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)
Brave New Climate 
164 replies on “Fukushima Daiichi nuclear saga – 2 to 9 April overview”
Update on JAIF radiation measurements in the surrounding areas:
Click to access ENGNEWS01_1302227043P.pdf
Highest reported from this data set, 6 microsievert/hour and dropping, in Iitate village.
This area, to the northwest of Daiichi, appears to require investigation for possible local spikes of radionuclides, as it was under part of the fallout.
Overall though, looks not too bad, very acceptable levels of radiation outside the plant fence.
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Back when the Chernobyl incident was happening I recall the media was worried about a meltdown. Back then, my understanding was that a meld down was when the whole reactor got so hot that it melted its way into the earth in a way that could never be controlled. Now a melt down only seems to be some melting of fuel rods. Has the term meltdown become meaningless? In one case it is to be feared and in the other it hardly seems to matter.
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Cyril R, on 9 April 2011 at 11:09 PM said:
Update on JAIF radiation measurements in the surrounding areas:
Click to access ENGNEWS01_1302227043P.pdf
Highest reported from this data set, 6 microsievert/hour and dropping, in Iitate village.
This area, to the northwest of Daiichi, appears to require investigation for possible local spikes of radionuclides, as it was under part of the fallout.
Overall though, looks not too bad, very acceptable levels of radiation outside the plant fence.
—-
[deleted personal speculation of radiation level possibilities. Please re-post with supporting refs.]
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Robert, you’re right… it’s basically just a buzzword without a good scientific definition.
If “meltdown” means that it melts through to China or something (the “China Syndrome”), then of course it’s meaningless because it’s utterly impossible nonsense.
But if “meltdown” means fuel melting to some partial extent inside the reactor pressure vessel inside the containment, like at TMI and possibly at Fukushima too… well, “meltdown” isn’t that scary, because it’s not actually likely to hurt anyone at all.
Recommended reading: Bernard Cohen’s The Nuclear Energy Option, chapter 6: The Fearsome Reactor Meltdown Accident.
http://www.phyast.pitt.edu/~blc/book/chapter6.html
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This one has up to 23.6 μSv/hour, and integrated doses up to 13.4 mSv.
http://www.mext.go.jp/english/radioactivity_level/detail/1304275.htm
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More recent reactor designs such as the EPR are designed to catch and cool a full core meltdown – and you wouldn’t even notice it when standing next to the reactor building!
The media like to portray meltdowns as apocalyptic events that will kill thousands if not millions, but what actually makes nuclear accidents dangerous is high dose from a large release of radionuclides. If your design takes into account full meltdown retention and cooling then meltdowns indeed become unimportant for public health. In stead containment failure combined with meltdown becomes dominant. Better make your containment aircraft crash, earthquake and tsunami proof.
Reprocessing plants release large amounts of radionuclides all the time, but the dose is tiny because the release is almost exclusively noble gasses that just float away in the higher atmosphere (unless the plants are poorly managed like Hanford). The Pacific ocean is decaying at a rate of 8000 EBq. Which is 8,000,000,000,000,000,000 radioactive decays per second. This does not mean the Pacific is dangerously radioactive because of its huge bulk making dose very tiny even if you swim in there all the time.
http://www.physics.isu.edu/radinf/natural.htm
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What would be your statement on the AREVA report about the spend fuel pool of Reactor 4 – there the following possible consequences are listed: “Core Melt on Fresh Air, nearly no retention, large release. (maybe it’s already discussed, if possible could you point me to the discussion?)
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[Deleted off-topic. Please re-post in Fukushma Philosophical Open Thread.]
MODERATOR
You are welcome to post your philosophical ideas/ thoughts on the Philosophical OT without substantiating refs.
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> full core meltdown – and you wouldn’t even notice it
(1) citation needed
(2) stuff like this won’t reassure people who want to know such problems _get_ noticed.
You’re trying to defend the industry, but this kind of defense makes new readers wonder why it’s needed.
It’s not needed. You can cite good sources and you can give information that’s evenhanded and acknowledges the range of possibilities, not take only one side and post only info favoring one side.
Please try.
MODERATOR
Hank- would you please state the name and time of the comment you mention.
I am just looking back at the overnight posts and can’t see this particular comment so I can’t edit and ask for refs.
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Following.
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How big was the tsunami –Google finds an estimate of 14 meters posted here some days ago; now the estimate is 15 meters:
http://www3.nhk.or.jp/daily/english/09_30.html
“15-meter waves hit Fukushima
The operator of the troubled Fukushima Daiichi nuclear power plant says the facility was hit by a tsunami as high as 15 meters on March 11th.
Tokyo Electric Power Company was reporting on Saturday on its survey of high-water marks left on the plant’s buildings.
It says it found that the tsunami reached up to 15 meters on the ocean side of the reactor and turbine buildings. The figure is far beyond the company’s originally estimated height of 5.7 meters.
TEPCO confirmed that the 6 reactors at Fukushima Daiichi power plant had been under as much as 5 meters of water….”
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Shelby, on 9 April 2011 at 11:54 PM said:
From what little I know about radioactive accidents, I’m not comforted by “spot” readings here and there around a 20 km radius
US DOE has updated it aerial radiation monitoring.
http://blog.energy.gov/content/situation-japan
MODERATOR
Selby’s speculations re radiation levels in more regions was deleted with a request for refs to support his discomfort. Thank you for providing such a link here.
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[Comment deleted. Violation of the citation rule]
b.MODERATOR
To everyone -a reminder of the rule.
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 interesting 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).
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Hank Roberts, this is meant to be explanatory to the issue of core melt versus large radionuclide release. Adding a core catcher is adding a layer of defense in depth that cannot fail. It is unique in industrial safety to have both PRA and effect based mitigation. There is much work done on core catchers, here is an example:
Click to access P01_11.pdf
If you google core catcher you can find a lot of good stuff beyond that.
I am not defending the industry. As a matter of fact, most of my pay is from design and controls of oil infrastructure including oil terminals. Having seen first hand what damage fossil fuels do, all the time, not just what they can do in an accident, just regular damage, I’ve come to the point of willing to look for another job and prefer for reason and rational choice to be victorious over personal interests.
Burning stuff is deadly.
http://nextbigfuture.com/2011/03/lifetime-deaths-per-twh-from-energy.html
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Thanks Cyril, I agree — just trying to say, as I say to myself every time I post — step back, imagine someone coming along reading this stuff later on or dropping into one posting via a Google search, and try to always give cites and enough information that the reader gets helped to make sense of this.
While it’s easy to fall into treating this like conversation with people who remember what was said yesterday — it’s actually writing that persists, and gets read later out of order by people searching.
Tiresome, I am, I know (wry grin). I applaud your posting more context, it helps a lot. Barry ought to give you a topic to go into this stuff.
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Was the length of time required for the TMI cleanup due to purely technical reasons? From one account of what happened at TMI: “Anti-nuclear groups across the country filed numerous lawsuits effectively delaying anyone actually opening the reactor to see what happened to the fuel.” Three Mile Island and the China Syndrome
The same groups often point to the high costs and plant construction delays of the nuclear industry as a reason why nuclear energy shouldn’t be pursued– but to what extent are the cost increases and delays exacerbated by the attacks from these same groups?
