On the 26th, the NRA’s study group, which analyzes the accident at TEPCO’s Fukushima Daiichi Nuclear Power Plant, compiled a draft report on the results of the investigation conducted after September 2019. He pointed out that a large amount of radioactive material had adhered to the upper lids of the reactor containment vessels of Units 1 to 3, and warned that it was necessary to carefully consider how to deal with the decommissioning work in the future. It will be discussed at the regular regulatory meeting on the 27th and will be officially decided within FY2008.
According to the draft report, the upper lid has a three-layer structure made of reinforced concrete. There is a possibility that radioactive cesium of 100 to 200 trillion becquerels in Unit 1 and 2K to 4K becquerels in Unit 2 and 3K Becquerels in Unit 3 are attached between the first and second sheets from the top. There is.