UPDATE: Matsumoto was speaking about the Reactor 4 Spent Fuel Pool, and mentioned the temperature. I took to mean the temperature of the SFP, but it is more likely that Matsumoto suddenly switched back to talking about the temperature of the Reactor 1 dry well. Sorry for the confusion. A lot of viewers apparently thought Matsumoto was talking about the Reactor SFP like I did.
So, it was the Reactor 1 dry well temperature that started to rise noticeably starting 4AM on April 13, 2012.
No word yet on exactly what the temperature is in the Reactor 4 SFP.
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According to Matsumoto, the temperature of the Reactor 4 Spent Fuel Pool started to rise noticeably starting 4AM April 13, 2012.
From 8PM on April 12, 2012 to 3AM on April 13, 2012, the temperature remained 49.9 degrees Celsius, he said.
Matsumoto didn't say what the temperature was at the time of the press conference (11AM on April 13), and none of the reporters asked him about it, with the reporter from Asahi again pressing on the nitrogen injection system.
On checking the TEPCO's handout for the press on April 12, 2012,
Reactor 4 SFP temperature as of 11AM, 4/12/2012: 28 degrees Celsius
Reactor 4 SFP heat exchanger stopped at: 2:44PM, 4/12/2012
Expected rise in temperature: 0.5 degrees Celsius/hour
Oh wait... 21.9 degrees Celsius rise in temperature in 12 hours (from 3PM on April 12 at 28 degrees Celsius to 3AM on April 13 at 49.9 degrees Celsius) is more like 1.825 degrees Celsius per hour. But it is possible that the temperature doesn't rise in a linear fashion.
For some reason, TEPCO's Japanese page that has the handouts does not have the April 12, 2012 handout.
Unless TEPCO's photos and videos were fake the other day, the fuel rods inside the Reactor 4 Spent Fuel Pool are completely submerged under water (6.8 meters deep to the top of the fuel rods according to the diagram).
Sorry, I am a little bit confused. If I understand the text correctly, than SFP4 had the following scenario :
ReplyDeleteApril 12th, 11:00 - 28 deg
April 12th, 15:00 - stop of cooling
April 12th, 20:00 - 50 deg
April 13th, 3:00 - 50 deg
April 13th, ~4:00 - rising again
This would mean the temp in SFP4 raised 22 deg in 5h (~4.4 deg/h).
This is based on the sentence in your post:'From 8PM on April 12, 2012 to 3AM on April 13, 2012, the temperature remained 49.9 degrees Celsius, he said.' Did TEPCO really say it remained 50deg or it reached 50 deg?
Thanks for the clarification and the hard work!
In the Dry-Well no one can hear you scream.
ReplyDeleteIs it possible to drop molten lead over these areas?
ReplyDeletesaw they have robots etc, but the robots get electrical disturbances from all the radiation, can we build a robot out of 3 inch lead or something?
Why aren't there any solutions? At the very least we should be dropping hundreds of thousands of gallons of water on these areas daily. A boat can't pump seawater onto shore? I thought the Japanese were creative and inventive. There has to be something we can do. I mean lets build a trench from Mt Fuji to Fukashima and let molten cover it up. Anything.
Who cares.... this is not news, it would be on real News channels... nobody cares
ReplyDeleteI do. That's why I'm still writing.
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ReplyDelete@Laprimavera/Ex-Skf,
You wrote: "Unless TEPCO's photos and videos were fake the other day, the fuel rods inside the Reactor 4 Spent Fuel Pool are completely submerged under water (6.8 meters deep to the top of the fuel rods according to the diagram)".
Note: a TEPCO DIAGRAM alleges that the water is 6.8 meters deep. Yes, recent video and photos may show that the fuel rods are submerged. However, neither the videos, nor the photos, provide proof that the actual depth of the water is 6.8 meters.
So, are you taking TEPCO's word for it? I wouldn't.
We all recall that, when TEPCO was hastening to declare a state of "cold shutdown" in December, 2011, they claimed that the cooling water level in Reactor No. 2 was 10 METERS DEEP (33 feet) from the bottom. Then in late March, 2012, TEPCO revealed that the water depth was astoundingly low: LESS THAN 1 METER (2 feet deep) from the bottom. Obviously, this raised fears that the fuel rods may not even be completely submerged and are in danger of heating up again.