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Following
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For example, anti-nuclear groups like to say: “No new nuclear plants have been built in the past 30 years in the US, therefore the nuclear industry is a failure.” Seems like a form of doublespeak.
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seamus, on 10 April 2011 at 3:10 AM said:
Was the length of time required for the TMI cleanup due to purely technical reasons?
According to MIT Nuclear Engineering Cesium 133/134 is about 6.8% of decay products with a 1/2 life of 2 years.
Absent a compelling reason to clean up in a hurry why would someone not take a long time?
The longer one waits the less highly radioactive material there is to clean up and the cheaper it is.
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Wow, the claims of the anti in the intelligence squared debate were shocking. He starts off by saying that if external power was lost AND back up power, then the cooling water would boil off within a few hours. A few hours? Even if that were the case I’m pretty sure it would be ample time to get some extra back up diesels in. Then he goes on to say that we are only a few hours away from a nuclear explosion – now that’s very disingenuous and and appeal to emotion .
MODERATOR
Video of the debate is embedded in the article.
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Small correction: the news reports about the bodies of the workers recovered said that they showed crushing injuries. So they would have died of trauma and blood loss, if not drowning.
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there obviously is a serious problem with back up diesel power in the japanese plants, as the last earthquake demonstrated:
2 out of three diesel generators not working? this simply should NEVER happen.
——————–
i am also surprised by the slowness of response in other countries. it is pretty obvious that measures must be taken immediately at plants that are threatened by quakes, tsunamis or both. even just temporary emergency measures, like sandbags or movable floodwalls should be moved into position.
it is also clear that the problem was loss of emergency electricity. moving in additional diesel generators, fuel and adding a couple of connections doesn t cost anything and should be done now.
the situation at Fukushima also demonstrated that there is a problem with spent fuel pools at the top level of reactor buildings. old fuel should also be moved out of those buildings in reactors all over the world immediately.
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[Deleted speculative scientific comment unsupported by refs/links.]
MODERATOR
If you want to raise these personal ideas/speculations, the correct forum is the Fukushima Open Thread where BNC rules are more relaxed. Please re-submit on that thread.We do not have the facility to transfer comments to the correct thread.
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Luke, Huw, et al
There are a few scary terms – meltdown, nuclear explosion – that are getting applied to less and less truly scary situations. The cachet, so as to speak, of the original word has been appropriated to situations which do not intrinsically warrant it. There are other examples throughout the language; it is not unique to the nuclear industry.
“Nuclear explosion” is a pretty egregious example. It is a well-defined term that simply does not apply to anything that happens at a nuclear power plant. I wouldn’t advise anyone to expect mere accuracy to stop the misusage of a term that is expedient for the speaker, however. But it can be defeated – if the discussion and emphasis on explosions in general will not distract too much.
Discussion of meltdown requires a little more flexibility. If it is being used (as often) to mean something that is automatically disastrous on a wide scale, then it more-or-less must also be talking about corium reaching groundwater (which is what I would take to be the “china syndrome”, rather than something which continues into the ground). Despite the massive quantities of corium produced in Chernobyl, and conditions that prevented anyone taking concerted action, this did not happen there, and as such can be comprehensively dismissed. Lesser “meltdowns” should be acknowledged as having far less effect, mostly confined to the plant itself. A useful guide here is that the other three reactors at Chernobyl were operated post-disaster.
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Right. There’s stunning footage of the wave crashing against the NPP here:
http://www.cnn.com/2011/WORLD/asiapcf/04/09/japan.nuclear.reactors/index.html
There’s some tsunami photos from the other plant (Daini) — note the scale of things, e.g. the seawall in the background. If I understand correctly, the elevation of the road is about 12 meters above sea level:
http://cryptome.org/eyeball/daiichi-npp5/daiichi-photos5.htm
The (Japanese language) report where I got that “12 meters” figure from. It has photos of the damage, how they measured out the 14+ meter tsunami runup:
http://www.meti.go.jp/press/2011/04/20110409007/20110409007-3.pdf
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To clarify — in the last link, they have photos of deposited dirt the NPP buildings, which show the high-water mark.
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Wow, I just watched that Royal Geographical Society debate clip and I hope the nukies got to reply to the ridiculous charge that “we are never more than a few hours away from a NUCLEAR EXPLOSION!” Where do they dig up these people!?
MODERATOR
See link in the current article.
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[Comment deleted. Violation of the citation rule. Please read them and re-post]
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Can someone interpret this very odd graph?
http://atmc.jp/plant/rad/?n=1
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The likelyhood of any more air release of radionuclides has become pretty remote. Why does not the Japanese government collapse the evacuation zone a bunch and let people who still have homes return to them? Looks to me at this point that they are just inflicting hardship for no good reason.
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Moderator, I believe EN is referring to the intelligence squared debate clip embedded in the article above.
EN – I was shocked by the video too. See my comment on the YouTube video. Please add your own 2 cents too.
MODERATOR
Ooops! Thank you Huw. There was so much to catch up on overnight that I haven’t yet watched that video myself!
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[Deleted double posting]
MODERATOR
Posting the same comment/information on more than one thread violates BNC rules.
This may be considered spamming and clogs the threads unnecessarily.
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Thanks for another simple, to the point update, Barry. Much appreciated.
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John Strong, that graph:
http://atmc.jp/plant/rad/?n=1
appears to indicate dose readings in the drywell (D/W) and suppression chamber (S/C) which is the torus structure. The torus contains water with scrubbed fission products in it so we’d expect the high but declining Sievert readings there (fission products decay). Readings in the drywell would also be high, being next to the reactor vessel, though that last spike seems weird.
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[Comment deleted. Violates citation rule]
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[Comment deleted. Wrong thread]
MODERATOR
Please re-submit your comment to the Fukushima Technical Open Thread where this discussion is taking place. We do not have the facility to move comments between threads.
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[Comment deleted. Wrong thread. Please re-post in correct thread.]
MODERATOR
Discussion moved to Fukushima Technical Open Thread.
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I found this nice image from Japanese ABWR, the most recent design, with a diesel generator inside the containment and smokestack going all the way to the roof. That’s reassuring!
Perhaps we need a post on ‘Fukushima versus new nuclear plants: lessons already learned’.
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[Comment deleted. Violation of the citation rule]
MODERATOR
Please supply ref to support your personal scientific opinion and re-post in the Fukushima Technical Open Thread.
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@John Strong:
That’s from the reactor data being released by METI (under “Earthquake Information and field monitoring information” reports, subsection “plant-related parameters”; latest is No. 85):
http://www.meti.go.jp/press/
They’re in Japanese, but here’s an English version of one of them to see what the fields are (the translations are several days delayed):
http://www.nisa.meti.go.jp/english/files/en20110410-1-3.pdf
Your graph is of the dose rates in the air in the drywell (D/W) and suppression chamber (torus) (S/C), as measured by the Containment Atmospheric Monitoring System (CAMS). The graph you linked is not current; a later measurement (4/8 13:00) sees the D/W dose fall to 68.3 Sv/hr, and after that it goes into an error state.
