LEAK AT REACTOR IN JAPAN PUTS ENERGY PROGRAM IN JEOPARDY.

Byline: Andrew Pollack The New York Times

Two months after an accident at its prototype reactor, Japan's program to use plutonium to provide a virtually inexhaustible supply of energy is at a crossroads and could be in danger of collapse.

Even the most optimistic officials think it will take three years to restart the fast-breeder reactor, where the leak of dangerous sodium coolant occurred in December. Some other analysts think that the reactor, which is in the city of Tsuruga on the coast of the Sea of Japan, will never be activated again.

Japan has spent three decades developing fast-breeder reactors, which produce more nuclear fuel than they consume, in an effort to rescue itself from its near-total dependence on imported oil and uranium.

So intent has this resource-poor country been on achieving energy independence that it has stuck with the breeder, which uses deadly plutonium as fuel, even as the United States and most other industrialized countries have abandoned such reactors, judging that they contribute to the spread of nuclear weapons, are too technologically daunting and no longer make economic sense.

But the December accident, as well as a ham-handed attempt to cover it up, has undermined public confidence in the government's assurances of safety and brought into the open serious opposition in Japan itself to the vast and expensive project.

Nuclear proponents and opponents agree that this political damage will take longer to repair than the damage to the reactor itself, named Monju after the Buddhist divinity of wisdom.

"It's not an engineering but a social problem now," said Dr. Yoichi Fujiie, a member of the Atomic Energy Commission, which sets nuclear policy.

For project engineers, who have thought they were working in the national interest, the doubts of their countrymen have come as a severe shock.

"The social problem is so big, which we never thought of 20 to 30 years ago when we started designing Monju," Tadao Aoki, a mechanical engineer who has spent 23 years on the project, said as he led a visitor through the reactor recently as crews worked to clean up the mess from the leak.

Japan is not likely to pull the plug on the plutonium energy program outright. There is too much pride and investment for that. The government has not changed its long-term goal of developing breeders, arguing that the rapid growth of other countries in Asia will eventually exhaust the world's supply of oil and uranium, even if it takes longer than they once thought. And officials point out that virtually no radiation was released during the accident.

But the program could die from attrition, or be changed into a research project to preserve the accumulated technology.

"The usual way is to postpone and postpone and postpone until there is nothing left," said Dr. Jinzaburo Takagi, executive director of the Citizen's Nuclear Information Center, an anti-nuclear group. Indeed, in the two months since the Monju accident, delays have been announced in two other key pieces of the plutonium program.

Still, some officials say that once the furor from the accident dies down, the project could resume, since the Japanese public in general tends to go along with government plans. And since the target date for developing commercial breeders had already been postponed until 2030, a delay of a few years now will not be that serious.

Breeder reactors offer a self-sustaining source of energy. Even as they generate electricity, they produce more plutonium than they consume by converting some uranium in the fuel to plutonium.