Japan Earthquake: Nuclear Plants at Fukushima Daiichi

[zapperzero]

Reactor 2 is still the worst polluter, Asahi reports:

The most radiation is being emitted from the No. 2 reactor, which is releasing 8 million becquerels an hour.

http://ajw.asahi.com/article/0311disaster/fukushima/AJ201207240087

 

[Ms Music]

Hi, long time since I have posted here... (thankfully)

What is the process for removing fuel from the storage pools? Just curious since they have only removed two new assemblies so far. I understand the used fuel is hotter, so what is the process (even if so far unknown) and how long can the used assemblies be out of water? How long does it take to inspect the assemblies?

Just curious why a/ it has taken so long to remove the two new ones (is it low priority?), and b/ why do they expect it to take so long to remove the rest? I have read this thread long enough now you can throw some meat at me, and I should understand.

Thanks in advance, back to being a lurker.

 

[Astronuc]

Hi, long time since I have posted here... (thankfully)

What is the process for removing fuel from the storage pools? Just curious since they have only removed two new assemblies so far. I understand the used fuel is hotter, so what is the process (even if so far unknown) and how long can the used assemblies be out of water? How long does it take to inspect the assemblies?

Just curious why a/ it has taken so long to remove the two new ones (is it low priority?), and b/ why do they expect it to take so long to remove the rest? I have read this thread long enough now you can throw some meat at me, and I should understand.

Thanks in advance, back to being a lurker.

The reactor service floor and spent fuel pools were covered with debris, and the areas were heavily contaminated. The new (fresh) fuel could be more easily removed, except that is has been contaminated on the outer surface by activated corrosion products and any fission products that escaped from the operating or spent fuel.

The normal course is the use the fuel handling machine (the green bridge structure) to install and remove fuel assemblies. The fuel racks have a little clearance with each fuel assembly, so usually the fuel handling machine is indexed to the spent fuel pool racks.

The fuel assemblies sit under several meters of water which provides shield from the radiation to the workers operating on the machine. They will move the assemblies underwater to a cask. Once loaded, the cask lid is installed and the cask is then drained - really the water inside is displaced by an inert gas - helium. The cask environment is dried and finally sealed. There is an outer shield and protective container in which the cask sits. The whole set is then lifted and moved to a transporter - trailer or truck. The cask may be transferred to another pool (interim storage), or it may be sent to a dry storage facility onsight. If the fuel is sufficiently cool, it may be sent to a reprocessor, if the utility is part of a program to reprocess its fuel.

The overhead crane is used to lift the heavy cask and its contents. The overhead cranes were destroyed in the explosions and fires.

 

[Ms Music]

The FHM is functioning on #4? I thought they would have to use an external (outside of the building) crane to remove the assemblies, and other methods of getting them into a cask. Well, at least 3 and 4. 1 and 2 still have a roof...

I am just surprised it has been a year and a half before they removed two fresh fuel assemblies out of 4.

Thanks again.

 

[LabratSR]

The FHM is functioning on #4? I thought they would have to use an external (outside of the building) crane to remove the assemblies, and other methods of getting them into a cask. Well, at least 3 and 4. 1 and 2 still have a roof...

I am just surprised it has been a year and a half before they removed two fresh fuel assemblies out of 4.

Thanks again.

Video shot from news helicopters of the operation.

http://www.youtube.com/watch?v=j_kDf2JB8-Q&feature=related

 

[zapperzero]

The FHM is functioning on #4? I thought they would have to use an external (outside of the building) crane to remove the assemblies, and other methods of getting them into a cask. Well, at least 3 and 4. 1 and 2 still have a roof...

I am just surprised it has been a year and a half before they removed two fresh fuel assemblies out of 4.

Thanks again.

No, the FHM is not operational. They have used a small crane for this operation but there will be a need for a much larger one to handle casks, as well. Most of the time has been spent in waiting for the radiation fields to lower somewhat and then in clearing debris (a rather involved operation, but one which has taken shorter than planned, iirc)

 

[mscharisma]

... Just curious ... why do they expect it to take so long to remove the rest? ...

Am also a lurker and a complete nontechnical person. Apart from the difficulty of the process and the destroyed equipment/more or less improvised new equipment, I believe to remember that, per regulations, the used fuel rods have to be cooled a certain number of years in the pool before they are cool enough be moved.

 

[Astronuc]

Am also a lurker and a complete nontechnical person. Apart from the difficulty of the process and the destroyed equipment/more or less improvised new equipment, I believe to remember that, per regulations, the used fuel rods have to be cooled a certain number of years in the pool before they are cool enough be moved.

