According to NHK (11/15/2013), TEPCO will start removing the fuel assemblies from the Spent Fuel Pool of Reactor 4 at Fukushima I Nuclear Power Plant on Monday, November 18.
TEPCO will start with unused (therefore not irradiated) new fuel assemblies (there are 202 of them in the pool). 22 new fuel assemblies will be the first to be moved UNDER WATER into the container (called "cask") in the cask pit, using the fuel handling machine. Then the sealed cask will be lifted out of the pool by the gantry crane onto the truck waiting on the ground, which will transport the cask to the Common Pool about 100 meters away. TEPCO has two casks to be used for transport.
After removing 22 new fuel assemblies, then TEPCO will start removing the spent fuel assemblies. The removal is scheduled to continue until the end of next year, "ahead of schedule" as has been loudly demanded by the LDP politicians.
The fuel handling machine in the foreground, over the Spent Fuel Pool, and the gantry crane in the back, as workers conduct a dry-run on November 14 using mock fuel assemblies on the Reactor 4 operation floor (from TEPCO, 11/15/2013; click to enlarge; follow the link for more photos):
Workers who tweet from Fukushima I Nuke Plant say the people who will be operating the fuel handling machine and the gantry crane are the workers with long experience and expertise in fuel handling, from TEPCO's primary contractors. Not "yakuza and rank amateurs".
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To disabuse some people, including scholars and experts (albeit in different fields, not related to nuclear energy or nuclear power plant technologies, or who simply have not followed the Fukushima nuclear accident much other than catching some soundbites), the following is NOT, I mean NOT, how the fuel assemblies will be removed. (I couldn't believe it at first, but there were many in Japan for example who thought the removal would be done exactly like this. Maybe they still do...)
First, we use a crane like this one (whose jib mast collapses after 1:35 into the video)...
And we will take out individual fuel "rods" (and not fuel assemblies) one by one, like this one being taken out of the fuel assembly (casing has been already removed)(from TEPCO, 8/28/2012):
And using the crane in the first photo, and pull the fuel "rods" out of the pool into open air, irradiating the workers regardless of whether the "rods" are new or used, like this (except in this case it was an unused new fuel ASSEMBLY with the casing, not an individual rod)...
Then the "rods" will then be placed in a container, and the container will be lowered to the ground...
In the process, a mishap may occur, and the fuel rods may be scattered on the ground, then they go critical.
And on and on till the end of either the northern hemisphere or the entire planet.
This dire scenario is best summarized by a Yale University sociology professor (emeritus), who says the Reactor 4 SFP is in danger of collapsing (from Huffington Post 9/20/2013; emphasis is mine):
Much more serious is the danger that the spent fuel rod pool at the top of the nuclear plant number four will collapse in a storm or an earthquake, or in a failed attempt to carefully remove each of the 1,535 rods and safely transport them to the common storage pool 50 meters away. Conditions in the unit 4 pool, 100 feet from the ground, are perilous, and if any two of the rods touch it could cause a nuclear reaction that would be uncontrollable. The radiation emitted from all these rods, if they are not continually cool and kept separate, would require the evacuation of surrounding areas including Tokyo. Because of the radiation at the site the 6,375 rods in the common storage pool could not be continuously cooled; they would fission and all of humanity will be threatened, for thousands of years.
Just like many North American experts, the professor simply declares conditions in the Reactor 4 SFP are "perilous". The common Pool is 100 meters away, not 50 meters. It's not "rods" but "assemblies". No idea what he's talking about when he says "two of the rods touch", but I have seen this phrase in other places from other experts. It must be part of the standard things to say if you are to comment on the fuel "rods" from the SFP at Fukushima I Nuke Plant. That Tokyo is part of "surrounding areas" of the plant would be news to most Japanese.
Compared to other reactors that suffered the core melt, the air radiation levels in Reactor 4 have been low enough (measured in microsievert/hour instead of millisievert/hour in other reactors) to allow human workers to work inside the reactor building and on the top floor for the past two and a half years.
For a fond memory, this was the operating floor of Reactor 4:
March 16, 2011:
April 10, 2011:
June 30, 2011:
30-Day free trial by following the link.
