Transformers Damaged at Shika N-Plant in Quake-Hit Area in Ishikawa Pref.; Watchdog to Request Operator to Investigate Cause

The Yomiuri Shimbun
An aerial photo of Hokuriku Electric Power Co.’s Shika nuclear power plant taken on Jan. 3 in Shika, Ishikawa Prefecture

The chairman of the Japanese nuclear watchdog on Wednesday requested Hokuriku Electric Power Co. to investigate the cause of issues at its Shika nuclear power plant that had suffered damage to its transformers as a result of the powerful earthquake that struck Noto Peninsula, where the plant is located.

Nuclear Regulation Authority Chairman Shinsuke Yamanaka said the results of the investigation will be utilized when considering the implementation of future safety measures.

The power company announced Friday that transformers in the No. 1 and No. 2 reactors that receive electricity from outside the nuclear plant in Shika, Ishikawa Prefecture were damaged, causing 19,800 liters of insulating oil to leak.

Some of the radiation monitoring posts were rendered unusable, and water to cool spent fuel spilled from the pool onto the floor. The operator has kept revising its announcements concerning the fire, the amount of oil leaked and fluctuations in the water levels due to the tsunami.

At an NRA meeting on Wednesday, a member pointed out that the operator had not anticipated a situation where system failures — including those of the transformers — would stop the plant from receiving electricity.

Yamanaka denied any impact on the safety of the Shika plant and urged other nuclear plants to take adequate measures once the cause of the issues were identified. He also said that the NRA would give the Hokuriku power company “proper guidance” on how to disseminate information.