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Fukushima Daiichi nuclear saga – 2 to 9 April overview

The nuclear crisis at Fukushima Daiichi has, alas, now evolved into more of a saga. The last seven days of events has been acted out in slow motion compared to the first dramatic week (dating back to almost a month ago), but there continues to be plenty of headaches for TEPCO — and no clear sign of things being locked down any time soon. The economic cost of the earthquake and tsunami has now been put at ~$300 billion, and will probably rise further in the coming months.

I last wrote an update post a week ago (although I’ve also been providing daily updates in the comments section), so it’s best to start this one by looking at what’s happened, day by day, since then. Here is my somewhat potted update summary, with just the main points highlighted.

It was 2nd of April (Saturday) that it was first reported that a stream of contaminated water was flowing into the ocean, leading to extremely high radiation levels immediately offshore of the plant. The water appeared to be coming from the vicinity of Unit 2, and after some diagnostics, including the use of a coloured tracer (dye), the source was identified as a 20 cm crack in a maintenance pit which lies between Unit 2 and the sea. The pit is used to hold cables to power the seawater pumps. Its radiation was measured as ~1 Sv/hr.

In the evening of 2 April, concrete injection was trialled as a means to seal the crack, but this failed. Throughout 3 April, a second attempt was made,  this time via  injection of a water-absorbing polymer, mixed with sawdust and shredded paper (to aid in the swelling process). This also did not set. To mitigate the leaks to the ocean, plans were then made to try and pump a large amount of the contaminated water out of the pit and into storage, including some barges that had been anchored offshore.

It was also announced by TEPCO that the bodies of the two workers who had been missing in the turbine building of Unit 2 since the tsunami struck had been recovered on March 30. They’d apparently been drowned when the site had been innundated. The image above illustrates just how devastated the landscape around the plant is after the monster wave (14 m in this area of the coastline) wreaked its havoc.

Along with the crane operator at Fukushima Daiini, WNN reports

… these three are the only deaths at nuclear power plants from the earthquake, tsunami and subsequent nuclear emergency. No effects on health or significant contamination cases have been identified among the general public evacuated from the area. The tsunami travelled up to five kilometres inland in Fukushima prefecture, causing a 1113 deaths with 4626 more people still missing. The totals for Japan as a whole are 12,087 dead and 15,552 missing as of today.

Among the 370 workers working to bring stability to the damaged reactor units of the Daiichi plant, 21 have so far experienced radiation doses of over 100 millisieverts.

By Monday, there was mounting concern about the possible build up of hydrogen within the containment buildings of Units 1-3 — and some risk of a repeat of the earlier chemical explosions, perhaps this time within the drywell, which would, in turn, risk damaging the reactor pressure vessel (RPV). To counter this, plans were made to inject inert nitrogen gas (which makes up 78% of our atmosphere), to dilute the hydrogen and expel oxygen. (This had commenced this operation in Unit 1 by Thursday 7 April.)

On 5 April, the flow from the cable storage pit had been linked to a faulty duct joint. On Wednesday 6 April, a large volume of polymer coagulant was forced into the pit and adjacent gravel, and this was reported as being successful in hardening and sealing the leak. However, water had continued to accumulate and so 11,500 tonnes of mildly contaminated water was released into the ocean to allow for storage of the highly radioactive water. This is what apparently led to the high levels of iodine-131 detected soon after in the sea water in the immediate vicinity of the plant.

On Thursday 7 April, another particularly large (magnitude 7.1) aftershock struck northeast Japan, 118 km from Fukushima Daiichi. It caused some damage to infrastructure in the Sendai area, and took down power lines leading to the Ongagawa Nuclear Power plant, which has all units in cold shutdown (but still requires power in order to maintain heat dissipation systems, pumps, monitors etc.). An external line to the Onagawa plant remained intact, and another backup line was soon restored. There did not appear to be any significant impact of the aftershock on operations at Fukushima Daiichi.

The main development in the last day has been preparation of a huge floating platform (136 x 40 m) next to the site, in order to store contaminated water. It is expected to arrive on site in less than two weeks.

What of the reactor statuses? The latest FEPC and JAIF summaries are given at the foot of this post. The IAEA gives a useful summary:

In Unit 1 fresh water has been continuously injected into the reactor pressure vessel through feed-water line at an indicated flow rate of 6 m3/h using a temporary electric pump with off-site power. In Units 2 and 3 fresh water is being injected into the reactor pressure vessels continuously through the fire extinguisher lines at indicated rates of 8 m3/h and 7 m3/h using temporary electric pumps with off-site power.

The reactor pressure vessels’ temperatures remain above cold shutdown conditions (normally less than 95 °C). In Unit 1 indicated temperature at the feed water nozzle of the RPV is 224 °C and at the bottom of RPV is 117 °C. The pressure in the RPV is increasing as indicated on both channels of instrumentation. NISA has indicated that some instruments in the reactor vessel may not be working properly. Drywell pressure is increasing slightly due to the addition of nitrogen. In Unit 2 the indicated temperature at the feed water nozzle of the RPV is 144 °C. The temperature at the bottom of RPV was not reported. Indicated Drywell pressure remains at atmospheric pressure. In Unit 3 the indicated temperature at the feed water nozzle of the RPV is 88 °C and at the bottom of RPV is 112 °C. Fresh water was sprayed onto the spent fuel pool by concrete pump vehicle (50t/h) from 21:53 UTC, 6 April.

In the news this week, there were all sorts of ongoing speculation, most of it unfounded or at least lacking any concrete evidence. Probably the strangest was the declaration by US Rep Markey that he’d been informed by the NRC that Unit 2 had undergone a complete meltdown — a claim that was later quashed by an NRC official, who said that they’d supplied no such information. Go figure.

A few other things:

(i) This is an interesting blow-by-blow summary of the Fukushima Daiichi events, with lots of interesting pictures, produced by someone at AREVA. However, it may (?) have since been yanked by AREVA, and I can’t vouch for the accuracy of all the data — or speculation. Still it’s an interesting overview.

(ii) Japanese reactor maker Toshiba claims it can decommission the Fukushima Daiichi site within 10 years — less time than it took to fully clean up after Three Mile Island (I’ve not found further details on this).