(This won’t help you interpret the data, but I thought these links could be useful).
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TEPCO, NRC think that reading is an instrument malfunction:
http://www.nytimes.com/2011/04/10/world/asia/10japan.html?pagewanted=all
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dear Moderator, the statement “a glass can not contain more water than it can hold” does NOT require a citation.
the same is true for a reactor.
MODERATOR
Your statement was not “a glass can not contain more water than it can hold” i.e. that the reactor was overflowing. But that you “thought/guessed” it was leaking. Why did you think so and where are your sources.
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Uvdiv: why are high readings always due to mistakes but low readings re accepted without reservation? Why not just take another reading?
–bks
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Mike Keefer, on 10 April 2011 at 11:22 AM said:
Why does not the Japanese government collapse the evacuation zone a bunch and let people who still have homes return to them?
Radiation monitoring has been expanded inside the 30 km radius in the last couple of days…sites numbered above #83 have recently been added.
Click to access 1304690_0919.pdf
According to NHK the Fukushima prefecture is going to measure radiation level at 2,700 points outside of the 20km zone next week.
http://www3.nhk.or.jp/daily/english/10_20.html
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Re uvdiv 10:41 The NRC spokesman says that there has not been a sharp increase in the pressure and temperature in the drywell.
As far as I know, drywell pressure is measured and released in the NISA updates, but D/W temperature never has been.
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bks, on 10 April 2011 at 11:00 PM said:
why are high readings always due to mistakes but low readings re accepted without reservation?
The sensor side of many gauges are inside the containment building.
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> Why does not the Japanese government
> collapse the evacuation zone a bunch
> and let people who still have homes
> return to them?
They explained this, and the NYT went into it at some length a few days ago; I’m sure I posted quotes and cites at the time.
The reason is that the short term evacuation criteria are for a one-time event. The event is no longer short term and the small exposures have to be added up over the longer time span.
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I tried searching for the cite I posted earlier but couldn’t find it (is the search function for the blog in need of a manual update of its index? Suspect so)
(hope I get this typed in before the moderator gets to the previous post with the brush-cutter)
I found a new and different cite for the same information that I found from the NYT and posted a few days ago — here it is, answering the question:
http://edition.cnn.com/2011/WORLD/asiapcf/04/07/japan.nuclear.reactors/index.html?hpt=T2
“Tokyo (CNN) — Japan may set standards for long-term radiation exposure that would effectively extend the evacuation zone around the damaged Fukushima Daiichi nuclear power plant, a top government official said Thursday, as a strong new aftershock rattled the area
Government readings show that people beyond the current restricted zone may be exposed to dangerous long-term doses of radiation even though the readings fall below levels that now require an evacuation, Chief Cabinet Secretary Yukio Edano said.
“It is the time for the government to consider setting another category for accumulated exposure,” Edano, the government’s point man on the crisis, told reporters Thursday evening….”
MODERATOR
You were safe from the brush-cutter overnight – the moderator was asleep :-)
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TEPCO is now posting graphs as well as text charts, this is helpful. This is from their press release page, described as “Fukushima Daiichi: the result of the dust nuclide analysis” (showing both “volatile” and “particle”)
(whatever that means, I haven’t found it explained)
Click to access 110410e7.pdf
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Compare that to this and it’s very different, in ways I can’t interpret — can someone?
Click to access 110410e6.pdf
(“The result of the nuclide analysis of radioactive materials in the air ….”) — Cs137 at 9.1E-06 — so there’s much less in the air than in the dust collected, I gather. That would make sense.
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Is there something peculiar about a reading of
“2200 (μSv/h)” in the radiation monitoring?
2200 is repeated for every column for Fukushima in this document — far in excess of the numbers for anywhere else and far above the normal level: http://www.mext.go.jp/component/english/__icsFiles/afieldfile/2011/04/10/1304834_041013.pdf
Makes me wonder if it could be a “no info” or “pinned the meter” indication.
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PS — I think it’s more likely that’s a “2.200” in the radiation reading; there’s a little blurry pixel there; the’ve used a font for their PDFs that has all the digits slightly overlapping so a decimal point gets lost in a “2” where it’s visible next to a “0”
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Hank Roberts, on 11 April 2011 at 2:28 AM said:
Government readings show that people beyond the current restricted zone may be exposed to dangerous long-term doses of radiation even though the readings fall below levels that now require an evacuation
The reading 30 km NW at monitoring post #32 is at 26 uSv.
Mext Monitoring data.
http://www.mext.go.jp/component/english
/__icsFiles/afieldfile/2011/04/10/1304690_0401010.pdf
The readings af Fukushima Daini, which is 10 km South of Fukushima Dai-ichia are below 2.8 uSv
Click to access 11041006a.pdf
Radius isn’t a particularly good metric at this point.
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Here’s a graphic-and-text summary of the sequence of events:
Click to access en20110406-1-1.pdf
I’m puzzled their graphic shows venting from the torus being sent out through the “stack” after passing through an acronym that’s probably the standard filter system. The “stack” would be the very tall tower, but the pipes to that visible in the satellite photos appear to have been broken off by the tsunami. Does anyone know where the venting from the torus is going, on each reactor?
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Harry — please be careful. You attributed words to me, from something I quoted directly from the news story cited.
This is the full paragraph:
Government readings show that people beyond the current restricted zone may be exposed to dangerous long-term doses of radiation even though the readings fall below levels that now require an evacuation, Chief Cabinet Secretary Yukio Edano said.
That’s not my opinion. It’s a quote. You posted radiation levels following that but not the time span.
Point from the story is — a small dose per hour still adds up to exceed the permitted dose, eventually, and releases are continuing. The evacuation levels were set for a one-time release, not an ongoing release.
That’s why they are restricting return to the area — cumulative dose can’t be capped until the releases are stopped and they don’t know how long the current leaks will continue.
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Here’s a bit I hadn’t seen before — the reason that Unit 4 was shut down:
“Nov.29,2010 -All fuel assembly was
removed from the core and located in the pool due to the core shroud replacement”
(from http://www.nisa.meti.go.jp/english/files/en20110406-1-1.pdf at p.35, section 4-2)
Looking that up — there’s a lot of history to the core shrouds, and that was one of the big problem areas covered up in the past.
http://www.google.com/search?q=fukushima+nuclear+power+“core+shroud”
That finds: replacement of the Unit 3 core shroud, first time it was ever done anywhere (photos, text)
http://www.toshiba.co.jp/nuclearenergy/english/maintenance/replace/shroud01.htm
“The world’s first shroud replacement project for a Boiling Water Reactor (BWR) has been completed at Fukushima Daiichi Nuclear Power Station Unit No.3 (1F-3) ….”
Lots of detail and photographs there — more than I’ve seen anywhere else of the innards of the actual working reactor Unit 3, as it was taken apart and put back together to replace the core shroud not long ago (not sure exactly when)
So — Unit 4 had just recently been shut down and emptied of fuel so they could do this same replacement procedure of its core shroud.
