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Japan Earthquake: nuclear plants

by gmax137
Tags: earthquake, japan, nuclear
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Rive
#13753
Oct11-12, 02:13 AM
P: 355
Quote Quote by zapperzero View Post
And so we get to ask another round of questions.
The measured dose rate decreases with height, which makes zero sense to me. Any ideas?
If the models are correct then there are only a relative small amount of core debris still in the RPV and the rest, slumped down to the slump pit on the bottom of the PCV (and even lower than that as it burned some hole in the concrete) is shielded by water.

So for first look it looks OK for me.

Ps.: can't wait for the water sample. The low dose measured in the water can indicate that the corium has little direct connection with the cooling water.
rmattila
#13754
Oct11-12, 02:25 AM
P: 242
Quote Quote by Rive View Post
Ps.: can't wait for the water sample. The low dose measured in the water can indicate that the corium has little direct connection with the cooling water.
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
#13755
Oct11-12, 02:37 AM
P: 64
Quote Quote by rmattila View Post
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.
Or most of the core is still in the bottom of the RPV
Rive
#13756
Oct11-12, 02:42 AM
P: 355
Quote Quote by Cire View Post
Or most of the core is still in the bottom of the RPV
That would be a miracle... For the other two cores the models are not necessarily suggests the RPV-damage, but for unit 1...

Quote Quote by rmattila View Post
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.
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
#13757
Oct11-12, 10:38 AM
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P: 21,808
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
An investigation is underway into the internal conditions of the primary containment vessel (PCV) of the reactor at unit 1 at the damaged Fukushima Daiichi nuclear power plant. Tokyo Electric Power Company (Tepco) said that the water level in the vessel has been found to be higher than previously estimated.

An investigation is underway into the internal conditions of the primary containment vessel (PCV) of the reactor at unit 1 at the damaged Fukushima Daiichi nuclear power plant. Tokyo Electric Power Company (Tepco) said that the water level in the vessel has been found to be higher than previously estimated.

Some retrospective - old news

http://eetd-seminars.lbl.gov/sites/e...04052011-1.pdf
a.ua.
#13758
Oct12-12, 06:05 AM
P: 119
Quote Quote by Rive View Post
.

Ps.: can't wait for the water sample. The low dose measured in the water can indicate that the corium has little direct connection with the cooling water.
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
#13759
Oct14-12, 12:45 PM
P: 6
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
#13760
Oct15-12, 06:54 AM
PF Gold
P: 1,220
Quote Quote by tsutsuji View Post
24 September 2012 government-Tokyo Electric mid and long term response committee, steering committee (10th meeting)

3-2 Treatment of accumulated water
http://www.meti.go.jp/earthquake/nuc...120924_01n.pdf Ground water bypass action plan
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
Attached Thumbnails
Groundwater bypass 01of11.png  
tsutsuji
#13761
Oct15-12, 06:56 AM
PF Gold
P: 1,220
2) Translation:

02/11

03/11

04/11
Attached Thumbnails
Groundwater bypass 02of11.jpg   Groundwater bypass 03of11.png   Groundwater bypass 04of11.jpg  
tsutsuji
#13762
Oct15-12, 06:58 AM
PF Gold
P: 1,220
2) Translation:

05/11

06/11

07/11
Attached Thumbnails
Groundwater bypass 05of11.jpg   Groundwater bypass 06of11.jpg   Groundwater bypass 07of11.jpg  
tsutsuji
#13763
Oct15-12, 12:42 PM
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P: 1,220
Quote Quote by tsutsuji View Post
24 September 2012 government-Tokyo Electric mid and long term response committee, steering committee (10th meeting)

3-6 Preparations for fuel debris removal
http://www.meti.go.jp/earthquake/nuc...20924_01ee.pdf Survey of accumulated water inside unit 1 reactor building triangle corners
Translation:

01/06

02/06

03/06
Attached Thumbnails
Unit 1 triangle corner water 2of6.jpg   Unit 1 triangle corner water 3of6.jpg   Unit 1 triangle corner water 1of6.jpg  
tsutsuji
#13764
Oct15-12, 12:45 PM
PF Gold
P: 1,220
Translation:

04/06

05/06

06/06
Attached Thumbnails
Unit 1 triangle corner water 4of6.jpg   Unit 1 triangle corner water 5of6.jpg   Unit 1 triangle corner water 6of6.jpg  
zapperzero
#13765
Oct16-12, 06:33 AM
P: 1,042
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
#13766
Oct16-12, 07:05 AM
P: 242
Quote Quote by zapperzero View Post
So the idea, if I understand it right, is to lower the local water table level to that of the water inside the reactors?
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
#13767
Oct16-12, 07:11 AM
P: 355
Quote Quote by rmattila View Post
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.
So they are meant to keep the inflow?
zapperzero
#13768
Oct16-12, 08:13 AM
P: 1,042
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
#13769
Oct16-12, 02:09 PM
P: 64
Quote Quote by Rive View Post
So they are meant to keep the inflow?
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
#13770
Oct17-12, 12:53 PM
PF Gold
P: 1,220
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).


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