Japan Earthquake: Nuclear Plants at Fukushima Daiichi

[tsutsuji]

http://www3.nhk.or.jp/news/genpatsu-fukushima/20120128/index.html on 28 January at 10:30, a 9 litre leak was found close to one of the 3 pumps that inject water into the reactors. The leak stopped after shutting the pump down. There was no flow into the sea. Then near noon, two other leaks were found on valves at the water processing facility. In both cases a few litres of processed water leaked, but remained inside the building(s).

 

[nikkkom]

News seem to dry up, but there should be some activity.

For example, what's the status of basement water level reductions? How many tons are still there?

The plan was to seal off reactor building basements, to at least stop leaking into turbine buildings and further into the ground. Is there progress?

On this video I see that TEPCO is doing something around Unit 4:


Are these preparations for dismantling the ruined top part?

 

[Yamanote]

Thanks for these questions nikkkom and I hope there is some activity. I asked something similar already, as I wonder if enough progress is made. Well, one could also wait 300 years until most of the radioactive stuff has decayed away...

And I also wonder about the plan for the accumulated water. There is still a high inflow of groundwater and soon the storage tanks will be full. And then?

 

[etudiant]

Afaik, the JAIF provides the best ongoing summary of the situation on its web site.
http://www.jaif.or.jp/english/
It indicates some 200,000 cubic meters of water have been treated, but the ongoing influx of groundwater means 80,000 cubic meters remain in the facility continually.
TEPCO is building a sea wall to seal off the site from the ocean, but the larger issue of sealing off the entire site from groundwater has yet to be tackled. It is not happening imho because it would be a monster job whose utility could be destroyed in an instant by another small earthquake.
The cleaned water probably will eventually be used as irrigation water, as the idea of dumping it into the ocean has encountered objections by the local fisheries. There is no public plan for what to do with the concentrated waste water or the contaminated filters and sludge material.

 

[tsutsuji]

News seem to dry up, but there should be some activity.

For example, what's the status of basement water level reductions? How many tons are still there?

Their mid-term goal is not to reduce water levels but to keep them stable : "based on the view of limiting inflow of underwater to buildings and reducing the amount of emerged accumulated water, we are planning to transfer accumulated water keeping its level in the building below OP. 3,000 considering water tank capacity." : http://www.tepco.co.jp/en/press/corp-com/release/betu12_e/images/120125e5.pdf

The plan was to seal off reactor building basements, to at least stop leaking into turbine buildings and further into the ground. Is there progress?

On http://www.tepco.co.jp/en/press/corp-com/release/betu11_e/images/111221e14.pdf page 42/94, "Target：Complete Switch to Water Withdrawal from Reactor Building (or lower part of PCV)" is set for mid-fiscal year 2015. There is also "(HP1-1): Completion of stopping inter-building water leakage between reactor and turbine buildings and repairing lower part of the PCV" which is planned for the middle of phase 2 around 2017. On page 48/94 you can see that "R&D for PCV Leakage Point Survey/ Repairs (including stopping inter-building water leakage)" is scheduled for fiscal years 2012-2013-2014 including "Design, Manufacture and Test, etc. of PCV Leakage Point Survey Equipment ②" and "Design, Manufacture and Test, etc. of PCV Repair Equipment ③⑥", with "Investigation of Leakage Points (including field test of R&D results)" starting in mid fiscal year 2014.

In the documents of the mid-long term meeting of 26 December you can find a slideshow about accumulated water : http://www.tepco.co.jp/nu/fukushima-np/roadmap/images/m111226_08-j.pdf page 16/37 - 24/37. It is divided into 3 parts:

1) Radical countermeasures against inflow of groundwater : they want to repair the subdrains that were damaged by the tsunami, then decontaminate them, and finally pump ground water from the subdrains to control ground water level and reduce ground water inflow into the turbine buildings.
2) Increase removal capacity and secure stable operation of decontamination facility
3) Further install on-land equipments. (The red areas are already used. The blue areas are still free for adding more tanks)

There was a second mid-long term meeting on 23 January. The documents are available on Japanese only (as far as I know) at http://www.tepco.co.jp/nu/fukushima-np/roadmap/conference-j.html (for example including the following presentations on mock-up debris : http://www.tepco.co.jp/nu/fukushima-np/roadmap/images/r120123_04-j.pdf and water treatment secondary waste products (sludge, zeolite) : http://www.tepco.co.jp/nu/fukushima-np/roadmap/images/r120123_05-j.pdf and an announcement of a workshop on fuel removal techniques (open to the public and press) to be held on 24 February http://www.tepco.co.jp/nu/fukushima-np/roadmap/images/r120123_06-j.pdf ).

