NPS to the sea

    (2) Outflow of fluid containing radioactive materials to the sea from areas near intake channel of Fukushima Daiichi NPS Unit 2

    (3) Missing TEPCO Employees at Fukushima Daiichi NPS

    Contacts:
    TEPCO Washington Office 202-457-0790
    Kenji Matsuo, Director and General Manager
    Yuichi Nagano, Deputy General Manager,
    Masayuki Yamamoto, Manager, Nuclear Power Programs =============================================================

    (1) Discharge of low level radioactive accumulated water in the Fukushima Daiichi NPS to the sea

    There is currently great amount of radioactive waste water in the turbine buildings of the Fukushima Daiichi NPS and especially the turbine building of Unit 2 has extremely high level radioactive waste water.

    We think it is necessary to transfer the radioactive waste water to the Central Radioactive Waste Disposal Facility in order to store it in a stable condition. However, ten thousand tons of low level radioactive waste water has been already stored and we have to discharge the existing low level radioactive waste water to receive new liquids.
    In addition, as low radioactive subsurface water is piling up in sub drain pits of Unit 5 and 6 and a part of subsurface water is running into buildings, important equipment to secure the safety of reactors will be submerged.

    Based on the Section 1 of the Article 64 of the Nuclear Reactor Regulation Law, we have decided to discharge to the sea approximately ten thousand tons of the accumulated low level radioactive water and a total of 1,500 tons of the low level radioactive subsurface water stored in the sub drain pits of Unit 5 and 6.

    We evaluate approximately 0.6 mSv of effective radioactive doses per year for adults as the impact on the discharge of the low radioactive waste water to the sea if they eat adjacent fish and seaweeds every day. The amount (0.6 mSv of effective radioactive doses per year) is one-forth of annual radioactive dose to which the general public is exposed in nature.

    Afterwards, we were preparing to discharge the low radioactive waste water to the sea. We started discharging the low radioactive waste water stored in the Central Radioactive Waste Disposal Facility to the sea at 7:00 pm on April 4th. In addition, at 9:00 pm on April 4, we started discharging the low level radioactive subsurface water stored in the sub drain pits to the sea.

    (2) Outflow of fluid containing radioactive materials to the sea from areas near intake channel of Fukushima Daiichi NPS Unit 2

    On April 2, at around 9:30 am, TEPCO detected water containing radiation dose over 1,000 mSv/h in the pit* where supply cables are stored near the intake channel of Unit 2. Furthermore, there was a crack about 20 cm on the concrete lateral of the pit, from where the water in the pit was outflowing. At around 12:20 pm, we reaffirmed the event at the scene.

    We have implemented sampling of the water in the pit, together with the seawater in front of the bar screen near the pit. These samples were sent to Fukushima Daini NPS for analysis.

    In addition to seawater sampling conducted in the coastal areas of Fukushima Daiichi /Daini NPS (sampling conducted at 4 points), we have initiated additional seawater sampling at 3 points in the areas 15 km offshore from the relevant power stations. Taking into account the result of these monitoring, we are intending to conduct a comprehensive assessment.

    In order to block the leakage, we have injected concrete to fill up the pit and close the crack. But it turned out that leakage into the sea still continues. Then we tried to plug the path by putting sawdust, polymer and newspaper into the path from the afternoon on April 3. The water still keep spilling into the sea. This morning (April 4th), from 7:08 to 7:11 am, tracer (opaque white powder) was poured into the pit through the horizontal shaft of the trench for seawater piping and began to investigate the water path. The amount of tracer power was approx 13kg.

    We will investigate the influx route of contaminated water in the pit and implement necessary measures to prevent such influx.
    *pit: a shaft made of concrete

    (3) Missing TEPCO Employees at Fukushima Daiichi NPS

    Due to the Tohoku-Taiheiyou-Oki Earthquake which occurred on March 11th 2011, two TEPCO employees, who had been working at the turbine building of Unit 4 for site investigation, went missing.

    We had put all our efforts to search them, and approximately at 3:25 pm and at 3:53 pm, March 30, those employees were found at the basement of the turbine building and we confirmed their death on March 31.

    We would like to offer our deep regret that our employees died while working at the plant and heartfelt condolences to the bereaved families.

  141. MODERATOR
    Please note that off-topic comments will be deleted and, as we are unable to transfer comments, you will be asked to re-post in the correct thread. In particular comments regarding your personal opinions, beliefs etc should be posted in the Fukushima Philosophical Open Thread.

  142. thanks for the update, but an important information about cesium in the sea seems to be missing:

    but it has been reported in media, like the nytimes:

    “The announced standards for fish came hours after the Tokyo Electric Power Company said it found radioactive iodine 131 in seawater samples collected to be 200,000 becquerels per cubic centimeter, or five million times the legal limit. The samples were collected Monday near the water intake of the No. 2 reactor of the Daiichi plant.

