Further Delay in Completion of Safety Measures at Japan's Tokai Daini Nuclear Power Plant

Japan Atomic Power Company (JAPC) announced on August 28 that the safety measure works required for the restart of the Tokai Daini Nuclear Power Plant in Tokai Village, Ibaraki Prefecture, are now expected to be completed between October 2028 and March 2029 (the second half of fiscal 2028), delayed from the original target of December 2026. This marks the fourth postponement of the completion schedule for the plant's safety measures.

One of the key projects among the safety measures at Tokai Daini is the construction of a seawall approximately 17 meters high to protect against tsunamis. In June 2023, defects including incomplete concrete filling and deformed rebar were discovered in the seawall's foundation works, and related construction was subsequently suspended. JAPC has since applied to the Nuclear Regulation Authority (NRA) for approval of a revised construction plan.

According to JAPC's earlier explanations, the new construction plan will retain the foundation sections where defects were found, add pile foundations around them, and strengthen the ground with cement grouting. At a review meeting held on the 27th, the Nuclear Regulation Authority considered the seawall design change to be generally appropriate. JAPC plans to submit a revised construction plan to the NRA to further clarify the new completion schedule and resume construction after completing the necessary procedures.

The Tokai Daini Nuclear Power Plant passed the review under the new regulatory standards of the Nuclear Regulation Authority in 2018 and was approved for an operating period extension of up to 60 years. JAPC initially planned to complete the relevant safety measures by March 2021, but has adjusted the schedule multiple times due to factors such as construction progress, the impact of the COVID-19 pandemic, and defects in the seawall construction. In August 2024, the completion date was postponed from September of that year to December 2026; in January of this year, JAPC President Mamoru Muramatsu stated that completing the work by December under the original plan would be "extremely difficult."

Yutaka Sakabe, head of JAPC's Tokai Business Unit, stated at a press conference that although the project is large in scale, the company will prioritize safety, ensure proper construction management, and prevent the recurrence of problems. Tokai Village Mayor Osamu Yamada also expressed hope that the company will prioritize safety, earn the trust of the local community, and take all possible measures to further enhance safety.

Since the safety measure works, including the seawall, are a prerequisite for the restart of the Tokai Daini Nuclear Power Plant, the delay in construction means that the restart of the unit will also be pushed back accordingly. Regarding the wide-area evacuation plan for surrounding areas required for the restart, the relevant municipalities are still in the process of formulating it.