Japan Earthquake: nuclear plants Fukushima part 2

[Hiddencamper]

The bigger concern is with the water that leaks INTO the plant. Because this creates new contaminated water. If they can stop water leaking in, yes they may still have to deal with the stuff that's already gotten out, but they can prevent new contaminated water from being created. This greatly simplifies the problem.

However, the long term goal, and the reason they are looking to plug all the leaks, is to flood up the containment vessels to provide sufficient shielding so that they can open up the containment heads and start digging out the nuclear fuel.

 

[Rive]

Why would you want to clean it up? It's already below ground and poses risk only to the bacteria in that soil. Digging it up creates more problems than it solves.

Well, with time it'll make its way to the ocean.
I know that it's not really much as it is now (compared to the previously released amounts), but it would mean an unwelcome precedent. The water leaking IN creates contaminated water under control. The water leaking OUT creates contaminated water (and soil) OOcontrol. Even if the former - as measurable and visible - might be more sensitive topic, I don't like these stuffs stuffed under the rug.

I think the way through this is to decontaminate that water and release it afterwards.
The continuous failures of the ALPS is not really an excuse, there is no emergency now. They should be able to deal with it.

Previously there was some discussions about the release of water with tritium. I've found some interesting opinions regarding this: right now I'm checking the sources mentioned here.

 

[ronaldkr]

Previously there was some discussions about the release of water with tritium. I've found some interesting opinions regarding this: right now I'm checking the sources mentioned here.

Unfortunately the author of these pages, "The Hiroshima Syndrome", Leslie Corrice, seems to be a shill for the nuclear industry. Not only that he posits that tritium poses no risk for mankind ("oh, it's so small an energy of the betas" despite acknowledging that these betas are ionizing, only you must not call them "beta rays").
I read his tractate on Chernobyl (yes, I had better stopped, I know). He totally disappeared the xenon effect. But describing the aftermath he serves the sentence: "To be blunt, no negative long-term health effects have been detected in the monitored population, other than those that could have been medically anticipated if the Chernobyl accident had never happened." Tell that to the population. Even the governments know better.

 

[Sotan]

From the METI site:

Progress Status and Future Challenges of the Mid-and-Long-Term Roadmap towards the Decommissioning of TEPCO’s Fukushima Daiichi Nuclear Power Station Units 1-4 (Outline)(May 29, 2014)(PDF:4,510KB) PDF File

It's the English translation of the roadmap report of May 29th (most recent). You can find it here.

 

[nikkkom]

Unfortunately the author of these pages, "The Hiroshima Syndrome", Leslie Corrice, seems to be a shill for the nuclear industry. Not only that he posits that tritium poses no risk for mankind ("oh, it's so small an energy of the betas" despite acknowledging that these betas are ionizing, only you must not call them "beta rays").

I don't know anything about this guy, but re tritium, he is right. It's one of the most benign contaminants: low energy, not bioaccumulating, not accumulating in soils or sediment.

 

[ronaldkr]

[re tritium] It's one of the most benign contaminants: low energy, not bioaccumulating, not accumulating in soils or sediment.

Well, the "low energy" comes into play when tritium is an external contamitant. Electrons with av. 5.4 keV are sufficient to break bonds in organic matter. And there is some double action: the former T, now He will not bind to its former place, leaving an OH- or carbon radical, which is not helpful for cell chemistry either.

Indeed it's not bioaccumulating, and having a large body of water at the doorstep thinning would be a good idea. Good if the ALPS would be working. But then the introduction of tritrated water to the Pacific seems to be politically blocked, the credibility of both TEPCO and the government being below zero.

 

[Rive]

Unfortunately the author of these pages, "The Hiroshima Syndrome", Leslie Corrice, seems to be a shill for the nuclear industry.

As long as he is giving sources which can be tracked, checked for relevance, credibility and further sources I don't mind how is the man titled.

I'm not yet completely through tracking the sources down to the secondaries but till now that article seems to be correct.

 

[ronaldkr]

More on tritium: the report referenced by Sodan has this passage that indicates that TEPCO plans to do tritium removal.

