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revelarts
06-09-2011, 09:51 PM
Nuclear fuel has melted through base of Fukushima plant

The nuclear fuel in three of the reactors at the Fukushima Dai-Ichi nuclear plant has melted through the base of the pressure vessels and is pooling in the outer containment vessels, according to a report by the Japanese government.

The findings of the report, which has been given to the International Atomic Energy Agency, were revealed by the Yomiuri newspaper, which described a "melt-through" as being "far worse than a core meltdown" and "the worst possibility in a nuclear accident."

A spokesman for Tokyo Electric Power Co. said the company is presently revising the road-map for bringing the plant under control, including the time required to achieve cold shutdown of the reactors.

In a best-case scenario, the company says it will be able to achieve that by October, although that may have to be revised in light of the report.

Water that was pumped into the pressure vessels to cool the fuel rods, becoming highly radioactive in the process, has been confirmed to have leaked out of the containment vessels and outside the buildings that house the reactors.

Tepco said it is trying to contain the contaminated water and prevent it from leaking into the sea, but elevated levels of radiation have been confirmed in the ocean off the plant. ...

http://www.telegraph.co.uk/news/8565020/Nuclear-fuel-has-melted-through-base-of-Fukushima-plant.html

revelarts
10-06-2011, 12:01 PM
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Fukushima Nuclear Plant has 38-Hour Margin for Meltdown (http://oilprice.com/Latest-Energy-News/World-News/Fukushima-Nuclear-Plant-has-38-Hour-Margin-for-Meltdown.html)
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Written by Joao Peixe



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Wednesday, 05 October 2011 23:18

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The Tokyo Electric Power Co., still coping with the aftermath of the 11 March earthquake and tsunami that damaged its six-reactor Fukushima nuclear power complex, announced that if the water injections cooling the power plant are halted again, the fuel rods could start melting within 38 hours. If the fuel rods start melting, it could result in another massive release of radioactivity. TEPCO’s estimate said that the fuel’s temperature, which is now believed to have congealed into a solid mass at the bottom of the pressure vessels, in the absence of cooling water would rise about 50 degrees each hour until it hits its melting point of 2,200 degrees in about 38 hours, The Japan Times reported.

If the cooling procedures failed, then the crippled reactors would start emitting radioactive fallout, which could reach over 10 millisieverts, the threshold for evacuation.
An independent 14 September radiation survey found up to 307,000 becquerels of cesium per kilogram of soil near Fukushima, triple that of the benchmark above which the government requires tainted mud to be sealed by concrete. The Citizens Against Fukushima Aging Nuclear Power Plants NGO announced that the readings are comparable to the high levels in special regulated zones where evacuation was required after the April 1986 Chernobyl accident in Ukraine...


http://oilprice.com/Latest-Energy-News/World-News/Fukushima-Nuclear-Plant-has-38-Hour-Margin-for-Meltdown.html

Nukeman
10-06-2011, 01:59 PM
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Fukushima Nuclear Plant has 38-Hour Margin for Meltdown (http://oilprice.com/Latest-Energy-News/World-News/Fukushima-Nuclear-Plant-has-38-Hour-Margin-for-Meltdown.html)



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Written by Joao Peixe




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Wednesday, 05 October 2011 23:18


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http://oilprice.com/Latest-Energy-News/World-News/Fukushima-Nuclear-Plant-has-38-Hour-Margin-for-Meltdown.html



Ok I dont know if someone screwed up on their calculations but 10mSv is almost NO radiation at all. In fact 1 rem = 10mSv (millisievert) So what your saying is that if it releases again we will get the equivalant of 1 heart catheterization... Hmm.. doesn't seem all that bad to me

http://en.wikipedia.org/wiki/Sievert



Frequently used SI multiples (http://www.debatepolicy.com/wiki/SI_multiple) are the millisievert (1 mSv = 0.001 Sv) and microsievert (1 μSv = 0.000001 Sv).
An older unit for the equivalent dose, is the rem (http://www.debatepolicy.com/wiki/Roentgen_equivalent_man),[3] (http://www.debatepolicy.com/#cite_note-EPA-2) still often used in the United States. One sievert is equal to 100 rem:

