Japan Earthquake: Political Aspects

[htf]

Um, nope...?

He proved that even with very little fuel damage (~ 5%) and NO recriticality the iodine levels in the pool (~150 Bq/cm³ if I remember correct) could be explained.

You are etirely missing the point. The Cs vs. I ration has not been explained. No doubt about the absolute levels. But the ratio has to be explained. And I am not only talking about the SPF#4. The Cs/I ratio is not what you would expect in many cases. There have been speculations from the beginning of the crisis.

I am not saying that it is impossible to explain but I'd like to hear a plausible explanation. As long as there is none I consider Gunderson's re-criticality theory as very plausible.

 

[Luca Bevil]

And in any case, I would not say that Arnie Gundersen has lost credibility for offering a possible explanation.

 

[htf]

Gunderson has a bad reputation in this form because in his videos he was sometimes speculating too much. Of course, he wanted people to watch his videos. But in the Chris Martenson interview he makes some very important statement that I do not consider as speculations:

1. The worst case has happened in Fukushima. The RPVs have holes and the containments are leaking.

2. Massive inland contamination has only been prevented by fortunate winds.

3. The situation is still not under control and the reactors are still emitting massive amounts of radioactivity.

4. The stability of the buildings may be in danger when flooding the containments and massive aftershocks hit them.

5. The nightmare is not yet over.

You may think I am against nuclear power. But I personally never was. Not until Fukushima. And I still think nuclear power plants can be safely operated from a technical point of view. But I am now convinced that profit oriented companies have disqualified themselves for this job.

 

[jlduh]

"[...] experts on nuclear power generation are an enclosed group and they tend to avoid vigorous discussions and uncomfortable subjects"

I think this is maybe not the case only in nuclear business (I know many other occurences of this phenomenon), BUT in case of nuclear industry, this can have much more consequences than in many other fields. Lack of counter forces and alternative discussions INSIDE the business is what is happening, in other words. In other words again, you can get blind by shutting your eyes to much and too long.

http://www3.nhk.or.jp/daily/english/05_23.html

The chairperson of Japan's Nuclear Safety Commission, Haruki Madarame, has told NHK that the engineering guidelines for nuclear power plants should be thoroughly revised as they do not include the possibility of a long-term power failure.

[...]

The guidelines were last modified by the commission in 1990.They state that a long-term power failure can be ignored as emergency back-up systems are expected to supply electricity. The complacency about blackouts has been pointed out as one of the causes of the severe accidents at the Fukushima Daiichi plant. Madarame told NHK that the guidelines clearly state that a long-term power failure can be disregarded. He said he paid no attention to the explanation until the accidents and he regrets his lack of knowledge, adding that the guidelines should have included the worst-case scenario.

He said the guidelines were not revised because experts on nuclear power generation are an enclosed group and they tend to avoid vigorous discussions and uncomfortable subjects. He concluded that the Fukushima accidents were caused by human error.

 

[zapperzero]

Wow, if you applied that logic consistently you'd never do anything unless you did it yourself. Toilet backed up? Better call the carpenter, you know that plumber makes his living off broken pipes...

[EDIT} oh yeah, don't bother looking, I've been a 'shill' for the "nuke complex" for over 30 years.

Well I tend to do the routine maintenance work on my motorbikes myself, after having been ripped off by mechanics once too often. I even went so far as to acquire the skills needed to change lightbulbs in the house :D.

But other than that, I tend to trust those who have demonstrable expertise. I would certainly trust QuantumPion to understand a decay chain or a jet pump and be able to discuss such subjects in a reasonable and balanced manner.

Yet, I would not blindly trust him, or you, or anyone else in the industry when the talk turns to "is nuclear power really necessary?" just as I wouldn't trust my mechanic to answer truthfully if I ask "hey, do you think it would be an issue if I checked my spark plugs all by myself from now on?".

 

[Dmytry]

Um, nope...?

He proved that even with very little fuel damage (~ 5%) and NO recriticality the iodine levels in the pool (~150 Bq/cm³ if I remember correct) could be explained.

that little fuel damage would also release Cs-137 , with Cs to I ratio far in excess (factor of >1000) of what was observed (due to how Cs-137 did not decay appreciable whereas i-131 decayed by more than 10 half-lifes), or conversely requiring >1000x better selectivity in transfer of Cs than I versus *everything else*. It is not some puny factor of 10 or so you can see elsewhere. It is massive selectivity. [edit: and to anticipate some stuff, no it's not transfer as CsI because CsI has 1360:1 ratio of I-131 to Cs-137 in Bq and only a very small fraction of Cs there could have been in form of CsI]

Got to love how those with self interest provide stuff for the entire range of gullibility, from the reactor being in centre of Pripyat to simple math proof of Gundersen being wrong so that whatever Gundersen says can be dismissed (albeit that one might be non-deliberate, leaving the mis-interpretation as exercise of the reader). Sigh.
What can work as non-criticality explanation for the isotope ratio is contaminated cooling water.

Think critically guys, don't approach it with preconception that someone from nuke industry will always get it wrong (the inclination to get stuff wrong doesn't mean everyone necessarily will), don't approach it with preconception that someone from nuke industry will get it right (just coz they know some stuff doesn't mean they'd not make something misleading; deception is extremely common), just think yourself.

