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PostPosted: Oct 21, 2013 2:43 am 
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jon wrote:
'The issue is that there are giant holes melted through the RPV bottom head..'
Is there evidence for that? Since the melted fuel at TMI didn't get very far into the bottom of the pressure vessel there, I'd thought it was just blown seals where cables and pipes went through.


http://www.world-nuclear-news.org/rs_ne ... 11111.html


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PostPosted: Oct 22, 2013 10:24 pm 
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Cyril R wrote:
Great thinking, Kiteman! Another option could be to send the entire ship to a detritiation facility, if you've gone through the trouble of further non-tritium purification and have it in a ship already. There's a big one in Canada. Surely more expensive than dumping, but surely also easier on the public relations and Japanese regulator. One could then brag about all the water being totally cleaned up.
Hideously expensive and not built for the volumes we are talking about. Also, you still have the tritium to worry about. Freezing the tritiated water into a stable glacier will hold it long enough to decay away and is effectively free.

If someone could develop a cheap way of concentrating the tritiated water enough to make the REMAINDER low enough concentration to be dumped, that might help things a bit. I suspect that a process similar to freeze drying would work since tritiated water freezes at about 4C while water triple points at about 0.1C. Vacuum distilling tritiated water at ~1C might leave frozen HTO and T2O behind. This would make finding a place to freeze it all the simpler. Mt. Fuji might do. Just a thought.

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Last edited by KitemanSA on Oct 22, 2013 10:36 pm, edited 2 times in total.

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PostPosted: Oct 22, 2013 10:28 pm 
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E Ireland wrote:
Does anyone know how much land was originally in the exclusion area and how much has/will be spent decontaminating it?

I am going to assume that the cost of decontaminating a hectare of farmland is more than the cost of the land? Why don't they simply put up a fence around said land and leave it?
Have you priced land in Japan?

There is a mycologist who has mushrooms that will bio-concentrate Cesium very cheaply. Maybe TEPCO and the JapGov will deign to contact him.

PS: hemp does a pretty good job too.

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Last edited by KitemanSA on Oct 23, 2013 11:32 pm, edited 1 time in total.

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PostPosted: Oct 23, 2013 11:41 am 
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E Ireland wrote:
Does anyone know how much land was originally in the exclusion area and how much has/will be spent decontaminating it?

I am going to assume that the cost of decontaminating a hectare of farmland is more than the cost of the land? Why don't they simply put up a fence around said land and leave it?
Here's another option - just for sake of comparison:

https://www.facebook.com/photo.php?fbid=504242869655620&set=a.493867307359843.1073741828.493843777362196&type=1&relevant_count=1


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PostPosted: Oct 30, 2013 10:18 am 
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125 slides from Tepco on the casualty
and the response. Some of the slides
take a microscope to read.

http://www.fukuleaks.org/web/wp-content ... 4e0202.pdf


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PostPosted: Oct 31, 2013 6:54 am 
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Thanks Jack, lots of good info there.

It also explains a long mystery to me, why the isolation condenser of unit 1 stopped working after the station blackout. It was the condensate return valve that was closed. Probably this is a motor or pneumatic valve and they forgot to design it "fail open". It sounds like a serious design error, even if it was a mechanical valve malfunction (in which case it would also be a design error, as they should have two condensate return valves in parallel).


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PostPosted: Oct 31, 2013 9:40 am 
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Im confused. In their November 2011 report,
Tepco clearly shows two IC's (A and B),
the return valve to B was closed, but A
was operating. In this report, there were several open/close
cycles of the A valves. The slides
only show one IC presumably this is A.
Are they saying the return valve from A
eventually failed closed?

BTW, both the inlet and outlet lines
to the IC's had two valves in series,
one inside the PCV and one outside,
The slides are unclear at least to me
which one of these valves
they are talking about.


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PostPosted: Oct 31, 2013 10:11 am 
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Yes, looking at the drawings it is confusing. The drawings in the report show an inboard and outlet steam valve, and the same for condensate valves. Pre-tsunami all four valves are opened, which is of course not possible since that means the IC is normally operating, which isn't the case. This leads me to believe that the drawing only shows steam and condensate isolation valves, and not the normally closed condensate return valves (I believe ICs operate their steam valves normally open so that the IC fills with condensate and the condensate return valve is then closed to prevent operation during normal reactor power operation).

So, it could be that the steam isolation valves closed up upon loss of power and couldn't be opened again due to lack of power to actuate them (assuming they're MOVs).