1 rem = 0.01 Sv = 10 mSv
1 mrem = 0.01 mSv = 10 μSv
1 Sv = 100 rem
1 mSv = 100 mrem = 0.1 rem
1 μSv = 0.1 mrem

Nukeman
10-06-2011, 02:02 PM
Rev,

You need to go to a web page called depletedcranium.com the host of the site is very good at cutting through the hype and giving the straight facts about a number of topics. He has a very nice article regarding Fukushima power plant.

avatar4321
10-06-2011, 03:12 PM
This isn't good is it?

Maybe i should learn nuclear physics.

revelarts
10-06-2011, 05:30 PM
Ok I dont know if someone screwed up on their calculations but 10mSv is almost NO radiation at all. In fact 1 rem = 10mSv (millisievert) So what your saying is that if it releases again we will get the equivalant of 1 heart catheterization... Hmm.. doesn't seem all that bad to me

http://en.wikipedia.org/wiki/Sievert

I'll check it out. But
you didn't comment on any of the other items mentioned

is that a good thing, is it ultimately harmless?

"..307,000 becquerels of cesium per kilogram of soil near Fukushima, triple that of the benchmark above which the government requires tainted mud to be sealed by concrete..."
is that an over reaction by the Japanese gov't. Would you feel comfortable with you kids there?

is the amount of radiation being emited going down or up constant ? if it's constant isn't the effect in the local area cumulative?
Can it ever be sealed or stopped?

But the question I had after reading the article and your comment was,
OK 10mSv per what? I'm guessing this is a Constant state. is it getting a 1 heart Catheterization every 5 minutes, every yr or a one time relaese as you imply? what does the measure showing.

the news media has dropped the ball or covered up this story -take your pick-

Nukeman
10-06-2011, 06:58 PM
I'll check it out. But
you didn't comment on any of the other items mentioned

is that a good thing, is it ultimately harmless?

"..307,000 becquerels of cesium per kilogram of soil near Fukushima, triple that of the benchmark above which the government requires tainted mud to be sealed by concrete..."
is that an over reaction by the Japanese gov't. Would you feel comfortable with you kids there?

is the amount of radiation being emited going down or up constant ? if it's constant isn't the effect in the local area cumulative?
Can it ever be sealed or stopped?

But the question I had after reading the article and your comment was,
OK 10mSv per what? I'm guessing this is a Constant state. is it getting a 1 heart Catheterization every 5 minutes, every yr or a one time relaese as you imply? what does the measure showing.

the news media has dropped the ball or covered up this story -take your pick-No a Sv is a measurement of exposure and absorption.. No you dont want to hang around and receive 10mSv every hour for a prolonged amount of time.. Usually the time refered to is per hour

As for the Cs-137 they are talking about, I love how they switch to Bq all the time. We in the US have always used Curie and Millicurie as a standard of measuring. it takes 37 MBq to equal 1 mCi. When they talk about 307,000 Bq they are saying approx 0.3 Mbq which is the equivalent of 8.2 micro curies uCi. this is a VERY tiny amount, Now I am not saying you want to get this in your system due to the fact that Cs has a half life of 30 years and is primary a beta emitter and can cause damage if ingested over a period of time, but the amounts that they are talking about are EXTREMELY low. Not to mention that most of the activity being emitted by the Cs-137 can be blocked with a simple PLASTIC shield. The media likes to use the new international standard of Bq instead of Curie due to the fact it sounds like MORE.. Its stupid and disingenuous on their part..I hope this helps a little.. If not I will try to explain in more detail..


On a side note I use EVERY day in my calibration procedure 200 uCi of Cs-137 that is a total of 7,400,000 Bq. So you see when you use Bq instead of Ciries it SEEMS like a lot..