Japanese operator agrees to shut down nuclear reactor for inspection after cover-up

A nuclear power plant operator agreed on Thursday to shut down a reactor in central Japan for inspections after it acknowledged a cover-up of an uncontrollable nuclear chain reaction eight years ago, raising concerns about nuclear safety.

Hokuriku Electric Power Co. failed to report to authorities that the self-sustaining nuclear chain reaction occurred for 15 minutes at the No.1 reactor of Shika Nuclear Power Plant in Ishikawa prefecture in June 1999, the company said in a statement. Power companies are required by law to report such an incident to the government.

Three control rods fell by accident during preparations for a checkup, which caused the reaction, according to the company statement.

The company reported the accident to authorities Thursday following a government order late last year for power companies across Japan to conduct inspections following a spate of data cover-ups.

No radiation escaped from the plant and there were no injuries from the accident, according to Toshiyuki Kadono, an official of the Nuclear and Industrial Safety Agency, a safety watchdog under the Ministry of Economy, Industry and Trade.

The agency urged the company to shut down the reactor as soon as possible for safety checkups, and the power company agreed to do so, Kadono said.

"We cannot forgive a cover-up like this," Prime Minister Shinzo Abe told reporters. "We must ensure safety for nuclear power," he said.

The revelation follows similar cover-up cases by the nation's power companies earlier this month involving Tokyo Electric Power Co. and Tohoku Electric Power Co.

In November, the agency ordered all power companies in Japan to conduct investigations if there have been any data cover-ups or other problems. Companies have until March 31 to report to the agency.

Resource-poor Japan depends on nuclear power plants for a third of its energy needs and aims to raise that to nearly 40 percent by 2010.

But Japanese public has grown increasingly wary of the nuclear power industry following a series of safety problems, shutdowns and cover-ups.

In August 2004, five workers at Mihama Nuclear Power Plant in western Japan were killed and six others were injured after a corroded pipe ruptured and sprayed plant workers with boiling water and steam. The accident was the nation's worst at a nuclear facility.