TOKYO (Reuters) – Japan’s Hokuriku Electric Power on Sunday reported a small oil leak from its Shika nuclear power station, which was shaken by a powerful earthquake on New Year’s Day.
External radiation levels were not affected and there were no adverse impacts on the environment or human health, the company said.
The magnitude 7.6 quake, which has killed more than 120 people in the Hokuriku region, shook the idled Shika power station, which is located around 65 kilometres (40 miles) from the quake’s epicentre.
The utility had already reported temporary power outages, oil leaks at the transformers, and water spill-over from spent nuclear fuel pools following Monday’s jolt, but no radiation leakage.
On Sunday, a small amount of oil film was detected in the gutter and on the road surrounding the main transformer of the No. 2 reactor, it said.
Additionally, an oil slick measuring about 5 meters by 10 meters was observed floating on the sea surface in front of the power station, Hokuriku Electric said, adding it promptly treated the oil film using a neutralizing agent.
The utility believes the oil slick resulted from a transformer insulating oil leak during the Jan. 1 quake, which triggered the fire extinguishing system, dispersing oil and spraying water around the transformer.
Subsequently, the oil appears to have entered the gutter due to rainfall, the company said, adding it was still analysing further details.
The oil slick is not within the radiation-controlled area and there are no external radiation effects, the company said.
Key external power supplies, monitoring facilities, and cooling systems at the plant are functioning normally, it added.
(Reporting by Yuka Obayashi; Editing by Mark Potter)