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The areas of concern are the ones in the line northwest of Daiichi, because some wind took fallout there and put it down as you can see here:
There appears to be 1-10 mrem/hour (10-100 microsievert/hour) in the fallout area. Not particularly hazardous but the government goal is to restrict total dose to under normal nuclear plant worker conditions which is 50000 microsieverts (50 millisieverts).
All the data, including JAIF radiation trends, does indicate that doses have been on constant decline for at least two weeks now. Highest cumulative dose in Hank’s NISA reference above is 6 millisievert. Perhaps there are some areas in the northwest fallout area that are higher, and they want to make sure people there aren’t getting above the 50 millisievert normal worker dose?
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Cyril, from what I read the publicly stated concern is not about the worker dose limits — those are all adults, and being tracked for total exposure individually. Likely they’ll be watched for a long time as individuals.
Rather prolonging the evacuation is about limiting the longterm population dose residents would begin to accumulate starting with return to the area.
That can’t be known because it’s impossible to set a limit on it until all the sources adding new fallout are controlled. Tiny amounts, but from unknown sources, until they can get into all the reactor vessels and fuel pools and not just stabilize them but inventory them.
I’d imagine there’s also a practical concern about possessions and salvage being picked up and transported out of the area, and dust being disturbed.
Once the releases from the plant stop — when the only change in radiation level is the predictable decrease due to decay, the existing material — if undisturbed and left where it fell — will wash out with further rainfall, and move off roofs and streets into the soil and sewers and otherwise away from areas people will occupy on their return.
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[…] https://bravenewclimate.com/2011/04/09/fukushima-daiichi-2-to-9-april/ […]
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I’ve been looking for that tsunami footage, thanks!
No wonder Toshiba thinks it can tear down the facility in such a short amount of time; having replaced the core shroud, they should have plenty of records and projections to use in the planning process.
Well, that and Toshiba would like to further expand its reputation in the nuclear energy market. It is common sense to make such a bold claim.
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@Hank Roberts 4:39 Thank you very much for your posting of NISA’s April 4 summary of events at Fukushima NPS R1-6.
I am disappointed by NISA’s summary since I believe that some things (that persons following the situation closely know) are concealed or distorted.
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 explosionscould have been instead from the PCV containment cover seals leaking.
The other thing that jumped out at me was that there is no mention of the March 15 06:00 H2 explosion in R4 bdlg [due to H2 generated by radiolysis and/or zirc-steam reaction in the R4 SFP]. See NISA slide 32 for their R4 chronology.
Satellite photos clearly show that the damage to R4 bdlg happened after the R3 building explosion on Mar 14. It’s as if the R4 building explosion never happened in NISA’s account.. Slide 35 only talks about H2 explosions in terms of “possible concerns about spent fuel pool”. There is no assesment of the R1-R4 SFPs.
BTW, the R4 SFP temp is shown to be increasing from 84C on Mar 15 to 100C on Mar 24 (slide 40). The 100C reading has never been mentioned before.
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That Areva presentation was from a meeting at Stanford on 21 March, and the full audio and video is available at http://fsi.stanford.edu/events/the_nuclear_crisis_in_japan/. The presentation wasn’t and official release, so the version on Stanford’s site has the Areveva logo removed.
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Status of Fukushima Daiichi Nuclear Power Station
April 9th, 2011
The Tokyo Electric Power Company, Inc.
Water is planned to be transported to condensers for Units 1 ~ 3, whilst for Unit 4, it is being considered.
Turbine Building basement Condenser Condensate Storage Tank (CST)
Unit 1 Waiting for water to be transported to condenser 13:55 April 3rd ~ Transportation to CST commenced. April 2nd:
Transportation to SP(*1) surge tank completed.
Unit 2 April 10th: Planned to be transported to condenser 13:10 April 9th: Transportation to CST completed. April 1st:
Transportation to SP surge tank completed.
Unit 3 Waiting for water to be transported to condenser Planning transportation to CST March 31st: Transportation to SP surge tank completed.
(*1) SP: Suppression Pool
・ Bored holes on penetration of Turbine Building walls at Units 2 to 4 (completed on April 7th).
・ Temporary pumps; set up power supply.
(Setup of Vertical shaft water resistant pump for unit 2 was completed, others underway.)
Attached PPT file (20110409 Water drain from Turbine Building.ppt) shows overall picture of drainage process.
・ Inspection inside Central Waste Treatment Facility (underway).
・ 5:38 April 6th: Confirmation of stoppage of leakage from beneath the supply cable pit.
・ April 6th ~ Leakage part was further treated by rubber board and fixer. Stoppage of leakage and monitoring is continuously done.
Other measures (April 5th)
・ For reducing ocean spillage, steel walls are being set up (April 9th ~). Silt fences are being prepared.
・ Setup of large sandbags at banks south of outlet is cancelled following bad weather.
Up to “Initial pressure + 100kPa” of nitrogen gas was injected (Temporary nitrogen generator).
・ 22:30 April 6th: Operation started. (system structure, leakage check, etc)
・ 1:31 April 7th ~ Injection started (by first nitrogen generator), 2:58: second device added.
・ D/W pressure before nitrogen injection (April 7th 1:20) 156.3kPaabs → April 9th 12:00 190kPaabs
【Central Waste Treatment Facility】
Process Building
・ 19:03 April 4th ~ 6:30 April 6th: discharge from Unit 1 ~4 outlet.(Approx. 5,800t)
・ 23:45 April 8th ~: Discharging remaining water of the base from Unit 1 ~4 outlet (Approx. 800t)
High Temperature Incineration Building
・ 18:00 April 6th ~ 18:00: April 7th: discharge from Unit 1 ~4 outlet.(Approx. 1,600t)
・ 14:30 ~ 22:20 April 8th: Discharge of remaining water of the base from Unit 1 ~4 outlet completed (Approx. 300t)
【Unit 5/6 Sub-drain】
・ April 4th 21:00~ Commenced discharge from Unit 5/6 outlet.
・ As of 6:00 April 9th: Approx. 1,300 t has been discharged
(Approx. 200t remaining. Discharge will be completed if as planned)
Density of Iodine-131 in the ocean (Reference figures)
Sampling points (coast) Date/Time Density Versus standard
30m north of outlet of Unit 5~6 Fukushima Daiichi 4/8 9:15
4/8 14:25 50 Bq/cm3
46 Bq/cm3 Approx.1300 times
Approx.1200times
330m south of outlet of Unit 1~4 Fukushima Daiichi 4/8 8:55
4/8 13:55 19 Bq/cm3
1.9 Bq/cm3 Approx.480times
Approx.48times
Around north outlet of Fukushima Daini (10km from Fukushima Daiichi) 4/8 9:05 1.4 Bq/cm3 Approx.35times
Around Iwasawa Coast (Approx. 16km from Fukushima Daiichi) 4/8 8:10 1.2 Bq/cm3 Approx.30times
Approx. 15km offshore of Minami-Souma 4/8 Sampling unable due to bad weather
Approx. 15km offshore of Ukedogawa 4/8 Sampling unable due to bad weather
Approx. 15km offshore of Fukushima Daiichi site 4/8 Sampling unable due to bad weather
Approx. 15km offshore of Fukushima Daini site 4/8 Sampling unable due to bad weather
Approx. 15km offshore of Iwasawa Coast 4/8 Sampling unable due to bad weather
Approx. 15km offshore of Hirono 4/8 Sampling unable due to bad weather
* Sampling on 9th April was also unable due to bad weather.