 

[Dmytry]

But other than that, I tend to trust those who have demonstrable expertise. I would certainly trust QuantumPion to understand a decay chain or a jet pump and be able to discuss such subjects in a reasonable and balanced manner.

in my opinion anyone who thinks that Chernobyl NPP was in middle of Pripyat and Pripyat was not evacuated for several days, could not be trusted at all. There is a plenty of balanced information on the Chernobyl. There is generally a very strong correlation between ignorance on different but related topics; I'm pretty sure that the people who manage to pick up such gross misconception about Chernobyl despite the availability of good data also managed to pick up more misconceptions about decay chains or jet pumps or what ever than average. Yes, in principle, if someone does not get right facts about Chernobyl, that does not preclude perfect knowledge of decay chains or the like, but in reality there's often a common cause to mistakes.

TL;DR: I'd not trust anyone there, it is a much better idea to check it yourself.

 

[robinson]

Those who make a living and depend on nuclear reactors for power can not be objective about the current disasters. It's just not possible. Those with a preexisting objection about the dangers may also suffer from bias. It's human nature.

An issue as complicated and connected to weapons and world governments and the military is often muddled by politics.

 

[NUCENG]

the hell he proved it. All he shown was that there is enough i-131 in the fuel, but not the mechanism that would be several thousands times more selective in transfer of I-131 vs cs-137 than anywhere else (which would be required to have such I-131 concentration without much higher than observed Cs-137 concentration).

Dmytry is correct. My calculations were only aimed at determining if the data could be explained without assuming recriticality. I determined that fuel damage equivalent to a 5% gap release could explain the levels at that time. I did not make any claim that there was or was not recriticality. There were several potential explanations being debated at that time and some were claiming that recriticality was evident. Others (TEPCO) were trying to float a lead baloon blaming deposition.

Further, I have repeatedly pointed out that the interpretation of I-131 to Cs-137 ratios is a very difficult nut to crack unless you know a lot more that we did about the transport path, temperatures, pH, and chemistry. In the case of the turbine building subdrain levels in one building I frankly admitted that the trends seemed to be backwards at that time with increasing I-131 and little or no change in Cs-137.

If you have a specific sample point in mind, I can look at this again, but please be careful in interpreting my results.

 

[clancy688]

If you have a specific sample point in mind, I can look at this again, but please be careful in interpreting my results.

Okay, I'm sorry. I did misinterpret your statements. Recriticality cannot ruled out. But I still think it's unlikely.

 

[Dmytry]

Dmytry is correct. My calculations were only aimed at determining if the data could be explained without assuming recriticality. I determined that fuel damage equivalent to a 5% gap release could explain the levels at that time. I did not make any claim that there was or was not recriticality. There were several potential explanations being debated at that time and some were claiming that recriticality was evident. Others (TEPCO) were trying to float a lead baloon blaming deposition.

Further, I have repeatedly pointed out that the interpretation of I-131 to Cs-137 ratios is a very difficult nut to crack unless you know a lot more that we did about the transport path, temperatures, pH, and chemistry. In the case of the turbine building subdrain levels in one building I frankly admitted that the trends seemed to be backwards at that time with increasing I-131 and little or no change in Cs-137.

If you have a specific sample point in mind, I can look at this again, but please be careful in interpreting my results.

well ya... anyways on the topic of the transport paths, temperatures, pH, and chemistry, the point is that it has to be over 1000 times more preferential for I versus Cs than any other transport we seen anywhere there so far, even for seriously long and complex paths. That makes it fairly implausible, don't you think? Extraordinary claims shouldn't be taken as default hypothesis. If something can get 99.9% of Cs out of the solution by accident, they should just use that miracle on basement water.
The simplest explanation IMO is use of contaminated water for cooling. The basements and such, well, what is really strange is that they are not testing for other isotopes, or not releasing results. If there was re-criticality they wouldn't publish those isotopes data, but its uncertain if they would if there is no re-criticality. In any case TEPCO can easily find out if there was recriticality or not.

BTW, do you think, based on photos, that the freshly spent fuel in #4 pool was damaged? It looks this way to me, the grid on top is distorted on some of the blocks... which does suggest damage to the boral plates and definitely to boraflex (which is plastic). Half-burnt fuel has the maximum reactivity. Of course what is not seen in #4 is any signs of re-criticality of any note, with any kaboom-type disassembly, so the re-criticality in the pool does seem quite implausible.

 

[NUCENG]

Okay, I'm sorry. I did misinterpret your statements. Recriticality cannot ruled out. But I still think it's unlikely.

It is natural to look for information that confirms our opinions. I don't know if there has been recriticality. I hope that it hasn't occurred because the Japanese already have enough troubles dealing with plants that are shut down. But I am watching for evidence that it has happened.

Despite what suspicions some posters have expressed here about "plant men", "shills", or several other negative references, most engineers that are successful in the nuclear industry are successful because they don't accept things at face value. They "pull the string" to find out what is really behind an event. Experience is the best teacher and an engineer (whatever his or her industry) who is afraid of being wrong is in the wrong occupation. You may never be able to prove WHAT happened, but by elimination of what did NOT happen you may actually learn more. I am learning a lot here, and not just techical stuff.

BTW CLANCY is my favorite author.

 

[clancy688]

BTW CLANCY is my favorite author.