    The sample also showed levels of cesium 137 to be 1.1 million times the legal limit, according to the public broadcaster NHK. Cesium remains in the environment for centuries, losing half its strength every 30 years. ”

    http://www.nytimes.com/2011/04/06/world/asia/06japan.html?_r=1&ref=global-home

    [deleted personal scientific assessment not borne out by reference quoted.]

  143. Some good news today. Might help some of the nuclear “worriers” stop worrying about radiation levels.

    Japan stops leaks from nuclear plant
    Posted 23 minutes ago

    Engineers have stopped highly radioactive water leaking into the sea from a crippled Japanese nuclear power plant, a breakthrough in the battle to contain the worst nuclear crisis since Chernobyl.

    Here is the full story.

    http://www.abc.net.au/news/stories/2011/04/06/3183588.htm?section=justin

  144. @Ms.Perps

    I found the TEPCO press release which says just this:

    At 5:38 am on April 6th, we observed the stoppage of the water spilling
    from the crack on the concrete lateral of the pit. Details of the
    situation will be announced after checking the blockage of the water
    flows.

    We will continue the countermeasure in order to prevent further outflow
    of high level radioactive materials to the ocean.

    http://www.tepco.co.jp/en/press/corp-com/release/11040601-e.html

    If the radiation was mostly coming from the R2 torus…

  145. The Federation of Electric Power Companies of Japan (FEPC) Washington DC Office
    FEPC UPDATE, 6 April:

    • Radiation Levels
    o The concentration of radioactive nuclides from the seawater sampled at the screen device (installed to remove waste before the intake of seawater) of Unit 2 of Fukushima Daiichi Nuclear Station was as follows:
    The details of this report are available at:

    http://www.tepco.co.jp/en/press/corp-com/release/11040506-e.html

    Nuclides
    (half-life) Concentration (Unit : Bq/cm3)
    Sampled at 11:50AM on April 2 Sampled at 6:25PM on April 3 Sampled at 9:00AM on April 4 Maximum Permissible Water Concentration
    I-131
    (8 days) 3.0 x 105 7.9 x 104 2.0 x 105 4.0 x 10-2
    Cs-134
    (2 years) 1.2 x 105 3.5 x 104 9.6 x 104 6.0 x 10-2
    Cs-137
    (30 years) 1.2 x 105 3.6 x 104 9.6 x 104 9.0 x 10-2

