After it became clear that the cylindrical foundations supporting the reactors at Unit 1 of the Fukushima Daiichi Nuclear Power Station that suffered the meltdown were broken almost all the time, the Nuclear Regulation Authority decided to urge TEPCO to urgently compile possible risks and necessary countermeasures.
At Unit 1 of the Fukushima Daiichi Nuclear Power Plant, an internal investigation conducted in March revealed that the reinforced concrete cylindrical base that supports the reactor, called a pedestal, was broken almost all the entire circumference, exposing the reinforcing bars.
TEPCO has stated that even if the pedestal can no longer support the reactor, it will not collapse significantly due to being held back by surrounding structures, but at the Nuclear Regulation Authority meeting held on the 24th, members expressed a series of opinions, such as "We cannot be as optimistic as TEPCO's explanation" and "We need to take immediate action in case the PCV is further damaged."
On the premise that pedestals cannot support the reactors, we decided to ask TEPCO to compile by July what risks are expected and what measures are necessary to prevent the spread of radioactive materials to the outside.
TEPCO has stated that it will once again investigate whether there are any problems with earthquake resistance based on the results of the internal investigation, but the NRA has requested an immediate response, saying that it is necessary to assume the worst-case scenario, based on the fact that there are still many areas where the situation has not been grasped.