Japan’s Kansai Electric Power Co said it will resume a geological survey at its Mihama NPP in Fukui Prefecture in preparation for construction of a safer, next-generation nuclear reactor. The Mihama town government approved Kansai’s plan to conduct the survey in August.
Units 1&2 at Mihama are set to be decommissioned, leaving only unit 3 in operation. However, next year, unit 3 will reach its 50th year in operation, 10 years beyond the standard design life of 40 years.
Surveys for a replacement reactor at Mihama began in late 2010 but halted after the 2011 Fukushima disaster. The new round will be more extensive to meet stricter safety regulations implemented after the disaster, a company spokesperson said.
The renewed surveys, first announced in July, mark Japan’s first concrete step towards building a new reactor since the Fukushima accident. The surveys, expected to run to around 2030, will start with extensive geological studies inside and outside the plant site to identify suitable areas, followed by assessments of topography and ground conditions, the company said. The initial work, scheduled to start in November, will include boring tests in two areas near Mihama 3 to investigate ground hardness and whether there are any active faults.
“From today onward, we will be proceeding with offering explanations to local residents and others in preparation for the geological survey,” Kepco President Nozomu Mori told a news conference. “In our resource-poor country, it is important for nuclear power to continue to play a role in the future” from the standpoint of safety, energy security, economic efficiency and the environment, he said.
A final decision on whether to build the new reactor will be made after a detailed survey, to examine the impact of earthquakes, which is expected to start in April 2027 for completion between 2029 and 2030. Kansai Electric said it will then weigh the findings alongside the development of advanced light-water reactors, regulatory policies, and business environment before deciding on a new unit.
Since 2022, Mitsubishi Heavy Industries and four utilities, including Kansai Electric, have been jointly developing a next-generation reactor. Kyushu Electric Power, Shikoku Electric Power and Hokkaido Electric Power are also part of the consortium designing the 1,200 MWe advanced light-water reactor known as SRZ-1200.
During his news conference, Mori said that especially given the growth of data centres and the semiconductor industry, Japan’s power needs would only continue to grow. He added that his lesson from the Fukushima accident was to “prioritise safety over all else” in the operation of the reactors. “I understand that there are those who are cautious about nuclear energy … but we will continue to work to improve the safety of nuclear power,” he said. “This means not only complying with regulations, but also continuing to improve safety on a voluntary basis, and accumulating the results of safe operation one day at a time.”