(iii) There is an upcoming debate for those in the UK, on the contention: “Nuclear power is still worth it“, to be held on Thursday 14 April 2011 at the Royal Geographical Society (RGS), London. Here is an example of an earlier event:

They’ll be streaming the new event free and live from their site, and one of the organisers, Kit Cockburn, tells me that they’d also be happy to give a 50% discount on tickets to BNC readers, should they want to watch the debate in the venue itself (the discount code is ‘NUCLEAR’).

To close, the latest JAIF update:

…and the Federation of Electric Power Companies of Japan (FEPC) Washington DC Office report:

  • Radiation Levels
    • 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 7:45AM on April 7  (a) Sampled at south side discharge point at 2:00PM on April 7  (b) Maximum Permissible Water Concentration (c) a / c b / c
I-131 

(8 days)

2.5 x 103 1.7 x 100 4.0 x 10-2 63,000 43
Cs-134 

(2 years)

1.5 x 103 1.8 x 100 6.0 x 10-2 25,000 30
Cs-137 

(30 years)

1.5 x 103 1.8 x 100 9.0 x 10-2 17,000 20
    • At 7:00PM (JST) on April 8, radiation level at main gate (approximately 3,281 feet from Unit 2 reactor building) of Fukushima Daiichi Nuclear Power Station: 94 micro Sv/hour.
    • At 7:00PM on April 8, radiation level at west gate (approximately 3,609 feet from Unit 2 reactor building) of Fukushima Daiichi Nuclear Power Station: 53.4 micro Sv/hour.
    • Measurement results of environmental radioactivity level around Fukushima Nuclear Power Station announced at 7:00PM on April 8 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.
  • Plant Parameters
Unit 1 Unit 2 Unit 3 Unit 4 Unit 5 Unit 6
pressure inside the reactor core (gauge pressure, MPa) 0.395 -0.020 -0.004 0.003 0.005
4/8 

12:00PM

4/8 

12:00PM

4/8 

12:00PM

4/8 

2:00PM

4/8 

2:00PM

pressure inside the primary containment vessel (absolute pressure, MPaabs) 0.185 0.100 0.1052
4/8 

13:00PM

4/8 

12:00PM

4/8 

12:00PM

water level inside the reactor core (meter) *1 -1.65 -1.5 -1.85 +1.644 +1.668
4/8 

12:00PM

4/8 

12:00PM

4/8 

12:00PM

4/8 

2:00PM

4/8 

2:00PM

temperature of the reactor vessel measured at the water supply nozzle (degrees Fahrenheit) 475.9 

*2

286.2 191.8 

*2

4/8 

1:00PM

4/8 

12:00PM

4/8 

12:00PM

temperature of the spent fuel pool (degrees Fahrenheit) 127.4 94.5 86.9
4/8 

12:00PM

4/8 

2:00PM

4/8 

2:00PM

the temperature directly above the spent fuel pool by thermography measurement (degrees Fahrenheit) 73.4 132.8 114.8
4/8 

7:30AM

4/8 

7:30AM

4/8 

7:30AM

temperature directly above the primary containment vessel by thermography measurement (degrees Fahrenheit) 91.4 95
4/8 

7:30AM

4/8 

7:30AM

temperature directly above the second containment building  by thermography measurement (degrees Fahrenheit) 86
4/8 

7:30AM

Amount of water in total shot/injected to the spent fuel storage pool (tons) 90 299 – 314 5,048 1,531
as of 4/8 

7:00PM

as of 4/8 

7:00PM

as of 4/8 

7:00PM

as of 4/8 

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
    • As of 6:00PM on April 8, injection of nitrogen gas into the primary containment vessel to prevent an explosion by accumulated hydrogen gas continues.
    • As of 6:00PM on April 8, the injection of freshwater into the reactor core continues.
  • Fukushima Daiichi Unit 2 reactor
    • As of 6:00PM on April 8, the injection of freshwater into the reactor core continues.
  • Fukushima Daiichi Unit 3 reactor
    • At 5:08PM on April 8, TEPCO began to shoot water aimed at the spent fuel pool, with a specialized vehicle normally used for pumping concrete.
    • As of 6:00PM on April 8, the injection of freshwater into the reactor core continues.
  • Fukushima Daiichi Common Spent Fuel Pool
    • At 7:20AM on April 8, the temperature of the spent fuel pool: 82.4 degrees Fahrenheit.

Others <Influences of the aftershock occurred at 11:32PM on April 7>

  • Fukushima Daiichi Nuclear Power Station
    • As of 4:00PM on April 8, no significant changes have been detected at monitoring posts at the site.
  • Fukushima Daini Nuclear Power Station (Unit 1, 2, 3 & 4)
    • Plant operation was suspended at all units when the aftershock occurred.
    • As of 4:00PM on April 8, no significant changes have been detected at monitoring posts at the site.
  • Onagawa Nuclear Power Station (Unit 1,2 & 3)
    • Plant operation was suspended at all units when the aftershock occurred.
    • The spent fuel pool cooling system was suspended automatically but has been recovered immediately.
    • As of 4:00PM on April 8, no significant changes have been detected at monitoring posts at the site.
  • Higashidori Nuclear Power Station
    • Plant was under periodical maintenance when the aftershock occurred.
    • Immediately after the external power was lost, backup diesel generators turned on to supply electricity to maintain the cooling system of the spent fuel storage pool.
    • As of 4:00PM on April 8, no significant changes have been detected at monitoring posts at the site.
  • Tokai Daini Nuclear Power Station
    • Plant operation was suspended when the aftershock occurred.
    • As of 4:00PM on April 8, no abnormality has been reported.
  • Tomari Nuclear Power Station (Unit 1, 2 & 3)
    • All units were under normal operation when the aftershock occurred.
    • As of 4:00PM on April 8, all units are under normal operation.
  • Rokkasho Reprocessing Plant and Accompanying Facilities
    • Immediately after the external power was lost, backup diesel generators turned on to supply electricity..
    • As of 5:00PM on April 8, power supply has been switched from backup power generation systems to the external power. It was confirmed that no fire, damage to equipment, injuries to personnel occurred. Radiation levels were measured at a normal level of safety.

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)

By Barry Brook

Barry Brook is an ARC Laureate Fellow and Chair of Environmental Sustainability at the University of Tasmania. He researches global change, ecology and energy.