Regarding the units A and B of the IC, didn't the operators closed one system early on due to overcooling rate?


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PostPosted: Oct 31, 2013 10:20 am 
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Hmm, this again though suggest noncondensable gas buildup in the IC:

Quote:
The operator open the valve because
the valve status indicator lamp lit up,
but the operator closed the valve
again because steam generation from
IC stopped.


I have no idea why the operator closed the IC. It wasn't necessary, and the IC was all they got. Even with a lot of concondensables building up there's still some heat removal, and they could have attempted to purge the concondensables with the vent line (assuming they had one, considering the poor plant safety philosophy this may be questionable). And I don't understand why no more attempts were made to put either IC back into operation later in the events.


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PostPosted: Nov 06, 2013 10:06 pm 
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http://www.bbc.co.uk/news/science-environment-24843657

Fukushima nuclear plant set for risky operation

Quote:
A task of extraordinary delicacy and danger is about to begin at Japan's Fukushima nuclear power station.

Engineers are preparing to extract the first of more than 1,000 nuclear fuel rods from one of the wrecked reactor buildings.

This is seen as an essential but risky step on the long road towards stabilizing the site.

The fuel rods are currently in a precarious state in a storage pool in Unit 4.

One senior official told me: "It's going to be very difficult but it has to happen."


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PostPosted: Nov 07, 2013 12:28 am 
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Axil wrote:
http://www.bbc.co.uk/news/science-environment-24843657

Fukushima nuclear plant set for risky operation

Quote:
A task of extraordinary delicacy and danger is about to begin at Japan's Fukushima nuclear power station.

Engineers are preparing to extract the first of more than 1,000 nuclear fuel rods from one of the wrecked reactor buildings.

This is seen as an essential but risky step on the long road towards stabilizing the site.

The fuel rods are currently in a precarious state in a storage pool in Unit 4.

One senior official told me: "It's going to be very difficult but it has to happen."



More non-sense. Nothing exciting will happen and then they will proclaim how lucky we got and humanity just barely escaped but now even riskier operations will follow when the try to remove the fuel from the other units.


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PostPosted: Nov 07, 2013 3:33 am 
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Oh yes Axil, after a gazillion of these scare stories, we're all lucky to be alive huh?

Is your learning curve a flat line or what?


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PostPosted: Nov 07, 2013 9:08 am 
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As it has all been heavily aged now.... will it be removed into a dry cask or into some other wet storage facility?


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PostPosted: Nov 07, 2013 10:12 am 
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E Ireland wrote:
As it has all been heavily aged now.... will it be removed into a dry cask or into some other wet storage facility?


Current plan is to move to the central large spent fuel pool. Has a lot more water and easy access (about at grade level). Very safe. It actually wasn't damaged at all in the eartquake plus many aftershocks...

Likely they will later transition towards more dry casks, moving oldest fuel from the central large spent fuel pool, into casks. They have some casks already and plenty space for more.


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PostPosted: Nov 07, 2013 1:00 pm 
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It appears to me that competitive commercial interests in S. Korea and China have an interest in inciting more radiation phobia in Japan. Both are competitors on the world market for reactor sales. And both would hardly cry tears if Japanese industry continued to be saddled with sky high electrical costs due to the shutdown of all of Japan's reactors and the import of huge amounts of LNG and coal. Recently S. Korean fisheries expressed anger at the (non-existent) contamination of the Pacific Ocean. Now, China is throwing a hissy fit over benign levels of radiation leaking water. For example, this just in from the NEI digest:

Japan is urged to provide data on radioactive water management at Fukushima plant

China is demanding the Japanese government provide clear information on how it handles radioactive water leaks from the Fukushima Daiichi nuclear plant. "We urge the Japanese side to spare no effort in minimizing the subsequent impact of the accident and provide timely, comprehensive and accurate information to the international community," said China's deputy United Nations ambassador, Wang Min. The International Atomic Energy Agency "has recommended that Japan establish an effective plan and mechanisms for the long-term management of contaminated water," said IAEA Director General Yukiya Amano. South China Morning Post (Hong Kong) (free registration)/Agence France-Presse (11/

Russia as well appears to be piling on, putting on frowny faces over Fukushima radiation, while salivating over LNG sales to Japan.

When capitalists see an opportunity to cut a rival's throat, it appears irresistible, even if there might be some kickback damage to themselves from promoting radiation hysteria.


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