Absorbent used to soak up radioactive water, 2 found dead at nuke plant
TOKYO, April 3, Kyodo
 
Workers prepared Sunday to block the leakage of highly radioactive water into the sea from the crisis-hit Fukushima Daiichi nuclear plant by injecting polymeric powder that can absorb 50 times its volume of water, the government's nuclear safety agency said.
 
The plant operator Tokyo Electric Power Co. said the same day that two workers in their 20s who had been missing since the March 11 killer quake and tsunami that crippled the power station were found dead in the basement of a reactor's building last Wednesday.
 
They died of bleeding from multiple injuries about an hour after the quake struck the plant, according to the utility known as TEPCO. It is the first time that TEPCO workers have been confirmed to have died at the Daiichi plant.
 
Engineers will inject the polymeric water absorbent used for diapers later in the day into pipes leading to a pit connected to the No. 2 reactor's building where a 20-centimeter crack has been found to be leaking radioactive water.
 
The Nuclear and Industrial Safety Agency said the water is still flowing from the pit into the Pacific Ocean and that the rate of the leak remains unchanged despite TEPCO's efforts on Saturday to encase the fracture in concrete.
 
Highly radioactive water has been filling up the basement of the No. 2 building and a tunnel-like underground trench connected to it. The water in the pit is believed to have come from the No. 2 reactor core, where fuel rods have partially melted.
 
Hidehiko Nishiyama, a spokesman for the nuclear regulatory body, said the operator has confirmed that pits from the plant's other reactors have no similar cracks.
 
Workers have also been checking the condition of the embankment at the plant on the coast to find out other possible routes for radiation leakage into the sea, the agency added.
 
TEPCO has revealed that radioactive iodine-131 more than 10,000 times the legal concentration limit was detected in the water found in the pit.
 
Levels of radioactive materials have been skyrocketing in the sea near the nuclear power plant, fanning concerns about the expansion of sea contamination and the impact on fishery products.
 
A seawater sample collected Wednesday afternoon near the plant had iodine-131 at a concentration 4,385 times the maximum level legally permitted.
 
But TEPCO has since been unable to release the latest monitoring data on the sea, with a programming error damaging the credibility of its analysis to some extent, and is bolstering efforts to raise the accuracy, according to the agency.
 
In addition to efforts to block the radiation-contaminated water leakage, technicians continued operations Sunday to secure enough space at tanks to remove radioactive water that has been soaking the basement of the plant's Nos. 1-3 reactors. The stagnant water has been obstructing work to restore the vital cooling functions at the reactors.
 
Later in the day, engineers will also connect pumps used to inject fresh water into the troubled reactors to an external power source, switching from emergency diesel generators, to stably pour in the coolant water, according to the agency.
 
Nishiyama said TEPCO will inject nitrogen into the containment vessel of the No. 1 reactor on Tuesday or later to help prevent the risk of more hydrogen explosions caused by overheating of the reactor.
 
Once the mission to block the radiation leakage by the absorbent is completed, TEPCO will try to move the radioactive water in the pit to storage facilities to be prepared at the plant, he said.
 
To store the tainted water, the utility is considering using a large artificial floating island, called a ''megafloat,'' and U.S. Navy barges that originally carried fresh coolant water for injection into the reactors, Nishiyama said.
 
The company has been pouring massive amounts of water into the reactors and their spent nuclear fuel pools as a stopgap measure to cool them down, because serious damage to the fuel rods from overheating could lead to the release of enormous amounts of radioactive materials into the environment.
 
However, the measure is believed to be linked to the possible leak of contaminated water from the reactors, where fuel rods have partially melted.
 
