Nuclear mattersNew reactor design solves waste, weapon proliferation problems
A new nuclear reactor design — called Traveling-Wave reactor — is noteworthy for three things: it comes from a privately funded research company, not the government; it would run on what is now waste, thus reducing dramatically the nuclear waste and weapon proliferation problems; and it could theoretically run for a couple of hundred years without refueling
The rising cost of oil — even if such costs dipped of late owing to the global economic slowdown — and worries about the environment have prompted a renewed interest in nuclear power generation. Nuclear power, however, has its own drawbacks. Opening the reactor periodically to refuel it is among the most cumbersome and expensive steps in running a nuclear plant. Removing the spent fuel from the reactor and reprocessing it in order to recover usable materials has the same drawbacks, and two more: the risks of nuclear-weapons proliferation and the problem of safely storing nuclear waste.
Technology Review’s Matt Wald writes that these problems may mostly be accepted as a given, but not by a group of researchers at Intellectual Ventures, an invention and investment company in Bellevue, Washington. Scientists there have come up with a design for a reactor that requires only a small amount of enriched fuel. The design is called a traveling-wave reactor. We note this: the traveling-wave reactor is the product of an outfit the hardly exists in the nuclear industry: a privately funded research company.
Wald writes that as it runs, the core in a traveling-wave reactor gradually converts nonfissile material into the fuel it needs. Nuclear reactors based on such designs “theoretically could run for a couple of hundred years” without refueling, says John Gilleland, manager of nuclear programs at Intellectual Ventures.
The beauty of the new design is that it would run on what is now waste. Conventional reactors use uranium-235, which splits easily to carry on a chain reaction but is scarce and expensive; it must be separated from the more common, nonfissile uranium-238 in special enrichment plants. The traveling-wave reactor needs only a thin layer of enriched U-235. Most of the core is U-238, millions of pounds of which are stockpiled around the world as leftovers from natural uranium after the U-235 has been scavenged. The design provides “the simplest possible fuel cycle,” says Charles Forsberg, executive director of the Nuclear Fuel Cycle Project at MIT, “and it requires only one uranium enrichment plant per planet.”
The idea is as simple as it is audacious: the reactor itself will convert the uranium-238 into a usable fuel, plutonium-239. The traveling-wave reactor produces plutonium and uses it at once, eliminating the possibility of its being diverted for weapons.
Wald notes that the traveling-wave idea dates to the early 1990s, but that Gilleland’s team is the first to develop a practical design. Intellectual Ventures has patented the technology, and is now in licensing discussions with reactor manufacturers. There are still some basic design issues to be worked out, but Gilleland thinks a commercial unit could be running by the early 2020s.
The commercial industry is focused on selling its first reactors in the United States in thirty years. “The designs it’s proposing,” writes Wald, “are essentially updates on the models operating today. Intellectual Ventures thinks that the traveling-wave design will have more appeal a bit further down the road, when a nuclear renaissance is fully under way and fuel supplies look tight. ‘We need a little excitement in the nuclear field,’ says Forsberg. ‘We have too many people working on 1/10th of 1 percent change.’”
