According to a new report, scientists at the University of Texas at Austin have designed a new system that, when fully developed, would use fusion to eliminate most of the transuranic waste produced by nuclear power plants. The invention could help combat global warming by making nuclear power cleaner and thus a more viable replacement of carbon-heavy energy sources, such as coal.
The scientists propose destroying the waste using a fusion-fission hybrid reactor, the centerpiece of which is a high power Compact Fusion Neutron Source (CFNS) made possible by a crucial invention. The CFNS would provide abundant neutrons through fusion to a surrounding fission blanket that uses transuranic waste as nuclear fuel. The fusion-produced neutrons augment the fission reaction, imparting efficiency and stability to the waste incineration process.
The scientists' waste destruction system would work in two major steps.
First, 75 percent of the original reactor waste is destroyed in standard, relatively inexpensive light water reactors (LWRs). This step produces energy, but it does not destroy highly radiotoxic, transuranic, long-lived waste, what the scientists call "sludge."
In the second step, the sludge would be destroyed in a CFNS-based fusion-fission hybrid. The hybrid's potential lies in its ability to burn this hazardous sludge, which cannot be stably burnt in conventional systems.
One hybrid would be needed to destroy the waste produced by 10 to 15 LWRs.
The process would ultimately reduce the transuranic waste from the original fission reactors by up to 99 percent. Burning that waste also produces energy.
[Fusion–Fission Transmutation Scheme—Efficient destruction of nuclear waste, Fusion Engineering and Design Volume 84, Issue 1, January 2009, Pages 83-88]
Dr. Gopal Rao
Web Science Editor
Editor, Meeting Scene
Materials Research Society (MRS)