Japan Earthquake: nuclear plants

rowmag

To make an atomic bomb:
http://www.nytimes.com/2011/09/06/wo...pagewanted=all

jim hardy

their Manhattan Project was moved to North Korea because we kept bombing Tokyo where their labs were located..
It's believed that at war's end it was packed up and sent to Stalin.
though old anecdotes of a test exist.

One can search for some of Dr Paul Kuroda's memoirs. He was a minor researcher in Japan's bomb effort who came here after the war, worked on astrophysics.

old jim

rowmag

After doing some more research, it turns out there are several radon onsens dotted around the eastern half of Fukushima prefecture, including one in Hirono, about 20 km south of the Fukushima Daiichi power plant. So, there are likely to be uranium ores distributed over a rather wide area in the ground. In fact, there is even a radon onsen in Mito in Ibaraki prefecture, much closer to Tsukuba than anywhere in Fukushima, and also upwind of it that day.

So, unless someone has a calculation showing that the expected radon concentration from Fukushima Daiichi should be much higher than that from the natural emanations coming out of the ground in the general region, the significance of these precipitation-related radiation spikes would seem to be inconclusive.

SteveElbows

This document features diagrams that go a long way to answering the questions of orientation of the endoscope:

http://www.tepco.co.jp/en/nu/fukushi...20121_03-e.pdf

tsutsuji

http://www3.nhk.or.jp/news/genpatsu-...128/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:
http://www.youtube.com/watch?v=UDz2koAVEPI

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

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...s/120125e5.pdf
On http://www.tepco.co.jp/en/press/corp.../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-...11226_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-...ference-j.html (for example including the following presentations on mock-up debris : http://www.tepco.co.jp/nu/fukushima-...20123_04-j.pdf and water treatment secondary waste products (sludge, zeolite) : http://www.tepco.co.jp/nu/fukushima-...20123_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-...20123_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-...20123_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-...129/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/fukushi...20129_01-e.pdf "Water leakage in Fukushima Daiichi Nuclear Power Station (Discovered on 29 January)"

http://www.tepco.co.jp/en/nu/fukushi...20129_02-e.pdf (map of the leaks)

nikkkom

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

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

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

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

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-...30_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-..._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-...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/fe....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...201300070.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

[QUOTE=tsutsuji;3735342]http://www3.nhk.or.jp/news/genpatsu-...30_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/fe....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.


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

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.

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-..._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".