Japan Earthquake: nuclear plants Fukushima part 2

[LabratSR]

They appear to finally be moving forward with the long talked about Muon Detectors


Cosmic rays to pinpoint Fukushima cores

http://www.world-nuclear-news.org/RS-Cosmic-rays-to-pinpoint-Fukushima-cores-1108144.html

 

[Sotan]

They appear to finally be moving forward with the long talked about Muon Detectors


Cosmic rays to pinpoint Fukushima cores

http://www.world-nuclear-news.org/RS-Cosmic-rays-to-pinpoint-Fukushima-cores-1108144.html

This short article from the IRID site also relates to this subject. It reports about a test carried out in order to establish the shield thickness needed to isolate the muon measuring devices from the influence of the gamma radiation present at the site.

 

[Sotan]

http://ajw.asahi.com/article/0311disaster/fukushima/AJ201408280043

Asahi Shinbun article with a quick update and some numbers related to the contaminated water issue.

"As of Aug. 26, 367,000 tons of highly contaminated water sat in tanks placed inside plant grounds awaiting treatment."

 

[Sotan]

http://www.tepco.co.jp/nu/fukushima-np/handouts/2014/images/handouts_140901_04-j.pdf
(In Japanese)

On Aug. 29, during the remote-controlled operations of removing debris from the Spent Fuel Pool of Reactor 3, a ~570 kg piece of debris (the operating console of the Fuel Handling Machine and part of its platform) fell into the Spent Fuel Pool.

Using underwater cameras it was found that the fallen item is now standing above the other debris, mostly supported by a spent fuel rack and it is assumed that about 10 fuel assemblies are directly underneath. It was not possible to examine the assemblies themselves directly due to the large amounts of debris present in the area. Still, they seem inclined to believe that the assemblies are fine, as no changes in monitored parameters have been observed and the racks are designed to withstand 750kg of weight. They will continue to monitor the area and investigate the cause of the incident.

 

[LabratSR]

Ex-Skf has video of them dropping the console

http://ex-skf.blogspot.com/2014/09/fukushima-i-npp-reactor-3-sfp-debris.html

 

[zapperzero]

I did NOT expect it to look exactly like those carnival machines with the stuffed toys inside.

 

[Hiddencamper]

Unlike the carnival machine, these ones are designed to not drop stuff.

The grapple is sets of J hooks that interlock with each other when they are in the grapple position. Once they pull up on the fuel bundle, the bail handle on the bundle itself physically prevents the grapple from opening (passively safe) because to open up would require shearing through the bail handle.

As you begin to lift the crane, there is a weight gauge which can determine if fuel is loaded. If it is, then the control rods are all locked out and cannot move (if they aren't all in then the crane will lock out). If the reactor mode switch is not in REFUEL, then if it senses a fuel bundle on the handle it locks the crane out to prevent a core alteration while the control room is not prepared for monitoring the core during refuel ops.

There are also smaller auxiliary crane for lifting control rods, dry tubes, fuel/top guide support pieces, and other in core objects. These all lock out if they sense the weight of a fuel rod on them to prevent the aux hoist from lifting one up on accident.

 

[nikkkom]

The video isn't showing a standard refueling crane, it shows something like construction/demolition equipment (a big grapple, it seems) currently in use at Unit 3 for debris cleanup.

 

[Sotan]

http://www.nsr.go.jp/committee/yuushikisya/tokutei_kanshi/data/0026_03.pdf
The link above leads to a short document in Japanese, dated Aug. 18, presented in a NRA (Japanese Nuclear Regulation Authority) meeting, which contains some considerations regarding the need for defense measures against the potential damaging effects of external phenomena such as earthquakes and tsunamis on the crippled facilities in Fukushima Daiichi plant.

But the fragment I want to post here is actually something else: a quick list of objectives and the terms for their accomplishment. Recently I at least felt a bit lost when it comes to "what exactly are they doing now and what are the plans and the deadlines"; this list reminded me of how slow the work will proceed.

