Four dead, seven injured in worst-ever accident at Japanese nuclear plant

TOKYO — A nonradioactive steam leak killed four people and injured seven Monday in the worst-ever accident at a Japanese nuclear power plant, officials said. Two workers were reported in critical condition.

No radiation leaked during the incident, and there was no need to evacuate the area around the city of Mihama, about 200 miles west of Tokyo, officials said. Mihama's population is about 11,500.

The four dead suffered severe burns, said Takanori Amimoto, at the nearby Fukui state government office. Two workers had critical injuries, while three were in serious condition and two had minor injuries, a police official said on condition of anonymity.

Prime Minister Junichiro Koizumi promised a thorough investigation of the accident, which follows a string of safety problems and attempted cover-ups at Japan's nuclear power plants, the source of 30 percent of Japan's electricity.

Worries about the safety of the country's 52 nuclear power plants have surged in recent years. A 1999 radiation leak northeast of Tokyo killed two workers and exposed hundreds to radiation, and three years later an investigation revealed that Tokyo Electric Power, the world's largest private utility, systematically lied about cracks in its reactors during the 1980s and 1990s.

Monday's leak was caused by a lack of cooling water in the reactor's turbine, said Kimihito Kawabata, a spokesman for the plant's operator, Kansai Electric Power. The steam was believed to be about 518 degrees.

After the accident, Kansai Electric officials found a hole in a condenser pipe, public broadcaster NHK reported. It did not elaborate on the size of the hole, which it said was believed to be the source of the problem.

Takahiro Seno, another spokesman for Kansai Electric Power, said the plant automatically shut down when steam began spewing from a leak in the turbine building area at the No. 3 nuclear reactor in Mihama. The No. 3 reactor started operations 1976.

The Mihama plant's two other reactors were operating normally, officials said.

Koizumi expressed regret at the deaths, telling reporters that "we must put all our effort into determining the cause of the accident and to ensuring safety." He added the government would respond "resolutely, after confirming the facts."

The United States had a similar accident at the Surry nuclear power plant in southern Virginia almost two decades ago when an 18-inch steel pipe burst and released 30,000 gallons of boiling water and steam, killing four people.

In Japan's fatal 1999 accident, a radiation leak at a fuel-reprocessing plant in Tokaimura, northeast of Tokyo, killed two workers and forced the evacuation of thousands of nearby residents. That accident was caused by two workers who tried to save time by mixing excessive amounts of uranium in buckets instead of using special mechanized tanks.

A string of safety problems and attempted cover-ups since then has undermined public faith in nuclear energy.

In the most recent before Monday, eight workers were exposed to low-level radiation at a power plant in February when they were accidentally sprayed with contaminated water. The doses were not considered dangerous.