Experts criticize Japan’s nuclear safety standards


A panel of nuclear experts on Friday criticized Japan’s nuclear safety regime in its final report on the fatal accident in Tokai, Ibaraki Prefecture, in 1999.

The report by the panel led by Hideki Nariai, a professor emeritus at Tsukuba University, was submitted to the day’s meeting of the Atomic Energy Society of Japan held in Kyoto.

The nation’s worst radiation accident occurred Sept. 30, 1999, at a plant operated by nuclear fuel processor JCO Co., when two employees sidestepped safe operating procedures and, using buckets, poured too much uranium into a processing tank, triggering a fission chain reaction. It killed two JCO employees and exposed 663 others to radiation.

The deadliest nuclear plant accident, which didn’t involve radiation, occurred last month at Kansai Electric Power Co.’s Mihama plant in Fukui Prefecture. A corroded coolant water pipe that had not been checked since the reactor started up in 1976 burst, fatally scalding five workers with superheated steam.

The panel said communication errors and other aspects of the state response in the wake of the Tokai accident delayed effective countermeasures.

The government has reviewed regulations only on an ad-hoc basis after every nuclear accident since 1974, when a radiation leak was found on the nuclear-powered ship the Mutsu, the panel said.

The government needs to conduct a thorough review of the entire nuclear safety system to establish effective regulations and disaster prevention measures, it concluded.

The panel attributed the Tokai accident primarily to JCO’s failure to emphasize safety. But it also said the same problem was found with Tokyo Electric Power Co., which was found to have covered up reactor faults in 2002, prompting the shutdown of all 17 Tepco reactors.

It is essential that all those working in the nuclear industry realize the need for safety, the panel said.

In March 2003, the Mito District Court found JCO and six of its employees guilty of neglect. Kenzo Koshijima, then head of the nuclear plant in 1999, was sentenced to a suspended three-year prison term and fined 500,000 yen.