There is also a detailed review of what was done during the past 30 days up to January 23, and what they plan to do in the coming months at http://www.tepco.co.jp/nu/fukushima-np/roadmap/images/m120123_05-j.pdf, which includes a report on the water levels of unit 4 pool, drywell pit, and skimmer surge tank, and another report on the installation of new water-treatment facilities (tanks, or waste storage areas), and new areas to store wood from the cleared forests. The trial run of unit 3's PCV gas managing system is scheduled for February 23. The "basic design of shortening the water injection loop" is mentioned as a continuous line from January through April, or possibly later. The basic design of the multi-nuclide removal equipment [1] ends at the end of January, and the detailed design of the same starts in February. A forest clearance is more or less scheduled at the end of February in connection with this multi-nuclide thing. A subdrain purification test was started at unit 2 in the second week of January. There is a plan to change the seismic isolated building into a zone outside the controlled area, which means decontaminating (like cleaning the roof) and shielding the building (with steel and lead sheets). The design for the shielding ends at the end of January. At unit 4 reactor building, in January, they took care of the top part of the operating floor crane and removed rows R5 and R6 of the roof steel frame [this is on the south side]. In February they will remove rows R3 and R4, and remove "big machines" from the operating floor. They will start removing unit 4's north side wall and steel frame at the end of March.

[1] an equipment that would remove strontium, according to http://www.japantimes.co.jp/text/nn20120112a9.html

http://www3.nhk.or.jp/news/genpatsu-fukushima/20120129/index.html On 29 January Tepco announced 14 leaks [!]. It is believed that these leaks are due to the frost. One of them is a 40 litre leak found at unit 4 at 9:30 AM. Another one is a 600 litre leak found near one of the pumps that inject water into the reactors. Another one is a 7 ton leak of the circulating water of unit 6 (not contaminated). In the morning of 29 January, the temperature was 8°C of frost. Tepco's Junichi Matsumoto said "the freezing countermeasures are far from being sufficient. It is necessary to install heat insulating material at a higher pace than until now".

http://www.tepco.co.jp/en/nu/fukushima-np/images/handouts_120129_01-e.pdf "Water leakage in Fukushima Daiichi Nuclear Power Station (Discovered on 29 January)"

http://www.tepco.co.jp/en/nu/fukushima-np/images/handouts_120129_02-e.pdf (map of the leaks)

 

[nikkkom]

Afaik, the JAIF provides the best ongoing summary of the situation on its web site.
http://www.jaif.or.jp/english/
It indicates some 200,000 cubic meters of water have been treated, but the ongoing influx of groundwater means 80,000 cubic meters remain in the facility continually.

Uhhh... that's an awful lot of water. The influx is so large? Why?

the larger issue of sealing off the entire site from groundwater has yet to be tackled. It is not happening imho because it would be a monster job whose utility could be destroyed in an instant by another small earthquake.

Did it occur to TEPCO to drill a few dozen drainage wells and pump them out?

Do they really plan to keep basements drenched wet for five years or more? That stuff wasn't designed for this environment! Everything will rust into dust!

 

[nikkkom]

The cleaned water probably will eventually be used as irrigation water, as the idea of dumping it into the ocean has encountered objections by the local fisheries.

Somehow I think local farmers won't be happy either. In fact, dumping this very slightly contaminated water into the ocean is the best idea. If this will not be allowed, is it economical to distillate it once more?

 

[Rive]

...is it economical to distillate it once more?

IIRC the remaining contamination is partly Tritium, which cannot be removed easily.

Did it occur to TEPCO to drill a few dozen drainage wells and pump them out?

To prevent further contamination outside the containment they prefer water flowing in. This way they will have to deal with some more water: the other way would mean awful lot of contaminated ground beneath the buildings.

It's a kind of similar system which used in biology or chemistry. Inflow is better when you want to keep something inside.

 

[tsutsuji]

http://www3.nhk.or.jp/news/genpatsu-fukushima/20120130/2130_4kasyo.html Tepco found 4 more leaks in the night of 29 January and on 30 January. The temperature in the morning of 30 January was 8.7°C of frost. Tepco is reinforcing patrols and covering pipes and equipments with insulating material. Junichi Matsumoto said "as the severe frost is expected to continue, we want to urgently take countermeasures against freezing in the places that were not reached by those countermeasures".