Record of April 8th
【Unit 3】17:06 ~ 20:00: Spraying of freshwater (Approx. 75t)
Record and plan of April 9th
【Unit 4】Spraying of freshwater by concrete pump vehicles planned (checking of level change of skimmer surge tank)
【Unit 1】 Injecting freshwater to Reactor Pressure Vessel
Temperature of Reactor Pressure Vessel: 12:00 April 9th (at suction nozzle) 235.2 C (Bottom of RPV) 120.1 C
【Unit2】 Injecting freshwater to Reactor Pressure Vessel: 12:00 April 9th (at suction nozzle) 144.5 C
【Unit3】 Injecting freshwater to Reactor Pressure Vessel: 12:00 April 9th (at bottom of RPV) 109.2 C
【Unit4】 No status change
【Unit 5/6】 In cold shutdown. No status change.
【Common Pool】 No status change.
【Unit 1 ~ 6】Checking of equipment status is being continued.
・ April 3rd 9:52 ~ 11:15 Transportation of water from Burge 2 to Burge 1
・ April 4th 11:54 Burge 2 sailed into port after freshwater supply. On standby.
・ April 9th: Plant condition check by unmanned helicopter was cancelled due to bad weather.
・ April 9th: Spraying of inhibitor was cancelled due to bad weather.
・ Receipt of an order regarding interpretation of safety regulations on emergency generating facilities on April 9. Now Japanese utilities are required to have two emergency generating facilities operable which connect to necessary emergency alternate-current high-voltage bus line for each nuclear reactor. Please see details bellow.
=======
TEPCO received an order document, “Regarding interpretation of safety regulations on emergency generating facilities”, from Nuclear and Industrial Safety Agency (NISA), Ministry of Economy, Trade and Industry.
Based on this order, in conjunction with an order received on March 30, we will take actions immediately.
* Translation of the Order document: Regarding interpretation of safety regulations on emergency generating facilities by NISA
The Earthquake Off the Coast of Miyagi Prefecture occurred on April 7, 2011 and Higashi-dori Nuclear Power Station of Tohoku Electric Power Company lost the offsite power and emergency generating facilities started up to maintain the power source. Although the offsite power has been restored, emergency generating facilities shut down due to some troubles. Thus, it was reported as a failure to secure the restriction of operation regulated in the safety regulations.
Amongst the matters on operation of nuclear reactors facilities in the safety regulations stipulated in such as Article 16.7 of the current “Rules on the Installation and Operation of Commercial Power Reactors”(No. 77 of Ordinance of Ministry of International Trade and Industry, of Showa 53 (of 1978)), the interpretation on restriction of operation requires one emergency generating facility operable for each nuclear reactor in the condition of cold shutdown such as during regular inspections and fuel replacement (which includes the cases of storing spent fuels in spent fuel pools). However, in consideration of the accident of Fukushima Daiichi Nuclear Power Station caused by Tsunami induced by Tohoku-Chihou-Taiheiyo-oki Earthquake, 2011, it is extremely important to secure power source. Therefore, the interpretation was amended to require two emergency generating facilities operable which connect to necessary emergency alternate-current high-voltage bus line for each nuclear reactor (when power stations have more than one nuclear reactor, they can count the number of emergency generating facilities of other units which are connected to the necessary emergency alternate-current high-voltage bus line.)
As a result, it is required to immediately take actions for emergency safety measures, ordered on March 30, including securing power supply cars, fire fighting engines, fire fighting hose and others and also is required to immediately implement amendment of safety regulations of “Rules on the Installation and Operation of Commercial Power Reactors”, which fulfils the above interpretation and also is one of the safety measures for emergency, by April 28 of this year.
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http://www3.nhk.or.jp/daily/english/10_21.html
“Tokyo Electric Power Company has bugun using unmanned heavy equipment to remove radioactive rubble [from the area around the outside of] the Number One and Number Three reactor buildings. The debris is emitting hundreds of millisieverts of radiation per hour in some places, hindering the restoration work….
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and from another blog:
http://atomicpowerreview.blogspot.com/2011/04/sunday-evening-update-fukushima-daiichi_10.html
“… the most recent TEPCO hourly photo shows a barge with a crane on it (see yellow arrow I’ve added) working on the north end of the intake channel screen / wall. This equipment is probably either dredging to prepare for installation of the new contamination spread prevention screens, or else installing the screens themselves….
…
There is some data, which we’re looking at in detail, showing a spike increase in airborne contamination inside the drywells on the plants concurrent with, or shortly after, the recent ~7 scale quake off Miyagi prefecture. These readings may simply have been due to the quake shaking loose contaminated material that was already inside the drywells and which had settled .. perhaps a dry crud burst of sorts. (That’s for all you nukes out there.) We’ll keep watching these figures; they’re reported as CAMS figures on NISA / JAIF report documents… which we hasten to add are again slipping behind time-date wise. Speaking of which… NISA, we might recall, thinks that air tightness may have been lost on all three reactor pressure vessels, so that it’s also possible that the increase in CAMS readings is directly from core material. But it’s too early to tell this yet, with the sparse data we have right now.
10:01 PM Eastern Sunday 4/10 “
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And “crud burst” is in fact a technical term of art:
http://www.google.com/search?q=nuclear+reactor+dry+crud+burst
found for example six times in this reactor licensing multiple-choice examination sample:
http://www.nrc.gov/reactors/operator-licensing/generic-fundamentals-examinations/pwr/pwr-files/191007.pdf
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Interesting view inside the Fukushima Daiichi nuclear reactor evacuation zone, including an up-close of the Daiini plant (in cold shutdown):
Okay, I’ve got to ask – how did that patch of veggies survive the tsunami??
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> veggies
Deep roots. Most coastal plants can take quite a lot of salt water (storm spray blown inland) for a brief exposure, at least from my East Coast US hurricane experience. Trees would be stripped to bare branches by a storm and leafing out in springtime green within a few days after major hurricane inundation
> movie
5 micro-sieverts/hour, for example, and their dash mounted counter alarms — can you see what the detectors are detecting? can you tell if the alarm is for airborne particles in the air inside the car, or gamma coming through the windshield?
http://geospatial.blogs.com/geospatial/2011/04/fukushima-daiichi-and-daini-casualties-among-tepco-workers-and-health-impacts-on-general-public.html
“Since the earthquake 370 workers have been working at Daiichi to stabilize the damaged reactor units. Of these 21 have experienced radiation doses of over 100 millisieverts (mSv). According to WNN nuclear workers are permitted to receive a maximum aggregate dose of 20 mSv per year. If that limit is exceeded in any year, the worker is relieved of nuclear duties for the remainder of the year. In an emergency safety regulators may raise the aggregate maximum exposure to 100 mSv. Above 100 mSv it is possible to begin to relate radiation exposure statistically to health effects, specifically cancer. March 16 Japanese authorities authorized exposures of up to 250 millisieverts because of the seriousness of the situation at Daiichi. WNN says that at this point no one has been exposed to an aggregate annual dosage of 250 mSv.”