Yes - there is usually a 5 year or so cooling period before the any fuel is committed to dry storage. The exception would be a single assembly or a few fuel rods which could be removed soon after operation - several months to a year - in order to be sent to hotcell for examination. One can also mix cooler older fuel with hotter younger fuel to balance the thermal burden. One can also use lower burnup fuel to shield higher burnup fuel.

The higher the burnup, the more the decay heat, so a utility could elect to the let fuel cool longer than 5 years, which has been the case for much of the fuel, at least in the US, since the use of dry storage has been a more recent development due to lack of a repository or reprocessing program.

Dry storage casks may handle up to 68 BWR fuel assemblies, but Fukushima may use smaller transportation casks that might handle fewer assemblies.

See this discussion - Impact of Fukushima Accident on Spent Fuel Management in Japan
http://rampac.energy.gov/PCN/P8.pdf

 

[Ms Music]

Yes - there is usually a 5 year or so cooling period before the any fuel is committed to dry storage.

Yes, but that would be in a normal situation. Here we are dealing with a structurally unsound building. I thought there would be more of a push to get the rods into another pool quicker. Maybe they trust their temporary structural reinforcement more than I do.

I will read the other thread (edit PDF, not thread), maybe I can grasp this without dragging this thread too far into my own questions.

Thank you all!

 

[LabratSR]

Yes, but that would be in a normal situation. Here we are dealing with a structurally unsound building. I thought there would be more of a push to get the rods into another pool quicker. Maybe they trust their temporary structural reinforcement more than I do.

I will read the other thread (edit PDF, not thread), maybe I can grasp this without dragging this thread too far into my own questions.

Thank you all!

http://www.tepco.co.jp/en/press/corp-com/release/2012/1201934_1870.html

And that links to this.

http://www.tepco.co.jp/en/press/corp-com/release/betu12_e/images/120416e0201.pdf

 

[Astronuc]

Yes, but that would be in a normal situation. Here we are dealing with a structurally unsound building. I thought there would be more of a push to get the rods into another pool quicker. Maybe they trust their temporary structural reinforcement more than I do.

I will read the other thread (edit PDF, not thread), maybe I can grasp this without dragging this thread too far into my own questions.

Thank you all!

As far as I know, the reinforced concrete containment structure that supports the spent fuel pool is sound, and they added reinforcement to it. The upper containment structures (the structure above the reactor service floor) of Units 1, 3 and 4 were severely damaged - and the refueling bridges and overhead cranes were damaged or basically destroyed. In addition, the areas are heavily contaminated, so their immediate access for personnel is severely limited/restricted.

As far as I know, the spent fuel pools are receiving adequate cooling.

The spent fuel would normally be moved carefully underwater, especially since it may now contain failed rods. If that is the case, then movement of the fuel will be done carefully to avoid additional contamination of the spent fuel pool water and exposure to the personnel and current containment. Any failed fuel could also release Kr-85 (t_1/2 = 10.75 y) as well as other water-soluble fission products, e.g., Cs-134, -137, and fuel particles.

 

[tsutsuji]

http://www.nisa.meti.go.jp/shingikai/700/14/240724/BT-3-6.pdf Hiroto Inoue, JNES, "Seismic Safety Evaluation of the Spent Fuel Pool at the Unit 4", July 24, 2012 (English)

http://www.tepco.co.jp/nu/fukushima-np/images/handouts_120723_05-j.pdf Fukushima Daiichi accident workshop, July 23-24 2012 "middle and long term roadmap toward decommissioning and research & development"

http://www3.nhk.or.jp/news/genpatsu-fukushima/20120724/index.html The strontium removal device was publicly presented on 24 July in Yokohama. At present, more than 170,000 tons of contaminated water are stored at Fukushima Daiichi. In the device that was shown, nuclides contained in the contaminated water are adsorbed by resin in a stainless steel tank. By passing through different tanks, up to 62 nuclides can be removed, it was said. This way water can be decontaminated down to the level specified for release into the sea, which is a precaution against the risk of leaks into the environment. The facility will be installed at Fukushima Daiichi by the first 10 days of September, and then the test run will be started. For the time being, the decontaminated water is planned to be stored in tanks, but what will be done in the future has not been decided.

 

[tsutsuji]

Fukushima Daiichi accident workshop, July 23-24 2012

http://www.nisa.meti.go.jp/shingikai/700/14/240723/program.pdf program

http://www.nisa.meti.go.jp/shingikai/700/14/240723/240723.html presentations, July 23

http://www.nisa.meti.go.jp/shingikai/700/14/240724/240724.html presentations, July 24

http://www.tepco.co.jp/en/nu/fukushima-np/images/handouts_120723_05-e.pdf Tepco presentations, July 23

http://www.tepco.co.jp/en/nu/fukushima-np/images/handouts_120724_02-e.pdf Tepco presentations, July 24

 

[zapperzero]

http://www.nisa.meti.go.jp/shingikai/700/14/240723/240723.html presentations, July 23

Yet another MAAP accident simulation, yet another presentation wrt presumed causes of the explosion at #4, yet another iteration of the plan to find and plug leaks of radioactive water. I wonder, when will the simulations and projections start being replaced with actual data?