    o At 6:00PM on April 5, radiation level at main gate (approximately 3,281 feet from Unit 2 reactor building) of Fukushima Daiichi Nuclear Power Station: 112 micro Sv/hour.
    o At 6:00PM on April 5, radiation level at west gate (approximately 3,609 feet from Unit 2 reactor building) of Fukushima Daiichi Nuclear Power Station: 67.4 micro Sv/hour.
    o Measurement results of environmental radioactivity level around Fukushima Nuclear Power Station announced at 7:00PM on April 5 are shown in the attached PDF file. English version is available at: http://www.mext.go.jp/english/radioactivity_level/detail/1304082.htm
    o For comparison, a human receives 2,400 micro Sv per year from natural radiation in the form of sunlight, radon, and other sources. One chest CT scan generates 6,900 micro Sv per scan.
    • Fukushima Daiichi Unit 1 reactor
    o At 6:00AM on April 5, pressure inside the reactor core: 0.308MPa.
    o At 6:00AM on April 5, water level inside the reactor core: 1.7 meters below the top of the fuel rods.
    o At 6:00AM on April 5, pressure inside the primary containment vessel: 0.15MPaabs.
    o At 6:00AM on April 5, the temperature of the reactor vessel measured at the water supply nozzle: 452.3 degrees Fahrenheit.
    o At 7:20AM on April 5, the temperature directly above the spent fuel pool by thermography measurement: 64.4 degrees Fahrenheit.
    o At 7:20AM on April 5, the temperature directly above the primary containment vessel by thermography measurement: 78.8 degrees Fahrenheit.
    o As of 7:00PM on April 5, the injection of freshwater into the reactor core continues.
    o As of 7:00PM on April 5, preparation to recover and transfer the accumulated water at the turbine building continues.
    • Fukushima Daiichi Unit 2 reactor
    o At 6:00AM on April 5, pressure inside the reactor core: -0.018MPa.
    o At 6:00AM on April 5, water level inside the reactor core: 1.5 meters below the top of the fuel rods.
    o At 6:00AM on April 5, pressure inside the primary containment vessel: 0.10MPaabs.
    o At 6:00AM on April 5, the temperature of the reactor vessel measured at the water supply nozzle: 287.1 degrees Fahrenheit.
    o At 6:00AM on April 5, the temperature of the spent fuel pool: 159.8 degrees Fahrenheit.
    o At 7:20AM on April 5, the temperature directly above the second containment building by thermography measurement: 82.4 degrees Fahrenheit.
    o At 2:15PM on April 5, TEPCO announced that the tracer (white colored dye) was observed entering the ocean through a crack on the lateral surface of the pit (a vertical portion of an underground structure for housing electric cables) near the seawater intake.
    o At 3:07PM on April 5, TEPCO began injecting coagulator into the soil around the pit in an attempt to stop the discharge of water.
    o As of 7:00PM on April 5, the injection of freshwater into the reactor core continues.
    o As of 7:00PM on April 5, preparation to recover and transfer the accumulated water at the turbine building continues.
    • Fukushima Daiichi Unit 3 reactor
    o At 7:20AM on April 5, the temperature directly above the spent fuel pool by thermography measurement: 132.8 degrees Fahrenheit.
    o At 7:20AM on April 5, the temperature directly above the primary containment vessel by thermography measurement: 64.4 degrees Fahrenheit.
    o At 10:20AM on April 5, pressure inside the reactor core: 0.005MPa.
    o At 10:20AM on April 5, water level inside the reactor core: 1.85 meters below the top of the fuel rods.
    o At 10:20AM on April 5, pressure inside the primary containment vessel: 0.1071MPaabs.
    o At 10:20AM on April 5, the temperature of the reactor vessel measured at the water supply nozzle: 184.5 degrees Fahrenheit. (This figure is under investigation.)
    o As of 1:30PM on April 5, approximately 4,978 tons of water in total has been shot into the spent fuel storage pool.
    o As of 7:00PM on April 5, the injection of freshwater into the reactor core continues.
    o As of 7:00PM on April 5, preparation to recover and transfer the accumulated water at the turbine building continues.
    • Fukushima Daiichi Unit 4 reactor
    o At 7:20AM on April 5, the temperature directly above the spent fuel pool by thermography measurement: 122 degrees Fahrenheit.
    o At 5:35PM on April 5, TEPCO began to shoot freshwater aimed at the spent fuel pool, with a specialized vehicle normally used for pumping concrete, until 6:22PM.
    • Fukushima Daiichi Unit 5 reactor
    o At 1:00PM on April 5, the temperature of the spent fuel pool: 94.6 degrees Fahrenheit.
    • Fukushima Daiichi Unit 6 reactor
    o At 1:00PM on April 5, the temperature of the spent fuel pool: 81.5 degrees Fahrenheit.
    • Fukushima Daiichi Common Spent Fuel Pool
    o At 7:10AM on April 5, the temperature of the spent fuel pool: 84.2 degrees Fahrenheit.

    Our official sources are:
    • Office of The Prime Minister of Japan
    • Nuclear and Industrial Safety Agency (NISA)
    • Tokyo Electric Power Company (TEPCO) Press Releases
    • Ministry of Education, Culture, Sports, Science and Technology (MEXT)

  146. TEPCO Washington Update:

    Here are updates on radioactive material release from Fukushima Daiichi NPS and information on IAEA’s visit to the sites.
    (1) Outflow of fluid containing radioactive materials to the ocean from areas near intake channel of Fukushima Daiichi NPS Unit 2 (continued report)
    (2) Measures taken to stop outflow of radioactive fluid to the ocean from unit 2
    (3) IAEA visit to Fukushima Daiichi and Daini NPS

    Contacts:
    TEPCO Washington Office 202-457-0790
    Kenji Matsuo, Director and General Manager
    Yuichi Nagano, Deputy General Manager,
    Masayuki Yamamoto, Manager, Nuclear Power Programs

    (1) Outflow of fluid containing radioactive materials to the ocean from areas near intake channel of Fukushima Daiichi NPS Unit 2 (continued report)

    TEPCO detected water containing radiation dose over 1,000 mSv/h in the pit where supply cables are stored near the intake channel of Unit 2 on April 2. Furthermore, we identified a crack about 20 cm on the concrete lateral of the pit, from where the water in the pit was out flowing.

    We have implemented sampling of the water in the pit, together with the seawater in front of the bar screen near the pit. These samples were sent to Fukushima Daini Nuclear Power Station for analysis.

    Afterward, we implemented sea water sampling at the inside of the pit and in front of the bar screen near the pit. We conducted radionuclide analysis and found radioactive materials. We reported the results to Nuclear and Industrial Safety Agency (NISA), Ministry of Economy, Trade and Industry (METI), and Fukushima prefecture respectively.

