A Technical Bridge Across the Pacific Ocean

Share this article:

EPRI Informs Efforts to Extend Nuclear Plant Licenses in Japan

Drawing on decades of technical research on the U.S. nuclear fleet, EPRI research supported a successful effort by a Japanese utility to extend the operating license of three of its nuclear units.

Many nuclear plants in Japan are approaching 40 years of age—the endpoint of their original licenses. The Japanese regulator has endorsed a framework, similar to the International Atomic Energy Agency’s International Generic Aging Lessons Learned (IGALL) program, to support aging management up to 60 years. The IGALL identifies areas in nuclear plants that require aging management programs, providing references (including EPRI research results) to inform the programs’ development.

In 2014, the Japanese utilities asked EPRI for assistance in addressing challenges related to license renewal. EPRI brings decades of technical guidance to inform U.S. utilities’ aging management programs. After the Japanese utilities identified potential knowledge gaps in their aging management programs relative to the IGALL, they worked with EPRI to identify how EPRI guidance could help fill those gaps.

While conducting this assessment, Kansai Electric Power Company (KEPCO) in 2015 submitted its application to extend the license of Mihama Unit 3 and Takahama Units 1 and 2. In 2016, the regulator approved the extension—the first such approval in Japan. In 2017, two Japanese utilities, KEPCO and the Tokyo Electric Power Company (TEPCO), received an EPRI Technology Transfer Award for the effort. Following KEPCO, other Japanese utilities are using EPRI research and reports as technical bases for their license extensions.

“Working with the Japanese utilities, we found that many requirements in the U.S. and Japan are quite similar, but the details of implementation are dictated by local codes and regulations and by unique data sets and models,” said Kurt Edsinger, EPRI’s director of R&D for nuclear materials. “This was the first major effort to connect EPRI research with the IGALL approach, and it will likely be repeated as fleets in other countries look to extend the lives of their nuclear plants.”

Photo of Takahama Units 1 and 2 courtesy of Kansai Electric Power Company