 

[etudiant]

Well, it seems that the plan is to reprocess the decontaminated water sufficiently to be able to dump it, although 'no decision has been made'. That is pretty unavoidable, as otherwise there would be need to eventually store several million tons of processed cooling water.
The rest of the work is going deliberately slowly, which seems sensible.
There is no prospect of doing much with the reactors in this decade, apart maybe from emptying the spent fuel pools.
So why hurry, if all of the work has to be done by humans? Better to play for time and push the teleoperator technology forward as fast as possible. That way Japan might also hopefully still get something useful out of this disaster.

 

[zapperzero]

So why hurry, if all of the work has to be done by humans? Better to play for time and push the teleoperator technology forward as fast as possible. That way Japan might also hopefully still get something useful out of this disaster.

*sigh* for what it is worth, I will repeat what I have said here and in other fora. The site remediation work will, must be slow. This, however, should not be seen as an excuse to not instrument the site and not do forensics.

As for pushing teleoperator tech: don't be ridiculous, what is being done now is so far behind the curve, it would be funny if it weren't sad.

Humans are constantly being sent into high radiation fields to manipulate door-handles and other such things; contact with tele-operated machines (no they are not robots) is being lost, as if wi-fi repeaters, Faraday cages and lead shielding had not been invented yet.

In other words, the survey/forensics work is underfunded to an incredible degree.

 

[etudiant]

*sigh* for what it is worth, I will repeat what I have said here and in other fora. The site remediation work will, must be slow. This, however, should not be seen as an excuse to not instrument the site and not do forensics.

As for pushing teleoperator tech: don't be ridiculous, what is being done now is so far behind the curve, it would be funny if it weren't sad.

Humans are constantly being sent into high radiation fields to manipulate door-handles and other such things; contact with tele-operated machines (no they are not robots) is being lost, as if wi-fi repeaters, Faraday cages and lead shielding had not been invented yet.

In other words, the survey/forensics work is underfunded to an incredible degree.

Sadly, your comments are indisputable.
The site management has not changed since the accident, even though the emergency is past. There has not been any recognition that TEPCO is a power utility, not a nuclear cleanup expert.
The site needs a separate management, divorced from TEPCO, tasked solely with performing this cleanup. Leaving TEPCO as a paymaster avoids the problem of setting up a very visible, very costly remediation authority and ensures the site management remains eager to minimize the outlays required. The cheeseparing evident all through the past year makes sense for the TEPCO controllers, but is surely penny wise, pound foolish from a national policy perspective.

 

[jmelson]

The cheeseparing evident all through the past year makes sense for the TEPCO controllers, but is surely penny wise, pound foolish from a national policy perspective.

Well, that's THE problem. In fact, TEPCO cheapness is what CAUSED the accident, from
the siting to the resistance to fortifying the plant against obvious hazards. But, TEPCO
is so big, they SET national policy, not the other way around. And, this has been the
clear situation for decades, where they have had a number of serious accidents.

Jon

 

[HowlerMonkey]

yeah...everybody is prepared for a 40+ foot wave and a 9.1 earthquake.

I'm pretty sure this is the scientific discussion thread.

The apportioning of blame thread is elsewhere.

 

[etudiant]

yeah...everybody is prepared for a 40+ foot wave and a 9.1 earthquake.

I'm pretty sure this is the scientific discussion thread.

The apportioning of blame thread is elsewhere.

Well, if the fixing process is starved for funds, that is a factual operational issue imho, not an apportioning of blame.
Also, the certification process is usually somewhat respectful of local conditions.
Japan has excellent data on earthquakes and tsunamis going back over 1000 years.
Disregarding that record seems a mistake, in retrospect.Whom to blame is another topic.

 

[jmelson]

yeah...everybody is prepared for a 40+ foot wave and a 9.1 earthquake.

I'm pretty sure this is the scientific discussion thread.

The apportioning of blame thread is elsewhere.

The 9.1 magnitude earthquake was certainly at the upper end of what Japan experiences,
but they HAVE had earthquakes of this magnitude before. The 15 m tsunami run-up
is guaranteed in Japan, you just have to wait long enough for one of those to hit your
particular region.

Their earthquake resistance pretty much handled the event (we think, but there MAY have been some serious damage that has either been covered up or not discovered yet due to
difficulty inspecting parts of the plant.) One area where there seems to be a LOT of damage is in the water-tightness of the plant basements, where they seem to have massive water
leaks, now.