    We are announcing 3 type of nucleus (Iodine- 131, Cesium-131, and Cesium-137) as definite value at the result of the analysis. In addition, we will re-evaluate other type of nucleus based on the preventive measures under a strong warning of NISA on April 1st (we have reported this yesterday),

    (2) Measures taken to stop outflow of radioactive fluid to the ocean from unit 2

    In the afternoon on April 3, we injected 20 sets of sawdust (approx 60 kg), 80 sets of polymer (approx 8kg), 3 sets of newspapers and 2.5m3 of water to the trench for power cable of intake channel and stirred.
    Afterward, we observed the changes of water level inside the pit and the amount of outflow to the sea. However, as of 9:30, April 5th, we could not observe any changes in the amount of the outflow. Meanwhile, from 7:08 am to 7:11 am, we injected white powder as a tracer from the trench shaft of seawater duct and started a survey for the outflow condition. [Amount of injection: approx 13kg, 20 boxes x 660g/box = 13.2 kg] Currently, we are implementing the water shutoff method of the ground near the screen with the crack surrounding cable duct of the pit. We are injecting materials of water shutoff into the ground to block the outflow channel.

    In order to reduce the spread of the radioactive contamination to the sea, we are making efforts to shut the outflow from water intake by installing silt fences and steel sheet piles. Also we will continue to monitor the impact in front of the plant and in the area within 15km from the coast.

    (2) IAEA visit to Fukushima Daiichi and Daini NPS

    The IAEA plans to dispatch a survey mission to evaluate the incident once the plants are brought into stable condition. The purpose of the visit this time is to observe the situation to prepare for the main survey mission.
    The IAEA will conduct visual observation of plants at Fukushima Daiichi NPS and brief opinion exchange with chief of the plants.

    They will arrive at Fukushima Daiichi NPS during the afternoon of April 6(Wed). Then, they move to Fukushima Daini NPS and stay one night. In the morning of April 7(Thu), they will observe Fukushima Daini NPS and return to Tokyo.
    The IAEA team consists of Mr. Nobuhiro Muroya, Department of Nuclear Safety and Security, Mr. Edward Bradley and Mr. Katsumi Yamada, BWR experts from Department of Nuclear Energy.

  147. @Barry Brook 6 April 10:37 and elsewhere:

    “For comparison, a human receives 2,400 micro Sv per year from natural radiation in the form of sunlight, radon, and other sources. ”

    Barry, I don’t doubt your figure but I think you should say this is the “average” human dose per year. Clearly there are some very large variations in this figure (entirely or at least mostly from natural variation) depending on where one lives. Have you ever seen credible data which provides standard deviation or even 10th and 90th percentiles for this “average” world figure? Alternatively, can you suggest a source for common ranges in natural radiation?

    I think it might be useful for everyone to appreciate the natural ranges in order to put the added doses into context .

  148. @Leigh Bettenay, on 6 April 2011 at 10:59 PM

    Barry was just quoting the publicly posted FEPC Update. You can google “FEPC Update” and see the same text posted at many sites.

  149. Update to Information Sheet Regarding the Tohoku Earthquake
    The Federation of Electric Power Companies of Japan (FEPC) Washington DC Office

    As of 11:30AM (EST), April 6, 2011
    • Radiation Levels
    o On April 6, TEPCO announced that plutonium 238, 239 and 240 were detected in the soil sampled on March 25 and 28 at Fukushima Daiichi Nuclear Power Station. Concentration of detected plutonium 238, 239 and 240 are the same level of the fallout observed in Japan at the atmospheric nuclear tests in the past, but TEPCO assumes the detected plutonium are attributed to the Fukushima Daiichi Nuclear Power Station, considering the isotope ratio of Plutonium 238 to 239 and 240.
    o The concentration of radioactive nuclides from the seawater sampled at the screen device (installed to remove waste before the intake of seawater) of Unit 2 of Fukushima Daiichi Nuclear Station was as follows:

    Nuclides
    (half-life) Concentration (Unit : Bq/cm3) Ratio
    Sampled at 8:00AM on April 5 (a) Maximum Permissible Water Concentration (b) a / b
    I-131
    (8 days) 1.1 x 104 4.0 x 10-2 280,000
    Cs-134
    (2 years) 5.5 x 103 6.0 x 10-2 92,000
    Cs-137
    (30 years) 5.5 x 103 9.0 x 10-2 61,000