164 replies on “Fukushima Daiichi nuclear saga – 2 to 9 April overview”

I really haven’t got a clue why they have raised the INES level to 7 – what exactly does this accomplish, other than to cause more panic and confusion? The authorities must have known there would be an instant media frenzy, and misunderstanding to assume this is now ‘as bad’ or even ‘exactly like Chernobyl’.

I personally do not feel that Fukushima constitutes a INES 7 – ‘Major release of radio­active ­material with widespread health and environmental effects r­equiring implementation of planned and extended ­countermeasures’.

Even level 5 requires ‘Several deaths from ­radiation’ and there have so far been none.

http://en.wikipedia.org/wiki/International_Nuclear_Event_Scale#Level_7:_Major_accident

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Barry Brook wrote, “How many people have been killed by radiation as a result of this ‘disaster’?”

This question seems rather common around here, but I’m not convinced the answer is that relevant just yet. It’s about the same as asking how many people have been killed by recent climate change so far. Not too many, I guess. Does that mean it isn’t a problem?

It is true that I could be killed quickly by radiation if I stood in front of a hole firing x-rays at my chest or head (like an x-ray tube or synchrotron beam pipe), or from acute exposure to large amounts of radioactive substances. But I was under the impression that the more common health risks from radiation are long-term, cumulative, and insidious.

Unless one is a member of certain populations that may have evolved a resistance to high levels of background radiation (thanks for the Ramsar reference, Cyril R.), one might be wise to pay that some heed.

How many people have been killed by radiation as a result of this disaster so far? Not many. How many will be? I’d imagine it’s harder to say, particularly since we don’t yet know the full nature or scope of releases or contamination. I’m just not sure the question of how many people have died because of a few weeks of possible exposure is that relevant. Isn’t that argument kind of a non-starter?

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Huw Jones wrote,
“Even level 5 requires ‘Several deaths from ­radiation’ and there have so far been none.”

It seems it’s an “or”, not an “and” requirement. As in, an incident does not need to fulfill all criteria in order to be considered a certain level. Major release? Check. Extended, planned countermeasures? Check. Level 7.

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@ Mike

This question seems rather common around here, but I’m not convinced the answer is that relevant just yet. It’s about the same as asking how many people have been killed by recent climate change so far. Not too many, I guess. Does that mean it isn’t a problem?

This is a fallacious argument. Firstly, I haven’t heard anyone say “this isn’t a problem”. Secondly, comparing it to “how many people have been killed by recent climate change?” is irrelevant, as we only have one global climate, and the problem is cumulative.

This is all about perspective. Nuclear power is one of many energy technologies, and it’s record is sound. Indeed, including Chernobyl, less deaths have been attributed to nuclear energy than any other energy technology*.

So it is completely relevant to ask “How many people have been killed by radiation as a result of this ‘disaster’?” when comparing to other technologies, and it is relevant because of the number of lives it is no doubt saving in places where fossil fuels are not being burned.

*See: http://nextbigfuture.com/2011/03/deaths-per-twh-by-energy-source.html
and

Click to access 15%20-%20Polenp~1.pdf


MODERATOR
Tom – please re-post this comment to the Fukushima Philosophical Open Thread where this discussion is taking place.

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Japanese Officials have raised the INES rating to 7 due to the quantity of I131 and Cs137 calculated to have been released. The consequences to the public however have been far less.
http://www.world-nuclear-news.org/RS_Fukushima_moved_to_Level_7_1204111.html

The many reasons why the health consequence to the public are still reported as “no measurable effect” need to be emphasized, even while the industry takes the lessons learned seriously and incorporates the nuclear safety improvements that will come from those lessons learned. Reasons like the functioning containment (possible small leak at a torus), the emergency responses to evacuate the 20 Km area, the continued work by site staff with international support to restart fuel cooling and controlled containment venting with winds in the correct direction (when possible) using sea water and accepting the economic consequence for nuclear safety, monitoring personnel dose and ensuring no one suffers life threatening dose, restore power, contain leakage, plans to store highly activated water recovered releasing low active water to the sea the most favorable – least impact dose pathway. The extensive monitoring of dose rates contamination levels vegetation and seafood radiation levels etc to ensure no health impact. Some of these are the results of lessons learned from Chernobyl where lack of evacuations and monitoring would have much reduced the post release consequences to the local public.

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The censorship at this site is astounding….It is a fact that many commenters here had said that this will never be a level 7 on the scale of Chernobyl. They are now clearly wrong and I have been censored for pointing this out. [ Comment deleted.Please re-submit with links which show what you claim re TEPCO] These are facts and no amount of censorship on this one-sided website is going to stop them being known.
MODERATOR
You were not censored for pointing anything out.If we wished to censor you, your comment would have gone straight to the Trash, as happens all the time on anti-nuclear/green sites. At the time you made your first comment the official line was that a Level 7 was being considered. You commented that it was already so. You were asked not to pre-empt the decision with your own appraisal but to re-post when the determined level was official. The level is a preliminary assessment and still has to be confirmed by the IAEA.Those comments which reported on this, as it had actually occured,were of course let stand.

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[Comment deleted. Wrong thread]
MODERATOR
This conversation regarding radiation “beliefs” is taking place, and properly belongs, in the Fukushima Philosophical Open Thread. The rules for the OT’s are more relaxed to allow personal opinion not necessarily supported by refs.Please re-post as directed. We do not have the facility to move comments between threads.

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—————–
“Tepco even now admits that the total radioactive material release may equal or EXCEED that of Chernobyl. ”
——————

Could you supply the source of this claim? Because according to japan’s nuclear safety agency “the volume of radiation from Fukushima is one-tenth that at Chernobyl.” (http://www3.nhk.or.jp/daily/english/12_19.html)

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Leo Hansen wrote:

I am disappointed by NISA’s summary …Two things jumped out at me: 1) the PCV vents to the refueling floor are not shown. Instead PCV vents to a tall stack are shown (one thru a filter SGTS? and one thru a bursting disc), see slide 21. The PCV vents to the refueling operations floor are shown on the Areva slides and have been thought to be the source of H2 for explosions in R1 and R3 bdlgs. If the PCV vents to the tall stack were used instead of the ones to the refuel floor, then the source of the H2 bdlg explosions could have been instead from the PCV containment cover seals leaking.