But, since the tsunami threat was completely known and they knew their defenses were very inadequate, this seems to be a serious shortcoming of NISA (is that the right agency?) to make TEPCO harden the plant against the tsunami risk. So, that's why I made the comment about
TEPCO setting policy.

Jon

 

[gmax137]

The 9.1 magnitude earthquake was certainly at the upper end of what Japan experiences,
but they HAVE had earthquakes of this magnitude before.

really? when was that?

Actually, what is important is the ground motion at the plant site, not the magnitude of the 'quake (which is an attribute at the location of the earthquake itself). IIRC, the motion at Fukushima Dai-ichi did exceed the design basis (well, what they call the 'back-check' motion, which is like the latest design basis), but not by too much.

But, since the tsunami threat was completely known and they knew their defenses were very inadequate, this seems to be a serious shortcoming of NISA (is that the right agency?) to make TEPCO harden the plant against the tsunami risk...

I don't know about 'completely known' but I think most agree that the design basis tsunami was far too low. That (in my view) is a failure by the regulator and the licensee. They both had to close their eyes and say "I don't believe it will happen."

 

[SteveElbows]

I can't say I've been terribly disappointed with the real data so far, simply because I never expected it to be easy to obtain lots of high quality data and facts even if the operations were being carried out by the best resourced, most competent and open organisation imaginable. I want to know more, but some of the limitations are down to limitations of technology & science, not just lack of will or resources.

It strikes me as rather normal to be relying on model analysis for a range of things, and I was not expecting to learn much more about the cores of the reactors or much inside containment at this point.

Rather my main complaints are to do with the story told early on, lack of good data for people living there to act rationally upon, etc. There are things I wish had been presented to us in a far more cohesive manner, but plenty of it would still be model-based or speculative at this point. I actually want more speculation on various possible forms of containment breach, corium pathways etc, but I don't expect hard facts to emerge on this front any quicker than they have so far. But for example when they lowered that probe into the torus room and its water, and got some rather high readings, I would like either the company, government agencies, journalists or whoever to talk about what possibilities the resulting data, however limited, points to.

Perhaps my biggest complaint about data/facts since the first weeks of the disaster has been photographic etc evidence with decent analysis of various potential containment failure points. To say that they didnt go out of their way to draw attention to or explain even the stuff they have published about this sort of thing would be an understatement.

Meanwhile for those taking a more visual approach to observing the aftermath of the disaster, it seems that in a few hours the webcam will be moving to a new position that should afford us a better look at the work going on at reactor 4 (now that there is no interesting demolition stuff going on) & hopefully a vaguely reasonable view of 3 as well.

 

[HowlerMonkey]

Using the data from 1895 (edit), the nuclear power plants were carefully placed outside or at the edges of the new madrid area where the most damage occurred....for a 6 on the richter scale.

I'm pretty sure more than a few would be in danger if a 9.0 hit in new madrid.

My point is that I doubt anybody can successfully guarantee against damage from a 9.0 earthquake.

 

[mheslep]

Using the data from 1985, the nuclear power plants were carefully placed outside or at the edges of the new madrid area where the most damage occurred....for a 6 on the richter scale.

I'm pretty sure more than a few would be in danger if a 9.0 hit in new madrid.

My point is that I doubt anybody can successfully guarantee against damage from a 9.0 earthquake.

I'm inclined to always ask, what's the appropriate risk model (cost/benefit) in the case of 9.0 earthquake in an area with a nuclear power plant? That is, dedicate some amount of funds, whatever you like ($300B?) to prevention of damage to life and property in the case of that 9.0. What should be the priorities? Based on what I hazard to guess would save the most lives, near the top of my list would be reinforcement of existing structures (residential/office/municipal), gas lines, dams and the like, then perhaps training for emergency services. Or build sea walls at sites near the sea. Maybe down around 10th on the list I might start allocating money to improvements at the local nuclear plant.

 

[Tepconium-311]

What should be the priorities? Based on what I hazard to guess would save the most lives, near the top of my list would be reinforcement of existing structures (residential/office/municipal), gas lines, dams and the like, then perhaps training for emergency services. Or build sea walls at sites near the sea. Maybe down around 10th on the list I might start allocating money to improvements at the local nuclear plant.

Reinforced structures, gas lines and all this don't really matter in an exclusion zone, I guess.
And, how much is the genetic degenerative damage to be valued? Is genetic health of later generations a "priority" at all?
If you could ask your descendants seven generations later, they might strongly disagree with today's "priorities".

That's right. It was a mistranslation.