8. Others
Public offering of the contaminated water-treatment technology verification project (tritium-separation technology verification test project) commenced
・ This project is conducted to collect the latest insights concerning tritium-separation technology as of today. Specifically, it aims to verify (1) the separation performance related to tritium-separation technology and (2) if the equipment is installed in the Fukushima Daiichi Nuclear Power Station, the construction and running costs of the equipment required to treat water after treatment by the multi-nuclide removal equipment, which is actually generated. This does not constitute confirmation that separation and treatment of tritium will commence.
・ The term of public offering is from Thursday, May 15 to noon Japan time on Thursday, July 17, 2014.
・ A briefing session is scheduled from 13:00 to 15:30, Tuesday, June 3, 2014 (planned), at the hall on the 1 st floor of Bellesalle Onarimon-ekimae. This briefing session will be simultaneously delivered via the Internet on the dedicated website of the Mitsubishi Research Institute, which serves as secretariat of this project. Following the briefing session, a video of the session will also be available.

 

[Sotan]

http://www.tepco.co.jp/nu/f2-np/handouts/j140624a-j.pdf
(in Japanese)

One page report – short but packed with info about Fukushima Daini plant. Summary as follows:
- The plant is still in stable cold shutdown state.
- The 764 fuel units from Unit 1 Reactor are being transferred to the Spent Fuel Pool (since June 2). Although the operation is basically automatized, people are stationed even on the Fuel Handling Machine to visually observe the work and make sure everything goes well. (One photo shows a worker looking into the reactor using binoculars.)
- 382 units of fuel have already been moved by June 13. In the upper right of the page there is a detailed presentation of the procedure for removing fuel units. For every group of 4 fuel units there is a control rod in the center. Two fuel units are removed so two are remaining, diagonally, to support the control rod. An auxiliary device is then inserted to support the control rod while the remaining two fuel units are removed. Then the control rod is pulled out, and then the auxiliary device removed. In all, it is computed that 1200 such “steps” will be needed to remove the 764 fuel units.
- Lower left rectangle talks about results obtained in 1 year of activity by the 4 teams established last year in July with an aim to improve the technical capacities of the plant staff. One team is responsible for removal of debris; one deals with “replacement of motors”, one with cables and one with pumps. They train to be able to get better at their tasks and to be able to make repairs and replacements quicker and better, if needed.
- Lower right rectangle speaks about the fact that on June 21 Unit 3 has reached 30 years since start of operation. The law requires an evaluation of the facility at this time. Tepco has applied for this evaluation. It has already received similar approvals for Units 1 and 2.

A little bit larger photos are available here.

Edit: sorry for the confusion, made it clearer now that this is about Daini plant.

 

[Sotan]

http://www.tepco.co.jp/nu/fukushima-np/handouts/2014/images/handouts_140624_09-j.pdf
(in Japanese)

- Pages 1-9 present the planned investigation of S/C (torus) room at Unit 2 in Fukushima Daiichi, meant to check the functioning of two new robots that are developed for the purpose of finding the water leaks in such areas. The plan is to have this done by July 24.
- One robot floats through water and has mainly the role of taking images of pipe penetrations and walls. The other one crawls under water on the floor and performs Doppler (ultrasound) examination.

- From page 10 there is a report on what has been learned until now from research and investigations aimed at sealing the water leaks of the damaged reactors.
- Thus page 12 shows method considered for sealing water leaks in various areas of the lower side of the PCV. Weak points and strong points of each method are briefly stated. Red line shows the hypothetical new boundary of the PCV after sealing by use of those methods. The conclusion seems to be that the most promising method appears to be sealing the venting pipes that lead from the PCV towards the S/C.
- Page 13-17 deal with the investigations (performed until now and planned from now on) in the lower region of the PCV, both in order to discover leaks and to find ways how to plug them.
- Page 18 presents some results and plans for investigations of the upper region of the PCV, where there are pipe penetrations that may show cracks later on, after the PCV bottom has been fixed and they start raising the water level.
- Page 19 talks about investigations in the torus room using the two robots, one camera robot floating (suspended) in water and one ultrasound robot crawling on the floor (these two I mentioned in the previous post).
- Page 20 shows a proposed timeline of the various investigations mentioned above, for Unit 1. Page 21 = timeline for Unit 2. Page 22 = timeline for Unit 3.

 

[jim hardy]

(One photo shows a worker looking into the reactor using binoculars.)
- 382 units of fuel have already been moved by June 13. In the upper right of the page there is a detailed presentation of the procedure for removing fuel units. For every group of 4 fuel units there is a control rod in the center. Two fuel units are removed so two are remaining, diagonally, to support the control rod. An auxiliary device is then inserted to support the control rod while the remaining two fuel units are removed. Then the control rod is pulled out, and then the auxiliary device removed. In all, it is computed that 1200 such “steps” will be needed to remove the 764 fuel units.

They're lifting complete elements?
Do i understand then that they are in good enough shape to be lifted from the top, and so are the control blades?

 

[turi]

They're lifting complete elements?
Do i understand then that they are in good enough shape to be lifted from the top, and so are the control blades?

