Japan's Tomari Nuclear Power Plant Unit 3 Restart Review Still Requires Additional Fire Safety Documentation

On September 3, a review meeting was held for the restart plan of Unit 3 at Japan's Tomari Nuclear Power Plant. The Nuclear Regulation Authority (NRA) pointed out that the explanations submitted by Hokkaido Electric Power regarding fire safety measures still contain issues requiring further confirmation, and requested the company to provide more detailed assessment materials.

The equipment design and construction plan required for the restart of Tomari Unit 3 has been under review since last year. One of the current review priorities is whether relevant workers have adequate and feasible evacuation measures in the event of a fire on site.

At the meeting that day, representatives of Hokkaido Electric Power explained the revised fire safety measures. The company stated that it had verified the safety of the fire extinguishing agents to be used and the personnel evacuation methods in the event of a fire, in accordance with the relevant standards of the Fire Service Act.

In response, the Nuclear Regulation Authority stated that merely explaining that "verification has been completed" is insufficient to support the review conclusion, and required Hokkaido Electric Power to submit more detailed documents specifying the specific assessment methods, review processes, and their appropriateness. The authority indicated that additional review of the relevant content remains necessary.

Hokkaido Electric Power had previously stated that Tomari Unit 3 would resume operation "as early as next year," and planned to submit the final revised documents required for passing the review to the Nuclear Regulation Authority this month. As things currently stand, the submission of these documents may be delayed, and it remains to be seen how much impact the additional review will have on the restart schedule of the unit.