Japan Earthquake: Nuclear Plants at Fukushima Daiichi

AI Thread Summary
The Fukushima Daiichi nuclear plant is facing significant challenges following the earthquake, with reports indicating that reactor pressure has reached dangerous levels, potentially 2.1 times capacity. TEPCO has lost control of pressure at a second unit, raising concerns about safety and management accountability. The reactor is currently off but continues to produce decay heat, necessitating cooling to prevent a meltdown. There are conflicting reports about an explosion, with indications that it may have originated from a buildup of hydrogen around the containment vessel. The situation remains serious, and TEPCO plans to flood the containment vessel with seawater as a cooling measure.
  • #5,201
elektrownik said:
About explosions, I am not expert, I write only on base of observations: #1 explosion, big pressure in reactor building from venting then small, centered hydrogen explosion. #3 explosion, yest we can see it on video, first fireball from SFP location, then big explosion going up, but I don't think that it was from recriticality in SFP, I think that first explosion in SFP damaged drywell and reactor vessel so there was big release of pressure and maybe hydrogen explosion. If there would be so big explosion from SFP then there would be more very hight radioactive pieces of fuel rods, but they found only 300 and 900 mSv/h mayby from reactor cap... Also the big "up" explosion appear to be from center of building/core location not from sfp like fireball...

Nice side by side video on youtube of #1 and #3 explosion

http://www.youtube.com/watch?v=1Q3ljfLvHww"

Very impressive to see the difference in shape and power.

If you look at the frame by frame version of #3 explosion,
you can clearly see the fireball, followed by the implosion and catapult shot.

http://www.youtube.com/watch?v=9PHQ3IJHJbw"

It seems to me, that the implosion/explosion also has impact on structure of building #4.
Could be the reason for the curved damage seen on the left side of the building #4, after it blow up.
 
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  • #5,202
Assume a spent fuel assembly with no damage to any fuel rods was lifted completely up and out of its SFP, swung through the open air for a minute or two, and lowered into another pool at ground level. Is that feasible at all?

Every day those SFPs are left sitting there 30 meters off the ground supported by weakened concrete shells is another day waiting for something really bad to happen. If one could jury-rig a closed-loop cooling system for each SFP then it could buy some time, but even that assumes the pools are not leaking. And what if they are leaking? Their current feed and bleed strategy can't go on much longer. It boggles the mind to think that they might actually believe they can get out ahead of this thing with tonnes of contaminated water continuing to accumulate day in and day out.
 
  • #5,203
Hi Guys, keep up the fantastic work. This thread has keep me riveted for weeks!

I'd usually lurk but I would dearly like to hear you opinion on this.

Yesterday NHK reported that TEPCO had finally admitted a leak in spent fuel pool number 4 was likely.

TEPCO: Water may be leaking from No. 4 reactor fuel pool
http://www3.nhk.or.jp/daily/english/27_09.html

Today they have retracted:

TEPCO: Water isn't leaking from No. 4 reactor pool
http://www3.nhk.or.jp/daily/english/28_05.html
 
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  • #5,204
SteveElbows said:
And its not the first time he has made this mistake in a video. I first heard about the report in question via one of his videos weeks ago, and in that video I believe he used the phrase 'several miles'. I was already miffed with his iffy analysis of the unit 4 pool video, so I thought I better check the original source detail, and sure enough it said 1 mile not several miles.

I also note in this latest video that he is sloppy when describing the dimensions of the fuel pool.

I appreciate that members of this forum are wiling to consider all possibilities. It's open minded and good science. But I have serious questions about Gunderson's credibility, as well as Busby's. The latter's arguments concerning radiation epidemiology, his ecological studies of Sellafield, and his "Second Event Theory" of DNA mutation have been pretty well demolished more than once. The report of the CERRIE committee from 2004 makes very informative reading in this regard. It notes that as far as Busby's claims are concerned, "The Committee concluded that the available scientific evidence did not support these hypotheses and, in many cases, substantially contradicted them." He threw a fit. Time and again during committee, one of which he chaired, he was asked to provide the papers upon which he based various claims so the others could review them, and was unable to. Sloppy does not begin to describe it. He makes this stuff up.

http://www.cerrie.org/report/

(For the record, I've been lurking for a while and just signed on. I'm not a scientist, but direct a design theory lab in Tokyo, doing mainly environmental design studies as well as a long-term collaboration with a neuroscience team on hand-brain issues. I'm learning a lot here. My hats off to you all)
 
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  • #5,205
Jim Lagerfeld said:
Hi Guys, keep up the fantastic work. This thread has keep me riveted for weeks!

I'd usually lurk but I would dearly like to hear you opinion on this.

Yesterday NHK reported that TEPCO had finally admitted a leak in spent fuel pool number 4 was likely.

TEPCO: Water may be leaking from No. 4 reactor fuel pool
http://www3.nhk.or.jp/daily/english/27_09.html

Today they have retracted:

TEPCO: Water isn't leaking from No. 4 reactor pool
http://www3.nhk.or.jp/daily/english/28_05.html

I honestly don't think they know what they're doing, have a fraudulent "plan" to deal with the cleanup going forward, and cannot be trusted to tell the truth about anything. They cannot deny what others see in photographs or measure with monitoring devices. All else is spin at this point.
 
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  • #5,206
Is it safe to go to Japan now? Will the nuclear plants get worse or is it 100% under control now? Thanks.
 
  • #5,207
Astronuc said:
The fuel in the SFP is 'spent', in addition to the fact that is started with low enrichment. The available reactivity is low because it is 'spent'. The rate a which positive reactivity could be inserted is relatively low, so a prompt critical event is unlikely. Coming out of a subcritical configuration with a very low neutron source, rather than starting at a critical configuration, I don't believe the configuration in the SFP supports prompt supercritical.

The explosions at Units 1 and 3 occurred well before the pools would have dried out, and it is more likely the hydrogen came from oxidation of the cladding in the cores.

I don't see the explosions being nuclear.

If the pools had dried out, there certainly wouldn't be any moderator to allow criticality. If there was water covering the fuel at the time of the explosion, the pressure in the pool would have been more of an increase in hydrstatic pressure, and that would crush the fuel into a more critical configuration.