There are no pressure release valves or vents from the PCV (or drywell or wetwell) to the refueling floor. This operation cannot be done. The Areva summary is inaccurate on this detail (why they suggested as much is a mystery to me). You would think Areva would know better. But the deliberate venting of gas to the refueling floor never took place, and has never been included in any official accounts: by IAEA, NRC, NEI, NISA, JAIF, TEPCO, and others. I believe the original source for this faulty error are press accounts that simply suggested “there was venting” and “a hydrogen explosion” took place. GE (with the suggestion that “pressure held in primary containment“) and AREVA are two industry sources that have repeated these statements, as well as numerous other enthusiast accounts (such as some included on this site). The implications are as you suggests … a design basis failure of the GE containment Mark I design (likely a release of hydrogen gas to the refueling floor from the flange at the top of the containment vessel), or a failure of venting pathway to the external stack. There are many other penetrations and seals to primary containment, but the flange at the top of the containment vessel (where hydrogen gas is likely to accumulate) is certainly one likely pathway. And pressure tests at the North Carolina Brunswick BWR in the 1970s indicated this is a weak element.

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In spite of all the preventive responses to protect the public from radiation so far, level 7 would seem the proper rating of severity considering the reactors are still inaccessible, that no end is yet in sight, and that the wrath of large earthquakes are still occurring, some of which have recently been centered very near the nuclear plant.

Aside from other potentials for an increase in radiation emissions from the reactor core, mentioned in other media, I wonder, is the instability of the region and the threat of something happening that could stop the vital cooling process and elevate emissions of radiation a factor at all in calculating the level to 7?

Some of the strongest quakes of recent have been centered nearly below the Dai-Ichi nuclear plant.
http://www.jma.go.jp/en/quake/20110412141747391-121407.html
The tab for ‘Information on seismic intensity at each site’ on that link will show a list of locations, sizes, and a time table of how active it really is.

This is a record of all of the earthquakes since March 11 to re-play and get feel for the instability of the area:
http://www.japanquakemap.com/

Twice tsunami alerts have been sounded with evacuations for the area announced in the last week and the cooling process was temporarily stopped due to a cut off of power yesterday.

“the public should assume that an aftershock maxing out at 7 on the Japanese scale could hit eastern Japan “for the time being.”
http://search.japantimes.co.jp/cgi-bin/nn20110412a2.html

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@tokyo_reside

—————
“Here you go…
http://english.kyodonews.jp/news/2011/04/84828.html
—————

That article says that the levels of radioactive release could reach that of chernobyl eventually(if not stopped), not admitting that this already happened as your previous comment suggested(you left out the word ‘eventually’).

I believe this is an important difference.

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Question: when does TEPCO run out of qualified workers? I mean workers who have useful remaining radiation allowance.

Hopefully not before all the Daiichi reactors and pools are stable. Nobody knows how many man-hours will prove to be required. But I would like to know at least how fast the existing TEPCO manpower pool is being depleted (I mean their remaining radiological allowances). A week ago WNN reported that 21 out of 370 workers had reached 100 milliseverts [thanks to Hank Roberts 4/11/11 2:01]:

http://www.world-nuclear-news.org/RS_Deaths_confirmed_at_Fukushima_Daiichi_0304111.html

It would help to have an idea what part of the remaining work is high-skill and high-site-experience vs. competent cleanup labour. Is extensive site-experience even a big issue?

And is there a consensus on what the worker radiological allowance should be? Is the special authorization limit of 250 millisieverts appropriate?

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John Doe, on 12 April 2011 at 3:22 PM said:

—————–
“Tepco even now admits that the total radioactive material release may equal or EXCEED that of Chernobyl. ”
——————

Could you supply the source of this claim? Because according to japan’s nuclear safety agency “the volume of radiation from Fukushima is one-tenth that at Chernobyl.” (http://www3.nhk.or.jp/daily/english/12_19.html)

—–

[Comment deleted. Please supply refs – “I have read” is not good enough.]

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Tom Keen wrote,
“Firstly, I haven’t heard anyone say ‘this isn’t a problem’. Secondly, comparing it to ‘how many people have been killed by recent climate change?’ is irrelevant, as we only have one global climate, and the problem is cumulative.”

Really? I suppose we will just have to disagree then, on both counts. The first is just a matter of personal taste.

But the comparison between the question, “How many people have been killed so far by radiation from the Fukushima Daiichi incident?” and “How many people have been killed so far by recent climate change?” does seem rather relevant to me.

1) The effects are cumulative and long-term.
2) The feedback is not immediate (as it would be if I stood in front of a beam pipe and got irradiated, or ate a gram of neptunium–though I’d likely die from toxicity in that case, not radiation, or perhaps both).
3) The results are not necessarily obvious or easy to deconvolute from other causes (did a person die from radiation exposure or smoking? Did a person die from hunger or climate change?)

These sorts of questions really belong on a more philosophical thread, so I’ll stop here (I only posted here because Prof. Brook raised the question himself).
MODERATOR
You are right Mike this does belong on the POT – however I have left it here because of Barry’s comment. Please post any futue comments like this on the POT. Thank you.

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John Doe, on 12 April 2011 at 3:40 PM said:

That article says that the levels of radioactive release could reach that of chernobyl eventually(if not stopped), not admitting that this already happened as your previous comment suggested(you left out the word ‘eventually’).

Nope I used the word “may” in that sentence, and didn’t said that it has occurred. Please read the sentence again before criticising. {On a related matter, Tepco and many other nuclear experts have said that stopping this will take many months and could even be years!} Tell me now how likely will the radioactive release being stopped?
MODERATOR
Your comment was deleted as a deliberate distortion of the facts, BECAUSE you misquoted the headline and left out the “may.” You also have failed again to give refs to yourpersonal statements – I have bracketed same.
Your belligerent attitude will not be tolerated on BNC as per the commenting rules. Tone down or you will be banned for violating the rules which aim to keep BNC civil.

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“And is there a consensus on what the worker radiological allowance should be? Is the special authorization limit of 250 millisieverts appropriate?”

Well, here is one page on occupational dose limits:
http://www.remm.nlm.gov/ICRP_guidelines.htm

Of course, radiological workers typically have higher occupational dose limits. From that page, regarding doses received in emergencies:

“…effective doses below 1000 mSv should avoid serious deterministic health effects, and below ten times the maximium single year dose limit [i.e., 500 mSv effective dose] as given above should avoid other deterministic health effects.”