Yeah. It's a shame that he doesn't write anymore - at least that's what I wanted to type, but I'm seeing now that he's back with two more novels. I thought he stopped after Teeth of the Tiger. At least I read reports about a nasty divorce involving character rights and health problems...
Apparently learning something about nuclear disaster engineering isn't the only thing one can experience in this forum - seeing my favourite author being back in business quite made my day.
Well and if that isn't a coincidence - his second newest book is about terrorists trying to bomb a nuclear waste facility in the USA...

Regarding recriticality in SFP #4

As already mentioned, there are videos showing the pool's interior. There seems to be outer damage at the fuel assemblies, but I would expect more if there was a criticality going on. If I'm informed right, there are three conditions to be met for recriticality:

1) enough uranium in the fuel
2) presence of a moderator (water)
3) geometry

We can't argue about one and two, there's undoubtly new fuel in the pool and of course there's water... but I'm not so sure for the third one. I would store fuel in water only if it's assured that the fuel doesn't get critical. So I'd store it in a way (geometry) which doesn't support recriticality. So for recriticality to occur, the fuel must've moved!
The videos now don't show the whole pool (or what's below) but the upper side of the assemblies doesn't look as if it's been moved.
Further we'd need force to move fuel. That could either've been the initial earthquake or the hydrogen explosion.
As for the first one, I don't think that TEPCO engineers wouldn't spot a recriticality in the SFP, even with a station blackout and three other units melting down around them. And for the second one - the explosion wasn't as violent as in Units 1 and 3. Would it be possible for a shock wave to move fuel assemblies several metres submerged? I don't know. Perhaps here's someone who can answer that question.

 

[NUCENG]

well ya... anyways on the topic of the transport paths, temperatures, pH, and chemistry, the point is that it has to be over 1000 times more preferential for I versus Cs than any other transport we seen anywhere there so far, even for seriously long and complex paths. That makes it fairly implausible, don't you think? Extraordinary claims shouldn't be taken as default hypothesis. If something can get 99.9% of Cs out of the solution by accident, they should just use that miracle on basement water.
The simplest explanation IMO is use of contaminated water for cooling. The basements and such, well, what is really strange is that they are not testing for other isotopes, or not releasing results. If there was re-criticality they wouldn't publish those isotopes data, but its uncertain if they would if there is no re-criticality. In any case TEPCO can easily find out if there was recriticality or not.

BTW, do you think, based on photos, that the freshly spent fuel in #4 pool was damaged? It looks this way to me, the grid on top is distorted on some of the blocks... which does suggest damage to the boral plates and definitely to boraflex (which is plastic). Half-burnt fuel has the maximum reactivity. Of course what is not seen in #4 is any signs of re-criticality of any note, with any kaboom-type disassembly, so the re-criticality in the pool does seem quite implausible.

Actually no, there are several characteristics of Cs and I that would make significant differences in their transport. Cs readily deposits of colder horizontal surfaces. An order (or three) of magnitude can easily occur depending on how it gets to the sample point.

One of the principles of release analysis is the use of the SBGT system filters. The HEPA filter efficiency for CsI is assumed to be 99.9%. For other isotopes such as noble gases there may be some filtration in the charcoal filter beds but basically most noble gases are directly released to the environment. I know those systems didn't work here, but the point is there are things that can make big defferences in transport. In the long run Cs deposition could become a significant problem that will remain embedded in concrete and debris long after all the water is processed.

Use of contaminated water to cool the pools early in the event would be expected to add both Cs and I, but in what ratio? That depends on the transport to the poin of cooling water suction. If that path was fairly slow and had a lot of cool horizontal surfaces the Cs getting to the suction could have been at a much lower concentration. Before you jump on me, I do not know if that explains it or not . There are way too many unknowns for me to make that call.

SFP4 is a tough call. I was surprised by how little evidence of damage was shown in the video and photos considering that the roof was so heavily damaged. Most of the debris was blown out or over the pool. There is some debris in the pool and it could have damaged rods releasing fission products from the gap. There was an extended loss of fuel pool cooling, but my calculations tell me that the fuel was not uncovered. Debris could have blocked natural circulation water flow in some channeled fuel bundles allowing localized heatup.

The Boral inserts are in the sides of each rack position As such the rack and fuel bundles in the cells will actually tend to protect the Boral. If the pool didn't uncover fuel the boral would not have been much over 100 degC depending on submergence pressure. Further if the boral had been extensively damaged and allowed recriticality I would have expected more radioactivity in the pool because there is no forced flow in the pool to cool a critical fuel assembly. Inside the reactor the recirculation system cools the rods with millions of pounds of recirculation flow per hour.

My best guess for SFP4 is that it experienced hydrogen evolution by radiolysis and pool boiling and some limited mechanical damage due to debris that released some fission products into the pool. Additional pool contamination from cooling water is a strong possibility as well based on the large leaks, feed and bleed addition of water to fuel pools, and the high concentrations measured in the shore area.

 

[NUCENG]

Yeah. It's a shame that he doesn't write anymore - at least that's what I wanted to type, but I'm seeing now that he's back with two more novels. I thought he stopped after Teeth of the Tiger. At least I read reports about a nasty divorce involving character rights and health problems...
Apparently learning something about nuclear disaster engineering isn't the only thing one can experience in this forum - seeing my favourite author being back in business quite made my day.
Well and if that isn't a coincidence - his second newest book is about terrorists trying to bomb a nuclear waste facility in the USA...