Re-criticality would have been a concern AFTER the hydrogen explosions, when they TEPCO was reintroducing water into the SFPs. However, I would have expected them to borate that water.

All I see are chemical (H2+O2) explosions, not nuclear.
OK, thanks Astronuc. Then, at least in my opinion, having not been convinced otherwise by any hard data or inconsistency in the photographic or video evidence, I am still clinging to the sequence I had first hypothesized: 1) hydrogen explosion in the drywell containment of RPV3, 2) directed venting of the explosion into the upper SFP3 via the fuel transfer chute (and also into the torus), 3) secondary explosion of the hydrogen in the upper floor of Bldg 3 (also from hydrogen originating from the reactor core of Unit 3 and probably not SFP3 damaged fuel), and, almost simultaneously, 4) hot water vaporization/steam explosion mushrooming vertically from the SFP3.

I am not perhaps as sure as you about the time frame of when the SFP3 might have gone dry (not because I doubt you, but because I haven't done the math), but I am fairly sure that mushroom effect is steam, and that the origin of the steam must have been water in the SFP, and that is consistent with your assessment of water still in the SFP3. The shock wave --> hydrostatic wave --> mechanical damage to spent fuel racks would be a reasonable explanation of why some fragments of damaged fuel rods may have been carried aloft by the steam explosion, extraction of a fuel rod assembly by a "ballistic" FHM's mast now seeming to be most unlikely.

No one seems to have found an alternate "authentic" sound track other than the 3-Boom soundtrack of the Bldg 3 explosion, either. . .

Addendum: BTW, I doubt implosion of Bldg 3 occurred. I think the video shows explosion with a shadow of the cloud of exploding gas darkening the upper portion of the building. I can't imagine any physical process that could possibly have occurred to "implode" the upper portion of Bldg 3.
 
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  • #5,208
MiceAndMen said:
There have been decades of collusion between the nuclear industry, regulators, and the media in Japan. There are ample reasons having nothing to do with mass panic for them to want to withold information.

http://www.bloomberg.com/news/2011-03-17/japan-s-nuclear-disaster-caps-decades-of-faked-safety-reports-accidents.html

People are fired from their jobs if they dare to question the official company line.

http://japanfocus.org/-Makiko-Segawa/3516



Wow. They are certainly under tremendous pressure from many sides. I do not agree that their culture absolves irresponsible actions on their part in the name of some "path of least harm". If shame is necessary then it needs to be felt, and strongly, by those responsible. They should be shamed where appropriate. They NEED to be shamed where appropriate.

http://www.nytimes.com/2011/04/27/world/asia/27collusion.html?_r=1&hpw=&pagewanted=all

Does anyone think TEPCO's plan to remediate the situation over the next 3, 6 and 9 months is realistic? They barely got off of square one and found their plan to fill Unit 1's containment with water may be compromised by a leak. They are only now coming to the realization that Unit 4's SFP is probably leaking.

Here is what Japanese leaders have to fear: that at some point an international consensus develops that they are no longer capable of managing the ongoing problems on their own. At some point, perhaps, the international community may find it desirable to take away the keys to the car, so to speak, and TELL them how to proceed with the cleanup.

Patience does not last forever, and Japans's political and industrial institutions are well aware of that. The longer they are able to prolong a "fog of war" type atmosphere surrounding this fiasco, the longer they can put off their day of reckoning.

This is over the top, imho.
Does anyone have either the record or the competencies to assume entitlement to judge?
Japan is the very first victim of this disaster and they are certainly in constant communication with the world's nuclear community to get the best available counsel.
This situation is a mess exacerbated by the disaster that generated the problem and also hid its gravity during the crucial early days. At this point, with the plant flooded 20 feet deep by highly radioactive effluent, we are all in an unprecedented situation. No one knows what to do.
TEPCOs approach, going slow, building water treatment plants and cleaning up the site may be right or entirely wrong. With 500 people on site, versus the usual 5000, they are clearly biding their time.

Of course, maybe the only way to avoid a much greater problem is to throw people at it. However, unless someone has a plausible plan that shows real benefits, it is unreasonable to push for an acceleration, because the human cost would rise dramatically.
 
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  • #5,209
clancy688 said:
I'm not so sure about the hydrogen explosion. Wikipedia states that nobody is sure what caused the big explosion. There's only the fact that the reactor went to 30 GWt and then KABOOM.
I don't think that a hydrogen explosion is very likely. I'm not a chemist, but a hydrogen explosion would mean, that the reactor must have generated enough hydrogen to destroy the building and lift the 1000 ton heavy reactor cap upwards in just a few seconds <..>

I think the first fraction of a second of the blast did represent an initial hydrogen explosion, which blew away, crucially, the west wall support for the overhead crane, so that the two heavy booms and the crane itself fell on top of the reactor lid.

We know from overfly videos that the northern boom indeed has sunk partly into the service floor, and in that process has completely devastated the concrete deck at the west end where it fell. The fallen overhead crane has fallen on top of something, at the very least it must have its hook etc uderneath it, and those things must have pressed powerfully into the reactor lid. I think this hit from the overhead crane triggered something akin to a BLEVE (a boiling liquid expanding vapour explosion) from the area of the lid or from the area close to the SFP chute. A BLEVE can be extremely powerful, and it will produce a high buoyancy airmass (1 m³ of hot water flashed to vapor has a lifting power of about 1000 kg). A bleve will splash a lot of hot liquid water around too.

It is a somewhat overseen fact that the explosion of unit 3 really produced a lot of steam, quite unlike unit 1, and not only in the shape of a mushrooming cloud, but also coming from ground level from water apparently splashed as far as to unit 1 (counter to the wind direction!) , also a lot from the area around unit 4. Indeed the satellite photo taken 3 minutes after the explosion strongly suggest there's water on the roof of turbine building 4. As if it had just rained.

I may well be wrong about several things in this scenario, but whatever the exact chain of events may have been, I think the character of the explosion at unit 3 becomes inexplicable unless we assume that it in some way involved the expulsion of large amounts of hot water under pressure. It certainly was not (just) a hydrogen explosion.
 
  • #5,210
etudiant said:
This is over the top, imho.
You are entitled to your opinion, as I am to mine.
etudiant said:
Does anyone have either the record or the competencies to assume entitlement to judge?
Yesterday they said SFP was leaking. Today they say it is not. QED

One does not have to be a good actor to recognize a bad one.
 
