- Photo by AP

TOKYO: Japan plans to limit the life of nuclear reactors to 40 years, allowing extensions only under stringent conditions, and to legally bind plant operators to prepare for severe accidents, the nation's nuclear crisis minister said on Friday.

The plan is part of a revision in a law on nuclear plant operations following the devastating March 11 earthquake and tsunami that triggered meltdowns at the Fukushima nuclear plant and the world's worst nuclear crisis since Chernobyl 25 years ago.

With strong public opposition to building new reactors, Japan is bound to reduce its reliance on nuclear energy which before the disaster covered about a third of its electricity needs.

How long the existing reactors will remain in operation will affect utilities' long-term business plans and determine how rapid will be Japan's shift away from nuclear power.

Environment and Nuclear Crisis Minister Goshi Hosono told a news conference exceptions from the 40-year limit would be rare.

“It will be quite hard to operate nuclear reactors beyond 40 years and we will implement stringent measures on nuclear reactor operations as safety is the first priority.”

The planned legislation, which the government plans to submit in the current session of parliament starting later this month, would mark the first time that Japan would legally the limit how long nuclear reactors would remain in operation.

Under the current system, nuclear plant operators can file for an extension of operation after 30 years and they usually get granted a 10-year extension, if they provide required maintenance.

It can be further extended and Japan's oldest existing nuclear reactor is Tsuruga No.1 reactor, operated by Japan Atomic Power, which went into service in March 1970 and has been granted an extension to operate for 50 years.