A “deterministic health effect” here is something along the lines of acute radiation effects such as sickness. Stochastic health effects are things like cancer. So, I suppose there is still a margin of safety for “deterministic” effects built into the 250 mSv dose limit. For stochastic effects, it’s kind of anybody’s guess–it depends on what model you use to predict risk.
MODERATOR
Please move this discussion over to the Fukushima Philosophical OT – see my previous comment. Next comment in the wrong thread will be deleted and you will be asked to re-post. We do not have the facility to move comments between threads.

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>>>
Steve Darden, on 12 April 2011 at 3:40 PM said:
Question: when does TEPCO run out of qualified workers? I mean workers who have useful remaining radiation allowance.

I am concerned with that & how even any of the workers can get the plant in control because the workers are not allowed to go inside the reactor buildings. Levels 100mSv are often reached outside the buildings. Radiation up to 500mSv in debris are found outside.

This is a man in the radiation control section of the Dai-Ichi plant in charge of measuring radiation levels and has a vital role in risk measurement.
http://www3.nhk.or.jp/nhkworld/english/movie/feature201104052302.html
This is a 1 week old interview with the worker but he said then that radiation levels are so high that restoration work is still only in a preparatory stage and that he felt like a mountain climber looking at a mountain before even beginning to climb it.
Completion of the restoration is nowhere in sight.

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[Comment deleted. Violation of the commenting rules]
MODERATOR
The rules apply to everyone – you are not special. Personal attacks, tirades, and rudeness will not be tolerated. You are on permanent moderation and will be banned if you persist in this manner.

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I don’t think this site is about whether nuclear power is good or evil. Its about educating the public on nuclear energy. For those who post on this site about the virtues on solar power and how horrible nuclear power is, I would suggest reading all the excellent posts on this site and then to go to the Berkeley or MIT site and view their videos on physics and chemistry. After gaining some knowledge about radiation, one can then make an educated judgement on whether nuclear power is beneficial to man kind.

In response to the person who suggested that solar power is the answer if only the government invested in that technology. I posted the math in an earlier blog – the amount of solar panels needed to supply just the US with energy would cover the earth three times. I’m all for solar, wind, wave, ethanol from plants but the numbers show they will never be a major source of energy for the world. Thats reality. We are left with coal, oil, natural gas and nuclear power. Pick your poison.

However, nuclear power technology has made spectacular advances that should alleviate any fears of a nuclear disaster.

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@tokyo_reside
———————
“On a related matter, Tepco and many other nuclear experts have said that stopping this will take many months and could even be years! ”
———————

Do they say it will take years to stop the acute radioactive leak, or to clean-up after the disaster? A link to the original statement you are referring to would be welcome, because there’s an important difference between the two(again)

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@tokyo_reside
————————-
“Note the sentence at the bottom:
“Officials have warned it will be several months before the situation at the nuclear facility is brought fully under control.””
————————-

That sentence however is not directly related to stopping the radioactive leak, but rather to restoring the cooling systems of the reactors:

“The cooling systems at the Fukushima Daiichi nuclear plant were damaged in last month’s disaster and workers have been struggling to prevent several reactors from overheating.

Officials have warned it will be several months before the situation at the nuclear facility is brought fully under control.”

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MODERATOR
tokyo_reside has been banned for persistent violations of the commenting rules, including distortions of quotes and therefore facts.
As if to confirm the decision to ban him for violations of the commenting rules, tokyo_reside has re-named himself in various ways and is childishly spamming BNC

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[Comment deleted.Wrong thread]
MODERATOR
As advised before, this radiation discussion is now taking place in the Fukushima Open Thread, to avoid clogging the current threads with non-relevant information.
Several commenters, including pro-nuclear BNC regulars, have been asked to switch to this thread to continue the arguments.Please re-post your comments there. This version of WordPress does not enable us to move comments between threads.

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[[Comment deleted. Wrong thread]
MODERATOR
Your previous comments on this topic were in the Fukushima Open Thread. Discussions on alternative power including solar are now on the Fukushima Technical Open Thread. Please post there for these matters. Please do not continue to post on the “Fukushima Daiichi nuclear saga – 2 to 9 April overview” if you wish your comments to avoid deletion.

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[Comment deleted. Please re-post on the Fukushima Philosophical Open Thread]
MODERATOR
As we have informed you before the “Fukushima Daiichi nuclear saga – 2 to 9 April overview” is not the correct thread to comment on radiation and its effects, death rates etc. You will find this discussion on the above mentioned thread. To avoid deletion of your comments please do not post again on the wrong thread. We would like to simply move the comments between threads but this version of WordPress does not have the facility to do this.

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Moderator: I did not introduce these topics (radiation effects et al) you rule as belonging to another thread and that you are dillengently deleting, into this thread, but merely responded to them (other unmoderated commenters introduced these topics). It makes no sense to respond to a comment that in this thread by posting in another thread.
MODERATOR
Tom and Mike started this conversation on the wrong thread by mistake and were asked to move over to the Philosophical OT for continuity of discussion – many comments regarding this topic are posted there. Indeed Mike himself, even proposed that he was in the wrong thread and should move. The problem is that when the thread becomes clogged with off-topic remarks, the comments pertinent to the thread drop off as folk get bogged down in non-relevant comments and your position and ideas on the topic are divorced from the main conversation on the OT and will be missed by interested commenters.

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MODERATOR question:

Should I move my comment 12 April 2011 at 3:40 PM to Fukushima Technical Open Thread?
MODERATOR
I think you would find it a more fruitful area. I must have missed your comment before. Sorry – there has been a lot going on and I have only just got back to the blog to find multitudinous comments have appeared in my absence.

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This report from Asahi suggests that some workers did not have dosimeters in the early days of the accident and thus the actual exposure cannot be properly assessed, which could potentially be quite worrisome.This is especially true considering the anisotropy of radiation levels that do not strictly correlate with distance as illustrated by the video posted by Barry from within the exclusion zone. It is reasonable to speculate that within the plant these differences are even larger. Has anyone seen any independent confirmation of this?

http://www.asahi.com/english/TKY201104110137.html

thanks

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dumb question: is the “Central Waste Treatment Facility” for processing of radioactive waste water and if so how effective is this treatment? I query this as I have not seen much uproar about all the contaminated water that must be around the plant. TEPCO did state they dumped low level rad water into the sea so I am guessing that it is not cost efficient to treat it?

also, why not reuse radioactive water into the reactors? no good method to do so?

