Shika Nuclear Power Plant hit by 3 m (9.8 feet) tsunami waves after M7.6 earthquake on January 1

The Shika Nuclear Power Plant in Ishikawa Prefecture, Japan, experienced a 3 m (9.8 feet) tsunami waves after the M7.6 earthquake hit Noto Peninsula on January 1, 2024. While the plant sustained no major damage, the incident has raised concerns about nuclear safety, reminiscent of the Fukushima disaster.

In the aftermath of the M7.6 earthquake that hit Japan’s Noto Peninsula, the Shika Nuclear Power Plant witnessed tsunami waves reaching up to 3 m (9.8 feet). This was reported more than a week after the January 1 event by Hokuriku Electric Power, the plant’s operator.

The plant, situated 11 m (36 feet) above sea level and reinforced by a 4 m (13 feet) seawall built post-2011 Fukushima accident, withstood the tsunami without damage. Despite this, the earthquake’s impact on Ishikawa Prefecture was significant, resulting in 206 fatalities and extensive property damage.

The first tsunami, reaching 1 m (3 feet) in height, was recorded near the plant about 20 minutes after the quake, with later analyses indicating wave heights of up to 3 m (3.8 feet) 105 minutes after the quake.

Other nuclear facilities along the Sea of Japan shoreline reported minor damage, including water leaks used for cooling nuclear fuel and partial power shutdowns. However, the plant operators assured no environmental or structural risks to the nuclear power stations themselves.

Complications arose when Hokuriku Electric reported two oil leaks at the Shika plant, one on January 7 and another on January 10. Measures like oil absorption mats and closing drainage gates were implemented to contain the leaks. Despite these efforts, about 100 x 30 m (328 x 98 feet) oil slick was found floating near the station. The utility believes these leaks originated from a transformer during the earthquake and is analyzing the situation further.

At a Nuclear Regulation Authority (NRA) meeting, it was reported that the quake’s acceleration slightly exceeded design assumptions in some parts of the plant, though the NRA assured there is no safety issue. However, the authority urged Hokuriku Electric to thoroughly investigate the transformer damage and consider potential fresh damage from ongoing aftershocks.

Shika’s reactors, inaugurated in 1993 and 2006, have been offline since the 2011 disaster. Despite plans to restart the No. 2 reactor by 2026, these plans may now face delays due to the need for extensive safety reviews in light of the recent earthquake and tsunami.

References:

¹ Three-meter tsunami recorded at Japan nuclear plant after quake – Japan Times – January 10, 2024

² Japan’s Hokuriku Elec reports second oil leak from Shika nuclear plant – Reuters – January 10, 2024

³ Japan’s nuclear safety agency orders power plant operator to study the impact of Jan. 1 quake – January 10, 2024

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