The long-term problem of “peaceful” plutonium

In the early decades of the atomic age, using the enormous energy in plutonium atoms for the peaceful generation of electricity became a multibillion-dollar quest that shaped US energy research and development policies. In 1970, Glenn Seaborg, the discoverer of plutonium and then-chairman of the US Atomic Energy Commission, declared that “within the lifespan of a single generation this newcomer plutonium born on a humble research budget and cradled in a cigar box will have become the energy giant of the future.”

Seaborg and the AEC projected the growth of nuclear-powered electricity would be so great that global supplies of uranium would be exhausted, paving the way for the recovery of plutonium from spent power reactor fuel for the next generation of power plants, which would dot the global landscape. Seaborg estimated by the end of the 20^th century, power reactors would  cumulatively produce 1,600 metric tons of plutonium with the potential to fuel half the nation’s electrical generation.

With this much plutonium flowing through commerce, the possibility that some of it might be diverted for nefarious purposes was not lost on prominent members of the US national security establishment. Losing track of just .0003 percent of the amount estimated by Seaborg would be enough to fuel a Nakasaki-sized nuclear weapon. Opposition by America’s Cold War nuclear policy makers was galvanized following India’s nuclear weapons test in May 1974. India’s bomb was fueled with plutonium produced from “peaceful atom” technology provided by the United States and  Canada. Albert Wohlstetter, a prominent American nuclear strategist and cold warrior, concluded that the U.S. pursuit of plutonium fuel could result in “life in an armed nuclear crowd

In response to the Indian test, the Carter administration banned chemical separation of plutonium from irradiated power reactor fuel—the process known as reprocessing—in 1977.

The US “plutonium economy” was also dealt a major blow by the 1982 Nuclear Waste Policy Act, which underscored the Carter Administration’s non-proliferation goals by giving priority to the direct geologic disposal of spent nuclear fuel, without reprocessing. President Reagan lifted the ban and President George W. Bush attempted to revive reprocessing, but those efforts collapsed in the United States under the weight of the expense, safety problems, and security risks of a widespread reprocessing program. Since the early 1980s, the US Congress has shown little appetite for resuming support of the commercial development of plutonium as a reactor fuel.

As of the end of 2018, US spent power reactor fuel contained about 824 metric tons of plutonium—the world’s largest single inventory of that element. The intense radiation of used nuclear fuel assemblies makes them essentially impervious to theft or diversion to weapons use. But after 300 years, a great deal of the radiation barrier protecting them will have decayed. The Nuclear Waste Policy Act lays out a process for geologically directly disposing of spent nuclear power fuel in an underground repository, rather than allowing plutonium to be separated from it. Reprocessing “would incur a substantial cost penalty,” concluded an industry study in 2006 and would be far more costly more expensive than direct spent nuclear fuel disposal. “[Re]processing would have to be accompanied by deployment of fast reactor plants. But demonstration fast reactor plants to-date has mostly proved expensive and unreliable, which aggravates [re]processing’s economic handicap.”

But nearly 40 years later, geologic disposal of spent power reactor fuel remains uncertain after President Obama’s cancellation in 2010 of the proposed Yucca Mountain repository site in Nevada.

By the mid-21^st century, the amount of plutonium in spent power reactor fuel could grow to more than 1,400 metric tons. The 300-year clock measuring off the time until the radiation barrier diminishes to the point that this vast amount of weapons-usable plutonium can be readily obtained is still ticking.