A Fukushima il y a 69 tonnes de combustible au n°1, 94 tonnes de MOX dans les autres + ce qui est en piscine, peut être autant. Au total ça fait un maximum 1000 tonnes. Pas plus. C'est rien, dirait Anne Lauvergeon.
ca va quoi y'a de quoi s'amuser 
!
Gov't ups permissible radiation level
The Japanese government has revised upward the permissible level of radiation exposure for workers at the troubled Fukushima Daiichi nuclear power plant.
The health and labor ministry says that it raised the limit by a factor of 2.5, to 250 millisieverts, in cases of emergency.
The measure was adopted to secure enough time for workers at the power plant to engage in operations such as cooling down of the reactors.
Radiation above 250 millisieverts is said to cause health problems such as a temporary reduction in the number of white blood cells.
The health and labor ministry says it reached the decision after consulting with experts on the possible effects on workers.
The ministry explains that the measure was necessary to prevent a nuclear disaster. It says the international radiation limit is set at 500 millisieverts. It adds that medical experts have no clear knowledge about whether radiation of 250 millisieverts or lower will cause health damage.
Wednesday, March 16, 2011 09:56 +0900 (JST)
Avant :
High radiation levels detected 20 km. from plant
Japan's science ministry has observed radiation levels of up to 0.33 millisieverts per hour in areas about 20 kilometers northwest of the quake-damaged Fukushima Daiichi nuclear power plant.
Experts say exposure to such radiation for 3 hours would result in absorption of 1 millisievert, or the maximum considered safe for 1 year.
The ministry gauged radiation levels for 10 minutes from 8:40 PM local time on Tuesday at 3 places in Fukushima Prefecture, whose residents are being instructed to stay indoors. The measurements produced readings as low as 0.22 millisieverts per hour.
It is not known whether these levels have changed since the measurements.
A former chief of the Radiation Effects Research Foundation, Shigenobu Nagataki, said radiation at such levels does not immediately affect human health. But he said that if such levels continue to be observed, authorities must review ways to evacuate people.
The ministry said it also observed maximum radiation levels of 0.0253 millisieverts in areas 30 to 60 kilometers from the plant on Wednesday morning. The levels are slightly higher than normal.
Wednesday, March 16, 2011 17:58 +0900 (JST)
après :
Edano:No health risk 20km away from plant
Japan's Chief Cabinet Secretary, Yukio Edano says the level of radiation detected about 20 kilometers from the quake-damaged Fukushima Daiichi nuclear power plant does not pose an immediate health risk.
Edano was referring to a maximum radiation level of 0.33 millisieverts per hour detected by Japan's science ministry on Tuesday evening.
He told reporters on Wednesday that this level of radiation would not have a negative effect on human health even if one worked outdoors in the area for a period of several days.
Edano added that although people within 20 to 30 kilometers of the plant are being instructed to stay indoors, this does not mean people cannot enter the zone. He urged calm and called for delivery of supplies to the area.
Edano also said he has received reports that efforts have begun to spray water at the damaged plant, and he is hoping the cooling process would stabilize as soon as possible.
Wednesday, March 16, 2011 19:20 +0900 (JST)
Maximus Leo a écrit :Il faut :
- 100 millions de compteurs Geiger
- 100 millions de petites cuillères
- 300 millions de personnes (à cause des 35 heures)
Maximus Leo a écrit :A Fukushima il y a 69 tonnes de combustible au n°1, 94 tonnes de MOX dans les autres + ce qui est en piscine, peut être autant. Au total ça fait un maximum 1000 tonnes. Pas plus. C'est rien, dirait Anne Lauvergeon.
Ces réacteurs sont modérés au graphite et refroidis à l'eau. Le combustible est de l'oxyde d'uranium enrichi de 2 à 2,6% en uranium-235. Le cœur est volumineux, 20 fois celui d’un REP. Pas de cuve sous pression, mais un grand nombre de tubes verticaux, appelés « tubes de force » contenant le combustible. Il n’y a pas d’enceinte de confinement. Le réacteur de Tchernobyl comportait 190 tonnes d’oxyde d’uranium enrichi répartis dans 1681 « tubes de force ».
c) Quelle est l'influence de l'usure du combustible sur son impact lorsqu'il brûle / fusionne? Un combustible neuf est-il pire ou non qu'un usé?
Nous voilà a la fin du Japon et du monde relativement propre que nous connaissions Mr. Green
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