The president of the state-run Japan Atomic Energy Agency resigned Friday over the body's failure to properly inspect the troubled Monju prototype fast-breeder reactor in Tsuruga, Fukui Prefecture, science and technology minister Hakubun Shimomura said.
Shimomura told reporters that he had accepted Atsuyuki Suzuki's resignation and will name a successor shortly.
On Wednesday, the Nuclear Regulation Authority barred JAEA from engaging in any preparatory work toward restarting Monju after saying the agency had failed to properly inspect some 10,000 components, including those that are critical for the reactor's safe operation.
If in full operation, Monju is designed to have an output capacity of 280,000 kw.
The reactor began trial runs in 1991 but has mainly been shut down since 1995 after a sodium leak led to a fire that the operator tried to cover up. It resumed operation in May 2010 but was shut down again because of various problems, the main one being that fuel-loading equipment fell into its vessel.
Last November, JAEA said it had failed to conduct inspections at appropriate intervals on many of the reactor's components.
An NRA probe also determined the operator failed to inspect key equipment at the proper intervals.