Short term objectives: achievable in 1-2 years:
- removing the spent fuel assemblies from the SFP of Reactor 4 (by the end of 2014);
- removing the spent fuel assemblies from the SFP of Reactor 3 (from mid fiscal 2015, meaning ~September 2015, to last for about a year);
- cleaning the RO concentrated salty water stored in tanks on site, by means of decontamination facilities such as ALPS (until March 2015);
- removal of contaminated water from the trench on the sea side (until or perhaps before winter of 2014);
Medium term objectives (to be achieved in 3-5 years):
- removal of the spent fuel assemblies from the SFP of Reactor 1 (to start in April 2017 and take about a year);
- removal of the spent fuel assemblies from the SFP of Reactor 2 (planned to start around April 2019);
Long term objectives (to be accomplished later than 5 years from now):
- removal of the contaminated water stored in the reactor buildings and turbine buildings (will take 7 years after the establishment of the frozen soil wall);
- removing the molten fuel debris (planned to start sometime in 2020).

 

[jadair1]

http://www.nsr.go.jp/committee/yuushikisya/tokutei_kanshi/data/0026_03.pdf
The link above leads to a short document in Japanese, dated Aug. 18, presented in a NRA (Japanese Nuclear Regulation Authority) meeting, which contains some considerations regarding the need for defense measures against the potential damaging effects of external phenomena such as earthquakes and tsunamis on the crippled facilities in Fukushima Daiichi plant.

But the fragment I want to post here is actually something else: a quick list of objectives and the terms for their accomplishment. Recently I at least felt a bit lost when it comes to "what exactly are they doing now and what are the plans and the deadlines"; this list reminded me of how slow the work will proceed.

Short term objectives: achievable in 1-2 years:
- removing the spent fuel assemblies from the SFP of Reactor 4 (by the end of 2014);
- removing the spent fuel assemblies from the SFP of Reactor 3 (from mid fiscal 2015, meaning ~September 2015, to last for about a year);
- cleaning the RO concentrated salty water stored in tanks on site, by means of decontamination facilities such as ALPS (until March 2015);
- removal of contaminated water from the trench on the sea side (until or perhaps before winter of 2014);
Medium term objectives (to be achieved in 3-5 years):
- removal of the spent fuel assemblies from the SFP of Reactor 1 (to start in April 2017 and take about a year);
- removal of the spent fuel assemblies from the SFP of Reactor 2 (planned to start around April 2019);
Long term objectives (to be accomplished later than 5 years from now):
- removal of the contaminated water stored in the reactor buildings and turbine buildings (will take 7 years after the establishment of the frozen soil wall);
- removing the molten fuel debris (planned to start sometime in 2020).

I would be extremely surprised if they met any of those objectives in the time frame they outline.

Indeed, I do not think they are even working on, or have any idea how to achieve some of them.

I firmly believe that everything TEPCO says should be taken with a huge grain of salt!

 

[turi]

I would be extremely surprised if they met any of those objectives in the time frame they outline.

Indeed I do not think they are even working on, or have any idea how to achieve some of them.

At least SPF 4 will be empty soon and I don't see why they shouldn't be able to empty SPF 3 as well. I do expect setbacks and delays, but I also do see them planning for and working on their objectives.

 

[jadair1]

At least SPF 4 will be empty soon and I don't see why they shouldn't be able to empty SPF 3 as well. I do expect setbacks and delays, but I also do see them planning for and working on their objectives.

You are very optimistic and I hope you are right but TEPCO's track record so far has not been good and there are rumors they are running out of qualified workers.

Personally you could not pay me enough to work there.

 

[Rive]

I would be extremely surprised if they met any of those objectives in the time frame they outline.

Well...

The fuel removal process from U4 pool was restarted in this month, so it'll be finished before the deadline. For the end of autumn it can be finished.