Tokyo Time
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31 comments:
Too bad no one can get the terminology correct. Fuel pellets go inside fuel rods, fuel rods go inside fuel bundles (9"x9" hold about 63 fuel rods). Fuel 'assemblies' refers to a different type of reactor fuel load (a group of 4 bundles arranged so moderating blades can be inserted between them). Fuel racks hold the bundles and have dividers or 4 walls of boron around a bundle to keep it shielded from other bundles (absorbs neutrons thus prevents fission reactions).
The preparations for the SFP 4 cleanup were expensive but straightforward, working in a relatively uncontaminated space.
Presumably afterwards TEPCO will demolish the wrecked structure to improve the access to the remaining reactors.
The next step will be to create a similar setup on reactor 1, but that will take another couple of years at least.
My guess is TEPCO will try to get control of the ground water situation first, because that is now the largest problem. The three wrecked reactors are messes, but apart from the water pollution, they are not causing trouble.
TEPCO hopes to get to the point where the reactors can do without additional cooling water injections, or at least to the point where there is no further leakage from the site and the cooling water can be made up solely of decontaminated water. Then the problem will be contained enough for the political leadership.
Ahh thanks for the correction on the fuel terminology, I think I have been using it incorrectly.
Anyway, does anyone have any idea what was being stored in the machinery/equipment pool at #4? That is what blew up on March 15th, 2011 that destroyed the building walls, and everything on the reactor floor - but remarkably left the SFP4 and the reactor core able to still hold water. All of which is pretty clearly shown in the photos above.
In July of 2011 they completed the work reinforcing the floor of the SFP4, so there is no chance it will fall down - despite all the idiots who keep repeating the "world is doomed because of SFP4" crap.
That is misinformation to keep you focused on the least dangerous part of a very dangerous place.
The danger of Fukushima does not lie in SFP4, it lies in whatever exploded in the #4 machinery pool, and the core of #3 which blew up the day before #4 blew.
Please stop sucking down the misinformation folks. Arnie is on the nuke industry's payroll feeding it to you...
James
The old core shroud, just removed from the reactor, was in the Reactor 4 DSP when the accident happened. It was highly irradiated and "hot".
Core shroud might have been highly irradiated, but it didn't blow the building
up. Something else was in there. Something much, much hotter.
That's the pool that was dried up after the accident, not the SFP, and that's where the explosion came from.
I strongly suspect they had hot MOX in that pool ready to drop in as soon as the repairs were made.
James
Unit 4's equipment pool (opposite the fuel pool with the reactor in-between) is holding pieces of the old cut up shroud that was removed and why the reactor core fuel was emptied and moved into the spent fuel pool temporarily for the shroud replacement. Plus there is some special handling equipment for the shroud replacement either in the equipment pool and/or still in the reactor core.
While the old stainless steel shroud is radioactive, nothing in the equipment pool to go boom. Probably more misinformation from excitable people that gives a misleading picture of what happened in Unit 4. Not that the entire site is a disaster in itself. Mostly likely hydrogen coming from somewhere was the major contributor for an explosion. Fires, could have been caused from equipment fuel, oil, hydraulic fluids, etc.
Unless the emergency support structure built underneath Unit 4 pool is meant to be freestanding then worry about the pool is justified. The supporting structure uses the outside of the containment shell as support and is not completely supporting the entire pool bottom.
Unit 4 lost water in the pool when the gate's rubber seal to the reactor failed for some reason. I think workers used plastic sheets to stuff and stop the leak temporarily. If the pool did leak out through the gate it would only leak to a level that fuel travels in to and from the pool to the reactor as the fuel has to been underwater to be shielded when moved by the refueling crane at all times.
In other words, the bottom of the gate/channel is still above the top of the stored fuel in the pool and if the bundles are say 14' tall then their has to be at least 14'+ water over the top of the stored fuel so bundles can be lifted up out of the racks and over into and out of the reactor and still be underwater the entire time. So, so a gate leak can not empty the pool of all water. In fact there is no drain or pipe at the bottom of the pool, any water would have to boil away to leave a pool empty.
Arnie Gundersen wrote a best selling book in Japanese to explain to the people there what was going on and what might happen with Fukushima, Daiichi fallout. Hardly acting like a nuke industry lackey.
Neither the SFP nor the DSP went dry, it turned out.