http://www3.nhk.or.jp/news/genpatsu-fukushima/20120130/0730_mizumore.html The NISA has ordered Tepco to take countermeasures against frost in response to the 14 leaks discovered on 29 January, implying a 1 hour 40 minutes stop of unit 4's cooling system. In all cases either pipe junctions were loosened or parts were broken by the expansion of water caused by freezing. Tepco is increasing patrols, adding insulating material and, in some cases, heaters. At the important equipments such as those that perform reactor cooling and those that involve highly contaminated water, the countermeasures are almost complete, but as the frost is expected to continue for several days, Tepco is hurrying up with the remaining countermeasures.

http://www3.nhk.or.jp/news/genpatsu-fukushima/20120130/1845_robo.html Chiba institute of Technology has developped robots Quince No.2 and No.3. They were urgently developed after Quince No.1 had its cable entangled and could not move any more inside unit 2 in October. They have nearly the same shape and size as Quince No.1, but cable entanglement is being made more difficult. In case cable communication is impossible, they can communicate with another robot by radio. Quince No. 2 is equipped with a high sensitivity radiation measurement equipment, and Quince No. 3 with a scanner to measure distances. Quince No.2 and No.3 will start being used in mid-February.

http://www.tokyo-np.co.jp/article/feature/nucerror/condition/list/CK2012012902000091.html?ref=rank [29 January] During the week from 22 January to 28 January, the cesium released into the atmosphere by Fukushima Daiichi increased in comparison to the December level. The radiation released by units 1, 2, and 3 all together was 72 million Bq/hour , which is 12 million Bq/hour higher than in December. It is said that as more work was done inside units 2 and 3, the cesium accumulated on the floor soared into the air. Until then cesium release quantities had been steadily decreasing. Tepco said "It is difficult to dramatically decrease the releases. For the time being, the present level will be continuing". To prevent the spreading of the cesium accumulated on the sea floor, the sea floor in the harbour in front of the plant will be covered with a 60 cm thick layer of clay and cement. This work will be done from mid-February to March.

http://www.asahi.com/national/update/0130/TKY201201300070.html According to a November survey, the cesium concentration in the sea floor in the harbour is up to 1.6 million Bq/kg. The 60 cm thick cement layer will cover a 7 Ha area. The local fishing cooperatives had expressed worries that the construction work of the ground water shielding wall would spread cesium into the sea.

 

[Yamanote]

Thanks tsutsuji!

By the way, what happened to Quince No.1, was it left in Unit 2?

 

[thebluestligh]

http://www3.nhk.or.jp/news/genpatsu-fukushima/20120130/2130_4kasyo.html Tepco found 4 more leaks in the night of 29 January and on 30 January. The temperature in the morning of 30 January was 8.7°C of frost. Tepco is reinforcing patrols and covering pipes and equipments with insulating material. Junichi Matsumoto said "as the severe frost is expected to continue, we want to urgently take countermeasures against freezing in the places that were not reached by those countermeasures".

http://www.tokyo-np.co.jp/article/feature/nucerror/condition/list/CK2012012902000091.html?ref=rank [29 January] During the week from 22 January to 28 January, the cesium released into the atmosphere by Fukushima Daiichi increased in comparison to the December level. The radiation released by units 1, 2, and 3 all together was 72 million Bq/hour , which is 12 million Bq/hour higher than in December. It is said that as more work was done inside units 2 and 3, the cesium accumulated on the floor soared into the air. Until then cesium release quantities had been steadily decreasing. Tepco said "It is difficult to dramatically decrease the releases. For the time being, the present level will be continuing". To prevent the spreading of the cesium accumulated on the sea floor, the sea floor in the harbour in front of the plant will be covered with a 60 cm thick layer of clay and cement. This work will be done from mid-February to March.

Thanks tsutsuji!

By the way, what happened to Quince No.1, was it left in Unit 2?

So the theories of piping problems with freezing that was being discussed on this thread months ago appear to have had a pretty significant impact. Why wasn't this forseen?


I also found this interesting - Tepco said "It is difficult to dramatically decrease the releases. For the time being, the present level will be continuing"

If the levels are up because of the work in R2 and R3 (and I am not aware of any plans to perform that work again in the near future) why would the levels remain so elevated?

And @Yamanote - Quince 1 is still in the building where it ceased operations, in one of the articles I read it said that they currently have no plans to retrieve it.

 

[Joffan]

So the theories of piping problems with freezing that was being discussed on this thread months ago appear to have had a pretty significant impact. Why wasn't this forseen?

In a word - triage. Tepco fixed the big problems as quickly as possible, without being held back by looking for perfection, in the knowledge that lesser problems might arise that would have to be dealt with. I'd argue that these leaks have NOT had a "pretty significant impact" - in fact, essentially no impact in practical terms.