The fuel removal from U3 pool is tricky, they have to remove the broken FHM and build the machinery and the cover before they can start the actual removal - I expect some delays here, especially if there are some damaged bundles in the pool.

The 'RO concentrated water' is a trick, as I see it does not the same as 'all contaminated water on site'.

Emptying the trench - well, we will see. I think it's possible.

About the medium term objectives: I think it's possible to finish these before the deadline. With the experiences from U3 pool U1 pool should be relative easy. Indeed, U2 pool is the most difficult.

So I think it's OK.
Long term objectives are - well, they are for long term, so it's not a sin to make up the ideas later...

 

[nikkkom]

Unit 2 seems to be problematic because during the accident it did not explode (heh) and thus a lot of escaped radioactive steam recondensed on the inside.

IIRC more than one year after accident they measured about ~1 Sv/h at the reactor missile shield.

Looks like they want to wait until at least most of Cs-134 decays: "planned to start around April 2019".

 

[jadair1]

It is not only the long term objectives it is the technology that does not exist to deal with 3 meltdowns. Chernobyl only had one and they have still not resolved that many years later.

Three Mile Island only had a partial meltdown and it took 10 or 15 years to clean up the core. New technologies had to be designed to clean it up. Fukushima is far worse than that, we are looking at 3 complete meltdowns with corium's that nobody has any idea where they are.

There are areas that are too radioactive for people to go into still and might be for decades.

It is a huge mess and needs international cooperation to deal with it.

 

[nikkkom]

It is not only the long term objectives it is the technology that does not exist to deal with 3 meltdowns. Chernobyl only had one and they have still not resolved that many years later.

Three Mile Island only had a partial meltdown and it took 10 or 15 years to clean up the core. New technologies had to be designed to clean it up. Fukushima is far worse than that, we are looking at 3 complete meltdowns with corium's that nobody has any idea where they are.

There are areas that are too radioactive for people to go into still and might be for decades.

Try "centuries". Insides of PCB are upwards of 50 Sv/h. Chernobyl's reactor cavity is still far from being cleaned up (not even started, in fact) and it's been 30 years already.

It is a huge mess and needs international cooperation to deal with it.

I think what will actually happen is we will abandon energy generation methods which require such extremely costly and arcane technology when eventually it does malfunction in a big way. I'd take Sahara tiled with solar panels any day, thank you.

 

[jim hardy]

I think what will actually happen is we will abandon energy generation methods which require such extremely costly and arcane technology when eventually it does malfunction in a big way. I'd take Sahara tiled with solar panels any day, thank you.

I like to think that nuke will get mankind over the energy hump , buying time to get fusion going.

Alternative is to reduce our numbers. World population of a million or two could support some commerce, science and local symphony orchestras , but with a very small footprint and no traffic jams.

"Done because we are too menny".jude the obscure, a depressing novel

 

[Sotan]

http://ajw.asahi.com/article/0311disaster/fukushima/AJ201409180042
Asahi Shinbun article in English.
"TEPCO begins test runs of new ALPS system at stricken plant".

 

[Sotan]

METI (Ministry of Economy, Trade and Industry) has a FAQ updated on October 3 regarding the issue of contaminated water.
There are answers given only to 3 general questions, but they are in English and they are up to date.
Go http://www.meti.go.jp/english/earthquake/nuclear/decommissioning/contaminated_water_qa.html to read them.

 

[zapperzero]

Anything on the effects of the recent storm?

 

[Sotan]

Anything on the effects of the recent storm?

I only read in the daily report of TEPCO　of October 6 (in Japanese) that they had two alarm signals that went off, signalling water leaks. One was in Unit 1 Turbine Building first floor (at 10:59) and the second in Reactor 3 building first floor (at 11:07). They sent somebody to check the scene for the first one, and they examined the scene on the images provide by a web cam (plus they checked all the other plant parameters) - the conclusion in both cases was that it was rain water coming in which triggered the alarm devices.