Anon at 9:51PM, Gundersen claimed that fuel racks were totally outside the pool. I'm not aware he has retracted that statement. Bestselling in Japanese? That doesn't mean much other than the Japanese are naively gullible.
James, evidence is that the explosion took place NOT on the operating floor where the SFP and the DSP are located, but the floor below it.
Look at the fly over video of 4's pool, the top of the racks and fuel are clearly exposed to air with only steam occasionally wafting by them. If you have a hard-on for Gundersen, keep it to yourself.
>If you have a hard-on for Gundersen, keep it to yourself.
OK, you're talking to yourself, then.
All of the evidence points to the fact that SFP4 was dry for several days due to a major leak caused by the original earthquake. During that period there was a serious zirc fire (which likely volatilized most of the inventory) and subsequent H2 explosions destroyed the building. The NRC chairman reported the dry pool situation to the US congress at the time...
When TEPCO finally managed to get near enough to the building to try to refill the pool, a week after the earthquake, they found that for every 23 tons of water added 22 tons leaked!
It seems to me that this whole exercise is likely nothing more than a PR job, sadly :(
See the following site for the FOIA paper trail proving the above to be the case:
http://plumegate.wordpress.com/
Thank you, anonymous@4:01, for a very helpful link.
It seems to me that the more dire assessments made by the US NRC staff at the time of the accident and documented there were clearly incorrect.
For one, the SFP 4 is clearly intact and holding water today, contrary to what was asserted then.
For another, the fuel racks in the pool remain in an orderly array, which seems implausible if there had been a dry pool with a zirconium fire leading to massive explosions.
Finally, if there had been a serious fire, the pool water chemistry would be hugely altered, from the oxides etc created by the fire. We have had no indications of this.
It is of course true that we may have been fed a cover story and that the NRC reports were not the result of confusion and misunderstanding of an accident in progress, but that is quite improbable.
For one, the SFP4 clean up work is ongoing with pretty full coverage and there are enough workers transiting through that a coverup here is infeasible.
For another, the actual unloading is about to start Nov 18, so there will be more extensive coverage than at any time since the accident. TEPCO may be inept, but they are not suicidal. There is no way that they will launch this work unless they are super confident that it will run smoothly.
Of course, it is a PR job still, because the SFP 4 posed only a minimal danger, in contrast to the pools and cores in reactors 1-3, but the foolish focus of some on SFP 4 will, by clever PR judo, be used to burnish TEPCO's credentials when that relatively easy cleanup is executed smoothly.
This entire operation is little more than a photo-op. Once this job gets done, if it even can be done, then the insurmountable tasks TEPCO is still avoiding can begin.
NRC concedes Japan fuel pool not dry (Boston Globe, 6/16/2011) http://www.boston.com/news/world/asia/articles/2011/06/16/nrc_concedes_japan_fuel_pool_not_dry/ Some commissioners had already raised doubt on March 16, 2011.
Anon at 4:01AM, who are you? Are you the author of that blog you linked? If so, you and another blog seem to be responsible for the resurrected and wrong meme of "Unit 4 SFP is dry" in the past few days. Why are you doing this?
netudiant, why do you view the pools in reactors 1-3 as more dangerous? Weren't those buildings/pools deemed more stable than that of reactor 4? Of course, I understand that work to be done there is more problematic/impossible, but is that equivalent to the pools or their conditions being more dangerous?
Thanks.
*mscharisma*
"James, evidence is that the explosion took place NOT on the operating floor where the SFP and the DSP are located, but the floor below it."
Yes, the explosion was powerful enough below the reactor floor that it blew wall panels out beside the SFP - which is why they thought the SFP was dry.
However both the SFP and the DSP extend approximately 50 feet below the reactor floor. Studying the blast patterns, you find that the origin was somewhere within the confines of where the DSP was and yes, below the reactor floor. The blast blew the walls of the DSP out - it was gone.
The reason the SFP was spared was because the reactor itself shielded it from the explosion.
Which is exactly why I want to know what was in the DSP that blew. As I said, I strongly suspect it was a load of MOX ready to be inserted when the repairs were complete.
I have not seen any accounting of what was in the DSP at the time of the explosion.
James
"If you have a hard-on for Gundersen, keep it to yourself."