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  • #5,211
TCups said:
OK, thanks Astronuc. Then, at least in my opinion, having not been convinced otherwise by any hard data or inconsistency in the photographic or video evidence, I am still clinging to the sequence I had first hypothesized: 1) hydrogen explosion in the drywell containment of RPV3, 2) directed venting of the explosion into the upper SFP3 via the fuel transfer chute (and also into the torus), 3) secondary explosion of the hydrogen in the upper floor of Bldg 3 (also from hydrogen originating from the reactor core of Unit 3 and probably not SFP3 damaged fuel), and, almost simultaneously, 4) hot water vaporization/steam explosion mushrooming vertically from the SFP3.

What is the source of the oxygen for a hydrogen explosion in the dry well?
 
  • #5,212
etudiant said:
This situation is a mess exacerbated by the disaster that generated the problem ...

It was more like a problem waiting for a disaster, than a disaster that generated the problem. "Sitting duck" comes to mind, especially when thinking in terms of recorded seismic activity and tsunami maximums.
 
  • #5,213
Explosion of Fukushima Unit 3 (Spent Fuel Pool?)

Hello! Have a question about one aspect of the Fukushima disaster which is still a topic of contention: etiology of the explosion of Unit 3.

Based on what I have read here and elsewhere, the theory which makes most sense to me is

- Loss of power in the tsunami shut down the cooling pumps, Spent Fuel Pool Three (SFP3) heated up to the point that it boiled off the water that it contained, exposing fuel rods
- Zircalloy cladding overheated and evolved hydrogen
- The building imploded before it exploded. Looking at the video frame-by-frame, the white/blue exoskeleton of the building collapses inward before the orange flash of the detonation
- This was an oxyhydrogen implosion caused when the air/fuel mixture reached conditions ripe for it to ignite
- A small fraction of a second later, the orange flash appears, its initial location, size, and vertical shape are consistent with the SFP3 burning/exploding

Now, for the real question: is it physically possible for the implosion to have caused a criticality in the SFP3? If not, why not? If so, how?
I can imagine the already-damaged fuel rods being forced together, in a manner similar to the way in which shaped charges are used to implode the core of nuclear weapons, which causes the criticality, and increases the yield of the explosion.

But, is this plausible based on the kinetics of what we see happened in the building, and based on the composition of the nuclear fuel that was in the SFP? I heard that some of the fuel in SFP3 was not "spent" rods but actually fresh rods of MOX fuel, which would be radioactively "hotter" than spent fuel. Not sure if that makes any difference.

I did study some advanced physics courses at university but nothing thereafter, so can the experts reduce this question to the quasi-layman level? Then I can follow this better as more details emerge.

My sincere thanks,

Curious Curium
 
  • #5,214
dh87 said:
What is the source of the oxygen for a hydrogen explosion in the dry well?

I think that was hashed out and explained by others smarter than me back somewhere around post #600-800 or so.
 
  • #5,215
TCups said:
I think that was hashed out and explained by others smarter than me back somewhere around post #600-800 or so.

I thought that you might know, since you propounded a theory. In elektrownik's theory, the oxygen for the initial hydrogen explosion is in the building above the SFP. Then, the second fireball occurs above the building after the hydrogen released from the primary containment vessel has a chance to mix with atmospheric oxygen.
 
  • #5,216
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  • #5,217
dh87 said:
What is the source of the oxygen for a hydrogen explosion in the dry well?

See this post - https://www.physicsforums.com/showpost.php?p=3213820&postcount=1622

The drywell should have been inerted, but with an overpressure event, leaks could have developed. I'm not sure the explosion happened in the drywell, but above the drywell and above the reactor service floor in the seconary containment. The hydrogen and some steam leaked from primary containment up into the secondary containment where the hydrogen ignited in air.

Unit 3's explosion was significantly great than that of unit 1. Unit 3 has a larger core, and there is some thought that seawater is more corrosive than normal reactor water - it cerainly is for stainless steel - but it may be more corrosive for Zircaloy in the presence of soluble iron (Fe3+), and thus Unit 3's core produced a lot more hydrogen than Unit 1. Unit was didn't have seawater injection before it popped, whereas Unit 3 had seawater injection about 22 hrs or so before its explosion.
 
  • #5,218
Danuta said:
It was more like a problem waiting for a disaster, than a disaster that generated the problem. "Sitting duck" comes to mind, especially when thinking in terms of recorded seismic activity and tsunami maximums.

Very much agree. The site selection and setup was arguably criminally negligent.
So no brief for TEPCOs management or their government supervisors.
However, the workers and contractors on the site, plus their line managers, who are busting their hump in an extraordinarily bad situation, deserve all the support we can give them. Their cautious approach may be mistaken, the steaming spent fuel pools may poison so much more of Japan that the leadership insists on a quicker fix, but given the flooding in the plant, nobody, not KHG, not Sandia, not anybody has appropriate waterproof robotic tools ready to go. The TEPCO crews are on their own.
 
  • #5,219
I am still interested in the absurd readings in R4. I can suppose that it had used MOX fuel rods from R3 and, possibly, a load of fresh MOX fuel rods ready to be installed in R4. Even assuming the reactor was empty and a chunk of melted fuel from R3 landed in the middle of it after R3 exploded, the readings seem too high.

On the other hand, I am reading an increased but fluctuating background of ~.2 millirads/hr on the Big Island of Hawaii but I cannot quantify the source isotopes.

I disagree that seawater injection could have caused a Hydrogen explosion of the sort we saw at R3. The thermographs clearly show an immensely hot area just where we would expect a fuel core to be if the top of it's containment blew off.
 
  • #5,220
(If this is considered grossly O/T for this board, I'll try posting it on the newer one, but I do think it's highly relevant to the whole discussion.)

FWIW--

I'm a non-expert, a non-scientist, and was fairly agnostic about nuke power till recently.

I try very hard to objectively sort through the multitude of opinions and reports about the developments at Fukushima (and their implications on lots of broader policy issues).
A big part of that is gradually determining whose opinions are NOT worth taking seriously.