計装配管の健全性を確認　should have been translated as "checking instrumentation pipe soundess" or "we shall check instrumentation pipe soundness".

There is a second handout on the same topic dated July 13: www.tepco.co.jp/en/nu/fukushima-np/images/handouts_120713_04-e.pdf

Hmm, could the pipe simply have molten and welded shut?

 

[mheslep]

Reinforced structures, gas lines and all this don't really matter in an exclusion zone, I guess.
And, how much is the genetic degenerative damage to be valued? Is genetic health of later generations a "priority" at all?
If you could ask your descendants seven generations later, they might strongly disagree with today's "priorities"...

The 15,867 deaths from the Fukushima quake and tsunami are documented. The collapsed structures, fires, and flooding that killed them matter. They'll have no further descendants. The future genetic damage you refer to, though perhaps serious, is speculative.

 

[nikkkom]

And, how much is the genetic degenerative damage to be valued? Is genetic health of later generations a "priority" at all?
If you could ask your descendants seven generations later, they might strongly disagree with today's "priorities".

By the speed genetic engineering is moving, in a hundred years or so we will be able to "dial a genome" of our children.

 

[tsutsuji]

Fukushima Daiichi accident workshop, July 23-24 2012

http://www.nisa.meti.go.jp/shingikai/700/14/240723/program.pdf program

http://www.nisa.meti.go.jp/shingikai/700/14/240723/240723.html presentations, July 23

http://www.nisa.meti.go.jp/shingikai/700/14/240724/240724.html presentations, July 24

http://www.tepco.co.jp/en/nu/fukushima-np/images/handouts_120723_05-e.pdf Tepco presentations, July 23

http://www.tepco.co.jp/en/nu/fukushima-np/images/handouts_120724_02-e.pdf Tepco presentations, July 24

Here is the program with English titles when provided or translations of Japanese titles:


Workshop on Tokyo Electric Fukushima Daiichi nuclear power plant accident - distributed documents

Index

http://www.nisa.meti.go.jp/shingikai/700/14/240723/program.pdf Program (Japanese)

July 23 (meeting hall A)

AM-1 Session: accident events analysis (1)

http://www.nisa.meti.go.jp/shingikai/700/14/240723/AM-1-1.pdf Tepco, Detailed analysis of the accident progression of Units 1 to 3 by using MAAP code (some Japanese, some English)
http://www.nisa.meti.go.jp/shingikai/700/14/240723/AM-1-2.pdf JNES, Accident Sequence Analysis of Unit 1 to 3 Using MELCOR Code (English)
http://www.nisa.meti.go.jp/shingikai/700/14/240723/AM-1-3.pdf JAEA, Analysis for Accident Progression with THALES2 Code (English)

AM-2 Session: accident events analysis (2)

http://www.nisa.meti.go.jp/shingikai/700/14/240723/AM-2-1.pdf Toshiba, Hitachi-GE, Study for the leakage potential of PCV which have suffered by the condition of Fukushima accident (Japanese)
http://www.nisa.meti.go.jp/shingikai/700/14/240723/AM-2-2%281%29.pdf JNES, Analysis of reactor water level and PCV pressure and temperature in the hypothesis of very small piping leaks: (1) Reactor water level analysis using RELAPS5 Code (Japanese)
http://www.nisa.meti.go.jp/shingikai/700/14/240723/AM-2-2(2).pdf JNES, Analysis of reactor water level and PCV pressure and temperature in the hypothesis of very small piping leaks: (2) PCV pressure and temperature analysis using MELCOR Code (Japanese)
http://www.nisa.meti.go.jp/shingikai/700/14/240723/AM-2-3.pdf JNES, Accident sequence analysis using event tree of level 1 PSA (some Japanese, some English)
http://www.nisa.meti.go.jp/shingikai/700/14/240723/AM-2-4.pdf JNES, Analysis of concrete erosion depth caused by melted fuel (Japanese)

AM-3 Session: estimates of released quantities

http://www.nisa.meti.go.jp/shingikai/700/14/240723/AM-3-1.pdf JNES, Source Term Analysis Using MELCOR Code (English)
http://www.nisa.meti.go.jp/shingikai/700/14/240723/AM-3-2.pdf Tepco, Estimation of radioactive release resulting from Fukushima Dai-ichi NPS accident (English)
http://www.nisa.meti.go.jp/shingikai/700/14/240723/AM-3-3.pdf JAEA, Estimation of Time Trend of Atmospheric Releases on 131I and 137Cs (English)
http://www.nisa.meti.go.jp/shingikai/700/14/240723/AM-3-4.pdf CRIEPI, Direct release rate of radionuclides to the ocean from the Fukushima Daiichi Nuclear Power Plant estimated numerically by a regional ocean model (English)
http://www.nisa.meti.go.jp/shingikai/700/14/240723/AM-3-5.pdf JAMSTEC, Estimation of the total amount of 137Cs direct release associated with the Fukushima accident (English)July 23 (meeting hall B)

