With the cost of turning 34 metric tons of surplus, weapons-grade plutonium into reactor fuel rising, a cheaper burial option is one of the alternatives under consideration.

Despite a general consensus that highly radioactive spent nuclear fuel should be stored in underground repositories, finding appropriate sites for such repositories has been so politically fraught that none exist worldwide, panelists at a AAAS-organized Capitol Hill briefing explained.

With about 240,000 metric tons of spent nuclear fuel in storage at the end of 2009 and approximately 10,500 tons of spent fuel generated annually, the need for a long-term solution for spent fuel storage is growing quickly.

No new nuclear power plants have been built in the United States since the 1970s, and yet, in that span of time, reactor technology has made considerable strides. For nuclear engineer Eric Loewen, the progress is embodied in a reactor design called PRISM, short for Power Reactor Innovative Small Module. The reactor would be compact and easy to mass-produce, and where the problem of radioactive waste has long weighed against new reactor construction, PRISM would actually run on nuclear waste.