Japan's Tokai No. 2 Nuclear Power Plant Seawall Reinforcement Plan Receives Basic Approval

Japan's Nuclear Regulation Authority (NRA) held a review meeting on the 27th local time and basically approved the seawall structural modification plan for the Tokai No. 2 Nuclear Power Plant submitted by Japan Atomic Power Company (JAPC). The plant is located in Tokai Village, Ibaraki Prefecture, Japan, and the relevant seawall is an important component of the safety measures required for restart, with foundation defects having been discovered during construction.

According to JAPC's explanation, the modification plan does not remove the underground foundation where defects were found, but instead adds pile foundations around it and uses cement-based materials to reinforce the ground. Regarding this plan, JAPC submitted an assessment of the seawall's seismic and tsunami resistance performance after modification, concluding that the structurally adjusted seawall can still fulfill the functions required of a tsunami protection facility. The NRA evaluated at the meeting that the detailed design content is "generally appropriate."

The main review of changes to the design and construction methods of the Tokai No. 2 Nuclear Power Plant seawall has continued for approximately two years, and the core discussions have now basically concluded. Next, both parties will confirm supplementary details at the administrative level, and JAPC will submit a revised application reflecting the review results. Thereafter, the NRA will prepare a draft review report and initiate the formal approval process.

In June 2023, safety measure construction at the Tokai No. 2 Nuclear Power Plant was significantly delayed due to problems such as insufficient concrete filling and rebar deformation discovered in the seawall foundation. JAPC subsequently redesigned the relevant structures and had postponed the project completion target to December 2026. However, due to adjustments in construction methods and additional work, sources revealed that JAPC has decided to further postpone the completion of the seawall project by approximately two more years.

Since the safety measures at the Tokai No. 2 Nuclear Power Plant cannot be fully completed until the seawall project is finished, the restart of the unit is expected to be postponed to the second half of fiscal 2028 or later. JAPC plans to provide an explanation of the new construction schedule in the near future.

The Tokai No. 2 Nuclear Power Plant was confirmed in 2018 to comply with Japan's new nuclear regulatory standards, and its operating period was also approved for extension of up to 20 years, bringing the total operating life to 60 years. However, evacuation plans for surrounding areas in response to severe accidents are still being developed, and there remains no clear timeline for restart.