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Hank, I would guess they are measuring only the gamma dose rate. The total gamma exposure of their trip was probably ~40 uSv, which is about the same as an airplane flight from NY to LA according to http://xkcd.com/radiation/
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http://www.reuters.com/article/2011/04/11/us-japan-idUSTRE72A0SS20110411
TOKYO | Sun Apr 10, 2011 11:32pm EDT
(Reuters) – Japan plans to extend the evacuation zone around its crippled nuclear plant because of high radiation levels, local media reported Monday….
Engineers at the damaged Fukushima Daiichi plant north of Tokyo said Sunday they were no closer to restoring the plant’s cooling system which is critical if overheated fuel rods are to be cooled and the six reactors brought under control.
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[Comment deleted. Violation of the citation policy]
MODERATOR
The citation policy is as follows:
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).
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It certainly appeared that those veggies didn’t get hit. There are plastic trash bins and compost bins as well as frailer weeds beneath the heavy & deep daikon radishes. Bizarre when looking at the damage on Google Earth around the distance the guys posted on the video.
Tepco says the tsunami reached as high as 15 meters at the Dai-Ichi.
http://www.bloomberg.com/news/2011-04-10/tepco-says-damaged-fukushima-nuclear-plant-was-hit-by-a-15-meter-tsunami.html
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The workers certainly seem to be greatly inhibited so as to not get their maximum doses.
http://www.yomiuri.co.jp/dy/national/T110407006089.htm
Current levels at the three reactors are between 20 and 31 sieverts, down from 138-167 sieverts per hour on March 14th. “Two workers were killed in a 1999 nuclear accident in Tokaimura, Ibaraki Prefecture, after being exposed radiation levels of between six and 18 sieverts.”
Tepco is saying that the levels are so high that they can not do any work there now.
“The radiation levels are way too high for workers to get close [to the reactors],” “It’ll certainly take a very long time to inspect the condition of the damaged reactors.”
America will help gain the first good examination of the spent fuel racks in #4 that are listed as possibly damaged on the JAIF status report.
http://search.japantimes.co.jp/cgi-bin/nn20110408a5.html
Since workers are unable to approach the spent fuel pool, the U.S. will send a small remote control “micro air vehicle.” to gather images.
This article mentions “U.S. officials especially concerned about the No. 4 reactor, the drone is expected to be first used to examine its radiation levels.”
This was an April 8th article. Any more information on these drone images?
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Speaking of the 15 meter tsuanmi that washed over the Fukusima Daichi plant, I have only recent come across this information for the tsuami inundation at the DAINI plant. Tsunami height there seems to be 7m after countermeasures.
Picture Only:
Unrelated article which used the above picture:
http://news.xinhuanet.com/english2010/world/2011-04/10/c_13821917.htm
Tepco has more information about that plant (Daini) and the inundation here:
Click to access 110409e10.pdf
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Hank Roberts, on 11 April 2011 at 11:48 AM said:
http://www3.nhk.or.jp/daily/english/10_21.html
“Tokyo Electric Power Company has bugun using unmanned heavy equipment to remove radioactive rubble [from the area around the outside of] the Number One and Number Three reactor buildings. The debris is emitting hundreds of millisieverts of radiation per hour in some places, hindering the restoration work….
—–
Does this mean the debris could include spent fuel rod assemblies?
What other debris could emit so much radiation?
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> drone images
I saw mention they’d put off the flights due to adverse weather, yesterday
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> drone images
According to this, they flew it:
http://www.rcgroups.com/forums/showthread.php?t=1421764
Release of imagery is promised for “Monday” (is it Tuesday in Japan already?)
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T-hawk drone images:
http://photos.oregonlive.com/photo-essay/2011/04/new_aerial_images_of_fukushima.html
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Hank, my computer clock tells me that Tokyo time is 1/2 hour ahead of Adelaide time (which is the zone for the times on our comments here). So yes, it’s about 3:30am Tuesday morning in Japan right now.
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Sorry, make that 1/2 behind.
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According to the NSC assessment – already two weeks old – No. 1 to 3 RPV are leaking at least through a pump seal into their primary containment. Notice that despite continues water filling they never manage to rise the water level. No 3 or 4 did likely throw fuel from their SFP into the environment up to a mile away.
The report can be downloaded from a German newspaper that got it hands on it.
http://www.tagesspiegel.de/downloads/4037602/1/NRC%20Assessment
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T-hawk drone images:
http://photos.oregonlive.com/photo-essay/2011/04/new_aerial_images_of_fukushima.html
——-
Seriously!?
Those are the best quality images we can get?
My iPhone takes better pictures!
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Seems Fukushima soon is upgraded to a 7 on the INES-scale.
“The Nuclear Safety Commission of Japan released a preliminary calculation Monday saying that the crippled Fukushima Daiichi nuclear plant had been releasing up to 10,000 terabecquerels of radioactive materials per hour at some point after a massive quake and tsunami hit northeastern Japan on March 11.
The disclosure prompted the government to consider raising the accident’s severity level to 7, the worst on an international scale, from the current 5, government sources said. The level 7 on the International Nuclear Event Scale has only been applied to the 1986 Chernobyl catastrophe.”
http://english.kyodonews.jp/news/2011/04/84721.html
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> T-hawk drone images (from OregonLive site)
Disappointing blurry distance shots. I hope those are screen-grabs from some low-res television. They’re nothing like the quality the company shows from their hardware. This thing is supposed to be able to hover close up and get imagery down closer than anything else.
I’d expect better closeups from a camera on the end of the concrete pump boom — even using an old mechanical-advance film camera or windup movie camera ‘blind’ with a floodlight attached.
(How are they aiming the stream out of the concrete pump?).
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The New York Times is the original source that obtained the document mentioned in the previous comment. http://www.nytimes.com/2011/04/06/world/asia/06nuclear.html
From the document: Fuel particulates may have been ejected from the [Unit 4] pool (based on information of neutron emitters found up to 1 mile from the units, and very high dose rate material that had to be bulldozed over between Units 3 und 4. It is aIso possible the material could have come from Unit 3).
b, “may have” does not mean “did likely” as you say. “Particulates” are not pieces of fuel, as you seem to be implying.
There is an implication that seals on Units 2 and 3 may be leaking. Once again, “may be” is not the same as “is”.
What is needed is factual information, not spin.
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Re the neutron-emitting sources found in the fields around the plant (that they buried with bulldozers) — those should be dug back up eventually to find out what’s emitting and where it came from. We-the-public don’t know if the source was seen and identified, or if the area was identified as hot and quickly buried for short term safety.
Could be particulates, could be chunks — either of those from the fuel pool explosions — or could even be some previously unidentified dump or spill. They’ll want to know, whether we get told or not.
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Any more info on that article cited by commonGOOD ?
http://www.yomiuri.co.jp/dy/national/T110407006089.htm
Can someone explain where they’re measuring rates of 20 to 162 Sieverts per hour? Are there working radiation monitors inside the reactor vessels? If so, what is a normal reading for an active reactor?
