A law aimed at prevention and better handling of accidents at nuclear power facilities went into force Friday.

The law states that the central government must take the lead in dealing with nuclear accidents. Local governments in areas where nuclear power facilities are located have long been demanding such legislation.

The new law says the prime minister is responsible for declaring a state of emergency, setting up a crisis-management task force and requesting that Self-Defense Forces personnel be dispatched if deemed necessary in the event of a serious accident.

The Diet enacted the law in December, after Japan's worst nuclear power accident Sept. 30 in Tokai, Ibaraki Prefecture.

The law gives the prime minister power to decide whether to order evacuations or issue advisories for residents to stay indoors. It also requires operators of nuclear-related plants to set up disaster prevention bodies and report an accident to the authorities within 15 minutes.

The law requires the government to set up 21 "off-site centers" across the nation. At the centers, the central government, local governments and disaster prevention bodies will link up to help prevent any expansion of an accident.

Another law, also enacted in December and which revises earlier legislation, will come into force July 1.

It requires periodic inspections of nuclear fuel facilities, such as JCO Co.'s Tokai uranium processing plant. Regular safety checks are currently required only at nuclear power plants.