No, I'm not going to keep my opinions about Arnie to myself. I believe he has either been mounting a misinformation campaign for two years or he's incredibly ignorant.
Ask Arnie why he never mentions the MOX fuel on site...
Ask Arnie why he continually reports on the possible catastrophe of SFP4 - which is the single best example of where they've made progress in cleaning things up, and is the most stable fuel pool on site.
Ask Arnie why he talks about dangerous fires that might occur at SFP4, while a dangerous fire has actually been burning on site at #3 for two years running.
Ask Arnie why he never, ever talks about plutonium.
Ask Arnie why he never talks about the dangers of the Common Spent fuel pool.
Ask Arnie why he never mentions concerns about reactors 5 and 6.
Ask Arnie why he tried over and over again to prove that #3 explosion came from the SFP when overwhelming evidence proved it did not. Why he claimed over and over that the containment had not been breached when quite a bit of evidence to the contrary existed and he never even relented on that even after the truth had been told by Tepco.
I don't know what Arnie's gig is, but I know that over and over again he quotes directly from what I think must be the propaganda team's talking points. - "3 tons of radioactive water spilled from one of the tanks yesterday - it's a tragedy" or "#4 fuel pool is surely going to collapse and then Fukushima will be really dangerous".
Uhh knock, knock Arnie - The hot tub at the hotel down the street holds almost that much water - that kind of tiny spill is not the radiation release problem at the nuke plant. How about the source of the water that is steaming out of the fissures in the ground - the underground aquifer that laps up against three underground coriums daily
Knock, knock again Arnie - it's not about danger that might happen at SFP4, it's about danger that has happened, that is happening right now, elsewhere at the plant.
Sorry if it offends for me to point these things out.
James
Hi *mscharisma*,
I view the SFP 1-3 cleanup work as massively more difficult simply because they are collocated with hugely damaged and intensely radioactive reactor sites.
I recognize that TEPCO has been working steadily to remove debris and prepare the work surfaces, but afaik, no one has been able to walk on top of any of the three. There is a huge range of radioactivity within even reactors 1 and 2, from marginal to awful and there was really lethal contamination around reactor 3, some of which was bulldozed over.
So mounting the kind of fuel handling bridge that was built for SFP 4 will probably be impractical. There is an excellent status report here:
http://www-pub.iaea.org/iaeameetings/IEM4/30Jan/Suzuki_d.pdf
The SFP 4 crisis talk was deeply dishonest fear mongering, imho.
The building is upright, the pool is level and the blather about it collapsing into a sea of mud was and is just BS. It seems to be a common malady among true believers that any stick to beat the opposition with is good, even if this is more likely to injure you than the opponent. That is/was clearly the case here.
netudiant, I'm glad to see you meant SFPs 1-3 are more dangerous in the sense of "more dangerous to work on" rather than posing a greater threat to the environment than SFP 4 is or has been hyped up to be.
Thanks for the clarification.
*mscharisma*
Mscharisma - where do you get that #4 poses a greater threat to the environment than 1-3? Where does anybody get that?
Of course 1-3 are more dangerous to the environment. #4 is being cleaned up. 1-3 can't be touched and are releasing radioactivity continuously. They have melted fuel that has burned into the ground. It doesn't get any worse than that.
I had not seen the presentation netudiant linked. Nothing in there is surprising.
I might point out page 38 where they just casually mention that the fuel has melted out the bottom of the RPV and both the RPV and the containment are breached on 1-3.
Notice on slide 52 where they won't even be looking for any fuel in the RPV, the "investigation area" is the pedestal bottom - in other words they know the fuel is at best at the bottom of the pedestal and most likely in china syndrome under the building.
Oh, and if I read it right, they aren't even planning to look for it for 10 years or so.
James
The most interesting is the part
James,
I believe Gundersen mentioned very early that the NY Times reported that unit 3 pellets (hence plutonium) were found several km away from the plant.
Also, mscharisma is talking about the SPFs, not the units themselves.
Beppe
James, as Beppe pointed out (thanks, Beppe), I was referring solely to the state of the SFPs. I had since only come across info/hype regarding the SFP 4 being in a perilous state as far as building stability and/or pool integrity are concerned. In comments on this blog, I have read that SFPs 1-3 are more dangerous, so I asked for clarification.