The report is about Daini, not Daiichi.

 

[nikkkom]

Well, the "low energy" comes into play when tritium is an external contamitant. Electrons with av. 5.4 keV are sufficient to break bonds in organic matter.

Wrong. Energy does matter a lot for internal irradiation too.

18 kEv electron from Tritium can break only a few bonds.

Compare that to two beta electrons from Sr-90 -> Y-90 -> Zr-90 decay chain, first electon is 546 kEv, second is 2280 kEv - more than two orders of magnitude more energy. They damage A LOT of molecules while decelerating.

 

[jim hardy]

The report is about Daini, not Daiichi.

Whew ! Thanks ..

 

[Sotan]

Sorry, wasn't clear enough. I edited that post to make it clearer.

 

[turi]

ALPS is fully back online:
http://www.tepco.co.jp/en/press/corp-com/release/2014/1238403_5892.html

On May 23 Unit B was the first to be restarted after the upgrades, followed by Unit A on June 9 and now Unit C on June 22.

 

[Sotan]

That's good news.
But there's some bad news too:
http://www3.nhk.or.jp/nhkworld/english/news/20140625_09.html

 

[Rive]

That's good news.
But there's some bad news too:
http://www3.nhk.or.jp/nhkworld/english/news/20140625_09.html

Ex-SKF article about the same thing.

 

[Sotan]

A new monthly "roadmap" report has been published on June 27. Unfortunately all materials are in Japanese only, at this time.
All the documents are here.
The summarized version of the progress report (the one that will be translated in about 2-3 weeks, if the past trend continues) is here.
I only took a quick look but it doesn't seem to contain new information, meaning which hasn't been at least mentioned here previously.
One exception - for me at least this was news: [STRIKE]the crane above the spent fuel pool[/STRIKE] a crane on the first floor at Unit4 is entering a mandatory inspection, which means that the extraction of fuel units from SPF 4 will take a break from July 1st till the beginning of September. This is a scheduled inspection, not an unexpected delay.

Edit: the crane and its location can be seen on the last page of this document.

 

[Sotan]

http://www.tepco.co.jp/nu/fukushima-np/handouts/2014/images/handouts_140707_01-j.pdf
(In Japanese)

They had to stop the cooling of the SFP at Unit 5 in Fukushima Daiichi, because of a leak that occurred at a valve located on the pipe that brings in sea water, to be used for cooling pumps and to remove heat from the water used for cooling the SFP.

The water leaked - clearly sea water, based on analysis, with no trace of radioactivity - amounts to ~1300 liters and most of it went down to the lower levels, about two floors.

The SFP is safe even without cooling for about 9 days. Should the repair last longer than that they consider diverting some cooling water from the circuits used for cooling the reactor itself. These circuits are working normally.

 

[jadair1]

http://www.tepco.co.jp/nu/fukushima-np/handouts/2014/images/handouts_140707_01-j.pdf
(In Japanese)

They had to stop the cooling of the SFP at Unit 5 in Fukushima Daiichi, because of a leak that occurred at a valve located on the pipe that brings in sea water, to be used for cooling pumps and to remove heat from the water used for cooling the SFP.

The water leaked - clearly sea water, based on analysis, with no trace of radioactivity - amounts to ~1300 liters and most of it went down to the lower levels, about two floors.

The SFP is safe even without cooling for about 9 days. Should the repair last longer than that they consider diverting some cooling water from the circuits used for cooling the reactor itself. These circuits are working normally.

I have never worked in a NPP but I have worked many shutdowns in steam plants at pulp mills many years ago.

It seems like a simple procedure to replace the ruptured valve, lock out and isolate the valve, remove it and replace it.

It does not seem like radioactivity should be a problem, perhaps they have no replacement valves available, now that would be a different kettle of fish.

Even then they could burrow one from another company that has a suitable replacement on hand.

I know that Northwood Pulp in Prince George, BC did this on more than one occasion when they got into a bind.

 

[Sotan]

Well, replacement would have been my first choice too but for some reason that I don't know, they decided to do it in a completely different way. Enlarged that little hole in the valve's body, stuck a plug or something in it, and applied some hardening agent (?) on the surrounding area.
Check the link given above again, it contains the repair photos too now.

 

[Sotan]

http://www.tepco.co.jp/nu/fukushima-np/handouts/2014/images/handouts_140707_05-j.pdf
(In Japanese)

26-pages report of July 7 on the progress of works for sealing the trenches of Units 2 and 3, with a lot of info (including several photos) about the freezing of certain points in order to stop the water from going through.

