01 May 2002 Yucca Mountain: A Simple Solution, by Gerald E. Marsh and George S. Stanford

Energy Undersecretary Robert Card has said that the Bush Administration will seek more money from Congress for research into ways to reduce the volume of spent nuclear fuel and cost of its disposal. The purpose would be to extend the life of the Yucca Mountain used nuclear fuel repository.

We have a simple answer for how to do this, and at the same time eliminate fears that radioactivity will leak from the repository.

The debate over Yucca Mountain has focused on its safety, particularly whether radiation could leak out over thousands of years. Never mind that there are already far more plutonium and fission products under the ground at the Nevada test site with no special containment, and posing no threat to people, than could ever be expected to leak through the confinement barriers at the Yucca Mountain repository.

Spent fuel should not be regarded as “waste” – it is a valuable energy resource. What we now have on hand still retains over 95 percent of its original energy. So our proposal has two simple steps. First, the current once-through, “throw-away” cycle for reactor fuel should be abandoned in favor reprocessing. Card has said that “the administration is on record as being willing to reopen the reprocessing issue.” It’s about time.

But that’s only the beginning. The current “thermal” type of reactor, in conjunction with the reprocessing method called “Purex,” can recycle the fuel two or three times. Although this reduces the volume of spent fuel accordingly, some 80 percent or more of its energy is still present.

However, this spent fuel – no longer usable in thermal reactors – makes great feed for advanced “fast” reactors, which can extract essentially all of the remaining energy. The second logical step, therefore, is to deploy fast reactors as soon as possible. They consume the long-lived radioactive isotopes, leaving only the real waste, whose radioactivity will fall to harmless levels in a few hundred years.

Now, Yucca Mountain becomes an interim repository.

But what about proliferation of nuclear weapons? The concern that reprocessing would lead to the spread of nuclear weapons has been the principal argument against reprocessing for years. It no longer holds. The United States will not contribute to proliferation by reprocessing its spent fuel. Indeed, Japan, England and France already do it – without contributing to proliferation.

The root of the problem lies in the fact that the present Purex process does produce pure plutonium, which must be safeguarded against theft. When fast reactors come into service, however, Purex can be phased out. It will be replaced by a “pyroprocessing” method that never produces pure plutonium.

Thus fast-reactor fuel is far more proliferation-resistant than today’s unreprocessed “spent” fuel. In both cases, extraction of plutonium would require further chemical processing. And in both cases, the resulting reactor-grade plutonium makes lousy bomb material. No nation spending the enormous amount of money for a nuclear weapons program would use reactor-grade plutonium. Everyone has easier options.

The time has come to reopen the issue of reprocessing and to introduce fast, inherently safe reactors – and make Yucca Mountain a temporary repository.

Gerald Marsh is a physicist who served with the U.S. START delegation and was a consultant to the Office of the Chief of Naval Operations on strategic nuclear policy and technology for many years. He is on the advisory board of The National Center for Public Policy Research. George Stanford is a nuclear reactor physicist, now retired from Argonne National Laboratory after a career of experimental work pertaining to power-reactor safety.