BM-1 Session: Offsite status

http://www.nisa.meti.go.jp/shingikai/700/14/240723/BM-1-1.pdf Cabinet Office, Designating and Rearranging the Areas of Evacuation (English)
http://www.nisa.meti.go.jp/shingikai/700/14/240723/BM-1-2.pdf Ministry of Environment, Overview of offsite cleanup activities (English)
http://www.nisa.meti.go.jp/shingikai/700/14/240723/BM-1-3.pdf JAEA, Overview of the Results of the Decontamination Model Projects (English)

BM-2 Session: Present plant status and present countermeasure implementation status

http://www.nisa.meti.go.jp/shingikai/700/14/240723/BM-2-1.pdf Tepco, The overall status of Fukushima Daiichi NPS (Japanese)
http://www.nisa.meti.go.jp/shingikai/700/14/240723/BM-2-2.pdf Tepco, The mid to long term roadmap toward decommissioning and research and development plan (Japanese)
http://www.nisa.meti.go.jp/shingikai/700/14/240723/BM-2-3.pdf Tepco, Condition inside PCV assumed based on the atmosphere gas measurement results (hydrogen, xenon and krypton behaviors) (Japanese)
http://www.nisa.meti.go.jp/shingikai/700/14/240723/BM-2-4.pdf JNES, Evaluation of xenon concentration in unit 2 PCV atmosphere (Japanese)
http://www.nisa.meti.go.jp/shingikai/700/14/240723/BM-2-5.pdf Tepco, Progress status of the fuel removal from Unit 1-4 spent fuel pools (Japanese)

July 24 (meeting hall A)

AT-4 Session: Earthquake, tsunami

http://www.nisa.meti.go.jp/shingikai/700/14/240724/AT-4-1.pdf Tepco, Earthquake Ground Motion Observed at the NPS and the Ground Motion Simulation (English)
http://www.nisa.meti.go.jp/shingikai/700/14/240724/AT-4-2.pdf Tepco, Tsunami Survey Results in the NPS and Reproduction Analysis Using Tsunami Inversion (English)
http://www.nisa.meti.go.jp/shingikai/700/14/240724/AT-4-3.pdf JNES, The JNES model on the construction of a design basis tsunami based on probabilistic tsunami evaluation (Japanese)
http://www.nisa.meti.go.jp/shingikai/700/14/240724/AT-4-4.pdf Tepco, Fukushima Daiichi NPS after the Tohoku-Chihou-Taiheiyou-Oki Earthquake: Impact of ground motion on Fukushima Daiichi NPS Units 1-3 (Japanese)

AT-5 Session: Liquid phase leaks from PCV

http://www.nisa.meti.go.jp/shingikai/700/14/240724/AT-5-1.pdf Tepco, Investigation result of the inside of PCV and the investigation plan to identify the leakage path of radioactive materials (Japanese)
http://www.nisa.meti.go.jp/shingikai/700/14/240724/AT-5-2.pdf Tepco, Various Approaches for Understanding State of Plants (Japanese)
http://www.nisa.meti.go.jp/shingikai/700/14/240724/AT-5-3.pdf JNES, Inference of PCV cooling status based on data after nitrogen injection (Japanese)AT-6 Session: Lessons learned from the accident

http://www.nisa.meti.go.jp/shingikai/700/14/240724/AT-6-1.pdf Cabinet secretariat, Reform of Nuclear Regulation Organisation and System in Japan (English)
http://www.nisa.meti.go.jp/shingikai/700/14/240724/AT-6-2.pdf NISA, Discussion on basic direction of safety regulation on severe accidents (English)

July 24 (meeting hall B)

BT-3 Session: Unit 4 spent fuel pool

http://www.nisa.meti.go.jp/shingikai/700/14/240724/BT-3-1.pdf Tepco, Investigation of the cause of hydrogen explosion at the Unit 4 Reactor Building (English)
http://www.nisa.meti.go.jp/shingikai/700/14/240724/BT-3-2.pdf JNES, Study on the Issues about Hydrogen Explosion at Fukushima Dai-ichi NPS (English)
http://www.nisa.meti.go.jp/shingikai/700/14/240724/BT-3-3.pdf Tepco, Regarding the integrity of the spent fuel pool at unit4 (English)
http://www.nisa.meti.go.jp/shingikai/700/14/240724/BT-3-4.pdf JNES, Analysis of Fuel Heat-up in a Spent Fuel Pool during a LOCA (English)
http://www.nisa.meti.go.jp/shingikai/700/14/240724/BT-3-5.pdf Kajima corporation, Seismic safty evaluation of the Spent Fuel Pool at the unit4 (English)
http://www.nisa.meti.go.jp/shingikai/700/14/240724/BT-3-6.pdf JNES, Seismic Safety Evaluation of the Spent Fuel Pool at the Unit 4 (English)
http://www.nisa.meti.go.jp/shingikai/700/14/240724/BT-3-7.pdf US NRC, Fukushima Lessons Learned : Spent Fuel Pools (English)
http://www.nisa.meti.go.jp/shingikai/700/14/240724/BT-3-8.pdf IAEA, Safety of the Spent Fuel Pool (English)