Moreover, as reported by The New York Times: "The low water level also raises concerns that radioactive water may be leaking out of the reactor at a higher rate than previously thought, possibly into a part of the reactor known as the suppression chamber, and into a network of pipes and chambers under the plant -- or into the ocean. At the No. 2 reactor, workers still pump about 9 tons of water an hour into the core to keep it cool...Radiation levels measured 72.0 Sieverts inside the containment vessel, enough to kill a person in a matter of minutes, as well as for electronic equipment to malfunction". [LINK : http://www.startribune.com/world/145007755.html]
QUESTION: Under normal operating conditions, how deep is the water in the spent fuel pool at Reactor No. 4? That would also help people put the various reported levels in context. Thanks.
JP
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When it comes to actual plant parameters and survey data, TEPCO is the only game in town. It is not the matter of "taking their word for it". No matter how incomplete, that's the data available as of now. It may, probably will change. When it does we form a new hypothesis.
ReplyDeleteCold shutdown was declared by the Noda administration. In Reactor 2, what's supposedly under the 2 feet of water in the Containment Vessel is the corium.
How deep is the water level in SFP normally? Probably the same as what it is now, looking at the pool's spec.
People should not confuse TEPCO estimates, model results & assumptions with TEPCO actual measured data. Yes as we saw with reactor 2 drywell water level, their estimates and assumptions can turn out to be very wrong. But when it comes to stuff that can actually be really measured, observed etc, there is no reason to go overboard with doubting TEPCO data.
ReplyDeleteDon't get me wrong, it is always possible they will deliberately cover something up or be too optimistic in future. But that doesn't mean we should throw away or disbelieve all data that shows things to be ok.
Its quite easy to tell that there is enough water in reactor 4 to provide sufficient shielding from radiation, since we have seen people working on those floors of the building, lots of debris and broken walls and roof removed, etc. We have seen plenty of video and other studies of the pool, and we don't have any good reason to doubt that the water level is lower in the pool than TEPCO would admit. Be suspicious if you want to, but suspicions are better directed towards areas where there are alarming signs, lack of progress, estimates that were not matched by real data, etc.
I do not worry very much about fuel pool cooling unless it breaks for days in a row, since it takes time for the pools to heat up.
ReplyDeleteThe reactor 1 temperature increases are of more interest to me, but its usually pretty hard to work out exactly what is happening. In the past explanations have not been so great, partly because it is very hard for them to tell and also because they seem to prefer the most non-scary explanations. In the past reactor or containment temperature increases have not lead to anything dramatic and scary happening, but that doesn't meant we should be complacent, its always possible that something new is happening inside there. And its a joke that they ever described the situation at the reactors as being 'cold shutdown', I can't call it that. We can say that the reactors have been relatively stable compared to the state they were in during the first month or so of the disaster, and cooling is better than it was as we don't see lots of steam escaping. But that doesn't mean everything is completely stable, and term 'cold shutdown' sounds more safe and controlled than the actual situation deserves to be described as.
@elbows, why do you think stopping the nitrogen injection would cause the rise in temperature in Reactor 1 D/W? TEPCO's Matsumoto said the same thing had happened before when the nitrogen injection system stopped for one reason or another. As usual, TEPCO didn't seem eager to find out why.
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ReplyDelete@Elbows,
Your tone is very reasonable, but your comment doesn't add up.
You said: "People should not confuse TEPCO estimates, model results & assumptions with TEPCO actual measured data. Yes as we saw with reactor 2 drywell water level, their estimates and assumptions can turn out to be very wrong. But when it comes to stuff that can actually be really measured, observed etc, there is no reason to go overboard with doubting TEPCO data".
Note that TEPCO was also very wrong on the matter of insisting, for two months, that there had been no meltdowns. I wonder, whether you think independent analysts were going "overboard" when they disputed those false assurances. One also wonders whether TEPCO would have been compelled to fess-up had there not been many highly visible and outspoken critics who continually challenged the official story.
Contrary to your stated belief, TEPCO isn't just wrong about matters that involve speculation. The public record, of the past three decades, contains abundant evidence chronicling TEPCO's long and sordid history of corporate malfeasance -- it is a history that has frequently involved deliberate falsification of "actual measured data".