    o The level of concentration of radioactive nuclide I-131 (1.1 x 101 Bq/cm3) from the seawater sampled near the seawater discharge point of Fukushima Daiichi Nuclear Station at 2:10PM (JST) on April 5 was approximately 280 times higher than the maximum permissible water concentration (4.0 x 10-2 Bq/cm3) set by the government.
    o At 7:00PM on April 6, radiation level at main gate (approximately 3,281 feet from Unit 2 reactor building) of Fukushima Daiichi Nuclear Power Station: 82.5 micro Sv/hour.
    o Measurement results of environmental radioactivity level around Fukushima Nuclear Power Station announced at 7:00PM on April 6 are shown in the attached PDF file. English version is available at: http://www.mext.go.jp/english/radioactivity_level/detail/1304082.htm
    o For comparison, a human receives 2,400 micro Sv per year from natural radiation in the form of sunlight, radon, and other sources. One chest CT scan generates 6,900 micro Sv per scan.
    • Fukushima Daiichi Unit 1 reactor
    o On April 6, TEPCO announced that it will start the injection of nitrogen gas into the primary containment vessel at 10:30PM to prevent an explosion by accumulated hydrogen gas.
    o At 7:30AM on April 6, the temperature directly above the spent fuel pool by thermography measurement: 75.2 degrees Fahrenheit.
    o At 7:30AM on April 6, the temperature directly above the primary containment vessel by thermography measurement: 84.2 degrees Fahrenheit.
    o At 12:00PM on April 6, pressure inside the reactor core: 0.313MPa.
    o At 12:00PM on April 6, water level inside the reactor core: 1.65 meters below the top of the fuel rods.
    o At 12:00PM on April 6, pressure inside the primary containment vessel: 0.15MPaabs.
    o At 12:00PM on April 6, the temperature of the reactor vessel measured at the water supply nozzle: 417.2 degrees Fahrenheit.
    o As of 2:30PM on April 6, the injection of freshwater into the reactor core continues.
    • Fukushima Daiichi Unit 2 reactor
    o At 5:38AM on April 6, TEPCO confirmed the termination of water leakage into the ocean through a crack on the lateral surface of the pit (a vertical portion of an underground structure for housing electric cables) near the seawater intake.
    o At 7:30AM on April 6, the temperature directly above the second containment building by thermography measurement: 89.6 degrees Fahrenheit.
    o At 12:00PM on April 6, pressure inside the reactor core: -0.016MPa.
    o At 12:00PM on April 6, water level inside the reactor core: 1.5 meters below the top of the fuel rods.
    o At 12:00PM on April 6, pressure inside the primary containment vessel: 0.10MPaabs.
    o At 12:00PM on April 6, the temperature of the reactor vessel measured at the water supply nozzle: 288.5 degrees Fahrenheit.
    o At 12:00PM on April 6, the temperature of the spent fuel pool: 123.8 degrees Fahrenheit.
    o As of 2:30PM on April 6, the injection of freshwater into the reactor core continues.
    • Fukushima Daiichi Unit 3 reactor
    o At 7:30AM on April 6, the temperature directly above the spent fuel pool by thermography measurement: 140 degrees Fahrenheit.
    o At 7:30AM on April 6, the temperature directly above the primary containment vessel by thermography measurement: 89.6 degrees Fahrenheit.
    o At 12:00PM on April 6, pressure inside the reactor core: 0.005MPa.
    o At 2:00PM on April 6, water level inside the reactor core: 1.8 meters below the top of the fuel rods.
    o At 12:00PM on April 6, pressure inside the primary containment vessel: 0.1069MPaabs.
    o At 12:00PM on April 6, the temperature of the reactor vessel measured at the water supply nozzle: 173.8 degrees Fahrenheit. (This figure is under investigation.)
    o As of 2:30PM on April 6, the injection of freshwater into the reactor core continues.
    • Fukushima Daiichi Unit 4 reactor
    o At 7:30AM on April 6, the temperature directly above the spent fuel pool by thermography measurement: 134.6 degrees Fahrenheit.
    • Fukushima Daiichi Unit 5 reactor
    o At 1:00PM on April 6, the temperature of the spent fuel pool: 95.4 degrees Fahrenheit.
    • Fukushima Daiichi Unit 6 reactor
    o At 1:00PM on April 6, the temperature of the spent fuel pool: 85.1 degrees Fahrenheit.
    • Fukushima Daiichi Common Spent Fuel Pool
    o At 8:00AM on April 6, the temperature of the spent fuel pool: 80.6 degrees Fahrenheit.
    • Others
    o At 3:00PM on April 5, TEPCO began to install the components of a silt barrier near the south sea wall of Fukushima Daiichi Nuclear Power Station in order to contain the spread of discharged radioactive water.

    Our official sources are:
    • Office of The Prime Minister of Japan
    • Nuclear and Industrial Safety Agency (NISA)
    • Tokyo Electric Power Company (TEPCO) Press Releases
    • Ministry of Education, Culture, Sports, Science and Technology (MEXT)

  150. TEPCO Washington updates

    Here are updates on Fukushima Daiichi NPS.
    (1) Injection of nitrogen to reactor containment vessel of Unit 1
    (2) Detection of radioactive material in the soil in Fukushima Daiichi NPS: Detected Pu-238 might come from reactors.
    (3) Outflow of fluid containing radioactive materials to the ocean from areas near intake channel of Unit 2 was shut off.

    Contacts:
    TEPCO Washington Office 202-457-0790
    Kenji Matsuo, Director and General Manager
    Yuichi Nagano, Deputy General Manager,
    Masayuki Yamamoto, Manager, Nuclear Power Programs

    (1) Injection of nitrogen to reactor containment vessel of Unit 1

    Taking into account the possibility of hydrogen accumulating inside, we have been considering encapsulation of hydrogen by injecting nitrogen to the reactor containment vessel.

