Japan officially re-opened a contested fast breeder nuclear reactor May 6, a move that worries citizens and scientists, according to the Japan Times.
Fast breeder reactors are designed to produce more fuel than they consume.
With the Monju Protoype reactor, the Japanese government hopes to reduce its use of foreign oil, according to the Times.
The reactor was first opened in August 1995 but was shut down four months later after a sodium leak that had been covered up by plant operators, resulted in a public outcry.
Antinuclear activists say that the Japan Atomic Energy Agency, which runs the plant, has not met safety precautions. Monju is located near two seismic fault lines and it is not certain how the reactor will withstand earthquakes.