I also found this interesting - Tepco said "It is difficult to dramatically decrease the releases. For the time being, the present level will be continuing"

If the levels are up because of the work in R2 and R3 (and I am not aware of any plans to perform that work again in the near future) why would the levels remain so elevated?

The levels are not particularly elevated. This is "the present level continuing" - 20% variations are nothing much, compared to the previous reductions. There will be continuing work on the sites, so variations in this range may well continue.

 

[tsutsuji]

http://www3.nhk.or.jp/news/genpatsu-fukushima/20120131/1305_mizumore.html The temperature in the morning of 31 January was 4°C of frost. One 20 liter leak was found after 9 AM at the junction of pipes of the system bringing fresh water to the decontamination facility. After 11 PM on 30 January a crack was found on one valve on a pipe which brings water into the reactors, but there was no leak. Junichi Matsumoto said "The plan was to finish the countermeasures by next month. Retrospectively it was too late. We want to hurry up with the countermeasures".

 

[zapperzero]

what happened to Quince No.1, was it left in Unit 2?

yes it was

 

[zapperzero]

http://ajw.asahi.com/article/0311disaster/fukushima/AJ201201310043
This rather convoluted article from Asahi Shimbun was featured on enenews. Apparently

Piping and support structures at the No. 5 reactor of the crippled Fukushima No. 1 nuclear power plant did not have sufficient anti-quake strength under new government standards revised in 2006.

If I understand the article correctly, the calculations needed to determine this rather interesting fact were only just completed a few days ago.

 

[Joffan]

http://ajw.asahi.com/article/0311disaster/fukushima/AJ201201310043
If I understand the article correctly, the calculations needed to determine this rather interesting fact were only just completed a few days ago.

The contrived headline to confuse some theoretical quake with the actual event and the breathless recounting of forces to theoretical pipes under those imagined conditions misses the opportunity to actually inform us about the condition of the real structures at reactor #5. Based on past experience, if there was anything actually wrong, that would have been described in the most dramatic terms possible, so I'll assume, for now, that the structures at unit 5 are in reasonably good shape.

 

[tsutsuji]

http://ajw.asahi.com/article/0311disaster/fukushima/AJ201201300001 The multi-nuclide purifying facility will cover "also strontium, cobalt and manganese". They will "start installing equipment in March".

http://www.asahi.com/national/update/0128/TKY201201280396.html But the "detailed design" of the multi-nuclide facility has yet to be done. Radioactive substances are adsorbed on minerals or resins. By selecting adsorption enhancing chemicals, one can change which radioactive substances are removed.

http://www.jiji.com/jc/c?g=soc_30&rel=j7&k=2012013101023 In the report to NISA, Tepco said that the 125 liter highly radioactive water leak in December (containing strontium, flowing into the sea) had been caused a deformation of a gum packing, caused by bubbles, caused by a mistake in the operation manual.

http://www.tepco.co.jp/en/press/corp-com/release/12013108-e.html Report to NISA about the December strontium-water leak at the desalinating facility

http://www.tepco.co.jp/cc/press/betu12_j/images/120131g.pdf Attachment 7 page 24/46 mentions a "water-hammer effect".

 

[CaptD]

News on the Quince robots: http://is.gd/vkiFXy

 

[Yamanote]

http://ajw.asahi.com/article/0311disaster/fukushima/AJ201201300001 The multi-nuclide purifying facility will cover "also strontium, cobalt and manganese". They will "start installing equipment in March".

http://www.asahi.com/national/update/0128/TKY201201280396.html But the "detailed design" of the multi-nuclide facility has yet to be done. Radioactive substances are adsorbed on minerals or resins. By selecting adsorption enhancing chemicals, one can change which radioactive substances are removed.

Does it mean, that there is really no such facility available all around the world right now? Hard to believe for me.

Or is it again about saving money for Tepco - just remove the caesium and pour the rest into the ocean...?

And finally it surprises me that Tepco is surprised about frost in January.

 

[Sled Head]

Questions
Since cesium (radio active or non radioactive) gets absorbed by plants and animals as a nutritional supplement in place of potassium and becomes part of the World food chain.
Will this not effect health by lack of potassium levels and or by way of cell damage from cesium exposure? If so,

It stands to reason that the cesium plumes in the environment will continue to spread in concentrations by way of plant, animals, the wind and ocean currents, eventually becoming evenly dispersed throughout the planet.

Has anyone determined how much of this cesium can exist in the food chain or has anyone projected future cesium levels in the environment?

Another question regarding the use of cesium in the environment.

If we have all of these environmental agencies conducting test for the monitoring and protection of our atmosphere, land, and oceans.
How can their test and experiments be viable if certain agencies that are protected by national security waivers release huge amounts of cesium into the environment without disclosure to those agencies?