While it only took me several hours to recognize that TEPCO was not to be trusted, and only slightly longer to figure out that many of the 'Nuclear Experts' in the Media appeared to be shills for the industry, that does NOT mean that 'experts' with the opposite perspective are any more trustworthy.

I quickly discerned that Busby appeared to be a nut, with a serious axe to grind, and disregarded him offhand.

Helen Caldicott seems like a nice lady, and I think she's done some good in the world, by bringing attention to proliferation issues that have largely been ignored.
But she, like Busby, says a lot of stuff that doesn't make sense, and seems prone to extreme exaggeration. I stopped paying attention to her pretty quickly, too.

Gunderson gave me a little more trouble. He comes off as so rational, and level-headed, I took him fairly seriously at first.
Then I saw him carefully, earnestly explain that the FHM of Unit 4 had clearly collapsed into the SPF, and was clearly sitting right on top of the crushed, and totally exposed, fuel racks themselves. This, frankly, scared the crap out of me.
One slight problem, though. After thinking it over for several hours, studying pictures and video, reading discussion on this board and others,... I realized it wasn't true.
It was pretty clear that the FHM had *not* dropped down into the pool, and in fact seemed to be just about where it started.
After that I started to notice that Gunderson says lots of things that appear to be false, or at least unsupported, no matter how calm he seems when he presents them.
So I stopped paying much attention to him.

(A great analogy can be drawn, I think, with the stuff said by Matt Simmons around the BP spill last year. He seemed like a good, and reasonable guy. He'd written a well-received book, and was highly respected by lots of smart people. But the stuff he was saying was ridiculous, and didn't even make logical sense internally. So I stopped listening.)

You slowly figure out what's unreasonable, inconsistent, non-sensical, or obviously biased (whichever direction), throw that all out, and see what's left.
Then you gradually start to edge towards the truth, which is almost always somewhere between the most extreme representations.
One helpful guideline is when there's an 'official' account with a readily apparent bias.
That provides an easy common-sense limit.

For instance, I have no idea how many people have died because of Chernobyl.
While I'm pretty sure it's not the million or so claimed by Greenpeace and Helen Caldicott, I'm also fairly certain it's not the 43 claimed by the Soviet government for many years, and still claimed today by the Ann Coulters of the world.
So, at least that's a start.

Similarly with the numbers of civilian deaths involved in the war in Iraq.
Nobody knows exactly what that number is. I do remember that at some point (perhaps in '07 or so) the CIA issued a certain number (something like 30,000, I think), and it was soon rebutted by some fairly left-leaning advocacy group, who claimed a number more like 800,000.
I imagine the latter was probably way high, and I'm certain the CIA number was outrageously low (especially since the smartest, best-informed journalists uniformly agreed that the CIA number was completely impossible).

Anyway, to bring it back to the present discussion, let's consider the total radiation released at Fukushima.
When Busby tells me it exceeds Chernobyl by a large margin, with no supporting evidence I can see, I automatically toss that out.
When TEPCO tells me, after weeks of dithering, obfuscating, screwing up, dissembling, etc., that it's 10% that of Chernobyl... I figure that's probably a lower limit at which to start the discussion.
When I then find out that that number's from data two weeks old, that they seem to have conveniently 'ignored' all the water-borne contamination, that they used an assumption that roughly doubled Chernobyl's official release-numbers, not to mention that it's continuing to compound every day, and now that they grossly understated the current release-rates... well, those are all pretty good indications.

I'd figure maybe I could double TEPCO's number, and I'd likely be in the right rough ballpark.
I doubt very much I'd be too far low, and I'd probably be well within an order.

Anyway, that's all in the vein of general rambling about common-sense guidelines for analyzing disasters with scant information.

It served me very well in looking at the Gulf last year --as the numbers I was guessing weeks before ended up being pretty damn close to the ones BP publicly conceded later on--
and I'm finding the parallels here quite amazing.




Azby said:
I appreciate that members of this forum are wiling to consider all possibilities. It's open minded and good science. But I have serious questions about Gunderson's credibility, as well as Busby's. The latter's arguments concerning radiation epidemiology, his ecological studies of Sellafield, and his "Second Event Theory" of DNA mutation have been pretty well demolished more than once. The report of the CERRIE committee from 2004 makes very informative reading in this regard. It notes that as far as Busby's claims are concerned, "The Committee concluded that the available scientific evidence did not support these hypotheses and, in many cases, substantially contradicted them." He threw a fit. Time and again during committee, one of which he chaired, he was asked to provide the papers upon which he based various claims so the others could review them, and was unable to. Sloppy does not begin to describe it. He makes this stuff up.

http://www.cerrie.org/report/

(For the record, I've been lurking for a while and just signed on. I'm not a scientist, but direct a design theory lab in Tokyo, doing mainly environmental design studies as well as a long-term collaboration with a neuroscience team on hand-brain issues. I'm learning a lot here. My hats off to you all)
 
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  • #5,221
dh87 said:
I thought that you might know, since you propounded a theory. In elektrownik's theory, the oxygen for the initial hydrogen explosion is in the building above the SFP. Then, the second fireball occurs above the building after the hydrogen released from the primary containment vessel has a chance to mix with atmospheric oxygen.

Sorry if that sounded dismissive. There were several in depth exchanges about the nitrogen atmosphere, leaking steam, displacement of the nitrogen, steam + zircaloy reactions, earthquake damage to the containment structure and the like. My initial proposal of an explosion was first refuted because of the nitrogen atmosphere (which I was unaware of at the time), but then the possibility of an explosion within the drywell containment was credibly explained by someone much more knowledgeable than I about such things. Regrets that I don't seem to retain the exact explanation, other than perhaps the notion that it might have occurred that way wasn't totally out of the question.

Speculative, yes, but none of it impossibly so, IMO. And there must be some physical explanation to "fit" the various pieces of visual evidence which led to my speculation and subsequent theory in the first place. But I haven't the energy just now, and it is certainly not my intent to attempt to summarize anything that might or might not have been agreed to in thousands of posts and hundreds of pages of observations and opinions only to initiate yet another rehash of what was already hashed and rehashed before. To the extent I may have already done that, I apologize.

The point is that the explosion at Bldg 3 was 1) unique, and 2) not necessarily explained only by a "nuclear" explosion in the SFP.
 
