Centrale nucléaire de Fukushima : la situation plus grave qu’annoncée
Published on mai 16, 2011 with No Comments
Selon le quotidien japonais Asahi Shimbun, les toutes dernières données sur la situation à la centrale nucléaire de Fukushima révèlent un optimisme exagéré de Tepco (l’EDF japonais) sur sa capacité à stabiliser la situation d’ici six à neuf mois. [Réacteur N°3 - Photo Air Photo Service Co]
Tepco, l’exploitant de la centrale nucléaire de Fukushima, a admis hier que la majeure partie du combustible nucléaire du réacteur N° 1 avait fondu. Ce qui reste de barres de combustible intactes n’est plus recouvert par l’eau. Le combustible fondu a coulé au fond de la cuve qui s’est percée, laissant échapper l’eau vers l’extérieur.
Tepco avait annoncé précédemment (source NHK) que sur les 10 000 tonnes d’eau injectées dans le réacteur depuis le 11 mars dernier, il n’en restait probablement pas la moitié dans le réacteur, s’interrogeant sur cette disparition. L’eau serait dans le sous-sol du réacteur, une zone impossible à inspecter pour le moment. Le Asahi Shimbun envisage même que du combustible fondu a pu s’échapper de l’enceinte de confinement.
Le plan de Tepco pour ce réacteur était de mettre en place un système de refroidissement en circuit fermé. Mais la fuite, considérée comme importante, ne permettra pas de le faire. En tout état de cause, le plan de Tepco qui visait à stabiliser la situation à la centrale de Fukushima d’ici 6 à 9 mois, ne sera probablement pas tenable.
Risque de nouvelle explosion, selon Greenpeace
Greenpeace a urgemment invité Tepco a ne pas noyer le réacteur sous l’eau, indiquant qu’une explosion serait possible du fait du contact de l’eau froide avec du combustible fondu à une température élevée. Dans le pire scénario, l’enceinte du réacteur, endommagée par l’explosion, pourrait laisser échapper dans l’atmosphère une pollution radioactive pendant des jours, voire des semaines (Source The Guardian). Tepco a nié la possibilité d’une explosion mais a indiqué que son idée de noyer le réacteur devait être révisée.
Selon la télévision japonaise NHK, du fait des arrêts définitifs de 14 réacteurs considérés comme trop risqués, et d’arrêts temporaires de 19 autres réacteurs pour inspections, seul un tiers des 53 réacteurs du pays devrait être en mesure de fonctionner à la fin du mois.
Des dizaines de milliards d’euros
Le quotidien Asahi Shimbun écrit que le réacteur N°1 n’est probablement pas le seul dont la cuve a pu se fissurer. Tepco à fait savoir que les mesures des niveaux d’eau dans les réacteurs N°2 et N°3 ne sont plus considérées comme fiables. La décision de Tepco, ce 14 mai 2011, d’augmenter le débit d’eau injecté dans le réacteur 3 tendrait à confirmer ces craintes. De même la décision d’injecter de l’eau dans la piscine du réacteur 2 (le moins endommagée) avec de l’hydrazine, un composé très toxique, probablement destiné à éviter la corrosion.
Selon le quotidien anglais The Guardian, l’ensemble des dommages coûtera des dizaines de milliards d’euros, dont il est probable qu’une bonne partie sera payée par le contribuable, plus exactement par le public (voir les commentaires ci-dessous).
Fukushima Nuclear Power: the situation more serious as has been claimedWritten by Stefano. Posted in NuclearTagged: Fukushima, Nuclear
Published on May 16, 2011 with No CommentsAccording to Japanese newspaper Asahi Shimbun, the latest data on the situation at the Fukushima nuclear plant prove exaggerated optimism of TEPCO (Japan EDF) on its ability to stabilize the situation in six to nine months. [Reactor No. 3 - Air Photo Photo Service Co]
TEPCO, the operator of the nuclear power plant in Fukushima, admitted yesterday that the bulk of spent nuclear reactor No. 1 was melted. What remains intact fuel rods is no longer covered by water. The molten fuel sank to the bottom of the tank that was pierced, releasing water to the outside.