Do they really think that by burying it in mud and clay will stop it? Do biological life forms not exist in mud and clay?

Really now, what is the point of monitoring, measuring, and mapping cesium contamination, when the governments keep secret what has been contaminated in secret?

http://www.stripes.com/news/pacific/earthquake-disaster-in-japan/more-cesium-found-in-rice-harvested-in-fukushima-in-japan-1.161770

 

[nikkkom]

Questions
Since cesium (radio active or non radioactive) gets absorbed by plants and animals as a nutritional supplement in place of potassium and becomes part of the World food chain.
Will this not effect health by lack of potassium levels and or by way of cell damage from cesium exposure?

No, it won't. Plants will continue to absorb mostly potassium. Caesium is absorbed in very, very small amounts.

If so,

It stands to reason that the cesium plumes in the environment will continue to spread in concentrations by way of plant, animals, the wind and ocean currents, eventually becoming evenly dispersed throughout the planet.

Has anyone determined how much of this cesium can exist in the food chain or has anyone projected future cesium levels in the environment?

Another question regarding the use of cesium in the environment.

If we have all of these environmental agencies conducting test for the monitoring and protection of our atmosphere, land, and oceans.
How can their test and experiments be viable if certain agencies that are protected by national security waivers release huge amounts of cesium into the environment without disclosure to those agencies?

What "huge amounts" of caesium are you talking about? Caesium is not poisonous. Total inventory of caesium, all isotopes combined, in the fuel on the whole F1 site is on the order of 100 kg. Its danger comes solely from its radioactive isotopes, not chemical/biological effects.

 

[tsutsuji]

http://www.tokyo-np.co.jp/s/article/2012020190070438.html On 31 January, the NISA announced that during the 11 March earthquake, the Emergency Response Support Systems (ERSS) were temporarily suspended at 3 nuclear power plants, because their emergency uninterruptible power systems (systems with batteries inside) were not connected : Tokai Daini, Onagawa, and Higashidori nuclear power plants. Tokai Daini's ERSS was interrupted for more than 3 hours, and at Onagawa and Higashidori the signals were unstable for 8 and a half hours. The NISA found the emergency uninterruptible power system disconnection at Fukushima Daiichi in May, but did not start checking other plants until 7 months later.

http://www3.nhk.or.jp/news/genpatsu-fukushima/20120131/index.html Two more leaks were found at Fukushima Daiichi in the afternoon of 31 January. One 10 liter leak at a reactor injection backup pump, and a 20 liter leak at a "tank pipe". Both leaks are with water devoid of radioactive substances.

 

[thebluestligh]

http://translate.google.com/translate?hl=en&sl=auto&tl=en&u=http%3A%2F%2Fwww.tokyo-np.co.jp%2Farticle%2Fnational%2Fnews%2FCK2012013102000038.html

http://translate.google.com/translate?hl=en&sl=auto&tl=en&u=http%3A%2F%2Fwww.tokyo-np.co.jp%2Fs%2Farticle%2F2012013190071414.html

Re - Frozen piping

 

[zapperzero]

misses the opportunity to actually inform us about the condition of the real structures at reactor #5

According to the article, there is a survey in progress. Perhaps results will be published later.

 

[jim hardy]

""http://www.tepco.co.jp/cc/press/betu12_j/images/120131g.pdf Attachment 7 page 24/46 mentions a "water-hammer effect".

what equipment is that fractured pipe?

 

[tsutsuji]

http://www3.nhk.or.jp/news/genpatsu-fukushima/20120201/index.html An 8.5 ton leak was found on unit 4's first floor at 10:30 PM on 31 January. A ⌀ 9mm pipe connected to the reactor was pulled out of a junction part. The radiation of the water is 35.5 Bq/cm³ . The leak was stopped by closing a valve on the reactor side. The water went no further than the reactor building basement. Tepco said "we are unsure if this was caused by frost".

http://www.tepco.co.jp/en/nu/fukushima-np/images/handouts_120201_01-e.pdf "Status of Water Leakage on the 1st floor of Unit 4 Reactor Building, Fukushima Daiichi Nuclear Power Station (Test line of the Piping for Jet Pump Measurement)"

http://www.47news.jp/CN/201202/CN2012020101002248.html It is thought that the water started leaking at around 5 PM on 30 January. Tepco earlier reported a 6 liter leak, but after checking, announced the quantity was 8.5 tons. The 8.5 ton quantity is inferred from the water level drop in the tank installed on the side of the fuel pool. It is thought that the water expanded by freezing, creating an internal pressure pushing the pipe away.

