Court rules Monju fast reactor unsafe

The decision may be the death knell for the government's nuclear fuel strategy.

KANAZAWA-In an unprecedented decision that could throw the nation's nuclear power policy into disarray, a high court ruled Monday that safety standards are inadequate at the prototype fast breeder-reactor Monju in Tsuruga, Fukui Prefecture.

In siding with residents and their long-running suit, the court hammered another nail in the coffin of the mothballed nuclear facility that has been off-line since 1995.

In handing down the decision, Presiding Judge Kazuo Kawasaki of the Kanazawa branch of the Nagoya High Court said, ``With current equipment, there can be no denying the specific danger of radioactive materials leaking to the external environment in the event of a sodium leak.''

The ruling, the first time a court has decided in favor of residents seeking to overturn construction approval of nuclear reactors or an injunction on the construction and operation of nuclear reactors, is a severe blow to the government.

The Fukui residents filed their first suit in 1985. In December 1995, a sodium leak at the Monju reactor shut down operations.

The likelihood of getting Monju up and running was already dim, and Monday's ruling can only make matters worse for the Japan Nuclear Cycle Development Institute (JNC), which oversees the reactor.

While the central government is expected to appeal Monday's decision to the Supreme Court, the future of the nation's nuclear power policy appears murky.

Atsuko Toyama, minister of science and technology, expressed disappointment at the court's decision.

``As a nation lacking in energy resources, it is important for Japan to establish fast breeder-reactor nuclear cycle technology to maintain a stable long-term supply of energy,'' she said. ``Monju is a core facility for research and development in that area and its importance will not change at all.''

Judge Kawasaki, however, faulted the central government for failing to install an adequate safety inspection system.

``There are errors and defects in the safety inspection regime that cannot be overlooked,'' he said.

More ominously, he said the Monju reactor had the potential for a reactor core meltdown. Monday's decision overturned a March 2000 decision by the Fukui District Court which ruled against the plaintiffs.

Major points of contention in the high court case centered around nuclear reactor safety inspections.

Issues considered included the 1995 sodium leak; the possibility of a major accident, for example, pipes bursting simultaneously within the steam generator; and the ability of the reactor to withstand seismic activity.

The plaintiffs argued that original safety inspection standards were illegal because they did not envision a possible hydrogen explosion caused by leaking sodium. In this scenario, the sodium would eat through the 6-millimeter thick steel flooring starting a chemical reaction with the concrete underneath.

To bolster their case, the plaintiffs cited a government application, filed after the district court ruling, for improvements to the reactor.

Proposed design changes included equipment to quickly drain leaking sodium as well as measures to prevent pipes carrying heated sodium from bursting simultaneously.(IHT/Asahi: January 28,2003)