  • #5,222
SFP4 again ... TEPCO: Water isn't leaking from No. 4 reactor pool
confusion reigns again!

http://www3.nhk.or.jp/daily/english/28_05.html
Water is being injected into the pool to replace coolant that is evaporating due to the high temperature of its 1,535 spent fuel rods.

Despite sporadically injecting 140 to 210 tons of water a day, the company says the water level in the storage pool is still 10 to 40 centimeters lower than estimated.

But the company said on Wednesday that it now believes that the water has been evaporating at a rate in line with calculations by experts.

So let's believe Tepco:

Stock of SFP4
548 Spent/partially Fuel assemblies 4 month old about 2MW
783 Spent Fuel Assembles >> 4 months about 0.4kW
204 Brand new assemblies (heat negligable)
Total heat in pool 2.4MW which will boil away 80tons/day of water

only yesterday 27/4/2011 Tepco stated that 70 tons/day of water is required to cool SFP4
today they state they need to boil away 175 tons ((140+210)/2) of water
This would need 5.2MW of heat

were is this extra 2.8MW heat coming from
as we can believe Tepco then we need to believe that SFP4 is subcritical

Actually it looks like some clever dick at tepco rated the older 783 fuel rods as if they were unloaded of the reactor 4 months ago and then proudly announced to his manager that he can prove that the pool is not leaking
 
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  • #5,223
Astronuc said:
See this post - https://www.physicsforums.com/showpost.php?p=3213820&postcount=1622

The drywell should have been inerted, but with an overpressure event, leaks could have developed. I'm not sure the explosion happened in the drywell, but above the drywell and above the reactor service floor in the seconary containment. The hydrogen and some steam leaked from primary containment up into the secondary containment where the hydrogen ignited in air.

Unit 3's explosion was significantly great than that of unit 1. Unit 3 has a larger core, and there is some thought that seawater is more corrosive than normal reactor water - it cerainly is for stainless steel - but it may be more corrosive for Zircaloy in the presence of soluble iron (Fe3+), and thus Unit 3's core produced a lot more hydrogen than Unit 1. Unit was didn't have seawater injection before it popped, whereas Unit 3 had seawater injection about 22 hrs or so before its explosion.

The pressure vessel, the dry well, and suppression chamber were all well above atmospheric pressure leading up to the explosion, if the data that Jorge Stolfi has graphed are reliable. It seems to me that oxygen would have to be generated internally. And not just a little bit of oxygen. The water in the RPV is boiling, presumably, and purging the RPV rapidly. There might not be enough steam to purge the containment vessel rapidly (disclaimer: I don't understand the venting well enough to be clear about this), but there should be enough flow to prevent buildup of the oxygen generated by radiolysis.
 
  • #5,224
TCups said:
Sorry if that sounded dismissive. There were several in depth exchanges about the nitrogen atmosphere, leaking steam, displacement of the nitrogen, steam + zircaloy reactions, earthquake damage to the containment structure and the like. My initial proposal of an explosion was first refuted because of the nitrogen atmosphere (which I was unaware of at the time), but then the possibility of an explosion within the drywell containment was credibly explained by someone much more knowledgeable than I about such things. Regrets that I don't seem to retain the exact explanation, other than perhaps the notion that it might have occurred that way wasn't totally out of the question.

Speculative, yes, but none of it impossibly so, IMO. And there must be some physical explanation to "fit" the various pieces of visual evidence which led to my speculation and subsequent theory in the first place. But I haven't the energy just now, and it is certainly not my intent to attempt to summarize anything that might or might not have been agreed to in thousands of posts and hundreds of pages of observations and opinions only to initiate yet another rehash of what was already hashed and rehashed before. To the extent I may have already done that, I apologize.

The point is that the explosion at Bldg 3 was 1) unique, and 2) not necessarily explained only by a "nuclear" explosion in the SFP.

I will try to read some of the earlier pages during this week. I started reading maybe 75 pages ago (?). Sorry if this topic had been extensively discussed previously.
 
  • #5,225
etudiant said:
Very much agree. The site selection and setup was arguably criminally negligent.
So no brief for TEPCOs management or their government supervisors.
However, the workers and contractors on the site, plus their line managers, who are busting their hump in an extraordinarily bad situation, deserve all the support we can give them. Their cautious approach may be mistaken, the steaming spent fuel pools may poison so much more of Japan that the leadership insists on a quicker fix, but given the flooding in the plant, nobody, not KHG, not Sandia, not anybody has appropriate waterproof robotic tools ready to go. The TEPCO crews are on their own.

"Criminally negligent"? Talk about over the top, sheesh.

I seem to remember someone posting about an article that basically said there are no TEPCO personnel on the ground doing the dirty work; they're all "jumpers", i.e. paid mercenaries after a fashion, who are being compensated handsomely for doing very risky jobs. Do they "deserve all the support we can give them"? What does that mean, exactly? Is that like friending them on facebook or something?

Edit: Ah yes, here it is about jumpers...
http://www.reuters.com/article/2011/04/01/us-japan-quake-jumpers-health-idUSTRE7303HD20110401
 
  • #5,226
TCups said:
OK, thanks Astronuc. Then, at least in my opinion, having not been convinced otherwise by any hard data or inconsistency in the photographic or video evidence, I am still clinging to the sequence I had first hypothesized: 1) hydrogen explosion in the drywell containment of RPV3, 2) directed venting of the explosion into the upper SFP3 via the fuel transfer chute (and also into the torus), 3) secondary explosion of the hydrogen in the upper floor of Bldg 3 (also from hydrogen originating from the reactor core of Unit 3 and probably not SFP3 damaged fuel), and, almost simultaneously, 4) hot water vaporization/steam explosion mushrooming vertically from the SFP3.

If there was an explosion in the drywell on the 14th, why did Unit 3 not lose drywell pressure until a week later?

http://www.ic.unicamp.br/~stolfi/EXPORT/projects/fukushima/plots/cur/plot-un3-full.png
 
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  • #5,227
etudiant said:
This is over the top, imho.
Does anyone have either the record or the competencies to assume entitlement to judge?
Japan is the very first victim of this disaster and they are certainly in constant communication with the world's nuclear community to get the best available counsel.
This situation is a mess exacerbated by the disaster that generated the problem and also hid its gravity during the crucial early days. At this point, with the plant flooded 20 feet deep by highly radioactive effluent, we are all in an unprecedented situation. No one knows what to do.
TEPCOs approach, going slow, building water treatment plants and cleaning up the site may be right or entirely wrong. With 500 people on site, versus the usual 5000, they are clearly biding their time.