    On April 6, we received an order from minister of economy, trade and industry to report on matter such as necessity of encapsulating nitrogen, method for implementation, and impact assessment of safety. Accordingly, we have compiled related matters and reported to Minister of Economy, Trade and Industry. The report was approved after the deliberation in the Ministry of Economy, Trade and Industry.

    Base on the report, we began injecting nitrogen to the reactor containment vessel of Unit 1 around 10:30pm.

    [Comments]
    ・ In the Unit1, 2, and 3 of Fukushima Daiichi NPS, it is estimated that water injection to remove decay heat in RPV is generating steam inside of primary containment vessels (PCV). Because it is assumed that the inside of PCV is mostly steam, we evaluated hydrogen accumulation is not high, hence possibility of hydrogen explosion is limited.
    ・ However, there is a possibility that the RPV boundaries of all three units have been damaged. If we continue cooling reactors through injection of water, there is a concern regarding possible explosion caused by concentration of hydrogen which might leake from RPV to PCV. In order to prevent possible combustion of hydrogen for these units, we determined to inject nitrogen to each PCV.

    Volume of steam inside of the PCV will decrease through condensation at wall of PCV (Heat-transfer to the outside of the PCV) and injected water to the reactor which was not consumed for the decay heat removal. In addition, an impact of condensation from heat transfer at wall is no greater than that of the injected water. On the other hand, it is necessary to continue injecting water to the reactor to cool the core, and the amount of water injection will be more than needed for the decay heat removal.

    ・ As for unit1, the damage to D/W is supposed to be relatively light compared to unit 2. Therefore, in the case of increase in concentration of steam, pressure in PCV would become negative along with increase of hydrogen through cooling of the reactor. Moreover, oxygen might be supplied to PCV by in-leak and partial-pressure of hydrogen would increase, which would make the atmosphere susceptible to reach combustible limit. In order to prevent this, we determine injection of nitrogen to unit 1 first, then to unit 2 and 3.

    (2) Detection of radioactive material in the soil in Fukushima Daiichi NPS (continued report)

    As part of monitoring activity of the surrounding environment, we conducted analysis of plutonium contained in the soil collected on March 21st and 22nd at the 5 spots in Fukushima Daiichi Nuclear Power Station. As a result, plutonium 238, 239 and 240 were detected. (we reported this on March 28) Subsequently, from the 3 spots where periodic sampling was conducted on March 25th and 28th and from another spot which was supplemented on 25th, we conducted analysis of plutonium contained in the soil. As a result, plutonium 238, 239 and 240 were detected. See Table (1) and Figure (2) for detail.

    In addition, we conducted nuclide analysis of gamma ray contained in the soil collected on March 21st and 22nd at the 5 spots in Fukushima Daiichi NPS. Such analysis was also conducted on soil collected on March 25th and 28th at the 4 spots. As a result, radioactive materials were detected as described in the attached excel file. Accordingly, we have reported the result of analysis to Nuclear and Industrial Safety Agency and Fukushima Prefecture.

    [Comment]
    Density of detected Pu-238, Pu-239 and Pu-240 are within the same level of the fallout observed in Japan after the atmospheric nuclear test in the past. Activity ratio of Pu-238 detected in site field on March 25th and 28th and also detected in adjacent to industrial waste disposal facility against Pu-239 and Pu-240 are 1.6, 2.2 and 2.0 respectively. They exceed activity ratio of 0.026 which resulted from the atmospheric nuclear test in the past, thus those Pus are considered to come from the recent incident.

    Pu-238, Pu-239 and Pu-240 are also detected from samples collected from site field on March 21st. Pu-238 was (5.4±0.62)×10-1Bq/kg, Pu-239/240 was (2.7±0.42)×10-1Bq/kg)

    (3) Outflow of fluid containing radioactive materials to the ocean from areas near intake channel of Unit 2 was shut off.

    At around 9:30 am on April 2nd, we detected water containing radiation dose over 1,000 mSv/h in the pit where supply cables are stored near the intake channel of Unit 2. Furthermore, there was a crack about 20 cm on the concrete lateral of the pit, from where the water in the pit was outflowing.
    We have implemented sampling of the water in the pit, together with the seawater in front of the bar screen near the pit. These samples were sent to Fukushima Daini Nuclear Power Station for analysis.

    We also injected fresh concrete to the pit on April 2 to stop the outflow, but we could not observe a reduction in the amount of water spilling from the pit to the sea. Therefore, we started to inject the polymer on April 3rd.

    From 7:08 am to 7:11 am on April 4, we put the tracer into the pit and began an investigation of water flows. Additional tracer was put through the two new holes drilled near the pit. At 2:15 pm, April 5, it was observed that the tracer came out from the crack on the concrete lateral of the pit. At 3:07 pm, injection of coagulant from the holes was initiated.