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Howard B:

Your assertions about solar require some correction.

Solar photovoltaics to produce the present world energy (of all sources) require less than 1% of land area (numerous studies show this). I am not saying that is easily achieved or at present cost effective, but let us not dismiss it outright. We would need in the order of several 100,000 km2 of area, but that is similar to road areas already in place, or to areas of deforestation each year. Big, but not unimaginable.

Where is your source of data for,”However, nuclear power technology has made spectacular advances that should alleviate any fears of a nuclear disaster.”

cheers
MODERATOR
You are on the wrong thread.The discussion re solar/alternative energy sources is taking place on the Fukushima Technical and Philosophical Open Threads.

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What happened to reactor building 4?

http://photos.oregonlive.com/photo-essay/2011/04/new_aerial_images_of_fukushima.html

These photos show clearly that the damage pattern in 4 is very different from 1 and 3.

In 1 and 3, all the panels are missing in the top two rows (above the surface of the spent fuel pool), and none are missing “below deck”.

In 4, many panels remain “above deck” and many are missing “below deck.” If hydrogen from the spent fuel pool exploded, how could it have created this pattern of damage? What else could have created it?

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Chris,

If you look at this pic of building 4, you can see what appears to be either an entry or exit hole in the lower right of the building. The rest of this side is in tact. In the lower left foreground you can see some of Unit 3. Perhaps a part of building 3 was blown into the wall of building 4? Or perhaps something was blown out of building 4. Either way, the hole in building 4 is a fascinating clue.

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

(1) Result of discharge of low level radioactive water to the sea As to the low level radioactive wastewater stored at the Central Radioactive Waste Treatment Facility, we began discharging at 7:03PM, April 4th to the south of the water discharge channel and finished at 5:40PM, April 10th.

At 9:55AM, April 11th, we confirmed that the wastewater in the building had been discharged sufficiently so that the preparation work to accept high level radioactive wastewater in the building could be done.

In relation to the low level radioactive water in sub-drain pits of Units 5 and 6, we began discharging from 9 PM, April 4th via the water discharge channel of Units 5 and 6 and finished by 6:52PM, April 9th.

In terms of the discharge of low level radioactive water to the sea, as instructed by NISA, we have been conducting ocean monitoring in a steadfast manner. We have been increasing the number of monitoring points and the frequency to investigate and confirm the influence of the dispersion of radioactive substances and have been notifying the result.

The radioactive density monitored at the measurement points including near the power station did not indicate significant fluctuation in comparison with the trend one week before the discharge.

The amount of low level radioactive wastewater discharged to the sea this time was approx 9,070 tons from the Central Radioactive Waste Treatment Facility and approx 1,323 tons from the sub-drain pits of Units 5 and 6 (Unit 5: approx 950 tons, Unit 6: approx 373 tons). The total radiation discharged was approx 1.5 x 1011 Bq.

We evaluate approximately 0.6 mSv of effective radioactive doses per year for adults as the impact on the discharge of the low radioactive wastewater 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. The level is similar to the evaluation we made before the discharge to the sea.

With the completion of discharge, as soon as the preparation work completed to accept high level radioactive wastewater at the Central Radioactive Waste Treatment Facility, we will transfer the extremely highly radioactive wastewater in the turbine building of Unit 2 to the Central Radioactive Waste Treatment Facility and store under stable conditions.

Also, from now on, as to the low level radioactive water in sub-drain pits of Units 5 and 6, we will transfer to a temporary outdoor tank and consider an appropriate radiation mitigation plan.

[Calculation of Effective Radioactive Dose] –Annual Effective Dose (Whole Body) per 1 Bq/cm3 is based on “Regulatory Guide for the Annual Dose Target for the Public in the Vicinity of Light Water Nuclear Power Reactor Facilities”
I-131 : 2.42 x E+0 mSv/yr
Cs-134 : 4.99 x E+1 mSv/yr
Cs-137 : 3.41 x E+1 mSv/yr

–Sea water flow rate near Fukushima Daiichi NPS is 10 cm/sec. In this case, sea water radioactive density is diluted to 1/10 at 1 km down stream.

Since discharge period was 5 days, annual average radioactive density in the ocean areas is estimated by (radioactive density at discharge point) x (1/10) x (5/365).

–Conclusion
I-131 : (1/10) x (5/365) x 2.42 (mSv/yr) x 20 (Bq/cm3) = 0.066 mSv/yr
Cs-134 : (1/10) x (5/365) x 49.9 (mSv/yr) x 4.7 (Bq/cm3) = 0.321 mSv/yr
Cs-137 : (1/10) x (5/365) x 34.1 (mSv/yr) x 4.9 (Bq/cm3) = 0.229 mSv/yr

Total dose = 0.066 + 0.321 + 0.229 = 0.616 mSv/yr

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Does anyone have any information on the soil chemistry of the area around Fukushima? most specifically about the mica content in the soil. The reason being is that Cesium behaves like potassium, is fairly easy to take out of water with sunflowers (and a few other plants that also work well) in a rhizofiltration application – thats where there is the best data from the Chernobyl site (Cs contaminated pond water). In soil it can be more difficult depending on the type of clay. Micaceous clays are notorious for fixing K in the clay interlayers – there are small cavities in the clay crystal lattice structure that are a perfect fit for K (and Cs) ions. Once in there, its very difficult if not impossible, to get out without severe treatments to weather the clays. The longer the Cs stays in the soil, the more likely it is to become fixed in the micaceous clays. If you don’t have micas, then the situation is much easier. Thus bioremediation for Cesium removal will be critically dependent on the soil chemistry and early intervention.

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New TEPCO cooling strategy?