 

[tsutsuji]

http://www.nisa.meti.go.jp/english/files/program_en.pdf 23/24 July workshop program in English

http://www.nisa.meti.go.jp/english/files/1FWS_handout.html 23/24 July workshop document links with English titles

 

[tsutsuji]

The 8th mid & long term meeting was held on 30 July 2012: http://www.meti.go.jp/earthquake/nuclear/20120730_01.html

1) Previous related topics:

The 7th meeting (25 June 2012) https://www.physicsforums.com/showpost.php?p=3979794&postcount=13512

The 6th meeting (25 May 2012) : https://www.physicsforums.com/showpost.php?p=3933442&postcount=13399

The 5th meeting (23 April 2012) : https://www.physicsforums.com/showpost.php?p=3881074&postcount=12979

The 4th meeting (28 March 2012) : https://www.physicsforums.com/showpost.php?p=3838108&postcount=12764

The 3rd meeting (27 February 2012) was translated into English on Tepco's website : http://www.tepco.co.jp/en/nu/fukushima-np/roadmap/conference-e.html

2) Translation:

30 July 2012 government-Tokyo Electric mid and long term response committee, steering committee (8th meeting)

http://www.meti.go.jp/earthquake/nuclear/pdf/120730/120730_01a.pdf Agenda
http://www.meti.go.jp/earthquake/nuclear/pdf/120730/120730_01b.pdf Participants

Document 1
http://www.meti.go.jp/earthquake/nuclear/pdf/120730/120730_01c.pdf Abstract of the proceedings of 7th steering committee meeting

Document 2: Plant status
Document 2-1: Plant status
http://www.meti.go.jp/earthquake/nuclear/pdf/120730/120730_01d.pdf Plant parameters
http://www.meti.go.jp/earthquake/nuclear/pdf/120730/120730_01e.pdf Accumulated water storage status

Document 3 Study and execution of each special plan

3-1 Cooling by closed loop water injection
http://www.meti.go.jp/earthquake/nuclear/pdf/120730/120730_01f.pdf Schedule
http://www.meti.go.jp/earthquake/nuclear/pdf/120730/120730_01g.pdf Unit 2 alternative thermometer installation progress status

3-2 Treatment of accumulated water
http://www.meti.go.jp/earthquake/nuclear/pdf/120730/120730_01h.pdf Schedule
http://www.meti.go.jp/earthquake/nuclear/pdf/120730/120730_01j.pdf Improvement of closed loop line reliability
http://www.meti.go.jp/earthquake/nuclear/pdf/120730/120730_01k.pdf Multinuclide removal facility (ALPS) qualification test and facility design status
http://www.meti.go.jp/earthquake/nuclear/pdf/120730/120730_01m.pdf Subdrain purification test status report

3-3 Countermeasures to reduce environmental radiations
http://www.meti.go.jp/earthquake/nuclear/pdf/120730/120730_01n.pdf Schedule
http://www.meti.go.jp/earthquake/nuclear/pdf/120730/120730_01p.pdf Future schedule as regards harbour related works etc.
http://www.meti.go.jp/earthquake/nuclear/pdf/120730/120730_01q.pdf Consequences on water quality of the covering of the sea floor in the harbour
http://www.meti.go.jp/earthquake/nuclear/pdf/120730/120730_01r.pdf Future operation policy of the seawater circulation purification device
http://www.meti.go.jp/earthquake/nuclear/pdf/120730/120730_01s.pdf Results of evaluation of additional releases from reactor buildings

3-4 Improvement of working conditions
http://www.meti.go.jp/earthquake/nuclear/pdf/120730/120730_01t.pdf Schedule
http://www.meti.go.jp/earthquake/nuclear/pdf/120730/120730_01u.pdf Results of questionnaire survey in relation with improvement of working conditions at Fukushima Daiichi nuclear power plant and future course of action

