Reactor on Active Rift

Nuclear Regulation Authority accepted a report from researchers on safety of Shika Nuclear Power Plant in Ishikawa Prefecture. The report indicated that a rift called S-1, located right under the first reactor of Shika plant, could cause landslide. Although the owner of the plant, Hokuriku Electric Power Company, has been denying activeness of the rift, NRA turned down the opinion and admitted negative effect on the operation of nuclear generation. Since the report is unreviewable, it is likely that the first reactor of Shika plant will be dismantled.

New regulation for nuclear power plant after severe accident in First Fukushima Nuclear Power Plant requires every reactor not being built on an active rift that has a record of activity these 120,000 to 130,000 years. The report submitted to NRA recognized that S-1 rift moved within those years, based on the geological research before building the first reactor.

The report demanded Hokuriku Electric Power Company further data of analysis on mineral around there and boring survey at deeper layer. “It is apparent duty for Hokuriku Electric Power Company to tackle every issue with sincere eagerness. NRA will make final decision with submitted data on insufficient area,” told Chairman of NRA, Shun-ichi Tanaka. He also indicated that other rifts called S-2 and S-6, underground of the turbine building of the first reactor, might have caused transformation of ground surface these 120,000 to 130,000 years.

Hokuriku Electric Power Company firmly opposed to the report. “The report was made without enough opportunity to explain our viewpoints,” told the comment delivered from the company. In the survey for over two years, Hokuriku did not find any data that indicated activity of the rift. But, the report focused on the data obtained at the time before building the first reactor.

It seems hard for Hokuriku to change the conclusion of the report. But, the company is highly reluctant to dismantle the reactors, still seeking resumption of their operation. Since Shika plant is an only nuclear power plant for Hokuriku, it is going to pour a great amount of money for safety improvement.

The report concluded that the location of Shika plant was not suitable for nuclear power generation. The consecutive earthquake in Kumamoto proved that disaster could occur anywhere unpredictable. It is very costly to maintain a nuclear reactor built right on an active rift. Dismantlement is the most reasonable choice in terms of economic rationality.