    At 5:38 am on April 6, we observed the water spilling from the crack on the concrete lateral of the pit stopped.

    Shutoff of water outflow was confirmed at approx. 5:38 am on April 6th, 2011.

  151. Update to Information Sheet Regarding the Tohoku Earthquake

    The Federation of Electric Power Companies of Japan (FEPC) Washington DC Office

    As of 3:00PM (EST), April 7, 2011
    • Radiation Levels
    o The concentration of radioactive nuclides from the seawater sampled at the screen device (installed to remove waste before the intake of seawater) of Unit 2 and sampled near the seawater discharge point (south side) of Fukushima Daiichi Nuclear Station were as follows:

    Nuclides
    (half-life) Concentration (Unit : Bq/cm3) Ratio
    Sampled at the screen of Unit 2 at 7:40AM on April 6 (a) Sampled at south side discharge point at 2:05PM on April 6 (b) Maximum Permissible Water Concentration (c) a / c b / c
    I-131
    (8 days) 5.6 x 103 3.7 x 100 4.0 x 10-2 140,000 93
    Cs-134
    (2 years) 3.1 x 103 2.4 x 100 6.0 x 10-2 52,000 40
    Cs-137
    (30 years) 3.2 x 103 2.5 x 100 9.0 x 10-2 36,000 28

    o At 6:00PM (JST) on April 7, radiation level at main gate (approximately 3,281 feet from Unit 2 reactor building) of Fukushima Daiichi Nuclear Power Station: 99 micro Sv/hour.
    o At 6:00PM on April 7, radiation level at west gate (approximately 3,609 feet from Unit 2 reactor building) of Fukushima Daiichi Nuclear Power Station: 56.8 micro Sv/hour.
    o Measurement results of environmental radioactivity level around Fukushima Nuclear Power Station announced at 7:00PM on April 7 are shown in the attached PDF file. English version is available at: http://www.mext.go.jp/english/radioactivity_level/detail/1304082.htm
    o For comparison, a human receives 2,400 micro Sv per year from natural radiation in the form of sunlight, radon, and other sources. One chest CT scan generates 6,900 micro Sv per scan.

    • Plant Parameters
    Unit 1 Unit 2 Unit 3 Unit 4 Unit 5 Unit 6
    pressure inside the reactor core (gauge pressure, MPa) 0.375 -0.009 0.000 – 0.002 0.008
    4/7
    12:00PM 4/7
    12:00PM 4/7
    12:00PM – 4/7
    12:00PM 4/7
    12:00PM
    pressure inside the primary containment vessel (absolute pressure, MPaabs) 0.165 0.100 0.1059 – – –
    4/7
    12:00PM 4/7
    12:00PM 4/7
    12:00PM – – –
    water level inside the reactor core (meter) *1 -1.65 -1.5 -1.9 – +1.801 +1.816
    4/7
    12:00PM 4/7
    12:00PM 4/7
    12:00PM – 4/7
    12:00PM 4/7
    12:00PM
    temperature of the reactor vessel measured at the water supply nozzle (degrees Fahrenheit) 434.8 290.5 190.9
    *2 – – –
    4/7
    12:00PM 4/7
    12:00PM 4/7
    12:00PM – – –
    temperature of the spent fuel pool (degrees Fahrenheit) – 123.8 – – 96.8 69.8
    – 4/7
    12:00PM – – 4/7
    12:00PM 4/7
    12:00PM
    the temperature directly above the spent fuel pool by thermography measurement (degrees Fahrenheit) 75.2 – 140.0 134.6 – –
    4/6
    7:30AM – 4/6
    7:30AM 4/6
    7:30AM – –
    temperature directly above the primary containment vessel (degrees Fahrenheit) 84.2 – 89.6 – – –
    4/6
    7:30 – 4/6
    7:30 – – –
    temperature directly above the second containment building (degrees Fahrenheit) – 89.6 – – – –
    – 4/6
    7:30 – – – –
    Amount of water in total shot/injected to the spent fuel storage pool (tons) 90 299 – 314 5,048 1,493 – –
    as of 4/7
    7:00PM as of 4/7
    7:00PM as of 4/7
    7:00PM as of 4/7
    7:00PM – –
    *1: Minus figure means that water level is below the top of the fuel rods.
    *2: This figure is under investigation.

