IAEA Evaluates Mihama 3 for Long Term Operation

On October 28, the Kansai Electric Power Co. (Kansai EP) announced that it had received a report from the International Atomic Energy Agency (IAEA) evaluating its Mihama-3 Nuclear Power Plant (PWR, 826MW). The report was drawn up under the Agency's Safety Aspects of Long-Term Operation (SALTO) program, which supports the long-term operation of NPPs.

Having cleared examinations under Japan's new regulatory standards, Mihama-3 celebrated its 40th year of operation in July 2021, the first unit in Japan to do so. On October 15 of this year, Kansai EP then filed an application with the Nuclear Regulation Authority (NRA) of Japan for approval of its long-term facility plan, which is required by NPPs in Japan to operate beyond 30 years from their entry into commercial service, as stipulated by the GX Decarbonization Power Supply Law, which is to come into effect in June 2025.

The SALTO program evaluates an organization along with the systems involved in long-term operation of an NPP, particularly in terms of whether the management of the deterioration of facilities and equipment is compatible with the IAEA's safety standards.

After completing its review, the Agency then provides operators with recommendations and proposals for further improvement. Overseas, such reviews have already been conducted in Europe, China, South Africa, Mexico, and elsewhere. Mihama-3 was the first unit in Japan to receive one.

A SALTO team visited Mihama-3 seven months ago, from April 16 to 25. Its investigation identified six good practices and made seven recommendations and four suggestions.

Upon receipt of the report, Kansai EP said that its management of the reactor's deterioration and its activities for safe long-term operation were generally in accordance with the recommendations made by IAEA concerning safety standards. It added that it was well recognized that the company plans further improvements.

From now on, the power company will conduct improvements according to the proposals and recommendations, and receive a follow-up visit by the SALTO team sometime in FY26 (April 2026 to March 2027).