Why should TEPCO, an inveterate liar, be given any benefit of the doubt on any matter that can't be independently verified?
JP
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@JP, TEPCO didn't insist there was no meltdowns for two months. As early as March 28 they were admitting in the press conference that there was a hole at the bottom of the pressure vessel.
ReplyDeleteIndependent experts that you apparently hold in high esteem have been dead wrong on many speculations and assumptions on their part. But that clearly doesn't bother you a bit.
If there is only one temperature measurement point, depending on the measurement point, the high temperature could have been caused by convection because of the (illegal) non-distributed storage of hot fuel assemblies, as the DoE report indicates?
ReplyDeleteAnd, could the temperature increase in the d/w be because of just some localized boiling due to reduced water flow into some part of the debris piles?
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ReplyDelete@Anon at 2:41 pm...You said: "TEPCO didn't insist there was no meltdowns for two months. As early as March 28 [2011] they were admitting in the press conference that there was a hole at the bottom of the pressure vessel". Do you have a citation from the press conference you're referencing?
If you check again, I believe you'll find the announcement about "the hole" didn't happen until a press conference on May 12, 2011. It was reported thusly by numerous news agencies, including Reuters: "One of the reactors at Japan's crippled Fukushima nuclear power plant has a hole in its main vessel following a meltdown of fuel rods, leading to a leakage of radioactive water...Junichi Matsumoto, a general manager at the utility said: "There must be a large leak...The fuel pellets likely melted and fell, and in the process may have damaged the pressure vessel itself and created a hole." [http://www.reuters.com/article/2011/05/12/us-japan-nuclear-reactor-idUSTRE74B1H520110512]
Here's another related citation from The Japan Times, reporting that officials had knowledge of a meltdown on DAY 1 -- and TEPCO withheld the information from the public for a full two months thereafter: "A recently compiled summary of the meetings of the government's nuclear emergency headquarters showed the government was aware on March 11, 2011, of the possibility of a meltdown. And yet it took until May for Tepco to announce an estimate that meltdowns occurred in three reactors". [http://www.japantimes.co.jp/text/nn20120316a3.html]
@Elbows at 12:12 pm...I completely agree with your statement that it is "a joke" to refer to the condition of the reactors as "cold shutdown"; given that "cold shutdown" presupposes a reactor that is NOT melted down. I appreciate that you are taking a stand in this regard.
JP
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JP, instead of anon you are asking, I'll answer your question. TEPCO did say that because I wrote a post on what's reported on Asahi on March 28, 2011. I also watched the press conference later, recorded live that day. TEPCO's official was saying "imagine a hole...":
ReplyDeletehttp://ex-skf.blogspot.com/2011/03/fukushima-i-nuke-plant-reactor-pressure.html
Those days, TEPCO's press conference was not done by Matsumoto. He didn't come until sometime in April, after Vice President Muto stopped giving a press conference. He was an extremely knowledgeable guy, but the reporters were not up to speed in those early days and couldn't get enough information out of him.
I guess Reuters and Japan Times didn't read Asahi. Late by a month and a half.
@JP, I stick to the point I made earlier, and I will try to briefly explain why.
ReplyDeleteAlmost everything we know about the probability of meltdown, amount of melted fuel, possible location of fuel, is based on model analysis. The analysis uses some real measured data, but there are all sorts of reasons why model results may not match reality. And we have seen that TEPCO clearly prefer their analysis to show things that are not too alarming, especially in the early days. So even when I find their analysis interesting, I do not assume it matches reality, or that anyone else's analysis does either.
But when it comes to a range of measured data, I don't have quite the same opinion. Yes TEPCOS earlier record is not great, and I am not suggesting that it is impossible for them to lie or cover stuff up. But since we have seen plenty of occasions where they have bothered to share numbers with us, even when the numbers are not good news, I really don't think we should stretch this point too far. Just one recent example is that they did tell us that the water in reactor 2 was much lower than they had assumed, they didn't try to hide this discovery.
Im sure that they will continue to be as optimistic as they can get away with, but they know there are limits, and there is no reason for me to be overly suspicious of the day-to-day data that comes out of the plant, especially as we do get to hear about mistakes that they make, leaks that happen, systems that stop working, etc.