Of course, reactors 1-3 pose a much bigger problem and threat to the environment than the SFP 4.
Beppe, the NYT had somehow obtained a document from the NRC that subsequently got blown out of proportion in terms of what was found, where, and what it indicated. All of it was based on this paragraph from the NRC's daiichi-assessment.pdf, page 10, regarding Unit 3:
"Fuel pool is heating up but is adequately cooled, and fuel may have been ejected from the pool (based on information from TEPCO of neutron sources found up to 1 mile from the units, and very high dose rate material that had to be bulldozed over between Units 3 and 4. It is also possible the material could have come from Unit 4)."
http://www.pdf-archive.com/2011/04/16/daiichi-assess/preview/page/10/
So it looks like the only given is that Tepco found neutron sources up to 1 mile away from the reactor and some highly radioactive "stuff" between units 3 and 4. Despite the key word "may" in the NRC document, the story then quickly took on a life of its own in subsequent reiterations and interpretations.
I am not aware of further info for the source of the neutron beams reported by Tepco or the bulldozed-over, highly radioactive materials. Of course, that doesn't mean it doesn't exist.
*mscharisma*
Yes I understood you only meant 1-3 SFP's, and yes, I meant they are much more dangerous than #4.
#4 is the only one that has been structurally reinforced, and #4 is the only one they've made a move to clean up. I suspect that's because it's the easiest and safest to clean up - not because it's the most dangerous.
James
James, then I'm back to my original question: why would SFPs 1-3 be more dangerous than SFP4? If the fuel in the pools is sufficiently covered by water, the water shields the radiation. Is that not so? Are the pools themselves or structures supporting them more unstable than the SPF4?
I see nothing in your previous post to that regard or anything else that would help me understand the concrete danger(s) you see re. SFP 1-3.
*mscharisma*
From my point of view 1-3 SFP's are more dangerous than SFP 4 for three main reasons:
First SFP4 went through a significant structural reinforcement exercise after the accident in the summer of 2011. Perhaps that was necessary, because it was weak, but it was not weak after that. If you've looked at the pictures of what they did, you know this.
Second, SFP 1-3 are sitting next to melted down reactors. They have been able to work relatively freely around SFP3. There are significant radiation hazards between buildings 2 and 3 and buildings 3 and 4 which preclude much work from going on in those areas. I'm pretty sure that SFP 3 suffered numerous events either in the pool or around the periphery at the edge of the pool in the many months since the accident.
Third, the fact that they have a plan and are executing it to get the fuel out of 4 makes it much less of a danger. Not having a plan means the fuel will be eventually lost to the environment.
I would also say that all the spin about #4 SFP potentially being a global disaster is a good sign it's relatively safe - it has been obvious from the start that all that was spin. The dangerous stuff is what they don't talk about - not what they do.
James
James, thanks for elaborating on your view point.
From what I've read, not everyone would agree with you that the added support for SFP4 made it entirely stable. I lack the expertise to form an opinion one way or another, but I do know that one cannot assess building strength or stability by looking at pictures.
FYI, as for fuel removal from pools 1-3, per Tepco's roadmap, removal of SFP 3 fuel is scheduled to begin in 2014. SFP 1 and 2 are to follow with plans to be based on the experience with SFP 4 and 3. Completion time for all SFP is planned to be less than 10 years' total, at which point the next decommissioning phase is supposed to start, i.e., fuel debris removal.
http://www.tepco.co.jp/en/nu/fukushima-np/roadmap/images/t120730_01-e.pdf
It remains to be seen how this is all going to pin out.
*mscharisma*
"...And using the crane in the first photo, and pull the fuel "rods" out of the pool into open air..."
If you go back and look at all the pictures of this TEPCO slight-of-hand, you'll see they're actually pulling this fuel assembly out of the edge of the *reactor* pool, not the SFP. They never explained this and nobody took much notice. Makes perfect sense if you need a good, shiny bundle to reassure the public and your real SFP-stored fuel is mostly toasted and buried in garbage.
Yeah, I know they claimed the reactor was empty at the time. I'll only point out that it was TEPCO that was telling you this.
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Cask is made up of wood? The one you mention lifted by gantry crane?
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