Monju nuclear reactor restarted

Japan's Monju fast-breeder reactor resumed operations last 6 May 2010 after 14 years and five months of suspension due to a sodium coolant leak and a resultant fire.

The prototype fast-breeder reactor in Tsuruga, Fukui Prefecture, restarted after plant staff pulled out rods that had prevented nuclear reaction.

The reactor, operated by the Japan Atomic Energy Agency, is expected to reach criticality, or the point when a nuclear chain reaction becomes self-sustaining.

The reactor is then to gradually raise its power output and begin full-fledged operations in the spring of 2013.

Unlike regular light-water reactors that run on uranium, a fast-breeder reactor uses an oxide mix of plutonium and uranium and is designed to generate more plutonium than it burns.

The restart of the so-called fast-breeder reactor marks the start of the government's second attempt to complete a long-delayed program aimed at using such reactors to reduce Japanese dependence on foreign oil.