Someone please tell me those rates aren’t outside the reactor itself.
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Kyodo News is reporting that the NSC may increase the INES rating to level 7. Am I right in thinking that this is purely to do with the amount of radiation leaked rather than the potential affect to peoples health? Surely the Japanese have the evacuation situation under control and as such will minimize the dangers to the local population.
“The Nuclear Safety Commission of Japan released a preliminary calculation Monday saying that the crippled Fukushima Daiichi nuclear plant had been releasing up to 10,000 terabecquerels of radioactive materials per hour at some point after a massive quake and tsunami hit northeastern Japan on March 11.
The disclosure prompted the government to consider raising the accident’s severity level to 7. The level 7 on the International Nuclear Event Scale has only been applied to the 1986 Chernobyl catastrophe.”
http://english.kyodonews.jp/news/2011/04/84721.html
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[Comment deleted. Violation of the citation policy.}
MODERATOR
Several commenters are “sailing close to the wind” on the citation policy. This one was the worst with just a “cut and paste” quote plus the link.Borderline overnight violations will not be deleted but further violations today will be.
A reminder to all of the policy:
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 interesting 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).
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I read that to say “between units 3 and 4” and NOT “in the fields around the plant”…..
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[Comment deleted. Violation of the citation policy]
MODERATOR
This was another case of a throw away comment and a link. Please, read the citation policy, down-thread and abide by the rules.]
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[Comment deleted. Deliberate distortion of the truth.]
MODERATOR
Please present the facts as written and do not alter the wording on the the information you read before posting here.
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re: “… as bad as Chernobyl …”
Please actually read the NHK report linked earlier, which includes: “The agency [NISA] believes the cumulative amount from the Fukushima plant is less than that from Chernobyl.”
MODERATOR
The comment you refer to was deleted as a deliberate distortion of the facts – as you picked up on.
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[Comment deleted. Wrong thread. Please re-submit to the Fukushima Philosophical Open Thread]
MODERATOR
Your personal opinions without supporting scientific references belongs on the Open Thread where commenting rules are more relaxed. We do not have the facility to move comments between threads.
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@steve lapp, Not to worry CANDUs can’t fail like the Fukushima Daiichi plant, the design is very different and the areas that nuclear power stations are situated in Ontario are not vulnerable to major earthquakes – and tsunami don’t occur in Lake Ontario.
MODERATOR
The comment you refer to was directed to be moved to the Fukushima Philosophical OT.
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> between units … in the fields … around
All paraphrases of the original NYT article, I think, which quotes and paraphrases the leaked document it cites as its source:
“The document also suggests that fragments or particles of nuclear fuel from spent fuel pools above the reactors were blown “up to one mile from the units,” and that pieces of highly radioactive material fell between two units and had to be “bulldozed over,” presumably to protect workers at the site.”
—————–
“Suggests” probably means there’s no other credible explanation for finding that material where it was found when it was found, but hey, we don’t know.
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Right Hank, we don’t know. The poster known as “b”, however, turned all of the maybes and possibles into definites and probables. (The document itself says “particulates”, never implies “chunks”, and doesn’t say for sure where they came from.)
Regarding the rating: this incident can be classified as a “Major accident” and still not be as bad as Chernobyl. It’s not over yet either; it could get worse.
Reactors at old plants like Fukushima should be replaced with newer designs that aren’t vulnerable to loss of external power events. We’re not just going to stop using nuclear energy– a major source of carbon-free electricity.
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Barry Brook, March 13: “The plant is safe now and will stay safe.”
Reality, April 12: Fukushima crisis level raised to a 7, the worst on the international scale.
That deafening noise inside your head is cognitive dissonance.
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Actually ‘BlueRock’ (charmingly polite, as always), it was Joesef Oehman who wrote that, not me, but it was indeed published on this website on 13 March. I agree that the rating should be INES level 7, given the events of the last month (except for the deaths/exposure criteria, see below).
But could you answer me three fairly simple questions:
1. How many people have been killed by radiation as a result of this ‘disaster’? Chernobyl killed 43 workers from severe radiation sickness and another ~15 from cancer that almost certainly resulted from their over-exposure (see this excellent recent piece by Ben Heard: Giving Green the red light). How many in Fukishima?
2. How many members of the public in Japan have been overexposed to radiation as a result of Fukushima? (a bonus sub-question: what is the maximum dose a member of the public is likely to have received?)
3. What is your definition of ‘cognitive dissonance’? (and a bonus sub-question, how does the above fit that definition?)
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Seamus, yes, agreed–it’s very easy to slip from paraphrase into distortion; direct quote with cite is the best we can do, lacking any real information other than what’s made public.
Here are a couple of sites worth looking at, some material I haven’t seen before:
http://www.houseoffoust.com/fukushima/R3.html
(and other links there); overlaying the published imagery with graphics and labels from the known layout of the undamaged building, to identify stuff in the mess
hat tip to: http://fukushimafaq.wikispaces.com/Building+Maps+and+Complex+Maps
(fukushimafaq is a dense site with a lot of material; I’m suggesting it as a place to check out, there’s far more there than I’ve looked at so I’ve only recommended the one link there that I checked into)
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Aha, here’s the April 11 drone flyover, high resolution:
http://fukushimafaq.wikispaces.com/Miscellaneous
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Lots of PR stuff also linked to from that site, mostly ‘anti” — but also more information links worth looking. I don’t yet know if this fukushimafaq has any climate-change opinion either way.
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That flyover focuses mostly on Unit 3; seems to be clearly two separate sources for the plumes of steam.
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From TEPCO:
Here are updates on Work Progress at Fukushima Daiichi NPS as of 9:00 pm, April 11.
— There was a aftershock at Hamadori area (close to Fukushima Daiichi and Daini NPS) at 5:16 pm on April 11. Richter scale magnitude was 7.1. All workers in the field evacuated to TSC building in the Fukushima Daiichi site.
Due to the earthquake, off-site power for units 1, 2 and 3 tripped and water injection to the reactor vessel was stopped temporarily. Then the power supply to the pumps resumed at 6:00 pm.
Though no significant damages were made by the earthquake, radioactive water transfer and nitrogen gas injection were suspended.
Contacts:
TEPCO Washington Office 202-457-0790
Kenji Matsuo, Director and General Manager
Yuichi Nagano, Deputy General Manager,
Masayuki Yamamoto, Manager, Nuclear Power Programs
・ Total amount of injected nitrogen was about 3,000 m3 at 5:00 pm, April 11. Drywell Pressure is 199.0 kPa(abs) at 8:00 pm
・ There was an earthquake at 5:16. Epicenter was Hamadori Region (near Fukushima Daiichi and Daini NPS area) and Richter scale magnitude was 7.1. Due to this earthquake, hydrogen injection pumps stopped. We are checking the status of equipment.
・ When we started nitrogen injection on April 7, we announced that we would continue injection until about 250 kPa (100 kPa above the original pressure), and it would take 6 days. However, drywell pressure has been stable at about 190-195 kPa. We assume there might be some leakage path from the PCV, and because of the leak, drywell pressure does not increase as planned. Considering hydrogen and oxygen generation by water radiolysis, we determined to continue nitrogen gas injection to PCV.
