Editorial: Comprehensive nuclear safety review needed after central Japan quake

Japan, a country prone to earthquakes, has once again been reminded of the risks associated with continuing to operate nuclear power plants.

The Noto Peninsula earthquake caused damage to Hokuriku Electric Power Co.’s Shika Nuclear Power Station, located in the Ishikawa Prefecture town of Shika, where the intensity of the quake reached a full 7 on the Japanese seismic scale.

The two nuclear reactors at the plant were not operating at the time, and a serious situation such as a radiation leak was avoided, but the quake damaged a transformer used to bring in electricity from outside, and it leaked a large amount of oil. There are no prospects of its functions being restored.

There were also issues when it came to the release of information. Hokuriku Electric initially announced details including the amount of leaked oil and the height of the tsunami, but significantly amended the information later. The Nuclear Regulation Authority (NRA) criticized the utility’s lax approach toward crisis management.

The disaster at the Fukushima Daiichi Nuclear Power Station provided a heavy lesson — the need to be prepared for the unexpected. The Fukushima plant was struck by a tsunami that was higher than expected following the 2011 Great East Japan Earthquake, rendering emergency generators unusable. Reactors lost their cooling functions and suffered core meltdowns, while hydrogen explosions dispersed a huge amount of radioactive material.

In order to prevent such a situation from happening again, safety standards for nuclear reactors were tightened. But the latest earthquake has raised questions about the effectiveness of plans to evacuate residents.

The “Regulatory Guide for Emergency Preparedness and Response” created by the NRA specifies how residents should act in the event of a nuclear accident. Residents within a 5-kilometer radius are required to evacuate outside the area, while those within a 5- to 30-km radius are advised to take shelter indoors.

However, when roads are severed by a quake, residents have no option but to evacuate on foot, meaning they cannot avoid exposure to radiation. Furthermore, it is unrealistic to stay indoors in collapsed wooden houses with low earthquake resistance. It is also difficult to survive for an extended period when relief supplies are not arriving.

Hokuriku Electric has its eyes on restarting the Shika nuclear plant’s No. 2 reactor. The NRA must evaluate the danger posed by the active undersea faults that triggered the earthquake and strictly screen the response plans.

Many of Japan’s nuclear power plants are located in depopulated coastal areas. It is only natural that residents in the northeast Japan prefecture of Miyagi and the central Japan prefectures of Niigata and Aichi, which face similar situations, have raised concerns. Are the current risk evaluations appropriate? Are preparations sufficient? The government needs to conduct a comprehensive review.

The administration of Prime Minister Fumio Kishida, which seeks “achievement of a decarbonized society,” is in favor of restarting nuclear power plants. However, it must not push forward with such moves while disregarding the concerns of residents.