TOKYO: Japan's Kansai Electric Power Co said it would gradually shut down all of its nuclear reactors for safety checks starting Friday, four days after the deadliest nuclear industry accident in Japanese history.

Four workers were killed on Monday when super-hot non-radioactive steam gushed from a ruptured pipe at the company's Mihama nuclear plant, 320 kilometres west of Tokyo.

Japan's second-largest power utility, which has 11 reactors serving the heavily industrialized area around the city of Osaka, said no power shortages would result from the phased closures.

Kansai Electric said procedures would begin on Friday to shut down three units. The reactor where the accident occurred is already closed while two others are shut for regular maintenance.

The government of Fukui prefecture, the region where the plant is located, had asked for inspections to be conducted.

"Normally it would take about six weeks to carry out the checks," Kansai Electric spokesman Yonezo Tsujikura said at a news conference in Tokyo.

Kansai Electric said it would restart two oil-fired generators to help make up for lost nuclear production.

The company said the closures could cost it the equivalent of about US$90 million, depending on the duration.

Other power companies said they had no plans for shut-downs in the wake of the accident, which has heightened public mistrust of Japan's scandal-prone nuclear industry.

Industry Minister Shoichi Nakagawa said the government would do its utmost to ensure a stable supply of electricity.

Resource-poor Japan, which has 52 nuclear reactors, relies on atomic energy for over a third of its electricity needs.

Kansai Electric said on Tuesday the pipe that burst had not been inspected in 28 years and that it had not taken action even after being advised by a sub-contractor that it needed attention.

Police and officials from the national government's Nuclear and Industrial Safety Agency (NISA) were at the accident site on Friday gathering evidence that could lead to charges of negligence.

Media reports said Kansai Electric President Yosaku Fuji was likely to resign to take responsibility for the accident, but he told reporters: "I don't have that in mind for now."

The NISA, Japan's nuclear watchdog, has told power companies to check documentation to ensure inspections on pipes similar to the one that ruptured at Mihama have been carried out properly.

Similar checks have been ordered at non-nuclear power plants.

The NISA has told the companies to report back by August 18. If the records show they have neglected proper inspections plants may be required to shut down for checks.

Tokyo Electric Power Co, the world's biggest privately owned electric utility, denied a report that it would restart thermal power units in case its nuclear reactors needed to be taken out of service for safety checks.

Firing up thermal plants would increase demand for oil imports at a time when prices are at record highs and Japan is having one of the hottest summers in recent years.

(China Daily 08/14/2004 page7)