Eleventh Japanese reactor resumes operation

28 July 2023

Unit 1 of the Takahama nuclear power plant in Japan's Fukui Prefecture has been restarted after being taken offline more than 12 years ago. Kansai Electric Power Company plans to return the 780 MWe (net) pressurised water reactor (PWR) to commercial operation at the end of August.

The four-unit Takahama plant (Image: NRA)

Takahama 1 entered a regular inspection outage in January 2011, two months before the accident at the Fukushima Daiichi plant that resulted in all of Japan's operable reactors being taken offline. Unit 2 of the plant was taken offline in November 2011.

Kansai applied to the Nuclear Regulation Authority (NRA) to restart the two reactors in March 2015.

In April 2016, the NRA confirmed the units met new safety regulations. In December of that year, the NRA gave its approval for the reactors - which began operating in 1974 and 1975, respectively - to operate for up to 60 years, becoming the first Japanese units to be granted a licence extension beyond 40 years under the revised regulations.

Takahama 1 was originally scheduled to restart around early June, but the plan was postponed due to the need for additional work on fire protection infrastructure.

Kansai announced that Takahama 1 was restarted at 3.00pm on 28 July and expects the reactor to reach criticality on 29 July. Following various tests, the final stage of the periodic inspection will be carried out on 2 August. On 28 August, a comprehensive load performance test will be conducted and full-scale operation will be resumed. The next scheduled inspection of the reactor is in April 2024.

Takahama 2 is scheduled to resume operations on 15 September.

Takahama 3 and 4 - two 1180 MWe PWRs - were returned to commercial operation in February 2016 and June 2017, respectively. In April this year, Kansai asked the NRA for permission to extend the lifespan of Takahama units 3 and 4 - which both began commercial operation in 1985 - by 20 years.

The reviews of 17 reactors had been successfully completed and 11 of them have now returned to operation. The remaining 14 operable reactors are at various stages of the NRA review process, and several may be forced to shut down temporarily for not meeting NRA deadlines to construct back-up control centres or other facilities required by the new regulations.

In December last year, the Japanese government adopted a plan to extend the operation of existing nuclear power reactors and replace aging facilities with new advanced ones. The move is part of a policy that addresses global fuel shortages following Russia's invasion of Ukraine and seeks to achieve carbon neutrality by 2050.

Researched and written by World Nuclear News