Will Davis at Atomic Power Review has two new posts outlining what I speculate will be an important change in TEPCO’s strategy toward reestablishing recirculation cooling of R1, R2, R3. We have been concerned about the complexity and labor-intensity of repairing the original plumbing to support circulatory cooling. Possibly TEPCO has similar concerns, if it is true that their new approach is evidently to construct new primary and secondary cooling, condensing circuits. Here’s Will on 16 April:

(…) The most interesting news of the day is the still developing story that TEPCO has ordered a large number of special heat exchangers, planned for a new external cooling system that it will construct for each reactor plant. This is a novel approach, and probably the best idea TEPCO has had yet. According to the Kyodo story, TEPCO will use several heat exchangers for each plant, and will connect them to the existing external emergency connections that it’s been using prior to this for core injection. Apparently TEPCO will use electric pumps, and two core connections to establish recirculating cooling flow and then use hoses to bring in and return seawater, if we understand the plan correctly. No timeline is given on this plan — but given the mounting complications of the water in the buildings and in the ground, I would have to say that this plan should be given top priority.

And an update today from Will on 17 April:

I’ve just read the first concrete piece of evidence about how the new systems TEPCO is planning to install will work. Apparently, the idea is to obtain the feed for the pumps from, according to the article, “the reactor containment buildings.” This still isn’t clear, but it does seem to indicate that TEPCO acknowledges the leakage and intends to recycle water in a sort of non-sealed, but closed loop fashion for the primary cooling… the heat from which will be transferred to sea water.

Right now, without any further information, it might be assumed that TEPCO will be taking the water directly from the dry wells or the suppression pools. Important to note is that the primary side of this system will become highly radioactively contaminated, so that the equipment will need to be shielded or else access controlled as the rad level around the equipment will be very high.

My speculation is they will try to flood and circulate the PCV including drywell and wetwell. Any thoughts, comments on this idea?

UPDATE: Kyodo News has a new bulletin that touches on Will’s perspective:

(…) Meanwhile, the utility is considering installing circulating water cooling systems for reactors and spent fuel storage pools outside the reactor buildings at the plant in a bid to bring it under control, sources familiar with the matter said.

The new systems would cool nuclear fuel inside the reactors and spent fuel pools in a stable manner. They would involve heat exchangers and circulation pumps to drain reactor coolant water from the containment buildings, cooling it with seawater and then sending it back to the reactors, the sources said.

TEPCO appears to have already placed orders for dozens of gasketed plate heat exchangers — each measuring 3 meters high, 1 meter wide and 2 meters long — for such systems, the sources said.

The existing circulating water cooling systems at the plant were crippled by the March 11 earthquake and ensuing tsunami.

(…) Radiation levels inside the containment buildings remain high. TEPCO plans to utilize the pipes that it has been using to pump water into the reactors in the new circulating water cooling loops, so it can minimize the need for work inside the dangerous buildings.

There are more details at Kyodo News. Evidently the TEPCO chairman will make an announcement today at 3PM. I will report back…

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Another encouraging tidbit Kyodo News if these unmanned helicopters are more than just Lockheed PR department:

(…) The U.S. government has told Japan that it can use a U.S. unmanned cargo transport helicopter to set up cranes to remove spent fuel rods from storage pools at the crippled Fukushima nuclear power plant, Japanese and U.S. sources close to the matter said Saturday.

The K-MAX helicopter, developed jointly by Lockheed Martin Corp. and KAMAN Aerospace Group of the United States, is being considered to set up the huge cranes.

Wikipedia, and Kaman Aerospace.

This video of the unmanned K-MAX give a bit more perspective.

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The TEPCO chairman made his brief Sunday announcement as expected. See Kyodo News bulletins here and here. I am paraphrasing the english translation as this:

— three months to achieve stable cooling of R1, R2, R3 and all spent fuel pools

— six to nine months to achieve ”cold shutdown”

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Tokyo Utility Lays Out Plan for Its Reactors

gives TNYT’s take on the stabilization plan.

I’ll be very impressed if it only stakes six months and impressed even if it doesn’t run over nine months.

On the other hand, the so-called robots will certainly be of great aid.

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Further to David Benson, from TEPCO Washington:

On April 17, TEPCO has announced the Roadmap towards Restoration from the Accident at Fukushima Daiichi Nuclear Power Station.

With regard to the accident at Fukushima Daiichi Nuclear Power Station due to the Tohoku-Chihou-Taiheiyo-Oki Earthquake that occurred on Friday, March 11th, 2011, we are currently making our utmost effort to bring the situation under control. This announcement is to notify the roadmap that we have put together towards restoration from the accident.

1. Basic Policy
By bringing the reactors and spent fuel pools to a stable cooling condition and mitigating the release of radioactive materials, we will make every effort to enable evacuees to return to their homes and for all citizens to be able to secure a sound life.

2. Targets
Based on the basic policy, the following two steps are set as targets:

Step1. “Radiation dose is in steady decline” (our target is in about 3 months) Step2. “Release of radioactive materials is under control and radiation dose is being significantly held down” (3 to 6 months after achieving Step1) Step3. ” Target achievement dates are tentatively set as follows

3. Immediate Actions
Immediate actions were divided into three groups, namely, “I. Cooling”, “II. Mitigation”, “III. Monitoring and Decontamination.”

For the following five issues, targets are set for each of the five issues and various countermeasures will be implemented simultaneously.

[I.Cooling]
“Cooling the Reactors”
“Cooling the Spent Fuel Pools”
[II.Mitigation]
“Containment, Storage, Processing, and Reuse of Water Contaminated by Radioactive Materials (Accumulated Water)”
“Mitigation of Release of Radioactive Materials to Atmosphere and from Soil”
[III.Monitoring and Decontamination]
“Measurement, Reduction and Announcement of Radiation Dose in Evacuation Order/Planned Evacuation/ Emergency Evacuation Preparation Areas”

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TEPCO’s briefing slides (4) are available here. My speculation that they would flood the PCV appears to be correct:

Countermeasure [9]: Flood the PCV up to the top of active fuel.

I agree with David – if they achieve their objectives in 9 months I will be impressed and relieved. My understanding is that TEPCO knows little about the actual state of the machinery inside the buildings. And they have no experience of doing such construction in a hot environment – with or without robots.

