Japanese Prime Minister Keizo Obuchi, meanwhile, said he believed that the government should review safety measures for nuclear facilities to prevent a repeat of Thursday's accident.

``While reflecting on the accident, I believe the government has to review safety measures for nuclear power generation,'' Obuchi told the visiting governor of Ibaraki prefecture where the accident at a uranium processing plant took place. ``I have instructed the government ministries and agencies to work on measures to prevent the recurrence of the accident and enhance their crisis management,'' he said.

The move follows growing public criticism of the central government for lax supervision that many consider a big factor in Thursday's accident in Tokaimura, about 140 km northeast of Tokyo.

The Science and Technology agency, incharge of the nation's nuclear fuel policy, said it would inspect later this week scores of facilities handling nuclear fuel across the country to ensure they were ``properly'' operating.

``This is the step we are going to take to doubly make sure that accidents like what happened in Tokaimura will not occur in the future,'' an agency official told Reuters.

Critics charge that the agency could be held responsible for failing to ensure the operator of the Tokaimura uranium processing plant was enforcing proper safety procedures to prevent the accident.

Fifty-five people, mainly plant workers and emergency personnel who responded to the accident, were exposed to the radiation. Three remained in serious condition with some experts saying their chances of survival were slim.

Japan's ministry of international trade and industries also said it would carry out safety checks on all of the nation's 51 nuclear reactors that supply some 37 percent of the nation's electricity needs.