Of course, maybe the only way to avoid a much greater problem is to throw people at it. However, unless someone has a plausible plan that shows real benefits, it is unreasonable to push for an acceleration, because the human cost would rise dramatically.

Start with the Bloomberg article that is quoted at this http://www.bloomberg.com/news/2011-03-17/japan-s-nuclear-disaster-caps-decades-of-faked-safety-reports-accidents.html" . Greenpeace site has a history of cover ups by the Company. It's no big secret, record keeping, cracked shrouds, MOX fueling, trying to extended the end life of a 40 year old reactor...recently, some type of media scrubbing of any negative reporting...This Forum should be getting an email any day now.

Edit: Changed to a direct Bloomberg article link.
 
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  • #5,228
sp2 said:
Then you gradually start to edge towards the truth, which is almost always somewhere between the most extreme representations.
You have to be careful with that. It holds true when a situation is not entirely clear, but there are many cases where you have established facts on one side, and another party that wishes to obfuscate the truth. In those cases the truth does not lie in the middle. Facts do not require an extreme opposing view for "balance".
sp2 said:
Similarly with the numbers of civilian deaths involved in the war in Iraq.
Nobody knows exactly what that number is. I do remember that at some point (perhaps in '07 or so) the CIA issued a certain number (something like 30,000, I think), and it was soon rebutted by some fairly left-leaning advocacy group, who claimed a number more like 800,000.

It's telling that you consider http://www.washingtonpost.com/wp-dyn/content/article/2006/10/10/AR2006101001442.html" to be a "fairly left-leaning advocacy group".
 
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  • #5,229
razzz said:
.This Forum should be getting an email any day now.

Oh crap, not the dreaded/laughable "letter of request" from Japan's METI.
 
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  • #5,230
razzz said:
recently, some type of media scrubbing of any negative reporting...This Forum should be getting an email any day now.

Somebody want to provide a link that gives evidence for this assertion?
Did this come from some press conference or something?
 
  • #5,231
etudiant said:
Very much agree. The site selection and setup was arguably criminally negligent.
So no brief for TEPCOs management or their government supervisors.
However, the workers and contractors on the site, plus their line managers, who are busting their hump in an extraordinarily bad situation, deserve all the support we can give them. Their cautious approach may be mistaken, the steaming spent fuel pools may poison so much more of Japan that the leadership insists on a quicker fix, but given the flooding in the plant, nobody, not KHG, not Sandia, not anybody has appropriate waterproof robotic tools ready to go. The TEPCO crews are on their own.
Yep... if there is aftershock, spent fuel pool #4 might fall apart, and that is potentially a multiple Chernobyl-level disaster in terms of land lost (if the wind blows to land). The workers on-site realize that, and they are risking their lives, but there's so few of them, and it's all still handled by TEPCO for some reason, even though it really is a national emergency. The tsunami passed - there's no bringing back those who are dead - and this is a serious risk of severe loss of land there. IF spent fuel pool falls down - well i hope there is enough equipment on site to spray cool it, and i hope it won't go critical when cooled, and if it does, it'd be great if they start planning how to cool something that goes critical when you pour water on it (may still be possible to cool).
Upper management, however, I do not know.
I would think one could just directly check if the spent fuel pool is leaking or not, with some tracer.

This may be less than Chernobyl at the moment. But there's so many more things that have to be prevented. It is a more serious disaster in terms of work that has to be done.
 
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  • #5,232
rowmag said:
Somebody want to provide a link that gives evidence for this assertion?
Did this come from some press conference or something?

http://japanfocus.org/-Makiko-Segawa/3516"
 
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  • #5,233
rowmag said:
Somebody want to provide a link that gives evidence for this assertion?
Did this come from some press conference or something?

Excerpt from Asia Pacific Journal

"Now the Japanese government has moved to crack down on independent reportage and criticism of the government’s policies in the wake of the disaster by deciding what citizens may or may not talk about in public. A new project team has been created by the Ministry of Internal Affairs and Communication, the National Police Agency, and METI to combat “rumors” deemed harmful to Japanese security in the wake of the Fukushima disaster.

The government charges that the damage caused by earthquakes and by the nuclear accident are being magnified by irresponsible rumors, and the government must take action for the sake of the public good. The project team has begun to send “letters of request” to such organizations as telephone companies, internet providers, cable television stations, and others, demanding that they “take adequate measures based on the guidelines in response to illegal information. ”The measures include erasing any information from internet sites that the authorities deem harmful to public order and morality."
 
  • #5,234


rowmag said:
If there was an explosion in the drywell on the 14th, why did Unit 3 not lose drywell pressure until a week later?]

That's the thing about Unit 3, the pressure remained intact so it wasn't the reactor or its containment which exploded. Looks like the SFP (spent fuel pool) is what explodes, after an initial implosion. Something escaping from the reactor which secondarily ignited the SFP is possible.
 
  • #5,235
rowmag said:
Somebody want to provide a link that gives evidence for this assertion?
Did this come from some press conference or something?

TEPCO apparently complained that some of their blueprint drawings had "leaked" onto the internet http://www.asahi.com/english/TKY201104260122.html

The Japanese version was even more critical, at least when put through Google's translator.

Nancy Foust has posted her reaction http://www.houseoffoust.com/fukushima/

I don't particularly care for Foust's website, but my objections have more to do with her rampant speculations and bad photo analysis, and less to do with the documents she posts. If you've followed her pages over the last several weeks you would have noticed, more than once, where people right here in this thread discuss something, and then she picks up on it and modifies her analyses to match. For a while she had one photo up and claimed it was taken on the refueling floor of Unit 4. We discussed that photo here a week or so ago, and when evidence was presented that the photo was not, in fact, from Unit 4, her website changed its tune within a couple of hours. (Hi, Nancy!)