Regarding recriticality in SFP #4

As already mentioned, there are videos showing the pool's interior. There seems to be outer damage at the fuel assemblies, but I would expect more if there was a criticality going on. If I'm informed right, there are three conditions to be met for recriticality:

1) enough uranium in the fuel
2) presence of a moderator (water)
3) geometry

We can't argue about one and two, there's undoubtly new fuel in the pool and of course there's water... but I'm not so sure for the third one. I would store fuel in water only if it's assured that the fuel doesn't get critical. So I'd store it in a way (geometry) which doesn't support recriticality. So for recriticality to occur, the fuel must've moved!
The videos now don't show the whole pool (or what's below) but the upper side of the assemblies doesn't look as if it's been moved.
Further we'd need force to move fuel. That could either've been the initial earthquake or the hydrogen explosion.
As for the first one, I don't think that TEPCO engineers wouldn't spot a recriticality in the SFP, even with a station blackout and three other units melting down around them. And for the second one - the explosion wasn't as violent as in Units 1 and 3. Would it be possible for a shock wave to move fuel assemblies several metres submerged? I don't know. Perhaps here's someone who can answer that question.

Due to delays in the national commitment to accept spent fuel for geological storage US plants had to install dense pack fuel storage racks in spent fuel pools. That made the use of boral panels and inserts necessary to maintain the reactivity below criticality with the reqiuired margin. Later they had to begin installing dry fuel storage due to continued delays. If there is a criticism here it is that the lack of a go/no go decision on Yucca Mountain has led to the de facto risks of dense pack fuel pools and interim storage at over a hundred sites across the US. Nobody said, "STOP, we need to reevaluate this risk," instead of letting it force us into half measures to get through this short delay after that delay and so on. We are no closer to a solution today.

Back on topic, I don't know if Fukushima had dense pack storage or not. They have a common fuel storage pool on site and had fairly limited numbers of bundles in the units pools except for unit 4. Japan also sent their spent fuel to reprocessing. It is possible that the geometry was sufficient to prevent recriticality even in Unit 4, but I would have expected TEPCO to be shouting that from the rooftops if it were so. To be safe we have to assume that recriticality is a possibility and be alert to evidence that it is happening.

Because of the fresh fuel in Unit 4 the pool did boil in a little over a day after loss of fuel pool cooling. The steam would have introduced significant dilution and compressible vapor into the building. It is likely that helped mitigate the deflagration/detonation. It was also a significantly smaller production of hydrogen gas because there was little or no zirc-water reaction. As to the potential to move fuel racks, I am very doubtful that occurred. Incompressible Water level above the fuel would have actually spread the pressure pulse through the pool protecting the fuel and probably reflecting most of it back into the building. Fuel bundles are very fragile for side loading and I would expect to see evidence of broken fuel had there been much dislocation.

 

[tsutsuji]

http://mainichi.jp/select/jiken/news/20110607k0000e040078000c.html :

Disclosure of the main topics of the Japanese government's report to IAEA : in the future, the NISA is to become an independent body.

 

[jlduh]

Due to delays in the national commitment to accept spent fuel for geological storage US plants had to install dense pack fuel storage racks in spent fuel pools. That made the use of boral panels and inserts necessary to maintain the reactivity below criticality with the reqiuired margin. Later they had to begin installing dry fuel storage due to continued delays. If there is a criticism here it is that the lack of a go/no go decision on Yucca Mountain has led to the de facto risks of dense pack fuel pools and interim storage at over a hundred sites across the US. Nobody said, "STOP, we need to reevaluate this risk," instead of letting it force us into half measures to get through this short delay after that delay and so on. We are no closer to a solution today.

Back on topic, I don't know if Fukushima had dense pack storage or not. They have a common fuel storage pool on site and had fairly limited numbers of bundles in the units pools except for unit 4. Japan also sent their spent fuel to reprocessing. It is possible that the geometry was sufficient to prevent recriticality even in Unit 4, but I would have expected TEPCO to be shouting that from the rooftops if it were so. To be safe we have to assume that recriticality is a possibility and be alert to evidence that it is happening.

Because of the fresh fuel in Unit 4 the pool did boil in a little over a day after loss of fuel pool cooling. The steam would have introduced significant dilution and compressible vapor into the building. It is likely that helped mitigate the deflagration/detonation. It was also a significantly smaller production of hydrogen gas because there was little or no zirc-water reaction. As to the potential to move fuel racks, I am very doubtful that occurred. Incompressible Water level above the fuel would have actually spread the pressure pulse through the pool protecting the fuel and probably reflecting most of it back into the building. Fuel bundles are very fragile for side loading and I would expect to see evidence of broken fuel had there been much dislocation.

Wanted to mention here this interesting video:



Don't know this guy, but he seems to know what he is talking about concerning the high risk related to spent fuel pools in the US. As a french, with already much spend fuel on our territory because of the 58 reactors we have but with in addition a large amount stored at la Hague for treatment, I didn't know that the US had so many tons total (71 000 tons) and so many tons in average at each reactor in the SFP's (the guy says it's often 500 to 700 tons in the US reactors, so basically more than 5 times the average at Daichi plant, except gor N°4).