TEPCO had previously announced (source NHK) on the 10,000 tons of water injected into the reactor since March 11 last, there remained unlikely half in the reactor, wondering about the disappearance. The water would be in the basement of the reactor, an area impossible to inspect yet. The Asahi Shimbun even considering that the molten fuel could escape from the containment.
The plan for this TEPCO reactor was put in place a system of closed circuit cooling. But flight, considered important, will not do. In any event, the TEPCO plan aimed at stabilizing the situation at the Fukushima plant within 6 to 9 months, probably will not sustainable.
Risk of further explosions, according to Greenpeace
Greenpeace has urgently requested TEPCO has not drown the reactor under water, indicating that the explosion could be due to contact with cold water fuel melted at high temperature. In the worst scenario, the reactor vessel, damaged by the explosion, could leak into the air radioactive pollution for days or weeks (Source: The Guardian). Tepco denied the possibility of an explosion but said his idea to flood the reactor should be revised.
According to NHK, because of final judgments of 14 reactors considered too risky and temporary suspension an additional 19 reactors for inspections, only one third of the 53 reactors in the country should be able to function at the end of the month .
Tens of billions of euros
The daily Asahi Shimbun wrote that the reactor No. 1 is probably not the only one vessel could crack.TEPCO reported that measurements of water levels in the reactor No. 2 and No. 3 are no longer considered reliable. The decision to TEPCO, the May 14, 2011, increase the flow of water injected into the reactor 3 would tend to confirm these fears. Similarly the decision to inject water into the reactor pool 2 (least damaged) with hydrazine, a highly toxic compound, probably intended to prevent corrosion.
According to British newspaper The Guardian, the total damage cost tens of billions of euros, it is likely that much will be paid by the taxpayer, more precisely by the public (see comments below).
Published on May 16, 2011 with No CommentsAccording to Japanese newspaper Asahi Shimbun, the latest data on the situation at the Fukushima nuclear plant prove exaggerated optimism of TEPCO (Japan EDF) on its ability to stabilize the situation in six to nine months. [Reactor No. 3 - Air Photo Photo Service Co]
TEPCO, the operator of the nuclear power plant in Fukushima, admitted yesterday that the bulk of spent nuclear reactor No. 1 was melted. What remains intact fuel rods is no longer covered by water. The molten fuel sank to the bottom of the tank that was pierced, releasing water to the outside.
TEPCO had previously announced (source NHK) on the 10,000 tons of water injected into the reactor since March 11 last, there remained unlikely half in the reactor, wondering about the disappearance. The water would be in the basement of the reactor, an area impossible to inspect yet. The Asahi Shimbun even considering that the molten fuel could escape from the containment.
The plan for this TEPCO reactor was put in place a system of closed circuit cooling. But flight, considered important, will not do. In any event, the TEPCO plan aimed at stabilizing the situation at the Fukushima plant within 6 to 9 months, probably will not sustainable.
Risk of further explosions, according to Greenpeace
Greenpeace has urgently requested TEPCO has not drown the reactor under water, indicating that the explosion could be due to contact with cold water fuel melted at high temperature. In the worst scenario, the reactor vessel, damaged by the explosion, could leak into the air radioactive pollution for days or weeks (Source: The Guardian). Tepco denied the possibility of an explosion but said his idea to flood the reactor should be revised.
According to NHK, because of final judgments of 14 reactors considered too risky and temporary suspension an additional 19 reactors for inspections, only one third of the 53 reactors in the country should be able to function at the end of the month .
Tens of billions of euros
The daily Asahi Shimbun wrote that the reactor No. 1 is probably not the only one vessel could crack.TEPCO reported that measurements of water levels in the reactor No. 2 and No. 3 are no longer considered reliable. The decision to TEPCO, the May 14, 2011, increase the flow of water injected into the reactor 3 would tend to confirm these fears. Similarly the decision to inject water into the reactor pool 2 (least damaged) with hydrazine, a highly toxic compound, probably intended to prevent corrosion.
According to British newspaper The Guardian, the total damage cost tens of billions of euros, it is likely that much will be paid by the taxpayer, more precisely by the public (see comments below).
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