Japan Earthquake: nuclear plants

rmattila

Or that a year-and-a-half of flushing with fresh water has washed away most of the water-soluble substances and only the less soluble material remains in place.

Cire

Or most of the core is still in the bottom of the RPV

Rive

That would be a miracle... For the other two cores the models are not necessarily suggests the RPV-damage, but for unit 1...

I wonder if flushing through the turuses would reduce the radiation levels in the basements?
The contamination of the water in the basements are continuously falling, but the toruses are most likely still full with the stuff from the first days.

Astronuc

What would be found in the torus would have to be mostly insoluble. The radioactivity decreases with time, or otherwise the radionuclides have been transported either to collection systems or to the environment.

http://www.world-nuclear-news.org/RS...d-1110124.html

Some retrospective - old news

http://eetd-seminars.lbl.gov/sites/e...04052011-1.pdf

a.ua.

Analysis Result of the Accumulated Water in Unit 1 PCV
at Fukushima Daiichi Nuclear Power Station

http://www.tepco.co.jp/en/nu/fukushi...21012_02-e.pdf

MikeIt

Just a guess but shiny metal in the drywell could be mirror insulation. There's a fair amount of it. It's not out of the realm of possibility that the dynamic forces that resulted from the breach of the RPV by core debris also tore up some of this insulation and deposited some of it where the picture shows.

tsutsuji

1) Previous related topics:
http://www.physicsforums.com/showthr...36#post3882136 23 April 2012 Plan to reduce volumes of groundwater seeping into units 1~4 buildings by groundwater bypass
http://www.tepco.co.jp/en/nu/fukushi...20618_05-e.pdf 18 June 2012 Progress status of ground water bypass


2) Translation:

As pages 08/11 to 11/11 happen to be copies of older presentation, I translate only the new materials found on pages 01-07 :

01/11

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tsutsuji

2) Translation:

02/11

03/11

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tsutsuji

2) Translation:

05/11

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tsutsuji

Translation:

01/06

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tsutsuji

Translation:

04/06

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zapperzero

So the idea, if I understand it right, is to lower the local water table level to that of the water inside the reactors?

rmattila

The idea is to enable lowering the water level inside the buildings (and ultimately to pump them dry) without causing an increase in the groundwater inflow.

Rive

So they are meant to keep the inflow?

zapperzero

Have you guys seen this?

http://www.tepco.co.jp/en/nu/fukushi...21015_01-e.pdf

One of the pictures shows what appears to be part of an empty rack.

Cire

You want just enough inflow so you know contaminants are not flowing out. But not so much inflow that your pumps cant keep up.

tsutsuji

http://www3.nhk.or.jp/news/genpatsu-...017/index.html On 17 October, the NRA launched a new "Special Nuclear Facility Monitoring and Assessment Committee" composed of nuclear safety experts including Fukushima prefecture related persons, whose purpose is to continuously monitor Fukushima Daiichi's decommissioning.

http://www3.nhk.or.jp/news/genpatsu-...016/index.html The Nuclear Regulation Agency [an administrative body below the NRA] launched its bureau located in Fukushima prefecture Hirono town, where they borrow a soccer-related facility. It shall deal with Daiichi's decommissioning (8 people) and also the Fukushima Daini nuclear power plant (6 people).

http://www3.nhk.or.jp/news/genpatsu-...725_hairo.html The Chiba Institute of Technology - which developed Quince - has presented a new robot, called "Sakura", designed for Fukushima Daiichi. With a 50 cm height it is about 2/3 of the size of the older generation. As replacing the batteries of a contaminated robot takes too much time, it is rechargeable. The Institute said they would like to have it start being used at Fukushima Daiichi by the end of this year.

http://www.nedo.go.jp/news/press/AA5_100156.html Sakura related press release. The other item, called HAL, is a robot suit with a radiation shield, a cooling system, and a biological data monitoring system (such as body temperature, heart pulsation) (for human beings to carry) (for nuclear disasters in general, not specifically for Fukushima Daiichi).