In the afternoon press conference, Junichi Matsumoto makes a small drawing on the white board and explains to a journalist that the fuel pool's water level remained stable, even though the skimmer surge tank's water level decreased on 30 January by 60 to 90 mm/hour (instead of the usual 3 mm/hour caused by evaporation). Tepco started patrolling the plant to find the leak at 22:00 on 31 January. Junichi Matsumoto agrees with a journalist that this was late, but as the airfin cooler had been adjusted, the operators thought that the water level drop could have resulted of a drop of temperature, and hoped for about 24 hours that the water level would stabilize. When the leak was stopped, the skimmer surge tank water level had dropped by 1.10 m (1 February afternoon press conference video at http://www.tepco.co.jp/tepconews/library/movie-01j.html )

http://www.tepco.co.jp/en/nu/fukushima-np/f1/images/intake_canal_120201-e.pdf page 3 "There was no Pu-238, Pu-239 and Pu-240 detected from the sample for this analysis" [north water intake canal Units 1-4 Fukushima Daiichi Nuclear Power Station, 16 January]

http://www.tepco.co.jp/en/nu/fukushima-np/f1/images/soil_120201-e.pdf "Radioactive density of the Pu-239 and Pu-240 detected on January 16 was within the same level as that of fallout of past nuclear test in the atmosphere." [soil]

http://www.tepco.co.jp/en/nu/fukushima-np/f1/images/kakuhou_120201-e.pdf page 145/148 : 3.1E-05 Bq/cm³ of Ag-110m in the air at Upper part of reactor building of Unit 3 on 6 January

http://www.tepco.co.jp/en/nu/fukushima-np/f1/images/kakuhou_120201-e.pdf page 115/148 : 5.3 E-02 Bq/cm³ of Ru-106 in unit 3 subdrain on 11 January. (Ru-106 had been previously found in soil and dust samples in March, Junichi Matsumoto says in the 1 February afternoon press conference video at http://www.tepco.co.jp/tepconews/library/movie-01j.html )

http://www.tepco.co.jp/en/nu/fukushima-np/images/handouts_120201_03-e.pdf "Measures against Freeze of Water Treatment Facility / Measures against Freeze of Reactor Water Injection System at Fukushima Daiichi Nuclear Power Station" ["floodlight", on page 3, is a well coined English word]

http://mainichi.jp/select/jiken/news/20120202k0000m040080000c.html Tepco found 158 mistakes in the stress test report sent to NISA for Kashiwazaki Kariwa units 1 to 7. These are simple mistakes without consequences on the report's conclusions.

http://www.tepco.co.jp/cc/press/betu12_j/images/120131g.pdf Attachment 7 page 24/46 mentions a "water-hammer effect".

what equipment is that fractured pipe?

No pipe was fractured. Only a packing was deformed, as you can see on the photographs on attachment 6 page 23/46. The blue equipment (pink equipment on the diagram on attachment 7) is a preheater belonging to an evaporative concentration apparatus.

The contrived headline to confuse some theoretical quake with the actual event and the breathless recounting of forces to theoretical pipes under those imagined conditions misses the opportunity to actually inform us about the condition of the real structures at reactor #5. Based on past experience, if there was anything actually wrong, that would have been described in the most dramatic terms possible, so I'll assume, for now, that the structures at unit 5 are in reasonably good shape.

I tried to have a look at what was said about unit 5's earthquake resistance in the second report to IAEA.

On http://www.iaea.org/newscenter/focus/fukushima/japan-report2/chapter-2-1.pdf (English) page II-49 there is a "Table II-2-6 Overview of Impact Evaluation on Equipment and Piping Systems important for Seismic Safety (Fukushima Dai-ichi NPS, Unit 5)" with two columns with figures. The left column is the standard earthquake ground motion Ss, and the right column is the simulation result. Some of the figures in the right column are a few percent higher than those in the left column. Is it dangerous ? There is also a small peak on one of the plots on the same page marked with "peak considered to be generated according to the simulation analysis" and I am unsure what this means.

 

[Joffan]

Thanks tsutsuji, great reference. Those tables are discussed very briefly on p II-42/3:

Based on the comparison results, according to TEPCO, it was found that for Units 1 to 3, and 5, some of those indexes such as seismic load by the earthquake exceeded the ones from the seismic safety assessment. However, a seismic assessment of major components that have important safety functions relevant to "Shutdown" and "Cool down" of reactors, and "Containment" of radioactive materials was performed, and found that the calculated stress, etc. were below the criteria (Tables II-2-2 to II-2-7). For Units 4 and 6, it was found that those indexes such as seismic load by the earthquake, except some peak floor response spectra, were below the ones from the seismic safety assessment.
And also, a seismic assessment of the piping systems using floor response spectra was performed, for Units 1 to 6, and found that the calculated stress was below the criteria (Tables II-2-8 to II-2-13).

