Japan’s Nuclear Regulation Authority said on 19 April it will begin providing information every day on the safety of four NPPs located near the region recently hit by a series of earthquakes. It will update information on the condition of the Sendai, Genkai, Ikata and Shimane NPPs and radiation levels around them at 10 am and 8 pm every day to address public concerns.
More than 40 people have been killed and over 1,000 injured since the first major quake hit Kumamoto Prefecture on 14 April. The only two commercial reactors currently operating in Japan are at Kyushu Electric Power Co’s Sendai complex in Kagoshima Prefecture. Kyushu Electric’s Genkai NPP is located in Saga Prefecture, northwestern Kyushu, while Chugoku Electric Power Co’s Shimane plant is in Honshu, northeast of Kumamoto. Shikoku Electric Power Co is aiming to restart a reactor at the Ikata complex in Ehime Prefecture, east of Kumamoto in Shikoku, in late July.
Previously, the NRA did not provided information to the public unless an earthquake measuring at least lower 5 on the Japanese intensity scale of 7 was registered in the location of a NPP, even when a strong earthquake occurred in a neighbouring area. NRA did not provide any information about the safety of the four plants affected by the 14 April quake until the following day. The slow response prompted the government to instruct NRA to improve its information disclosure. In future, when an earthquake measuring lower 5 or higher is recorded in Kyushu, NRA will provide information immediately with data about the NPPs.
On 18 April NRA Chairman Shunichi Tanaka apologized for the lack of news on the state of the NPPs after the quake. "We have been warned that our provision of information may not have been sufficient," he said at an NRA extraordinary meeting called in response to the quakes. "We must reflect on our conduct in a candid way." Tanaka noted: "Currently there is no problem with safety" at the plants. Current safety standards ensure that a nuclear reactor will automatically shut down when quake-related ground acceleration reaches 140 to 190 gal for sideways movement and 70 to 90 gal for vertical movement.