I am also perhaps oversensitive to these issues because of what people who have an interest in overhyping the Fukushima disaster have said in the past. They try to use the understandable lack of credibility that TEPCO has, to prove that their own wacky worst-case scary scenarios may really have happened, despite all the reasonable evidence to the contrary. Everything from reactor 4 building leaning to one side, to fuel pools being destroyed or reactors exploding into the air or fuel rods being scattered everywhere. We don't hear as much about such extreme things now, because I think most people can see that actually a good chunk of the information we are given about the situation stands the test of time, is a fair match with reality.
And just to be clear, Im not talking about estimates of the state of the reactors, melted fuel location and state, estimates of damage to containment etc, which remain things that nobody, including TEPCO, has a precise idea about right now. We may find out in years to come, or some things may remain unknown. Thats not TEPCOs fault, although it is always possible they will cover something up at some point, I do not gain any insight into the situation by assuming that such a coverup will definitely happen.
@arevamirpal::laprimavera regarding why the stopping of nitrogen injection into reactor 1 causes measured temperatures from certain sensors to increase, I don't know why. I have asked people elsewhere on the web if they know of theoretical explanations for this phenomenon, as I am hoping to learn more about this.
ReplyDeleteIts certainly true that it has happened before at reactor 1, because this was mentioned in a graph in a recent report, but without an explanation as to why, just something about 'further investigation of possible reasons why'.
I am tempted to guess that it could be something to do with air flow in containment vessel and/or reactor vessel, and that when the nitrogen is being pumped in it makes some warmer air/gasses either leave the containment vessel more quickly, or change route so that these warmer gasses don't go near to the temperature sensors in question. But this is just a non-expert guess, I expect there are other possibilities.
I am certainly interested as to why this phenomenon happens with reactor 1 but not 2 or 3. It could be a clue as to the detail of the different damage & melted fuel location at the different reactors, but I don't know enough to guess more detail about this, and I suppose it could also have something to do with the smaller size of reactor 1.
Very helpful person on another site pointed me to these articles which seem to suggest that temperature rise at reactor 1 when nitrogen stops is because the temperature sensors that rise are close to the area where the nitrogen is injected. I guess this makes sense, and means that I cannot infer too much else of interest from these temperature rises.
ReplyDeletehttp://sankei.jp.msn.com/affairs/news/120413/dst12041311480002-n1.htm
http://www.shimbun.denki.or.jp/news/main/20120413_04.html
Note that I cannot read Japanese myself and relied on what the person told me about them, and also computer translation.
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ReplyDelete@Laprimavera at 5:44 PM...
OK, I see where you're coming from. And BTW, huge props to you for your original March 28, 2011 post with your translation of Ashai Shinbun's story on the press conference that day -- wherein a TEPCO spokesman first raised the prospect of there being a "hole" in the reactor pressure vessels. I do recall seeing some buzz about it at the time on a few blogs like Daily Kos and Zero Hedge and, when I recheck now, I see that they got the story via your post at Ex-Skf. [http://ex-skf.blogspot.ca/2011/03/fukushima-i-nuke-plant-reactor-pressure.html]
TEPCO obviously didn't want this story to break big. Note that in their March 28, 2011 official Press Release on the status of the facilities at Fukushima, TEPCO entirely failed to disclose any information whatsoever about the "hole"; there is no mention whatsoever of any "leak" coming out of any "hole"; nor any mention of the word "melt", let alone "meltdown".[http://www.tepco.co.jp/en/press/corp-com/release/11032801-e.html]
In my prior comment I made the the point that TEPCO didn't officially inform the world of the triple meltdowns until May 12, 2011, whereupon the news broke worldwide. And, indeed their prior admission of a "hole" does not equate to admission of a "meltdown". To wit, TEPCO didn't use the word "meltdown" on March 28/11; and I seriously doubt it intended the world to conclude that there had been a meltdown when they admitted to a "hole" on that date. TEPCO was, evidently, being purposefully cagey in the way they parsed the announcement of the "hole" -- at least that is how it appears in the translation of the Ashai story.