The reflexions about NRC's attitude on this subject (which acted to suppress the report made) are very much similar to the main conclusion that the chairperson of Japan's Nuclear Safety Commission, Haruki Madarame, has told NHK (see my post here: https://www.physicsforums.com/showpost.php?p=3341445&postcount=284 ): a closed world with too much co-dependency between NRC and nuke industry, in the selection process it seems (with one recent exception), and also in the fact that NRC is more and more relying on inspection programs from the industry instead of independant inspections, due to budget cuts.

Again I don't know this guy and the US situation, but I' would be glad to hear US citizens what they think on this matter. the guy states that an accident or terrorist attack in the US in one of this plants could because of this SFP storage lead to an exclusion zone 5 times the one in Chernobyl (the Chernobyl zone is half size the New Jersey, based on its words).

Nuclear spent fuel and waste treatment is, in my mind, one of the main reasons why nuclear power cannot be a long term and widely used technology.

When i was a kid, they were talking about the fact that in 10 or 15 years in the future they would do "transmutation" (that was kind of a magic word as it was presented!) and that's why they were storing spent fuel, in order in the short/mid term to convert it to safe stuff with this technology. Where is "transmutation" to convert danger to safe stuff? We are at the same state where we were 25 years ago: still going around the problem and just storing, storing storing...

All this seems to me a "dead end".

 

[Calvadosser]

I managed large engineering teams. You always have your analytical group that needs to think and re-thing everything 10 times until they propose something, those types are great for design work. But for crisis work I had the "drivers", they can think on their feet, they are able to elaborate complex plans in days, rather than months. When you use one group to do the task the other should do, you get a disaster. That is what seems to be happening here, they don't have the right type of people working on the problem. Contingency planning is a basic element of any plan.

Some time back, I read "Failure is not an Option" by Gene Kranz, the flight controller of the Apollo missions. They simulated and trained for combinations of failures that seemed to be ludicrously unlikely to occur. The result: when Apollo 13's command module lost its power on the way to the moon, they got the crew back.

I had (naively) assumed that all nuclear power organisations had a team who spent their time training for unlikely eventualities, using simulators to evaluate their plans. I'd believed there would be a pre-existing plan for just about everything - but clearly not.

Without pre-existing plans, you have to make your plans on the fly. If you have to make plans under pressure and in deteriorating conditions, you certainly don't need a group of procedure-oriented analysts debating all possibilities and suffering "analysis paralysis" while the situation continues to get worse. You also need people in charge who want to know what is the true situation, rather than bullgarbageting themselves that things are not really all that bad.

The Soviet military was heavily involved in the response to Chernobyl. I'm surprised that military involvement seems absent in the Fukushima crisis.

 

[zapperzero]

Despite what suspicions some posters have expressed here about "plant men", "shills", or several other negative references, most engineers that are successful in the nuclear industry are successful because they don't accept things at face value. They "pull the string" to find out what is really behind an event. Experience is the best teacher and an engineer (whatever his or her industry) who is afraid of being wrong is in the wrong occupation.

You have your basic hacker-engineer, the "let's see what we can see" type who tends to get very good at his chosen job simply because curiosity is egging him on. This kind of fellow may suffer from biases (such as, say, familiarity bias clouding his perception of risk or something).

But then there's the type of engineer that ends up in middle management. The one with the marginal skillset and the fearful outlook on life who ends up signing all the dodgy safety reports and gets promoted for it. You know a lot of guys like that. We all do.

 

[jlduh]

yes, we all know many examples everywhere, that's how things happen and that's why you need strong and REALLY independant counter forces to overcome this human tendancy. The independancy is also affected itself by this tendency so it's always on going process of equilibrium between "throttle and brakes" on this matter, the tendency being that an industry (and all the salaried people who earn the money for their families) will push as hard as possible to be heavy on the throttle to promote its interests.

A lot of engineers and scientist see this as a kind of "pollution" of pure science and tech by human problems and deviations, and consider that the science or the tech is not responible for it, so they don't want to care about these aspects (which they has for the most part difficulties with, they are unconfortable discussing this to take the words of Madarame above, even if in reality they are fullly part of the process everyday!).

But again, science and technology is made by humans for humans in a human's world, so this HAS to be discussed and considered, especially when that kind of disaster happen.

As Madarame says, this is a human caused accident, not only a "technical" accident. This doesn't mean that technology involved is not responsible, it means in my mind that ultimately, all have to recognize that whatever a technology is, you CANNOT throw away all the human aspects, which are also political in the large sense.

 

[Jorge Stolfi]

You also need people in charge who want to know what is the true situation, rather than bullgarbageting themselves that things are not really all that bad.

The Soviet military was heavily involved in the response to Chernobyl. I'm surprised that military involvement seems absent in the Fukushima crisis.

This topic may be more adequate for the political thread. (But indeed the government seems to be totally absent from the remedial efforts at the plant. Apparently it decided to let TEPCO run the entire operation, including diagnostic, planning, and on-site monitoring. Even AREVA seems to have more authority there than the Prime Minister; and NISA apparently can't even get TEPCO to send them legible faxes of the plant status forms.

This may have been the biggest mistake Kan made in this crisis. Recall that the Chernobyl managers and their bosses insisted that everything was under control, until Gorbachev pushed them aside.)

