Japan’s Nuclear Regulation Authority (NRA) appears ready to rule that unit 2 of the Tsuruga nuclear power plant in Fukui prefecture doesn’t meet the necessary safety standards.
This follows a review team’s conclusion that the possibility of seismic activity beneath the unit cannot be dismissed. The owner, Japan Atomic Power Company (JAPC), argues that additional investigations are warranted.
New Safety Standards and the Active Fault
Regulatory standards introduced in June 2013 strictly prohibit the placement of reactor buildings and other critical facilities directly above any active fault lines.
An NRA expert panel concluded on two separate occasions—in May 2013 and March 2015—that an active fault exists beneath the Tsuruga 2 reactor building.
JAPC has consistently maintained that its own analyses indicate the fault is not active and does not extend under the unit. In November 2015, the company submitted an application to the NRA for a review with the aim of restarting Tsuruga 2.
NRA Review Team’s Findings
An NRA review team presented their findings on the fault’s activity on May 31st and its continuity on July 26th.
The team’s conclusion was clear: the possibility of an active fault directly under the reactor building “cannot be denied.”
JAPC’s Response and NRA’s Position
JAPC, in a statement to the NRA on July 26th, expressed their intent to “examine the basis for the review team’s judgment … and consider additional investigation to obtain new data.”
They further stated their plans to thoroughly examine the results of the discussions, organize their views, and consider additional investigations regarding the fault’s continuity.
They also indicated a willingness to reconsider aspects beyond those outlined in the current amendment, such as logical structure and evaluation criteria.
JAPC requested the NRA to review the application again once these considerations and investigations have been completed.
In response, the NRA today stated, “We would like to ask President Muramatsu of Japan Atomic Power Company to confirm the purpose of the request at the Nuclear Regulation Authority and then discuss the handling of this application.”
Potential Decommissioning and JAPC’s Stance
If the NRA rejects JAPC’s application to restart the reactor—which would be the first such decision under the new regulations—the company may have no alternative but to decommission Tsuruga 2.
However, JAPC President Mamoru Muramatsu, following the panel meeting, expressed his intention to conduct further investigations and explicitly stated that they are “not considering decommissioning the plant,” as reported by Kyodo News Agency.