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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 18, 2011
• Roadmap
o On April 17, TEPCO announced “the Roadmap towards Restoration from the Accident at Fukushima Daiichi Nuclear Power Station.” This will be sent by another email and is also available at:
http://www.tepco.co.jp/en/press/corp-com/release/11041707-e.html
• Radiation Levels
o On April 17, TEPCO announced the result of the analysis of water samples from the skimmer surge tank (installed to receive the overflowed water and floating wastes) of the spent fuel pool at Unit 2 of Fukushima Daiichi Nuclear Power Plant taken on April 16.
o At 4:00PM (JST) on April 18, radiation level at main gate (approximately 3,281 feet from Unit 2 reactor building) of Fukushima Daiichi Nuclear Power Station: 61 micro Sv/hour.
o At 4:00PM on April 18, radiation level at west gate (approximately 3,609 feet from Unit 2 reactor building) of Fukushima Daiichi Nuclear Power Station: 31.4 micro Sv/hour.
o Measurement results of environmental radioactivity level around Fukushima Nuclear Power Station announced at 4:00PM on April 18 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 4:00PM on April 17, the surveillance of the reactor building began, with a remote controlled robot, until 5:30PM.
o As of 5:00PM on April 18, injection of nitrogen gas into the primary containment vessel to prevent an explosion by accumulated hydrogen gas continues.
o As of 5:00PM on April 18, the injection of freshwater into the reactor core continues.
• Fukushima Daiichi Unit 2 reactor
o At 10:13AM on April 16, TEPCO began to inject freshwater into the spent fuel pool, until 11:54AM (approximately 45 tons in total).
o At 1:42PM on April 18, the surveillance of the reactor building began, with a remote controlled robot, until 2:33PM.
o As of 5:00PM on April 18, the injection of freshwater into the reactor core continues.
• Fukushima Daiichi Unit 3 reactor
o At 11:30AM on April 17, the surveillance of the reactor building began, with a remote controlled robot, until 2:00PM.
o At 2:17PM on April 18, TEPCO began to shoot freshwater aimed at the spent fuel pool, with a specialized vehicle normally used for pumping concrete, until 3:02PM (approximately 30 tons in total).
o As of 5:00PM on April 18, the injection of freshwater into the reactor core continues.
• Fukushima Daiichi Unit 4 reactor
o At 5:39PM on April 17, TEPCO began to shoot freshwater aimed at the spent fuel pool, with a specialized vehicle normally used for pumping concrete, until 9:22PM (approximately 140 tons in total).
• Fukushima Daiichi Common Spent Fuel Pool
o At 2:34PM on April 17, the power supply to the spent fuel pool was temporarily interrupted due to an electrical short circuit.
o At 5:30PM on April 17, the power supply to the spent fuel pool was restored after the removal of the cable and checkups.
o As of 4:30AM on April 18, the temperature of the spent fuel pool: 91.4 degrees Fahrenheit.
• Others
o At 9:00AM on April 15, TEPCO began to install silt barrier containing zeolite (an absorbent of radioactive nuclides) between the screen pump rooms of Unit 1 and 2 and between the screen pump rooms of Unit 2 and 3, until 11:15AM.
o At 10:19AM on April 15, TEPCO began to transfer distribution panels of the pumps to inject water to the reactors of Units 1 to 3 to higher ground as a countermeasure against tsunami, until 5:00PM.
o At 2:30PM on April 15, TEPCO began to install silt barrier containing zeolite between the screen pump rooms of the Unit 3 and Unit 4.
o At 9:00AM on April 16, the removal works of debris at the site began, with a remote controlled excavation machine, until 4:00PM.
o At 9:00AM on April 17, the removal works of debris at the site began, with a remote controlled excavation machine, until 4:00PM.

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)
• Ministry of Defense (MOD)

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Roadmap for Fukushima Daiichi restoration
http://www.world-nuclear-news.org/RS-Roadmap_for_Fukushima_Daiichi_restoration-1804114.html
Robots investigate Fukushima reactors
http://www.world-nuclear-news.org/RS-Robots_investigate_Fukushima_reactors-1804115.html

You’ve also read likely it elsewhere, but I continue to find WNN much clearer than the various MSM articles, those by non-experts at matters nuclear. Alos, a few minor points not covered in some other articles.

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KBMAN has just posted a new commentary, which includes a thumbnail of the analysis by the Atomic Energy Society of Japan:

Nuclear fuel inside the crippled reactors at the Fukushima Daiichi power plant has partially melted and settled in granular form at the bottom of pressure vessels, according to an analysis by the Atomic Energy Society of Japan made public by Friday.

The academic body’s panel on nuclear energy safety has said the melted fuel at the Nos. 1 to 3 reactors has been kept at a relatively low temperature, discounting the possibility that a large amount of melted fuel has already built up at the bottom of the reactor vessels given the temperature readings there.

A large buildup of melted nuclear fuel could transform into a molten mass so hot that it could damage the critical containers and eventually leak huge amounts of radioactive materials.

The panel has also said that the fuel grains with a diameter of between several millimeters and 1 centimeter are believed to have settled evenly at the bottom of the vessels, leaving almost no possibility of a nuclear chain reaction called ”recriticality.”

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I am putting this post in this thread in additional to the technical thread. It seems more action is here.

The following is a quote from a WSJ article in this mornings WSJ

“Under its strategic plan unveiled Sunday, Tepco is planning to fill the containment vessels of the plant’s No. 1 and No. 3 reactor units with water and employ heat-exchanging systems that could include an air-cooling solution. Similar plans are in place for the heavily damaged No. 2 reactor unit but must await the repair of leaks that are allowing the escape of highly radioactive water contaminated by the damaged fuel rods.”

The entire article can be found here.
http://online.wsj.com/article/SB10001424052748703916004576270643486719236.html

As read from the quote above, Tepco is planning to fill the “containment” vessels.

This must be an error. I think they are just going to cool the water in the PRV by creating a new closed loop cooling system for the RPV and cooling this loop via an air cooled heat exchanger similer to french design. I would assume also that the air cooling would consist of an evap cooling tower.

Can anyone clear up what is going on here??

Thx,
GSB

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Cyril,

Thx for the response.
I put my original post today about CV flooding in the technical blog also and have gotten more responses so let’s move the CV flooding discussion over there.

OK ??

PS The JAIF update has said the same for some time now yes?? (I could be wrong).
Do you have a link for the AREVA presentation that says they flooded R1?? How could they send a robot into that CV if it is flooded??

Thx,
GSB

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