The problems that exist in the world today cannot be solved by the
level of thinking that created them. -- Albert Einstein​

 

[clancy688]

Despite what suspicions some posters have expressed here about "plant men", "shills", or several other negative references, most engineers that are successful in the nuclear industry are successful because they don't accept things at face value. They "pull the string" to find out what is really behind an event. Experience is the best teacher and an engineer (whatever his or her industry) who is afraid of being wrong is in the wrong occupation. You may never be able to prove WHAT happened, but by elimination of what did NOT happen you may actually learn more. I am learning a lot her

In my opinion the overall public reception of engineers is another problem. Because there is practically none. At least no positive.
The people are taking their working technology for granted. They can surf in the internet because there is a computer, they can drive a car because there are engines. It's a little bit like deus ex machina. The thing works because it works.
Engineers are technical blockheads who are living in their own little play world, but they are not connected to all these modern wonders - that's what many people are thinking subconciously. If there's someone who gets praise for very well engineered solutions, it's mostly the investor - people like Steve Jobbs for example.
But then there's an accident, an big accident, Fukushima. According to the public, there are many people at fault. Managers, politicians - but also engineers who dared to build such a ticking bomb called a "nuclear plant". They were blended by their own hybris, they are dangerous gamblers, that's why many people think they can't trust engineers anymore.

But they are missing the point. Engineers must be curious, they must have visions. Otherwise, there'll be no technological advance. Currently, the public is condemning the one thing which defines an engineer - his curiosity to solve a problem.
This curiosity brought us to the Moon and and in the sky, and it brought us to Hiroshima and Chernobyl.
Of course we have to make sure that those visions don't go overboard, we have to evaluate what impact our solutions will have to mankind. But condemning our curious nature and thus distrusting every engineer is the wrong way.

Note quite on topic, but I had those thoughts lingering around in my head for weeks~

 

[Dmytry]

Despite what suspicions some posters have expressed here about "plant men", "shills", or several other negative references, most engineers that are successful in the nuclear industry are successful because they don't accept things at face value.

well there's been one allegedly plant man who said chernobyl NPP was in middle of pripyat' and pripyat' was not evacuated for several days.
That what provoked (or re-provoked) the negative references. You can hardly blame people for negative response to such statement (and you are in no position to blame people for mixing you up with another nuke guy coz you've been openly declaring that you mix up me with someone else).

There is a lot of 'pro nuclear' websites online spreading this exact sort of nonsense (with articles written by nuclear engineers, supposedly); rather than achieving their stated goal of promotion of nuclear power, they make nuclear power look bad, very bad, to anyone who can check the facts.

 

[Dmytry]

Actually no, there are several characteristics of Cs and I that would make significant differences in their transport. Cs readily deposits of colder horizontal surfaces. An order (or three) of magnitude can easily occur depending on how it gets to the sample point.

Yes but does that apply for solutions? Cs compounds are very water soluble.

One of the principles of release analysis is the use of the SBGT system filters. The HEPA filter efficiency for CsI is assumed to be 99.9%. For other isotopes such as noble gases there may be some filtration in the charcoal filter beds but basically most noble gases are directly released to the environment. I know those systems didn't work here, but the point is there are things that can make big defferences in transport. In the long run Cs deposition could become a significant problem that will remain embedded in concrete and debris long after all the water is processed.

Hmm, so there may be filters in spent fuel pool sufficient to take out the Cs but not I ? The filter has to take out same molar amount of anions as cations.

Use of contaminated water to cool the pools early in the event would be expected to add both Cs and I, but in what ratio? That depends on the transport to the poin of cooling water suction. If that path was fairly slow and had a lot of cool horizontal surfaces the Cs getting to the suction could have been at a much lower concentration. Before you jump on me, I do not know if that explains it or not . There are way too many unknowns for me to make that call.

Well, I've been looking at various soil samples and seawater samples and fish samples and it just doesn't look like anywhere the ratio was changed this much over transport from the original leaks.

SFP4 is a tough call. I was surprised by how little evidence of damage was shown in the video and photos considering that the roof was so heavily damaged. Most of the debris was blown out or over the pool. There is some debris in the pool and it could have damaged rods releasing fission products from the gap. There was an extended loss of fuel pool cooling, but my calculations tell me that the fuel was not uncovered. Debris could have blocked natural circulation water flow in some channeled fuel bundles allowing localized heatup.

The Boral inserts are in the sides of each rack position As such the rack and fuel bundles in the cells will actually tend to protect the Boral. If the pool didn't uncover fuel the boral would not have been much over 100 degC depending on submergence pressure. Further if the boral had been extensively damaged and allowed recriticality I would have expected more radioactivity in the pool because there is no forced flow in the pool to cool a critical fuel assembly. Inside the reactor the recirculation system cools the rods with millions of pounds of recirculation flow per hour.

I dunno, the tops of some of the fuel racks look thermally damaged compared to other racks. But not very damaged. It can't get thermally damaged if it is covered by water, so it had to be uncovered at least a bit.

My best guess for SFP4 is that it experienced hydrogen evolution by radiolysis and pool boiling and some limited mechanical damage due to debris that released some fission products into the pool. Additional pool contamination from cooling water is a strong possibility as well based on the large leaks, feed and bleed addition of water to fuel pools, and the high concentrations measured in the shore area.

