原子炉「ふた」高濃度汚染　福島２、３号機、廃炉に影響か―規制委が中間報告案

　東京電力福島第１原発事故の原因を調査・分析する原子力規制委員会の検討会は２６日、２、３号機の原子炉格納容器上部をふさぐ「ふた」の内部に、高濃度の放射性セシウムがたまっている可能性が高いなどとする中間報告案を公表した。
　これまで、放射性物質の多くは溶け落ちた燃料デブリの形で原子炉の下部にあると考えられてきたが、上部でも高濃度の汚染が示唆されたことで、廃炉工程に影響が生じる可能性もある。（2021/01/26-18:17）

A study group of Japan's Nuclear Regulation Authority said Tuesday that a high concentration of radioactive cesium has highly likely accumulated in the lids of the containment vessels for the No. 2 and No. 3 reactors at the tsunami-hit Fukushima No. 1 nuclear power plant.
   The group showed the possibility in a draft of a new interim report on the nuclear accident.
   This could affect the decommissioning process for the Tokyo Electric Power Company Holdings Inc. plant in the northeastern Japan prefecture of Fukushima. It has been believed that most of the radioactive materials is left at the bottom of the reactors in the form of melted nuclear fuel debris.
   The group, which is investigating details of the accident, produced the draft report based on data obtained from on-site inspections of the No. 2 and No. 3 reactors conducted in September 2019 and later following the decline of radiation dose and progress in the decommissioning work. The first interim report was compiled in October 2014.
   On the fifth floor of the No. 2 and No. 3 reactor buildings, a very high radiation dose was measured near the three-layered reinforced concrete lids, or shield plugs, at the upper part of the reactor containment vessels, according to the draft report.