Despite the fact that her website is peer-review-proof (unlike here, heh), I think it's pretty low that TEPCO would try to actually go after her with legal action. I don't think they could, really. Trade secrets are not patents or copyrights, and once revealed publicly are fair game. Besides, the patents are most likely owned by GE anyway, and after 40 years there isn't much protection left, if any. It's pretty stupid to think anyone would want to copy TEPCO's Mark I reactor designs today.
 
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  • #5,236
AntonL said:
SFP4 again ... TEPCO: Water isn't leaking from No. 4 reactor pool
confusion reigns again!

http://www3.nhk.or.jp/daily/english/28_05.html


So let's believe Tepco:

Stock of SFP4
548 Spent/partially Fuel assemblies 4 month old about 2MW
783 Spent Fuel Assembles >> 4 months about 0.4kW
204 Brand new assemblies (heat negligable)
Total heat in pool 2.4MW which will boil away 80tons/day of water

only yesterday 27/4/2011 Tepco stated that 70 tons/day of water is required to cool SFP4
today they state they need to boil away 175 tons ((140+210)/2) of water
This would need 5.2MW of heat

were is this extra 2.8MW heat coming from
as we can believe Tepco then we need to believe that SFP4 is subcritical

Actually it looks like some clever dick at tepco rated the older 783 fuel rods as if they were unloaded of the reactor 4 months ago and then proudly announced to his manager that he can prove that the pool is not leaking
When you read between the Words. Tepco say the Pool is not leaking, but what about the Reaktor vessel, Water lines etc, the Gate to the Reaktor is open! It is the same Water in the Pool as in the Reaktor.
 
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  • #5,237
AntonL said:
SFP4 again ... TEPCO: Water isn't leaking from No. 4 reactor pool
confusion reigns again!

http://www3.nhk.or.jp/daily/english/28_05.html So let's believe Tepco:

Stock of SFP4
548 Spent/partially Fuel assemblies 4 month old about 2MW
783 Spent Fuel Assembles >> 4 months about 0.4kW
204 Brand new assemblies (heat negligable)
Total heat in pool 2.4MW which will boil away 80tons/day of water

only yesterday 27/4/2011 Tepco stated that 70 tons/day of water is required to cool SFP4
today they state they need to boil away 175 tons ((140+210)/2) of water
This would need 5.2MW of heat

were is this extra 2.8MW heat coming from
as we can believe Tepco then we need to believe that SFP4 is subcritical

Actually it looks like some clever dick at tepco rated the older 783 fuel rods as if they were unloaded of the reactor 4 months ago and then proudly announced to his manager that he can prove that the pool is not leaking
Hmm. Such revisions are pretty scary. I do hope for everyone's sake its some sort of miscommunication and they don't actually have to pour 175 tons of water per day, that it was just some 'whoops water level below optimal, need to add a lot of water' day.

TEPCO complaining about blueprint leak, that's just crazy, in terms of PR.
 
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  • #5,238
MiceAndMen said:
It's pretty stupid to think anyone would want to copy TEPCO's Mark I reactor designs today.

I put those blueprints up on this thread yesterday. They are all over the net by now. What's METI going to do, hire a room full of full time letter of request senders?

I agree, who the heck would want to copy that design. I don't think our enemies are that stupid.
 
  • #5,239
Danuta said:
I put those blueprints up on this thread yesterday. They are all over the net by now. What's METI going to do, hire a room full of full time letter of request senders?

I agree, who the heck would want to copy that design. I don't think our enemies are that stupid.

They were posted in this thread several times over the last few weeks. The first one I remember was on 7 April by Sirius (b), and it's possible his wasn't the first
https://www.physicsforums.com/showthread.php?p=3235048#post3235048

I'd be more concerned about a couple of (hate to use the word, but) kamikazes from North Korea aiming a few planes into the reactor buildings right about now, to be honest. Or a massive typhoon blowing through next month. Or another earthquake rattling the already unstable buildings. I think it's safe to say that if this happened on US soil a tight lid on all information would have descended in the name of national security. They would have established an evacuation zone, and we'd be hearing even less than what we're hearing out of Japan.
 
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  • #5,240
MiceAndMen said:
They were posted in this thread several times over the last few weeks.

Okay, didn't notice. It's a long thread.
I'd be more concerned about a couple of (hate to use the word, but) kamikazes from North Korea aiming a few planes into the reactor buildings right about now, to be honest. Or a massive typhoon blowing through next month. Or another earthquake rattling the already unstable buildings.

Not too worried about N.Korean suicide planes more than all their missiles. Taifuns are worrisome, more quakes are worrisome, just a steady shift of wind blowing inland is worrisome. SFPs are very worrisome.
 
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  • #5,241
MiceAndMen said:
TEPCO apparently complained that some of their blueprint drawings had "leaked" onto the internet...
The Japanese version was even more critical, at least when put through Google's translator...
I think it's pretty low that TEPCO would try to actually go after her with legal action. I don't think they could, really. Trade secrets are not patents or copyrights, and once revealed publicly are fair game. .



内部資料と思われる naibu-shiryou to omowareru

[TEPCO says] "These appear to be internal documents"


これまでも設計図について、東電は「メーカーのノウハウがある」などの理由で公表を拒否している。

koremade mo sekkeizu ni tsuite, TEPCO ha "meekaa no nouhau ga aru" nado no riyuu de kohyo o kyohi garbagee iru

"Regarding these blueprints, up until now TEPCO refused to make them public, saying "they contain the know-how of the maker"
 
  • #5,242
MiceAndMen said:
You have to be careful with that. It holds true when a situation is not entirely clear, but there are many cases where you have established facts on one side, and another party that wishes to obfuscate the truth. In those cases the truth does not lie in the middle. Facts do not require an extreme opposing view for "balance".

Thanks.
In general terms, you're correct, no doubt .

I was really trying to make a broad point that, in cases of widely divergent answers, from sources with obvious, and contrary agendas, it tends to be a good bet that the truth lies somewhere between.
There are lots of examples, but I think Fukushima is a very good one.

On one hand, you've got TEPCO, the Japanese government, and various reps of the nuclear power industry --all with obvious and powerful incentives to low-ball the numbers, and a proven track-record of lying and covering up.

