"Japanese Noto Nuclear Power Plant Transformer Failure, Radiation Meter Also Stops"

West Side of Noto Peninsula Shika Nuclear Power Plant
19,800ℓ Transformer Oil Leak
Nuclear Regulation Authority "Aftershocks Must Be Considered"

A strong earthquake that struck the Noto Peninsula in Ishikawa Prefecture, Japan, caused damage to the local nuclear power plant, including a broken transformer. The transformer is damaged, and the radiation monitoring devices are inoperable. Although authorities maintain that there are no safety issues, residents remain anxious. On the 11th, NHK reported that the Nuclear Regulation Authority instructed to expedite the repair of the transformer at the Shika Nuclear Power Plant, located on the western side of the Noto Peninsula, the previous day.

The Shika Nuclear Power Plant currently has damaged transformer piping that brings in external electricity due to the earthquake. As a result, some devices that use external electricity cannot be operated. The damaged piping caused a leak of 19,800 liters of oil used for insulation and cooling of the transformer, resulting in two oil barriers forming in the nearby sea area of the plant.

Photo of the damaged transformer inside Shika Nuclear Power Plant released by Hokuriku Electric Power Company. (Photo by NHK)

Hokuriku Electric Power Company, which manages the Shika Nuclear Power Plant, maintains that there are no safety concerns. Hokuriku Electric Power stated, "Since electricity is being supplied through a backup transformer, power for safety-critical equipment such as spent fuel cooling has been secured." However, the authority pointed out, "The currently operating transformer may also be damaged by aftershocks in the future." They added, "Please expedite the restoration and thoroughly investigate the cause," and suggested, "It may be necessary to review whether the current response is sufficient or should be strengthened."

The radiation monitoring devices that provide real-time radiation levels also stopped functioning due to the earthquake. NHK reported, "The monitoring devices measuring radiation levels within a 15 to 30 km radius around the Shika Nuclear Power Plant are inoperable due to the earthquake." The main cause is the inability to use mobile phone lines necessary for data transmission. Hokuriku Electric Power claimed that they installed alternative devices and are operating them as of the previous day, but the authority members said, "It is a serious problem that real-time situation monitoring became impossible after the earthquake," and similarly ordered an investigation into the cause.

The appearance of the Shika Nuclear Power Plant affected by the earthquake. (Photo by NHK)

Furthermore, it was revealed that the shaking of the nuclear power plant was greater than initially expected by Hokuriku Electric Power. For nuclear power plants, the maximum expected shaking for each facility or equipment is set in case of an earthquake, but the shaking at the foundation of the reactor buildings of Units 1 and 2 at the Shika Nuclear Power Plant exceeded this expected value. For Unit 1, 918 Gal (Gal is the unit of maximum ground acceleration) was expected, but verification showed that the shaking from this earthquake corresponded to 957 Gal. Gal is a unit that indicates how much the earth's crust shakes instantaneously during an earthquake.

Since a 3-meter tsunami already reached this nuclear power plant and the earthquake impact was significant, concerns are growing in Japan that the Fukushima nuclear disaster nightmare could be repeated. Despite the authority's warnings, Hokuriku Electric Power continues to claim, "There is no impact on the nuclear power plant," and Prime Minister Fumio Kishida caused controversy by remaining silent when a reporter asked about nuclear power plant-related questions due to the earthquake at the end of his New Year's press conference on the 4th.

Meanwhile, the Fukushima Nuclear Power Plant, which was damaged by the Great East Japan Earthquake, began removing melted nuclear fuel debris (the Japanese-style expression of debris) on the 10th. Since rainwater and seawater pass through the debris inside the plant, the debris is considered a cause of contaminated water. Tokyo Electric Power Company plans to proceed with work to break and push some sediment at the entrance of the reactor piping to remove the debris in the future.

This content was produced with the assistance of AI translation services.