Other two topics I want to mention:

- Asahi Shinbun article in English: [/PLAIN]
TEPCO doubles tsunami height in damage estimate for Fukushima plant

- On the TEPCO site dedicated to "Mid-and-Long-Term Roadmap towards the Decommissioning" which can be consulted here, but only in Japanese, there is a new comprehensive report dated September 25. (There is also a report dated September 22 on the matter of the contaminated water and other current topics.) Maybe some of you will want to browse the PDF files even though they are in Japanese only. The main document, as you know, usually gets translated in English in a month or two.

 

[Sotan]

Japan Times article:
http://www.japantimes.co.jp/news/2014/10/12/national/tritium-surges-10-fold-in-groundwater-at-fukushima-nuclear-plant-typhoon-effect-suspected/][/PLAIN]
Tritium up tenfold in Fukushima groundwater after Typhoon Phanfone

And, as you probably know, there's another typhoon on its way right now, bound to reach the area very soon.

 

[etudiant]

Sotan, thank you for your continuing contributions. They are really outstanding, as there is almost a veil drawn over the whole incident here.
The coverage now mostly from the antinuclear contingent, which rarely misses the chance to maximize the potential problems.

Given that, would someone with industry experience please help add some perspective to the tritium issue please.
Afaik, it is a pretty unavoidable byproduct of reactor operation which gets flushed out to the environment,
much as noble gases are still emitted during reprocessing.
So is the tritium now arousing concern more than before or is the issue simply that it is now permeating the site foundations?

 

[Sotan]

@etudiant
Thank you. My interest has not diminished - and I am sure I am not an exception, so I keep following all the sites I know and I will keep reporting what I find. Personally I can't venture too much in commenting, though, as I don't have the expertise.
----------------

Typhoon 19 went away without causing much trouble; there were 4 instances where sensors detected water in different places of the plant but all four were found to be caused by rain water. There's been quite a lot of rainfall there. (You can read more about this http://www.fukuleaks.org/web/?p=13921. I hope linking to this site is ok, it usually keeps to simply reporting facts.)

However, some effects of typhoon 19 may appear a little later - as it happened with typhoon 18 which apparently caused the increase in tritium levels reported 2 posts above. In connection with this, now there are reports that Cesium concentrations have risen too, to values especially high (251,000 becquerels/litre) in one well:

NHK article of October 14
http://www3.nhk.or.jp/nhkworld/english/news/20141015_05.html

Edit:
Found one more interesting material in English from TEPCO, regarding the situation and of contaminated water, a lot of information packed in 5 pages.

 

[Sotan]

Tepco report of October 15 (in Japanese)

It shows the tentative timeline of the process of removing the cover of Unit 1 building cover.

On Oct 22 they will make a hole in the roof and pour/spray a solution of some agent that prevents dust scattering.

On Oct 30 they will have removed two of the roof panels to allow for the inspection of the operating floor, to check the efficacy of the sprayed agent and the dust scattering conditions. At this time they will also gather info to plan and decide on the debris removal operations. The two roof panels will be placed back at the beginning of December.

The actual removal of Unit 1 building cover is scheduled to start in March 2015.

As for the removal of debris from the operating floor of Unit 1, it is planned to begin sometime after March 2016, after they finish and verify the functioning of the frozen wall.

 

[Sotan]

http://www.47news.jp/CN/201410/CN2014102001001998.html

On Oct 20 Tepco announced that they have removed 1320 of the 1331 used fuel assemblies stored in the Unit 4 Spent Fuel Pool at the time of the accident.
During the next fuel transfer operation they plan to move the remaining 11 spent fuel assemblies, as well as the 3 damaged assemblies present in the pool (one which is slightly curbed and two which in the past have shown signs of leaking radioactive substances).
Only some unused fuel assemblies - deemed low risk - will thus remain in the Unit 4 SFP.
The whole operation is scheduled to be over by the end of November.

