The Supreme Court of Japan has ruled that operations and development of an experimental fast breeder reactor can resume, a decade after a 1995 sodium coolant leak brought activity at the plant to a halt.

The ruling on the Monju reactor overturned a 2003 decision by the Nagoya High Court which had blocked government approval to build the plant.

The Supreme Court agreed that the safety screening of a government agency before the reactor’s construction was adequate saying, “The basic design of the plan, which was subject to safety screening, cannot be said in broad terms to have failed to be up to standards. Accidents could be prevented by designs in subsequent stages.”

The decision has reopened hopes of a ‘dream reactor’ that generates more fuel than it consumes and in response the Japan Nuclear Cycle Development Institute, which runs Monju, has started preparations for reinforcing areas of weakness that came to light when the leak occured. Construction work is now expected to accelerate with operations likely to resume in two years.

However, the economics of fast-breeder reactors are still questionable and in Japan, figures of as much as ¥2.8 trillion (€20.7 billion) have been reported as expenditure on the project. Even so, the government is expected to state that operations of fast-breeder reactors on a commercial basis will not start until 2050 or even later.

Government authorities confirmed in February that fast breeder development would continue and the government is expected to start looking into practical applications for the technology around 2015.