    • Fukushima Daiichi Unit 1 reactor
    o At 1:31AM on April 7, TEPCO began the injection of nitrogen gas into the primary containment vessel to prevent an explosion by accumulated hydrogen gas.
    o As of 3:30PM on April 7, the injection of freshwater into the reactor core continues.
    • Fukushima Daiichi Unit 2 reactor
    o At 1:29PM on April 7, TEPCO began to inject freshwater into the spent fuel pool, until 2:34PM (approximately 36 tons in total).
    o As of 3:30PM on April 7, the injection of freshwater into the reactor core continues.
    • Fukushima Daiichi Unit 3 reactor
    o At 6:53AM on April 7, TEPCO began to shoot water aimed at the spent fuel pool, until 8:53AM, with a specialized vehicle normally used for pumping concrete (approximately 70 tons in total).
    o As of 3:30PM on April 7, the injection of freshwater into the reactor core continues.
    • Fukushima Daiichi Unit 4 reactor
    o At 6:23PM on April 7, injection of freshwater into the spent fuel pool commenced.
    • Fukushima Daiichi Common Spent Fuel Pool
    o At 7:45AM on April 7, the temperature of the spent fuel pool: 82.4 degrees Fahrenheit.
    • Others

    Our official sources are:
    • Office of The Prime Minister of Japan
    • Nuclear and Industrial Safety Agency (NISA)
    • Tokyo Electric Power Company (TEPCO) Press Releases
    • Ministry of Education, Culture, Sports, Science and Technology (MEXT)

  152. TEPCO Washington Office 202-457-0790
    Kenji Matsuo, Director and General Manager
    Yuichi Nagano, Deputy General Manager,
    Masayuki Yamamoto, Manager, Nuclear Power Programs

    (1) Aftershock at 23:32, April 7: No damages at Fukushima Daiichi/Daini NPS

    At 23:32, April 7, there was a large aftershock near Fukushima Daiichi and Daini NPS.

    So far, no damages and injuries are reported at both sites.

    TEPCO will investigate the sites tomorrow morning then determine whether it would be necessary to change scheduled work.

    The figures indicated at monitoring posts at the station boundary are within the usual range, and there is no influence of radioactivity outside as of now for both Fukushima Daiichi and Daini NPS.

    Also there is no changes in radioactivity monitoring at the stacks in Fukushima Daini NPS.

    Maximum observed acceleration of the earthquake base was 58.1 Gal at reactor building of Fukushima Daini unit 3 (No data available from Fukushima Daiichi NPS).

    (2) Impact of radioactive water release to the sea

    The following is information regarding impact of radioactive water discharge to the sea.

    2-1: Impact of the discharge of the low level radioactive wastewater implemented on April 4th.
    –> The radioactive density measured around the south water discharge has been decreased slightly, and so we could say we will not find an impact of the water discharge.

    On the other hand, the radioactivity density measured around the north water discharge is a little bit bigger than yesterday’s. The discharge from the sub-drainage might have caused this to some degree but these 2 changes in the measured density are within the variation range already measured in the past, and we could think that there is no impact of the water discharge on the radioactivity density in the seawater. We will continue monitoring any changes in samples.

    –> After the water discharge, we have been taking samples at 3 more points 15km offshore, and we now do so twice in a day, but in any event the results are almost the same level as the other ones at the points 15km offshore.

    2-3: Impact of the water discharge to the environment and human bodies.

    –> As to this sampling, we are still at the stage for monitoring the tendency or the variation and collecting and analyzing data, therefore we think that we are not ready for conclusion. However we have been doing our best and trying to clarify and release them as soon as possible.

    The impact of the exposure to radiation might emerge by taking in radioactive materials but, since seawater is not for drinking and considering how the seafood is consumed, we would think that no immediate impact will be caused.

    2-4: Reportedly, Cesium of 510 Bq, which is bigger than the temporary regulation value for the fish (500 Bq/kg) has been detected in Ammodytes personatus landed in the Ibaraki offshore.

    –> We are very sorry that we have cause so many concerns and so much inconvenience to the people who live near the sites, people in Fukushima Prefecture and other people concerned.

    We think that it is possibly due to the accident in Fukushima Daiichi Nuclear Power Station and we need to take sampling in the wider range to verify the influence of radioactive materials discharged. We have added 3 more sampling points to the present 3 points 15km offshore and we are taking samples twice a day. We will continue monitoring the trends and changes.

  153. > Cesium of 510 Bq … We think that it is possibly
    > due to the accident in Fukushima Daiichi ….

    Vague PR/lawyer wording? Or a hint some other source out there may be showing up that’s been around undetected, until the intensive sampling lately?

  154. Pingback: Fukushima Daiichi nuclear saga – 2 to 9 April overview « BraveNewClimate

  155. Hank Roberts, Cesium-137, Strontium-90 and various plutonium isotopes are present all over the world due to nuclear weapons testing. You can google images them, here are some examples.

    http://maps.grida.no/go/graphic/cesium_137_from_nuclear_weapon_testing_fallout_1995_figures

    As we can see background deposition is quite high, at over 1000 becquerels per square meter.

    http://3.bp.blogspot.com/-6cz-0zfc5J4/TXy-BtIuJlI/AAAAAAAAAKg/Q2ykaZakGkQ/s1600/Chernobyl%2Bmap%2BCaesium-137%2Bcontaminated%2Bareas%2Bin%2BEuropean%2Bcountries.bmp

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