 

[Sotan]

On the IRID site (link) there is a posting dedicated to the 2014 Fall Meetings of Atomic Energy Society of Japan (Sep. 10, 2014) which includes 5 PDF presentations on the ongoing research of IRID:

• (1) IRID’s activities (overview)

• (2) Technological development related to decontamination, containment investigation and repair

• (3) Technological development related to understanding debris properties

• (4) Technological development related to investigation and removal of fuel debris

• (5) Technological development related to the treatment and disposal of radioactive waste

The presentations are, unfortunately, only in Japanese, but still worth a look, in my opinion, as many of the photos and diagrams are very suggestive (and Google translate can help, for small portions of text). They allow a glimpse into the large variety of long-term research activities aimed at developing those technologies we were told do not exist yet but will have to be invented in order to decommission the reactors, remove the molten fuel and generally render the place safe.

I will just one example that might make you peek in (there are so many interesting things in there...).
On page 23 of this presentation they talk about the muon technique that might help pinpoint the location of the molten fuel. But it's not talk only - there are results of experimental measurements carried out in the field - at the 2nd Tokay Nuclear Power Plant (no fuel in the reactors, but spent fuel present in the SFP). Its seems that the technique allows a precision of ~30cm in the detection of the nuclear fuel. There are also other experiments and simulations presented.

Oh and since you're here - check out the diagram on page 40...
If they are to employ the techniques used at TMI-2, the distance from the operation floor and the pedestal (where some of the fuel debris is thought to be) is 35 meters. The challenges will be enormous.

 

[Sotan]

TEPCO released 2 photos depicting the start of the operations aimed at dismantling the cover of Unit 1 Reactor Building.

They will make a number of holes in the roof and then use this device to thoroughly spray some dust-fixing resin onto the operating floor.

 

[etudiant]

It would be very desirable to get a good status overview of the Fukushima cleanup, because right now there is very little coverage, apart from the ongoing 'we're all doomed' reporting at ENE News and such.

Specifically, it seems the following is the actual status in the cleanup.
Reactor 4 is pretty much wrapped up, so on to reactor 1 and the reactor 3 SFP.
The ALPS systems are starting to operate reliably and effectively, which should solve the water storage issue.
The steel pilings wall has been completed, which should cut down the contaminated water leakage into the harbor.
The ice wall is progressing, which should also help the water issue.
While the site is still emitting contamination, the rate is no longer seriously troublesome, apart from the strontium leakage, which will require extensive water cleanup.

It seems to me that TEPCO has actually made good headway, with some elements such as the ALPS world leading technically.
Could some of the more experienced nuclear power specialists give their appraisal of the progress to date?

 

[nikkkom]

It would be very desirable to get a good status overview of the Fukushima cleanup, because right now there is very little coverage, apart from the ongoing 'we're all doomed' reporting at ENE News and such.

Specifically, it seems the following is the actual status in the cleanup.
Reactor 4 is pretty much wrapped up, so on to reactor 1 and the reactor 3 SFP.
The ALPS systems are starting to operate reliably and effectively, which should solve the water storage issue.

It can't remove tritium, right?
I assume they still don't release the "ALPS-cleaned" water, because of the tritium.

My preferred solution is that it should be released somehow: say, gradually over few years, or pumped underground, or loaded onto a tanker and released in the Pacific. Tritium radiation danger is far too overblown.

I imagine *tremendous* PR problems making that happen, though. No amount of explanations will convince an average badly educated person. Greenpeace et al will not miss the "We are all going to die!eleven" bandwagon either.

It seems to me that TEPCO has actually made good headway, with some elements such as the ALPS world leading technically.

I am still curious what benefits APLS has wrt a good old double distillation. I can't think of any.

