Japan strains to fix a another reactor damaged before quake

Fast Breeder Reactor Monju in Japan – Wiki Image

Hiroko Tabuchi
The New York Times

TSURUGA, Japan — Three hundred miles southwest of Fukushima, at a nuclear reactor perched on the slopes of this rustic peninsula, engineers are engaged in another precarious struggle.

The Monju prototype fast-breeder reactor — a long-troubled national project — has been in a precarious state of shutdown since a 3.3-ton device crashed into the reactor’s inner vessel, cutting off access to the plutonium and uranium fuel rods at its core.

Engineers have tried in vain since the accident last August to recover the device, which appears to have gotten stuck. They will make another attempt as early as next week.

But critics warn that the recovery process is fraught with dangers because the plant uses large quantities of liquid sodium, a highly flammable substance, to cool the nuclear fuel.

The Monju reactor, which forms the cornerstone of a national project by resource-poor Japan to reuse and eventually produce nuclear fuel, shows the tensions between the scale of Japan’s nuclear ambitions and the risks.

The plant, a $12 billion project, has a history of safety lapses. It was shuttered for 14 years after a devastating fire in 1995, one of Japan’s most serious nuclear accidents before the crisis this year at the Fukushima Daiichi Nuclear Power Station. Prefecture and city officials found that the operator had tampered with video images of the fire to hide the scale of the disaster. A top manager at the plant recently committed suicide, on the day that Japan’s atomic energy agency announced the cost of efforts to recover the device. And, like several other nuclear reactors, Monju lies on an active fault.

Even if the device can be removed, restarting the reactor will be risky, given its safety record and its use of highly toxic plutonium as fuel, said Hideyuki Ban, co-director of the Citizens’ Nuclear Information Center, a nuclear watchdog, and a member of an advisory government committee on Japan’s long-term nuclear energy policy. The plant is 60 miles from Kyoto, a city of 1.5 million people, and the fast-breeder design of the reactor makes it more prone to Chernobyl-type runaway reactions in the case of a severe accident, critics say.

“Let’s say they make this fix, which is very complicated,” Mr. Ban said. “The rest of the reactor remains highly dangerous. And an accident at Monju would have catastrophic consequences beyond what we are seeing at Fukushima.”

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