Plutonium, Nuclear Power, and Nuclear Weapons

Article excerpt

A new fuel cycle architecture for nuclear power would expand its potential to contribute to the future global energy economy and reduce its potential nuclear weapon proliferation risks.

Although nuclear power generates a significant portion of the electricity consumed in the United States and several other major industrial nations without producing any air pollution or greenhouse gases, its future is a matter of debate. Even though increased use of nuclear power could help meet the energy needs of developing economies, alleviate some pressing environmental problems, and provide insurance against disruption of fossil fuel supplies, prospects for the expansion of nuclear power are clouded by problems inherent in some of its current technologies and practices as well as by public perception of its risks. One example is what to do with the nuclear waste remaining after electricity generation. The discharged fuel that remains is highly radioactive and contains plutonium, which can be used to generate electricity or to produce nuclear weapons. In unsettled geopolitical circumstances, incentives for nuclear weapons proliferation could rise and spread, and the nuclear power fuel cycle could become a tempting source of plutonium for weapons. At the moment, the perceived risks of nuclear power are outweighing the prospective benefits.

One reason for the impasse in nuclear development is that proponents and critics both appear to assume that nuclear technologies, practices, and institutions will over the long term continue to look much as they do today. In contrast, we propose a new nuclear fuel cycle architecture that consumes plutonium in a "once-through" process. Use of this architecture could extract much of the energy value of the plutonium in discharged fuel, reduce the proliferation risks of the nuclear power fuel cycle, and substantially ease final disposition of residual radioactive waste.

The current problem

Most of the world's 400-plus nuclear power reactors use lightly enriched uranium fuel. After it is partially fissioned to produce energy, the used fuel discharged from the reactor contains plutonium and other long-lived and highly radioactive isotopes. Early in the nuclear era, recovering the substantial energy value remaining in the discharged fuel seemed essential to fulfilling the promise of nuclear energy as an essentially unlimited energy source. A leading proposal was to separate the plutonium and reprocess it into new fuel for reactors that in turn would create, through "breeding," even more plutonium fuel. This would extend the world's resources of fissionable fuel almost indefinitely. The remaining high-level radioactive waste - stripped of plutonium and uranium - would be permanently isolated in geologic repositories. It was widely assumed that this "closed cycle" architecture would be implemented everywhere.

In 1977, the United States abandoned this plan for two reasons. Reduced projections of demand for nuclear power indicated no need to reprocess plutonium into new fuel for a long time to come, and it was feared that if the closed cycle were widely implemented, the separated plutonium could be stolen or diverted for use in nuclear weapons. Instead, the United States adopted a "once-through" or "open cycle" architecture: discharged fuel, including its plutonium and uranium, would be sent directly to permanent geologic repositories. As the world leader in nuclear power production, the United States urged other nations to adopt the same plan. Sweden and some other countries eventually did, but most countries still plan, or retain the option, to reprocess spent fuel.

Current practices, whether open or closed cycle, lead to continuing accumulation of discharged fuel, which is often stored at the reactor sites and rarely placed in geologic isolation or reprocessed to recover plutonium. This accumulation has occurred in the United States because development of a permanent repository has been long delayed. …