On the other, you've got lots of groups with a dead-set position against any kind of nuke power, ever, anywhere, with an obvious incentive to make it look as bad as possible.
(You've got Arnie Gunderson, as the front man for a wind-power company. It doesn't take a whole lot of imagination to see his incentives, does it?)

When those two sources give me vastly divergent statistics, it's probably a pretty good bet that the truth lies somewhere in between.

Clear enough?


It's telling that you consider http://www.washingtonpost.com/wp-dyn/content/article/2006/10/10/AR2006101001442.html" to be a "fairly left-leaning advocacy group".

Actually, I don't. I simply didn't remember who it was, and didn't feel like looking it up just then. I remembered thinking that there were obvious reasons to distrust the CIA's numbers, but also that the high-end number sounded quite extreme, too.
I suspect that I was right on both counts, but I apologize if I mischaracterized the source of the higher number.

(I'm actually pleased to see that my hazy recollections of the numbers involved were extremely accurate. I had Bush's (CIA's) number perfect, and wasn't too far off on the other.)

In the Gulf Spill last year, I concluded after a while that doubling whatever BP said (that's after every time they re-evaluated, and issued updated, much-worse numbers) would probably put me in the right ballpark, and that served fairly well.

Until I have good reason to alter it, I'm working off a similar logical framework here.

When TEPCO tells me it's 10% of Chernobyl, I'll assume it's most likely at least 20%, and I'm fairly sure that I at least won't be way high.
Could I be way low? Yeah, I suppose so, but I'll wait for better evidence to support that.
(And, if it *is* way low, there will surely be evidence of that, eventually. Even if it takes a while to seep out, so to speak.)

Have a good night.

(Again, sorry to cast aspersions on the Iraqi and American epidemiologists.)
 
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  • #5,243
Curium said:
内部資料と思われる naibu-shiryou to omowareru

[TEPCO says] "These appear to be internal documents"


これまでも設計図について、東電は「メーカーのノウハウがある」などの理由で公表を拒否している。

koremade mo sekkeizu ni tsuite, TEPCO ha "meekaa no nouhau ga aru" nado no riyuu de kohyo o kyohi garbagee iru

"Regarding these blueprints, up until now TEPCO refused to make them public, saying "they contain the know-how of the maker"

Thank you for the translation. In the case of Unit 1, the maker was General Electric, so maybe they're trying to cover their butts with GE. I don't see that the technical details have any value whatsoever today. Nobody looking to compete with them in the reactor-building business is going to glean any useful information from those old Mark I designs. Although I must say, if it were not for the Spent Fuel Pools and their loads, this story would be playing out very differently.
 
  • #5,244
Curium said:
"Regarding these blueprints, up until now TEPCO refused to make them public, saying "they contain the know-how of the maker"

Pardon me if I bust a gut laughing.
 
  • #5,245
MiceAndMen said:
They were posted in this thread several times over the last few weeks. The first one I remember was on 7 April by Sirius (b), and it's possible his wasn't the first
https://www.physicsforums.com/showthread.php?p=3235048#post3235048

I'd be more concerned about a couple of (hate to use the word, but) kamikazes from North Korea aiming a few planes into the reactor buildings right about now, to be honest. Or a massive typhoon blowing through next month. Or another earthquake rattling the already unstable buildings. I think it's safe to say that if this happened on US soil a tight lid on all information would have descended in the name of national security. They would have established an evacuation zone, and we'd be hearing even less than what we're hearing out of Japan.



<< I think it's safe to say that if this happened on US soil a tight lid on all information would have descended in the name of national security. They would have established an evacuation zone, and we'd be hearing even less than what we're hearing out of Japan.>>

It's awfully tough to say, of course, but I think you're probably wrong on that point.

Best analog is BP last year. Their degree of forthright-ness was sickeningly low, just as with TEPCO.
But, if nothing else, we had Rep. Markey raising a stink, and forcing them to put up the webcam. That alone made a hell of a lot of difference, in the face of all the BS they publicly proclaimed.

The same thing at Fukushima would be absolutely invaluable, but there's no Rep. Markey, or anything remotely alike, anywhere in Japanese government.

I almost hate to say it, but the Japanese desperately need some loudmouthed, grandstanding congressmen.

In this case, that's one big edge we have on them.
 
  • #5,246
sp2 said:
<< I think it's safe to say that if this happened on US soil a tight lid on all information would have descended in the name of national security. They would have established an evacuation zone, and we'd be hearing even less than what we're hearing out of Japan.>>

It's awfully tough to say, of course, but I think you're probably wrong on that point.

Best analog is BP last year. Their degree of forthright-ness was sickeningly low, just as with TEPCO.
But, if nothing else, we had Rep. Markey raising a stink, and forcing them to put up the webcam. That alone made a hell of a lot of difference, in the face of all the BS they publicly proclaimed.

The same thing at Fukushima would be absolutely invaluable, but there's no Rep. Markey, or anything remotely alike, anywhere in Japanese government.

I almost hate to say it, but the Japanese desperately need some loudmouthed, grandstanding congressmen.

In this case, that's one big edge we have on them.

You're right on that last point. I really don't know. Years ago, absolutely, the information would be out and about. Today there are too many vested interests looking to control the flow of information. You may be right, though. With something this big public pressure would be enormous.
 
  • #5,247
Jumpin' Jesus, did anybody else see this?

http://af.reuters.com/article/energyOilNews/idAFN2718319320110428

I mean, hopefully, there's no big problem there, but I have to admit, the headline made my hair stand up a little.

It reads like God's having a crappy year, and decided to really teach the humans a lesson.

(I'm starting to think the Big Guy might be strongly Anti-Nuke.)
 
  • #5,248
I read it. The same thing happened with two reactors in Virginia recently. That Achilles heel of nuclear power plants is starting to look like it could be a real problem. Especially with spent fuel rods also being stored on sight, and needing a lot of power to keep them cool as well.
 
  • #5,249
robinson said:
I read it. The same thing happened with two reactors in Virginia recently. That Achilles heel of nuclear power plants is starting to look like it could be a real problem. Especially with spent fuel rods also being stored on sight, and needing a lot of power to keep them cool as well.


At least the Powers that Be have a sense of humor. (Who knew Alabama was a freaking tornado zone?)
 
  • #5,250

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