I'm kind of sceptical regarding radiolysis hydrogen. A lot of hydrogen had to be produced. With the boiling again, it can reduce the recombination some but I don't believe it'd go from barely any hydrogen to filling up entire building and blowing it apart (despite building not being exactly hydrogen-tight). Hydrogen and oxygen don't recombine very well to start with, that's the thing (there's multiple reactions going with atomic oxygen and atomic hydrogen, some ending with h2o and some ending with h2 and o2 , and h2 and o2 are stable and don't recombine unless themselves radiolysed), even if steam totally prevents recombination that's still not many orders of magnitude increase in h2 that gets out. There's very little bubbling in the SFP as seen on video. Definitely not cubic metres per hour.

The #4 explosion is just strange. You'd think it'd be easy to prevent by removing a panel. And there was so much damage on the lower floors, more than in #3.

 

[zapperzero]

h2 and o2 are stable and don't recombine unless themselves radiolysed), even if steam totally prevents recombination that's still not many orders of magnitude increase in h2 that gets out. There's very little bubbling in the SFP as seen on video. Definitely not cubic metres per hour.

Have you counted the bubbles you see in that short video? Can you get a volume estimate? For a visual reference, remember a fuel assembly is about 20cm on a side.

Ah. Here you go:
http://www.nrc.gov/reading-rm/doc-collections/nuregs/contract/cr6213/

 

[gmax137]

Wow, if you applied that logic consistently you'd never do anything unless you did it yourself. Toilet backed up? Better call the carpenter, you know that plumber makes his living off broken pipes...

[EDIT} oh yeah, don't bother looking, I've been a 'shill' for the "nuke complex" for over 30 years.

Well I tend to do the routine maintenance work on my motorbikes myself, after having been ripped off by mechanics once too often. I even went so far as to acquire the skills needed to change lightbulbs in the house :D.

But other than that, I tend to trust those who have demonstrable expertise. I would certainly trust QuantumPion to understand a decay chain or a jet pump and be able to discuss such subjects in a reasonable and balanced manner.

Yet, I would not blindly trust him, or you, or anyone else in the industry when the talk turns to "is nuclear power really necessary?" just as I wouldn't trust my mechanic to answer truthfully if I ask "hey, do you think it would be an issue if I checked my spark plugs all by myself from now on?".

Fair enough. I don't advocate blind trust. I also don't advocate blind distrust. It's the 'blind' part that isn't necessary or required.

 

[Dmytry]

Have you counted the bubbles you see in that short video? Can you get a volume estimate? For a visual reference, remember a fuel assembly is about 20cm on a side.

order of magnitude, easily. Remember, cubic metre of air is 1000 litres, and 1 litre is 10cm x 10cm x 10cm (obviously) . If you aren't numerically blind, its no problem to notice that it is quite a few orders of magnitude off. A couple small bubbles, the flow is what, under a litre per second? and probably a lot of it is dissolved air released by heat. The cube of 10x10x10 meters has 1000 cubic metres.
http://www.houseoffoust.com/fukushima/blueprint.html
so we get thousands cubic metres of air there.
The concentration, hydrogen in air is flammable at >4% <75% volume concentration and can detonate at >18% <60% , with steam its of same order of magnitude but you need more hydrogen. Tens to hundreds cubic metres of hydrogen needed.
The problem is whenever one would bother to notice or not, and then it boils down to motivation.
[[This is btw why houses don't blow up so often due to gas stoves (to think about it, i'd say houses blow up less often to gas stoves than nuclear reactors for varying reasons). You have to leave gas fully on for quite some time before it can blow. There's a lot of litres in a room.]]

Also if i recall correctly they removed a panel in #4 prior to explosion (hopefully someone can find reference). In any case it shouldn't have been totally air tight in first place and not after quake, tsunami, and after#3 blew up so hard there was a discussion that it might've damaged #4 this bad.

 

[zapperzero]

https://www.physicsforums.com/showpost.php?p=3346210&postcount=9332

Jap gov't is delaying the translation of their report to IAEA into English. Interestingly enough, the "late" bits are the technical appendices, where all the data is.

 

[zapperzero]

order of magnitude, easily. Remember, cubic metre of air is 1000 litres, and 1 litre is 10cm x 10cm x 10cm (obviously) . If you aren't numerically blind, its no problem to notice that it is quite a few orders of magnitude off. A couple small bubbles, the flow is what, under a litre per second? and probably a lot of it is dissolved air released by heat. The cube of 10x10x10 meters has 1000 cubic metres.
http://www.houseoffoust.com/fukushima/blueprint.html
so we get thousands cubic metres of air there.
Tens to hundreds cubic metres of hydrogen needed.

Let's say hydrogen production is really inefficient and you only get 10%. of steam volume radiolysed so 0.1 liter/second. Your 1000 cubic metres would get to be filled to 10% hydrogen (more than enough for deflagration) in a million seconds, which is about 15 days and a half. I take 4% as a lower concentration limit needed for deflagration, I only need seven days and change.

I don't see your "many" orders of magnitude here, sorry. Perhaps I am innumerate and I lost some zeroes somewhere.

You are seeing the pool in a relatively stable state, at 60 degrees Celsius or so, on April 30 I believe. Now try and take into account the much higher temps that the uncooled pool reached. At one point TEPCO said it was boiling. Way more steam. Way more radiolysis.

