Japanese regulator to decide fate of Tsuruga 2
31 July 2024
Japan's Nuclear Regulation Authority (NRA) looks set to rule that unit 2 of the Tsuruga nuclear power plant in Fukui prefecture does not comply with regulatory safety standards after a review team concluded that seismic activity beneath the unit cannot be ruled out. Owner Japan Atomic Power Company (JAPC) insists that further investigations are required.
The Tsuruga plant (Image: Wikipedia/Hirorinmasa)
New regulatory standards announced in June 2013 prohibit reactor buildings and other important facilities being located above any active fault.
On two occasions - in May 2013 and March 2015 - an NRA panel of experts concluded that an active fault lies under the Tsuruga 2 reactor building. However, JAPC has maintained that its own analysis has shown that the fault is not active and does not extend under the unit. In November 2015 it applied to the NRA for a review to restart the operation of Tsuruga 2.
An NRA review team presented the results of their confirmation of the activity of the fault at a meeting on 31 May, and the continuity of the fault at a meeting on 26 July.
The team concluded that the possibility of an active fault running directly underneath the reactor building "cannot be denied."
JAPC said in a 26 July statement to the NRA that it is "examining the basis for the review team's judgment ... and considering additional investigation to obtain new data".
It added: "Regarding continuity, we will carefully examine the results of today's discussions, organise the operator's views, etc., and consider additional investigations. At that time, we will also consider contents beyond those described in the current amendment (logical structure, evaluation criteria, etc.). We would like to ask you to review the application once these considerations have been completed and the results of the investigation have been compiled. In addition, if necessary, we would like to re-amend the amendment from August last year."
In response, the NRA said today: "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."
If the NRA denies JAPC's application to restart the reactor - which would mark the first instance that such a decision has been made under the new regulations - the company may have no option but to decommission Tsuruga 2.
However, JAPC President Mamoru Muramatsu said after the panel meeting: "We will conduct an additional investigation. We are not considering decommissioning the plant." Muramatsu's words were reported by Kyodo News Agency.
Researched and written by World Nuclear News