 

[etudiant]

While the Japanese NRA has put out requests for proposals for removing tritium from the cooling water, AFAIK the only such plant was in Canada, as part of the CANDU heavy water reactor program. Their heavy water moderator got contaminated with tritium during operations and they developed a distillation based cleanup if memory serves. The scale of a comparable facility in Japan would be unreasonable, even disregarding the reality that the witches brew in Japan bears no resemblance to the refined D2O moderator used by the Canadians.

In general, I thought most ocean front nuclear plants had a tritium disposal allowance and that TEPCO's coolant was actually within those limits.
So once ALPS cleans up the nasties such as strontium, my guess is that TEPCO could get the ok to ditch the purified coolant, even if there is opposition.

Re distillation, as an ex chemist, I'm not confident I could plan to distill a half million tons of water without gunking up my columns at some point, even disregarding the reality that some of the contaminants are pretty volatile or easily entrained. Vaporizing everything in light of these realities just does not seem preferable to me, but I've no experience in industrial scale distillation.
Is there some counterexample showing the effectiveness of double distillation in helping to deal with radioactive wastes?

 

[nikkkom]

that some of the contaminants are pretty volatile or easily entrained.

What contaminants do you have in mind?

If there's oil/gasoline, it has to be filtered out before distillation.

Other than that, only iodine comes to mind as capable of significant volatilization. I-129 is the isotope which can escape that way, but its half-life of 15 million years and lower yield makes it a much lesser concern than Cs and Sr.

The nastiest radioactive contaminants - Cs and Sr - form nonvolatile salts. Distillation should remove them easily.

 

[etudiant]

What contaminants do you have in mind?

If there's oil/gasoline, it has to be filtered out before distillation.

Other than that, only iodine comes to mind as capable of significant volatilization. I-129 is the isotope which can escape that way, but its half-life of 15 million years and lower yield makes it a much lesser concern than Cs and Sr.

The nastiest radioactive contaminants - Cs and Sr - form nonvolatile salts. Distillation should remove them easily.

You may indeed be quite right, I've no experience with industrial scale distillation and it may be a solution to the treatment problem.
My doubts reflect the unprecedented scale of the problem and the reality that the contaminants that are targeted are in vanishingly low concentrations chemically, part per hundred million level afaik, mixed in with all manner of substances. That seems to me to be asking a lot from distillation. The customer would certainly first want to see a pilot plant to show that this would be effective.
ALPS did get a pilot plant, has shaken down and seems to be functioning currently. Distillation did not get the nod and we don't know if it was even considered. Still, there is a substantial chemicals industry in Japan and it seems implausible that they did not think of it. Perhaps an opportunity was missed.

 

[nikkkom]

ALPS did get a pilot plant, has shaken down and seems to be functioning currently. Distillation did not get the nod and we don't know if it was even considered. Still, there is a substantial chemicals industry in Japan and it seems implausible that they did not think of it. Perhaps an opportunity was missed.

There may be a rational reason for this. I just can't see it, therefore I ask.

Think about it. Industrial-scale distillators are readily available. ALPS wasn't. It took literally years to be built. This just doesn't sound right.

 

[Sotan]

The Nuclear Regulation Authority (NRA) of Japan has just published an "Analysis of the TEPCO Fukushima Daiichi NPS Accident - Interim Report (Provisional Translation)".

137 pages, PDF document in English. You can find it http://www.nsr.go.jp/english/library/data/special-report_20141104.pdf .

"1.2 Aim of the Report
Among the various issues and unexplained issues raised in the reports by the National Diet
Investigation Commission, the Government Investigation Committee, the Nongovernmental
Investigation Committee, and TEPCO Investigation Committee, the NRA has selected the
unexplained issues that the National Diet Investigation Commission requires regulatory bodies to
conduct empirical investigations and examinations of those issues with sufficient evidences, and
then report its views. This report is the first one, and THE NRA continues to submitting report with
the progress of the investigation and review."