 

[jim hardy]

"""No pipe was fractured. Only a packing was deformed, as you can see on the photographs on attachment 6 page 23/46. The blue equipment (pink equipment on the diagram on attachment 7) is a preheater belonging to an evaporative concentration apparatus."'

THANKS, Tsujitsu !

i should have looked further...

 

[tsutsuji]

http://www3.nhk.or.jp/news/genpatsu-fukushima/20120204/index.html On 3 February, a leak smaller than 1 liter was found at a tank containing high strontium concentration. The gamma ray at the surface of the water is 22 mSv/hour and the beta ray is 2000 mSv/hour. The leak was stopped by tightening a bolt. This is the same sort of leak as on 10 January ( https://www.physicsforums.com/showpost.php?p=3704022&postcount=12136 ). As there are about 100 such tanks, the NISA ordered Tepco to check them and to take countermeasures. Tecpo is investigating, thinking that as the tanks were urgently built, they were assembled with bolts instead of welding.

http://www.tepco.co.jp/en/nu/fukushima-np/images/handouts_120203_04-e.pdf "Leakage from water desalinations(RO)concentrated water tank" 3 February

http://www.tepco.co.jp/en/nu/fukushima-np/images/handouts_120110_03-e.pdf "Water leakage from the concentrated water tank of the water desalinations (reverse osmosis membrane)" 10 January

http://www3.nhk.or.jp/news/genpatsu-fukushima/20120203/index.html The NISA will conduct its first inspection at Fukushima Daiichi since the accident for 3 weeks starting on 6 February. During that period, the status of the inspection will be released to the media.

http://www.jiji.com/jc/c?g=soc_30&k=2012020300467 On 3 February, Tepco said that the water level in unit 4's skimmer surge tank was decreasing at twice the usual pace and that there is a high probability that the water is leaking. Tepco is urgently looking for the location of the leak.

 

[Martin Peters]

Tepco has posted an English document describing the work they did to reduce the level of radiation in a parking lot: "Radiation dose reduction by collecting dust and small rubbles
at the parking lot in front of Main Anti-Earthquake Building of Fukushima Daiichi Nuclear Power Station"

http://www.tepco.co.jp/en/nu/fukushima-np/images/handouts_120203_01-e.pdf

The maximum value of radiation at 1 cm above the surface (shown below the lower left chart) appears to be erroneous. According to the color key, the red dots in the chart show locations where the surface radiation was >1000 µSv/hr. Since a comma appears to the left of the digits "240", I suspect that a digit to its left has been lost.

Edit at 0300 UT, 4 Feb 2012: The Japanese version of this doc shows that the value is 1,240 µSv/hr.

 

[tsutsuji]

http://www.jiji.com/jc/c?g=soc_30&k=2012020300467 On 3 February, Tepco said that the water level in unit 4's skimmer surge tank was decreasing at twice the usual pace and that there is a high probability that the water is leaking. Tepco is urgently looking for the location of the leak.

The above is dated 2012/02/03-12:54 so it is probably from the morning press conference. I watched the 3 February afternoon press conference video ( http://www.tepco.co.jp/tepconews/library/movie-01j.html ), where Junichi Matsumoto said that after refilling the skimmer surge tank, the dropping rate was around 10 mm/hour which is within the allowed range, taking evaporation into consideration.

I checked the skimmer surge tank water level data at
http://www.tepco.co.jp/en/nu/fukushima-np/f1/images/12020406_table_summary-e.pdf
http://www.tepco.co.jp/en/nu/fukushima-np/f1/images/12020312_table_summary-e.pdf
http://www.tepco.co.jp/en/nu/fukushima-np/f1/images/12011712_table_summary-e.pdf
http://www.tepco.co.jp/en/nu/fukushima-np/f1/images/12011812_table_summary-e.pdf

2997mm on 4 February 05:00
3179mm on 3 February 11:00
(3179-2997)/(24+5-11)=10.1 mm/hour

2318mm on 18 January 11:00
2388mm on 17 January 11:00
(2388-2318)/24 = 2.92 mm/hour

I don't understand why they refilled so little on 3 February (to perhaps between 3000 and 4000 mm, instead of refilling to more than 5000 mm)