【Unit 1】 Injecting fresh water
Reactor pressure vessel temperature: 4/11 12:00 pm 220.8C 119.9C
【Unit 2】Injecting fresh water
Reactor pressure vessel temperature：
4/11 12:00 pm 154.8C
【Unit 3】Injecting fresh water
Reactor pressure vessel temperature：
4/11 12:00 pm 111.0C
【Unit 4】 No particular changes on parameters.
【Units 5/6】 Reactor cold shutdown. No particular changes on parameters.
【Common spent fuel pool】 No particular changes on parameters.
・April 11: No spraying conducted.
・April 12(schedule) : Unit 3 16:00～
Unit 4 11:00～ Sampling spent fuel pool water sampling for analysis
・ Unit 1: Completed transfer from condenser to CST at 9:30 am on April 10.
・ Unit 2: Completed transfer from condenser to CST at 1:30 pm on April 9.
Planning to check for leakage in transfer piping between unit 2 trench to condenser (hotwell).
・ Unit 3: Planning to transfer from condenser to CST.
・ Preparation work to receive radioactive water in the Central Waste Treatment Facility.
> Construction of temporary piping, setting up power supply and installing shields in progress.
・ Completed installment of spillage prevention fences in the south side breakwater. (see picture bellow)
・ On April 12, steal plate is scheduled to be installed in front of the screen room at unit 2, spillage prevention fences (Silt Fence) for units 3 and 4 will be installed.
【Central Waste Treatment Facility 】
– We had discharged approximately 9,070 tons of water (tentative estimation) from the discharge canal of Units 1 to 4 from April 4 to April 10.
– On April 11, we are evaluating the situation after discharge.
【Sub drain of Unit 5 and 6】
– From April 4th, we started the discharge from the water discharge canal of Units 5 & 6 and at 6:52 pm, April 9, we completed it.
・ April 11: About 1,200ｍ２ was sprayed on the mountain side of the common spent fuel pool at 12:00 pm – 1:00 pm.
・ April 12(schedule): About 500ｍ２ will be sprayed on the same location.
> Tentative results of test spraying on April 1 and 5 were as below.
• April 1: Before spray 1 mSv/h –> After 0.8 mSv/h (as of April 3)
• April 5: Before spray 1.6 mSv/h –> After 1.5 mSv/h (as of April 6th)
・ Shooting from the air using the unmanned small chopper: 15:59—16:28, April 10
> Planned flight on April 11 was cancelled due to extra preparation time for setting the devise.
・ Rubble removal using remote control robots: 9:00—16:00, April 11.
> From April 10, two containers (3.2m x 1.6m x 1.1 m) of rubbles were removed.
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The Federation of Electric Power Companies of Japan (FEPC) Washington DC Office
As of 11:00AM (EST), April 11, 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:
o At 9:00AM (JST) on April 11, radiation level at main gate (approximately 3,281 feet from Unit 2 reactor building) of Fukushima Daiichi Nuclear Power Station: 83 micro Sv/hour.
o At 9:00AM on April 11, radiation level at west gate (approximately 3,609 feet from Unit 2 reactor building) of Fukushima Daiichi Nuclear Power Station: 45.2 micro Sv/hour.
o Measurement results of environmental radioactivity level around Fukushima Nuclear Power Station announced at 4:00PM on April 11 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 As of 4:00PM on April 11, injection of nitrogen gas into the primary containment vessel to prevent an explosion by accumulated hydrogen gas continues.
o As of 4:00PM on April 11, the injection of freshwater into the reactor core continues.
• Fukushima Daiichi Unit 2 reactor
o At 10:37AM on April 10, TEPCO began to inject freshwater into the spent fuel pool, until 12:38PM (approximately 60 tons in total).
o As of 4:00PM on April 11, the injection of freshwater into the reactor core continues.
• Fukushima Daiichi Unit 3 reactor
o At 5:15PM on April 10, TEPCO began to shoot freshwater aimed at the spent fuel pool, with a specialized vehicle normally used for pumping concrete, until 7:15PM (approximately 80 tons in total).
o As of 4:00PM on April 11, the injection of freshwater into the reactor core continues.
• Fukushima Daiichi Unit 4 reactor
o At 5:07PM on April 9, TEPCO began to shoot freshwater aimed at the spent fuel pool, with a specialized vehicle normally used for pumping concrete, until 7:24PM (approximately 90 tons in total).
• Fukushima Daiichi Common Spent Fuel Pool
o At 6:30AM on April 11, the temperature of the spent fuel pool: 89.6 degrees Fahrenheit.
• Others
o At 12:14PM on April 8, discharge of approximately 950 tons of low level radioactive water which had accumulated at the sub-drain pits of Unit 5 has completed.
o At 6:52PM on April 9, discharge of approximately 373 tons of low level radioactive water which had accumulated at the sub-drain pits of Unit 6 has completed.
o At 9:00AM on April 10, the removal works of debris at the site began, with a remote controlled excavation machine, until 5:00PM.
o At 8:45AM on April 11, TEPCO began to install a double layered silt fence of approximately 120m (=394 feet) near the south sea wall of Fukushima Daiichi Nuclear Power Station in order to contain the spread of discharged radioactive water, until 10:45AM.
• Fukushima Daiichi Nuclear Power Station
o At 5:40PM on April 11, Unit 1 and 2 lost the external power supply and pumping of freshwater into the reactor core was suspended.
o At 5:56PM on April 11, the external power supply was recovered at Unit 1 and 2.
o At 5:59PM on April 11, pumping of freshwater into the reactor core was suspended for Unit 3.
o At 6:04PM on April 11, pumping of freshwater into the reactor core for Unit 1, 2 and 3 was resumed.
o As of 6:00PM on April 11, no significant changes have been detected at monitoring posts at the site.
o As of 6:05PM on April 11, no abnormality has been reported in the temperature, pressure, or water levels in the reactor cores.
• Fukushima Daini Nuclear Power Station (Unit 1, 2, 3 & 4)
o Plant operation was suspended at all units when the aftershock occurred.
o As of 5:51PM on April 11, no significant changes have been detected at monitoring posts at the site and external power supply was maintained.
• Onagawa Nuclear Power Station (Unit 1,2 & 3)
o Plant operation was suspended at all units when the aftershock occurred.
o As of 5:45PM on April 11, no significant changes have been detected at monitoring posts at the site and external power supply and cooling systems were maintained.
• Higashidori Nuclear Power Station
o Plant was under periodical maintenance when the aftershock occurred.
o As of 6:54PM on April 11, external power supply and cooling systems were maintained.
• Tokai Daini Nuclear Power Station
o Plant operation was suspended when the aftershock occurred.
o As of 5:30PM on April 11, external power supply and cooling systems were maintained.
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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I want to know the consensus here, is this event going to be considered worse than Chernobyl if there are more than 10^18 becquerels released into the environment?
PS I don’t think it is philosophical, and more related to the level 7 move criticism.
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