By the way, those deflagration limits you cite are for normal air. Radiolysis produces hydrogen and oxygen. I'm not sure anyone ever tried to see what the limits are in an oxygen-enriched atmosphere, but I am willing to bet my bottom dollar the lower limit gets lower, not higher.

 

[Danuta]

Land is precious in Japan. Idle land barely exists there.

Fukushima’s nuclear meltdown puts forest industry near collapse

“If we can't go into thin the trees for a year or longer, the underbrush will grow and the saplings that have been newly planted will suffer from lack of sunlight,” said Hiroshi Sagara, a forestry cooperative chief, the Mainichi Daily News (MDN) reports. “The forest will fall into disrepair and trees will fail to grow well.”

Adding to the woes are concerns of severe soil contamination caused by radioactive materials, a probability which would impact the forest industry for some time to come. “Improving soil quality (in forests) is harder than it is for farmland. Even if the evacuation orders are rescinded, it may be a long time before radiation levels are low enough for workers to go in there,” Sagara added.

http://www.digitaljournal.com/article/307506#ixzz1OgtirATw"

 

[Borek]

Tsutsuji just posted details about water treatment facility, between othe rthings:

The buildings must be watertight to prevent leaks into ground water... etc.

Which makes me wonder, why reactor and diesel buildings have been not designed this way. Shouldn't be difficult, as they are already quite sturdy. Sounds easier and cheaper than antitsunami wall. It won't protect turbine buildings, but these - even if destroyed - are not source of problems we observe since the earthquake.

Could be that'll be one of the lessons learned.

 

[Danuta]

Which makes me wonder, why reactor and diesel buildings have been not designed this way. Shouldn't be difficult, as they are already quite sturdy. Sounds easier and cheaper than antitsunami wall.

Might be cheaper AND make more sense. An anti-tsunami wall, if breached, slows water from flowing back into the sea, which is another problem. So water tightness seems an excellent overall precaution to take. Also situating mobile fuel tanks so they are not the first to take a hit like front line soldiers would have been good too.

 

[causeceleb]

Tsutsuji just posted details about water treatment facility, between othe rthings:



Which makes me wonder, why reactor and diesel buildings have been not designed this way. Shouldn't be difficult, as they are already quite sturdy. Sounds easier and cheaper than antitsunami wall. It won't protect turbine buildings, but these - even if destroyed - are not source of problems we observe since the earthquake.

Could be that'll be one of the lessons learned.

we need a call from physicists and engineers all over the world for the United Nations
Security Council to take control of the situation at Fukushima Daiichi, and establish
a board of renowned physicists and engineers (where's Richard Feynman when you need him?) to direct these emergency operations (and, of course, Japan will provide any
and all resources that are needed).

 

[tsutsuji]

"The Japanese Government’s longer term response to protect the public, including evacuation, has been impressive and extremely well organized" : http://www.iaea.org/newscenter/focus/fukushima/missionsummary010611.pdf

Peter Karamoskos: Well, firstly, the problem lies in the exclusion zone. The Japanese instituted a 20 kilometre exclusion zone, and up to 30 kilometres they said people should stay indoors, but within the first week the IAEA, the International Atomic Energy Agency, as well as the US Nuclear Regulatory Commission, both said that that was too little and you needed to have an 80 kilometre exclusion zone.

So that would, that's just basic public health 101, if you like. Furthermore, it would have enabled appropriate counter measures for people exposed to radioactive iodine.

Now I don't know precisely what the doses of people outside the exclusion zone were, but the fact that the overseas authorities were advocating an 80 kilometre exclusion zone, tells me that it wasn't of a safe level. And, perhaps, people who could have benefited from iodine, failed to receive it, and children particularly.

Doctor Karamoskos is the public representative of the Radiation Health Committee of the Australian Radiation Protection and Nuclear Safety Agency, although he is not representing ARPANSA tonight.
Broadcast: 10/06/2011 http://www.abc.net.au/lateline/content/2011/s3241511.htm

I also wish we knew a little more of what happened at Futaba hospital and the exact number of casualties before the IAEA or anybody concludes that the evacuation was "extremely well organised". The 45 possible death figure mentioned by Mainichi on 26 April : http://mdn.mainichi.jp/features/archive/news/2011/04/20110426p2a00m0na006000c.html does not fit well with "extremely well organized".

The following 7 May article http://www.asahi.com/special/10005/TKY201105060448.html mentions 60 people reported by municipalities as having died immediately after evacuation, but the causal relationship between evacuation and death had yet to be investigated. The government will pay compensations in cases when the causal relationship is established. Compensations will also be provided when people's health deteriorated because of the evacuation.

The following 9 June article http://sankei.jp.msn.com/affairs/news/110609/dst11060918200014-n1.htm tells about 10 people, among which 7 bedridden elderly, who died while waiting for the Japanese military or other evacuation teams : 4 at Futaba hospital, 3 at Nishi hospital, and 3 at Imamura hospital, citing dehydration or the lack of medication as factors aggravating their illnesses.

 

[ElliotLake]

I'm not going to click the link, it would be too distressing to read the details, but I took care of my elderly mother as she was dying, and for them to leave bedbound people to die of dehydration means they left them for a really long time. A long, agonizing time. Not only in pain, but panicking and abandoned.

I've no words I can use in public for that.