In the 4 February afternoon press conference video ( http://www.tepco.co.jp/tepconews/library/movie-01j.html ), Tetsuya Terasawa says that they measured 4 mm between 6:28 and 6:53 in the morning which he calls "a stable 4 mm". He says they reached the conclusion that the variation of skimmer surge tank water level is explained by causes such as evaporation and the volume variation caused by temperature, and is not caused by a leak. The NHK journalist asked if it is 4 mm "per hour", and Terasawa said "yes" (until the NHK journalist asked, I thought it was 4 mm in the 25 minutes from 6:28 to 6:53). He also said that there was a 12 mm/hour drop at 11:00 on 3 February. Tepco has no plan to further investigate the causes of the water level drop, but will carefully survey the skimmer surge tank water level.

http://www.asahi.com/national/jiji/JJT201202040074.html [4 February 22:06] Tepco was studying the possibility of a leak as unit 4's skimmer surge tank water level was decreasing at twice the usual pace on 1 and 2 February, but after refilling the tank, the decrease rate became smaller. Tepco explains the temporarily quick pace with the reduction of volume due to the temperature fall and to the evaporation increase due to dry air.

 

[elektrownik]

I found top floor of unit 4 map:
http://twitter.com/#!/minorucchu/status/164533275312926720/photo/1/large

 

[MJRacer]

Elevation of Emergency Diesel Generators (EDG) at Fukushima Dai-Ichi
(O.P.: Onahama port base tide level for construction, page II-68 of http://www.iaea.org/newscenter/focus/fukushima/japan-report2/chapter-2-1.pdf (the second report to the IAEA linked by tsutsuji)):

From Table II-2-14 on page II-72:

Unit 1
A: O.P. +4.9m (Flooded)
B: O.P. +0.2m (Flooded)

Unit 2
A: O.P. +1.9m (Flooded)
B: O.P. +10.2m (Not Flooded)

Unit 3
A: O.P. +1.9m (Flooded)
B: O.P. +1.9m (Flooded)

Unit 4
A: O.P. +1.9m (Flooded, but out of service due to repair)
B: O.P. +10.2m (Not-Flooded)

Unit 5
A: O.P. +4.9m (Not-Flooded)
B: O.P. +4.9m (Not-Flooded)

Unit 6
A: O.P. +5.8m (Not-Flooded)
B: O.P. +13.2m (Not-Flooded)
C: O.P. +5.8m (Not-Flooded)

EDGs 2B, 4B, 5A&B and 6A&H were not flooded but were "unusable due to inundated main/ancillary equipment."

All of the power distribution panels were flooded, except that none of the panels in Unit 6 were and the DC main bus panels only in Units 3 and 5 weren't either.

Elevation of DC main bus panels:
Unit 1: O.P. +4.9m
Unit 2: O.P. +1.9m
Unit 3: O.P. +6.5m
Unit 4: O.P. +1.9m
Unit 5: O.P. +9.5m
Unit 6: O.P. +9.5m

Tsunami level: O.P.+14~16m (Figure II-2-20,page II-73)
Units 1-4 Ground level: O.P.+10m
Units 5&6 Ground level: O.P.+13m

The only usable diesel generator (Unit 6B) was apparently in a separate building (the Diesel Generator Building). (See Figure II-2-25, page II-77 for location of building and inset in Figure II_2-20, page II-73 for schematic showing elevation.)

Otherwise, Units 5 and 6 might have been lost also.

 

[tsutsuji]

http://www3.nhk.or.jp/news/genpatsu-fukushima/20120206/index.html One of unit 2's thermometers is rising. It displayed 45°C on 27 January, and it has been gradually rising since then, reaching 71.7°C a 04:00 PM on 5 February. At 1:30 AM on 6 February, the water injection rate was raised by 1 ton/hour to 10.6 tons/hour, but at 07:00 AM, the thermometer displayed 73.3°C. The other two PCV bottom thermometers are remaining stable at 44°C. Tepco says there is a possibility that the water flow changed when the injection was restarted after a temporary suspension on 26 January that was necessary for some works.

 

[elektrownik]

http://www3.nhk.or.jp/news/genpatsu-fukushima/20120206/index.html One of unit 2's thermometers is rising. It displayed 45°C on 27 January, and it has been gradually rising since then, reaching 71.7°C a 04:00 PM on 5 February. At 1:30 AM on 6 February, the water injection rate was raised by 1 ton/hour to 10.6 tons/hour, but at 07:00 AM, the thermometer displayed 73.3°C. The other two PCV bottom thermometers are remaining stable at 44°C. Tepco says there is a possibility that the water flow changed when the injection was restarted after a temporary suspension on 26 January that was necessary for some works.

And from tepco press conference:
"Tepco announced they are going to add 960 Kg of boric acid tonight in JST."