Nuclear mattersBreakthrough: New nuclear fusion-fission hybrid reactor

Nuclear power is attractive because it does not contribute to global warming. There is one major problem with nuclear power, though: Nuclear power generation creates tons of highly toxic waste - waste which remains toxic for tens of thousand of years. As more waste accumulates, the issue of safe burying place for this waste becomes more pressing. Physicists at the University of Texas at Austin have designed a new system which, 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.

“We have created a way to use fusion to relatively inexpensively destroy the waste from nuclear fission,” says Mike Kotschenreuther, senior research scientist with the Institute for Fusion Studies (IFS) and Department of Physics. “Our waste destruction system, we believe, will allow nuclear power-a low carbon source of energy-to take its place in helping us combat global warming.”

Toxic nuclear waste is stored at sites around the United States. Debate surrounds the construction of a large-scale geological storage site at Yucca Mountain in Nevada, which many maintain is costly and dangerous. The storage capacity of Yucca Mountain, which is not expected to open until 2020, is set at 77,000 tons. The amount of nuclear waste generated by the U.S. will exceed this amount by 2010 (see 10 November 2008 HS Daily Wire).

The physicists’ new invention could drastically decrease the need for any additional or expanded geological repositories. “Most people cite nuclear waste as the main reason they oppose nuclear fission as a source of power,” says Swadesh Mahajan, senior research scientist. 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. Kotschenreuther, Mahajan and Prashant Valanju, of the IFS, and Erich Schneider of the Department of Mechanical Engineering report their new system for nuclear waste destruction in the journal Fusion Engineering and Design.

There are more than 100 fission reactors, called “light water reactors” (LWRs), producing power in the United States. The