It is rather technical and I suppose harder to understand compared to other reports (at least to me), but may be worth browsing. Again one gets a hint of how big and difficult the task is.

 

[westfield]

Daiichi U5

Well, replacement would have been my first choice too but for some reason that I don't know, they decided to do it in a completely different way. Enlarged that little hole in the valve's body, stuck a plug or something in it, and applied some hardening agent (?) on the surrounding area.
Check the link given above again, it contains the repair photos too now.

Yes, well if that's how a multibillion dollar company stages "repairs", even a provisional one as they call it, then I am dumbfounded. Some sort of polyurethane sealant from the hardware store, a wooden block and ratchet straps. The valve body is obviously shot, corroded\eroded from inside which is surely a predictable failure.

A continuing sad farce.

 

[Sotan]

The "range" of their attitudes and accomplishments is what amazes me. The distance between the highs and the lows.
You see them building ice walls, or the ALPS, installing countless tanks, handling robots, removing debris and cleaning and preparing and so on, so many huge tasks which I am not sure somebody else would have done much better.
But then you also see them pressing the wrong buttons, sending contaminated water where it shouldn't go, forgetting to cut electricity before doing some work, or repairing a valve hole with plug and sealant.
How to explain that. Different teams and different approaches? And the human factor?

 

[jim hardy]

Don't be too quick to condemn that temporary patch on the valve. From out here we do not know what else is connected to that piece of pipe, it may well be that to drain it renders something else inoperable that they'd rather not shut off just now.

 

[zapperzero]

How to explain that. Different teams and different approaches? And the human factor?

Under the keiretsu system, sub-sub-sub-sub-contractors end up doing most of the grunt-work; they do it for very little money and with very little oversight. Big-ticket items get handled by the big fish directly, and they actually pay people, train them and care about their corporate reputation.

 

[Sotan]

Don't be too quick to condemn that temporary patch on the valve. From out here we do not know what else is connected to that piece of pipe, it may well be that to drain it renders something else inoperable that they'd rather not shut off just now.

I agree, there must be reasons.
They could have explained them a little, though.
Otherwise, just showing that repair there... may seem a little weird.

 

[Rive]

Well, replacement would have been my first choice too but for some reason that I don't know, they decided to do it in a completely different way.

IMHO it can be about the usual papermill of the permissions and components. It might be weeks to get everything ready for the work - while that cooling would run on reserve, without any further reserves.

With that patchwork it'll have the 'main' and the 'reserve' for all the time of the papermill.

I would be worried only if the proper replacement would not be performed within a month or two.

 

[Sotan]

Two short new reports on Tepco site (unfortunately only in Japanese):

1. (Daiichi plant) 2 pages report with 2 photos of the collapsed NW portion of the Unit 3 building here (the photos can be seen in larger size here.

2. (Daini plant) This report announces that all 764 fuel units of Reactor 1 have been moved to the spent fuel pool.

 

[zapperzero]

That beam which is featured in both pictures is cracked in the middle. I guess it's a good thing they cleared the debris above it so (relatively) fast.

 

[Sotan]

IMHO it can be about the usual papermill of the permissions and components. It might be weeks to get everything ready for the work - while that cooling would run on reserve, without any further reserves.

With that patchwork it'll have the 'main' and the 'reserve' for all the time of the papermill.

I would be worried only if the proper replacement would not be performed within a month or two.

In a new post on their site, TEPCO announces that they will replace the pierced valve with the similar one from Fukushima Daini Unit 3.

This should take until the end of month. Until then, they will cool the reactor and the SFP alternately using the cooling system that is in working state.

http://www.tepco.co.jp/nu/fukushima-np/handouts/2014/images/handouts_140717_03-j.pdf (in Japanese)

 

[Sotan]

http://www.tepco.co.jp/nu/fukushima-np/handouts/2014/images/handouts_140717_05-j.pdf
(in Japanese)

Overview on the planned dismantling of the cover of the Reactor 1 building.
General presentation of the dismantling operation.
Measures for preventing the spreading of dust and other particles. (Spraying of water and some special agent that fixes dust and other particles in place.)
Throughout the operation they will monitor 19 spots for changes in radioactivity.

This article from Asahi Shinbun kind of relates to the above:
http://ajw.asahi.com/article/0311disaster/fukushima/AJ201407160064

 

[zapperzero]

Thank you for the update. I wonder why they put up the tent in the first place.

 

[Sotan]

The "Mid-and-Long-Term Roadmap" report of June 27 (most recent one) has been translated in English and posted on the METI site here.