That additional level of transmutation might prove too costly, both in terms of getting the technology licensed to operate in the U.K. and in constructing the reactor itself. Such fast reactors are more expensive than even traditional reactors, such as Westinghouse's new AP-1000 under construction in China and the U.S., which are estimated to cost roughly $7 billion apiece. Conventional light-water reactors can also "consume" plutonium, if need be. "If I was going to try to get rid of 100 tons of plutonium, I'd burn it in a light-water reactor," Cochran says, by making it into the mixed oxide fuels. And "the cheapest thing to do is vitrify it [convert it to glass] and mix it with other nuclear waste."
Plus, the U.K. has a poor record in the past with its own experimental fast reactor designs—the Dounreay Fast Reactor and the Prototype Fast Reactor—including multiple sodium leaks. Dounreay also suffered an explosion at its dumping ground for used sodium coolant that may have contributed to radioactive particles from spent fuel turning up on nearby beaches. The Dounreay and Prototype cleanup and decommissioning continue today, despite both having been shut down for decades.
Originally, such fast reactors were developed to solve a problem that never panned out: scarcity in the global supply of uranium. The idea was to create fuel within the reactors themselves once fission began, in effect making more than they consumed. But, factoring in inflation, uranium prices remain the same today as they were at the dawn of the nuclear era. "Like all minerals, improvements in the efficiency of extraction and the ability to dig for deeper ores outpaces the depletion of the resource over 100 years or more," Cochran notes. "Economically, fast reactors are not competitive and they're never going to be competitive."
"We're not going to run out of uranium," Loewen admits. "Here's a solution for this stuff that's piled up."
Ultimately, however, the core problem may be that such new reactors don't eliminate the nuclear waste that has piled up so much as transmute it. Even with a fleet of such fast reactors, nations would nonetheless require an ultimate home for radioactive waste, one reason that a 2010 M.I.T. report on spent nuclear fuel dismissed such fast reactors. Or, as Cochran puts it: "If you want to get rid of milk, don't feed it to cows."