By your translation, the Ashai article directly quotes the TEPCO spokesman as saying only this: "Imagine there's a hole... probably a hole near the bottom, that's the image we have". The article then states that said hole is leaking "contaminated water" (although there is no word of radioactivity).
When asked why there was a hole, TEPCO reportedly answered they did not know. However the article then presents a paraphrased summary which offers two possible explanations for the hole. Scenario #1): "The RPVs at Fukushima I Nuclear Power Plant is made of 16-centimeter thick steel, and it has an outlet at the bottom to insert measuring instruments. It is possible that the leak is from that area". Then, in the next breath, we are given the option of Scenario #2): "TEPCO admitted to the possibility of the exposed nuclear fuel rods overheating and damaging the RPVs. According to the nuclear experts, if the fuel rods get damaged and start to melt, it will fall to the bottom of the RPVs and settle. It then becomes harder to cool with water effectively, because the surface area is smaller. It is possible that the melted fuel rods melted the wall of the RPVs with high temperature and created a hole".
So, in the end, we are left with a "hole" that was either already there as an "outlet", or a "hole" that was "possibly" caused by melted fuel rods. TEPCO thus handily evaded the full-blown spectre of a "meltdown". Based on the foregoing, I gather Asahi didn't use the word "meltdown" in the headline; nor does the word appear in the translated text of the article; nor does it appear in the Ex-Skf headline or article. That being said, the Asahi article and the Ex-Skf post were invaluable informative texts that also provided further evidence of proof for other commentators who had previously suspected a meltdown.
JP
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JP, meltdown is not the official definition anyway. It's "core melt" that is official.
ReplyDeleteIf you want the earliest reference of core melt or meltdown from an official source, it was the NISA's press conference at noon on March 12, 2011. The NISA spokesman said quite candidly that a meltdown was possibly taking place. And that was before Reactor 1 blew up.
Information was out there. People weren't looking.
Yes, "core melt" may be the "official definition" for what is known in plain-speak as a "meltdown". The question, with regard to TEPCO's tendency to prevaricate, is: when did TEPCO know the cores had melted down; when did they officially, and definitively, announce that information; why did they delay; and who helped them in the process; and why?
ReplyDeleteI hope you don't mean to suggest that TEPCO was actually doing full diclosure in a timely fashion, but the media just failed to report?
If that's what you're saying, I'd suggest that what we're seeing instead is a dandy collusion that ultimately served the corporate interests of all concerned. TEPCO is off the hook because they 'disclosed' information, albeit in a limited, obfuscatory fashion; and the international mainstream press explains away their lack of coverage on the pretext that Japan is a 'foreign' country and the details 'went over their heads'.
Trust me buddy, some of us saw it all, back in 2010, during the BP oil spill in the Gulf of Mexico when big business, the media, and a government colluded to promote global corporate interests over the public interest. Acquaint yourself with that immediate precedent. Japan: same $hit, different day, different country - much higher $takes.
@elbows: "...the temperature sensors that rise are close to the area where the nitrogen is injected."
ReplyDeleteIf so, they measure NOT the water temperature, but the "air" right next to the cooling source? I hope I misunderstand something here.
@ everyone in general:
This valuable discussion about what knowledge existed and was disclosed when and with exactly which words makes one thing very clear: you often learn more from what is NOT being said or not being said clearly than you do from what IS being said. It all comes down to saying as little as possible in as "harmless" a way possible to uphold the appearance of truthfulness while, in fact, skewing the truth and therefore misleading the public.
It creates distrust (if it didn't already exist based on TEPCO's record in that regard) and, imho, makes even measured and released data questionable in so far that they are too often incomplete, for example, the released radioactive substances measured/not measured.
In any event, thanks to you all - and especially laprimavera - for diligently following up on all of it and interpreting, analyzing, and discussing here.
*mscharisma*
read the words of yohann friede, an austrian monk of 750 years ago; "mankind will dig into the bowels of the earth, gambling with their own existence."
ReplyDelete@Anonymous.
ReplyDeleteI do not know what you mean by water. Although we do not know how much water there is in the drywell of reactor 1 or 3, findings from reactor 2 do not suggest that we should be optimistic about water levels in the other reactors. It has never been safe to assume that the various temperature readings from inside containment & reactors are water temperatures, and I don't think anybody has claimed that this is whats being measured.