• Yomiuri Editorial
  • Restart of nuclear reactors

Make steady progress in securing electricity sources

Russia’s invasion of Ukraine is putting Japan’s energy strategy to the test. To secure stable electricity sources, the government should steadily promote the restart of nuclear power plants.

Shimane Gov. Tatsuya Maruyama has said he would approve the restart of the No. 2 reactor at Chugoku Electric Power Co.’s Shimane nuclear plant. Surrounding local governments, including those in neighboring Tottori Prefecture, have already agreed to allow the reactivation of the reactor. This is a reasonable judgment based on the opinions of the regional communities.

Chugoku Electric plans to complete work on safety measures as early as next year. If the reactor comes back online, it will be the 11th reactor restarted and first since the No. 3 reactor at the Mihama nuclear power plant in Fukui Prefecture in June last year. There is large significance in the fact that it would be the first restart of a boiling water reactor, the same type as those at the Fukushima No. 1 nuclear power plant.

Nuclear power is an important electricity source that can provide a stable supply, but most reactors have been shut down since the 2011 Great East Japan Earthquake.

Renewable energy, such as solar and wind power, are susceptible to weather conditions. The aging of thermal power plants is also conspicuous. Therefore, electricity supply is expected to be tight again this summer.

The central government needs to make the most of nuclear reactors that can be restarted to prevent large-scale power failures.

The reason nuclear reactor restarts have been delayed is that the Nuclear Regulation Authority’s safety inspections have not progressed smoothly.

Safety inspections at Hokkaido Electric Power Co.’s Tomari nuclear power plant have been ongoing for nine years. In a trial over the restart of the nuclear reactors at the Tomari plant at the Sapporo District Court, Hokkaido Electric did not sufficiently explain about a seawall’s safety on the grounds that the NRA is continuing safety inspections, stalling the lawsuit.

The district court has stopped hearings and handed down a ruling ordering that the plant should not operate. The court likely lost patience with a lawsuit lasting more than 10 years.

The ruling stated that the possibility of the seawall’s foundations undergoing liquefaction could not be ruled out. The seawall in question was to be replaced with a new one more than 16 meters high. The removal work began after the case concluded.

The risk of tsunami can be reduced not only by seawall functions, but also by a number of other types of protective equipment, such as watertight doors and drainage pumps that are installed at the facility. The ruling ordering that the plant should not operate focused only on the seawall, which might have been concluded based on insufficient understanding of the overall concept of the safety design.

Primarily, the assessment of earthquakes and tsunami is highly specialized, and it is questionable that the judges made their own conclusion ahead of the NRA. Even though district court rulings have ordered against nuclear plant operations in the past, the finalized rulings in this regard show that all such decisions have been overturned by higher and other courts, resulting in confusion.

However, the Hokkaido Electric side also has many problems. The NRA cited Hokkaido Electric’s poor handling of this issue as a reason for the delay in the safety inspections. The district court also severely criticized the lack of explanations. There is an urgent need to secure professional human resources capable of responding to safety inspections and judicial trials.

(From The Yomiuri Shimbun, June 3, 2022)