3-5 Countermeasures for spent fuels pools
http://www.meti.go.jp/earthquake/nuclear/pdf/120730/120730_01v.pdf Schedule
http://www.meti.go.jp/earthquake/nuclear/pdf/120730/120730_01w.pdf Debris removal work, reactor building top part, unit 3
http://www.meti.go.jp/earthquake/nuclear/pdf/120730/120730_01x.pdf Debris removal work, reactor building top part, unit 4
http://www.meti.go.jp/earthquake/nuclear/pdf/120730/120730_01y.pdf Unit 1 operating floor status survey
http://www.meti.go.jp/earthquake/nuclear/pdf/120730/120730_01z.pdf Unit 4 spent fuel pool fresh fuel (unirradiated fuel) integrity survey

3-6 Preparations for fuel debris removal
http://www.meti.go.jp/earthquake/nuclear/pdf/120730/120730_01aa.pdf Schedule
http://www.meti.go.jp/earthquake/nuclear/pdf/120730/120730_01bb.pdf Survey into unit 3 torus room, reactor building underground floor

3-7 Treatment and disposal of radioactive waste
http://www.meti.go.jp/earthquake/nuclear/pdf/120730/120730_01cc.pdf Schedule
http://www.meti.go.jp/earthquake/nuclear/pdf/120730/120730_01dd.pdf Debris, cut down trees management status
http://www.meti.go.jp/earthquake/nuclear/pdf/120730/120730_01ee.pdf Collection of samples to analyse debris and cut down trees

Document 4
http://www.meti.go.jp/earthquake/nuclear/pdf/120730/120730_01ff.pdf Fukushima Workshop on the development of machinery and equipments toward the decommissionning process, etc. of Tokyo Electric Fukushima Daiichi NPP (event guide) [7 August 2012, in Koriyama, Fukushima prefecture]

Document 5
http://www.meti.go.jp/earthquake/nuclear/pdf/120730/120730_01gg.pdf roadmap progress (abstract)

 

[Tjfjfjgh99]

When will the area around the Fukushima Daiichi Nuclear Power Plant be repopulated?

How much land is off limits in terms of Square Miles or Kilometers?

Are the radiation risks serious or negligible within this area if one lives there permanently?

Do the benefits of nuclear power offset the economic loss of this land possibly being rendered useless?

 

[Tepconium-311]

Off-topic (sorry):

I logged in and read the following ad:

Hi Tepconium-311, have you thanked a PF Mentor today? They spend hours each day making sure PF is a great site! Spend two minutes and send a Mentor a PM or VM thanking them. Makes their day! :)

May I ask why tsutsuji has not yet been awarded Mentor status?
IMHO he deserves it. May I suggest him as a Mentor candidate?

(Thank you tsutsuji for your great contributions)

Edit:

Do the benefits of nuclear power offset the economic loss of this land possibly being rendered useless?

I'd be curious, too, how much all that restricted land and property would have cost if bought at once at a real estate broker. (Before accident, of course)

 

[etudiant]

Has there been any analysis of the seawater contamination incident at the Chubu Electric Hamaoka #5 reactor?
According to this article posted Aug 4, 2012 at Atomic Power Review:
http://atomicpowerreview.blogspot.com/2012/08/hamaoka-no-5-seriously-contaminated.html
there was a pipe failure in the main condenser during shutdown, so that a lot of secondary cooling circuit sea water contaminated the reactor.
In the current environment, that unit is probably a writeoff, but there are surely some real lessons to be learned if a deliberate shutdown can cause such a damaging failure to occur.

 

[tsutsuji]

http://www3.nhk.or.jp/news/genpatsu-fukushima/20120806/index.html Tepco has released part of the accident's teleconference videos. Journalists can go to Tepco's main office and watch there 150 hours of the videos taken for 5 days starting on 11 March 2011. They are not allowed to record the videos or the sound. An about one and a half hour edited abridged version prepared by tepco is available for the public to watch.

http://www3.nhk.or.jp/daily/english/20120806_30.html (same story, English version)

http://www.tepco.co.jp/tepconews/library/movie-01j.html The teleconference edited version is available on the last tab on the right, under "2012/8/6 本店会議録... (1:28:58)".

(Thank you tsutsuji for your great contributions)

Thanks for your support. I was given the "PF contributor" status and I feel very honoured by that.


http://www.tepco.co.jp/en/nu/fukushima-np/images/handouts_120803_02-e.pdf Investigation on the Misconnection of Thermometer Wiring at Fukushima Daiichi Nuclear Power Station :

[unit 1] 3. Dry well water level*: 1
Connected to the digital recorder with the wiring on the work site side switched off
→Connection was redone properly
* Set value: O.P. +27,150mm (Approx. 20m from the bottom of PCV)

What are we supposed to do with this "set value"? Isn't the water level more likely to be very low, a few cm above the bottom like at unit 2?