The Nuclear Regulation Authority will officially prohibit the Monju prototype fast-breeder reactor from resuming operations, dashing the operator’s hopes of restarting the facility by the end of next March.
The harsh measure is a setback for the Japan Atomic Energy Agency, a national research institute, and came in response to slack safety checks observed at the Monju reactor in Fukui Prefecture. A written order was to be given to JAEA on Thursday.
The agency is expected to face further scrutiny after 33 of the 55 people working at its laboratory in Tokai, Ibaraki Prefecture, were exposed to radiation in an accident on May 23.
In a meeting of NRA commissioners Wednesday, Chairman Shunichi Tanaka highlighted how a radiation protection supervisor allowed radioactive substances to be released into the atmosphere via a ventilation fan in a laboratory building where contamination was confirmed.
“It is regrettable that people lacked preparedness for the use of radiation,” Tanaka said, while calling on the need to check in detail what appeared to be a mistake by the supervisor.
JAEA also waited more than 24 hours before reporting the accident to the state, claiming it had underestimated the seriousness of the incident.
In regard to the operation of Monju, JAEA will be barred from engaging in preparatory work for restarting the reactor until it rebuilds a maintenance and management system for the facility.
The delay in restarting Monju is expected to affect the nation’s nuclear fuel-recycling goals.
The government had been hoping the Monju project would play a key role in the fuel-recycling flow, having spent more than ¥1 trillion on its maintenance and construction. But the reactor has remained largely offline since first achieving criticality in 1994, due to a sodium coolant leak, fire and other major problems.
JAEA was also found to have failed to conduct inspections at appropriate intervals on nearly 10,000 components, including those deemed key for safety.
The NRA also said Wednesday it will start from June a process to assess whether geologic faults at the Monju site are active.
No Tepco suit statute
The Diet passed a law Wednesday to enable people affected by the Fukushima nuclear crisis to sue Tokyo Electric Power Co. for damages after the three-year statute of limitations runs out.
While a government organization has been mediating settlement talks between victims and Tepco, some claims may become invalid after next March, the third anniversary of the start of the disaster, if deals are not reached. Under the new law, plaintiffs will be able to file damages suits within one month of settlement talks breaking down.