==Kyodo

"Nous ne sommes pas sortis de la situation d'urgence, mais elle est à peu près stabilisée. La principale préoccupation des Japonais est de savoir quand la fuite de substances radioactives s'arrêtera", a souligné dimanche Goshi Hosono, collaborateur du Premier ministre Naoto Kan, qui s'est rendu pour la première fois la veille dans la zone dévastée.
Tokyo Electric Power co (Tepco) a annoncé samedi la découverte de cette fissure dans un puits de béton du réacteur n°2 où la radioactivité atteint 1.000 milliSieverts par heure.
Du béton y a été injecté en vain et Tepco va tester dimanche des polymères absorbants.
"Nous espérons que les polymères absorberont l'eau et combleront la conduite pour l'empêcher de fuir", a expliqué Hidehico Nishiyama, directeur général adjoint de l'Agence de sûreté nucléaire et industrielle. La fissure, a-t-il poursuivi, "clarifie la relation" entre l'eau contaminée et la mer.
"Avec des niveaux de radiation en élévation dans l'eau de mer proche de la centrale, nous essayons de confirmer les causes et, dans ce contexte, (cette fuite) pourrait en être une source", avait-il déclaré la veille.
D'AUTRES MOYENS DE REFROIDISSEMENT À L'ÉTUDE
Aucune autre fissure n'a été découverte lors de l'examen des cinq autres réacteurs de la centrale.
L'Agence de sûreté nucléaire réfléchit en outre à d'autre moyens que l'eau pour refroidir le coeur des réacteurs et éviter une fusion catastrophique.
Un système improvisé qui projetterait une fine brume sur les barres de combustible est notamment à l'étude, a ajouté Hidehico Nishiyama.
Trois semaines après la catastrophe qui a fait 28.000 morts et disparus, Naoto Kan, dont la gestion de la crise a été mise en cause, s'est rendu samedi à Rikuzentakata, ville de 23.000 habitants dont il ne reste que des ruines baignant dans la boue.
Il a ensuite pénétré dans la zone de 20 km autour de la centrale dont les 70.000 habitants ont été évacués et s'est rendu sur un terrain de sports transformé en camp de base pour les militaires, les pompiers et les ingénieurs qui s'efforcent de refroidir les réacteurs.
Les barres de combustible sont toujours en surchauffe et une radioactivité 4.000 fois supérieure à la limite légale a été détectée au large de la centrale.
Il faudra des années, voire des décennies, pour nettoyer le site, qui se trouve à 240 km au nord de Tokyo.
Henri-Pierre André et Jean-Philippe Lefief pour le service français

Thierry Charles est directeur de la sûreté à l'Institut de radioprotection et de sûreté nucléaire (IRSN). Dix-huit jours après l'accident nucléaire de Fukushima, il analyse la situation en cours et nous livre son point de vue sur les questions de sûreté nucléaire. Interview réalisée le 29 mars 2011.

TEPCO are such an important advertiser that the television and newspapers are completely silent. Even now, they're running TEPCO commercials on the television, aren’t they? This week, there are also full-page advertisements in the newspaper. Despite the fact that they've caused such a scandal, TEPCO are still putting ads in the newspaper. If they have such enormous sums of money, they should send it to the areas hit by the disaster

Basically, something that I knew from the beginning, but has become more blatant yesterday and today [March 27-28], is this terrible situation where the government and TEPCO are suppressing information. To be more specific, I thought it was strange that there was nothing written about plutonium when the data about reactor 3 was given out at the TEPCO press conference on the 27th, so I asked them if it was true that no plutonium had been detected in reactor 3, and for how long it had not been detected. TEPCO answered: 'Plutonium hasn’t been detected.' To confirm what they were saying I asked if perhaps it wasn't that none had been detected, but that they hadn't actually taken any measurements. They were alarmed, and it turned out that it wasn't even that they hadn't taken any measurements, but that they didn't have the instruments to do so in the first place.

Basically, something that I knew from the beginning, but has become more blatant yesterday and today [March 27-28], is this terrible situation where the government and TEPCO are suppressing information. To be more specific, I thought it was strange that there was nothing written about plutonium when the data about reactor 3 was given out at the TEPCO press conference on the 27th, so I asked them if it was true that no plutonium had been detected in reactor 3, and for how long it had not been detected. TEPCO answered: 'Plutonium hasn’t been detected.' To confirm what they were saying I asked if perhaps it wasn't that none had been detected, but that they hadn't actually taken any measurements. They were alarmed, and it turned out that it wasn't even that they hadn't taken any measurements, but that they didn't have the instruments to do so in the first place.=> Yet another TEPCO-bullshit : les relevés publiés par TEPCO le 28 sont datés du 23 mars !
 
Visiblement TEPCO est nettement plus doué en désinformation qu'en gestion du nucléaire...