The March/April edition of MIT's Technology Review has an article on traveling-wave reactors, a new design for a nuclear reactor that only uses a small amount of highly enriched uranium, reducing the risk of weapons proliferation. In fact, it would use up much of the nuclear waste we now have. Most of the core of a traveling-wave reactor uses uranium-238, "millions of pounds of which are stockpiled around the world as leftovers after the uranium-235 has been scavenged." The way the reactor works is that it converts depleted uranium into a usable fuel, plutonium-239. A "wave" moves through the core at only a centimeter per year, transforming depleted uranium into plutonium, which then undergoes fission. Only a small amount of enriched uranium is used to get the reaction started.
The design does away with the need for refueling, which is the most expensive part of running a nuclear reactor. According to the designers, a reactor based on such a design could theoretically run for hundreds of years without refueling. The article quotes an outside party, the Executive Director of the Nuclear Fuel Cycle Project at MIT, saying that the design provides "the simplest possible fuel cycle, and it requires only one uranium enrichment plant per planet." The article did not address the question of how safe such a reactor would be compared to existing plants.
The design for the reactor was developed by a private company, Intellectual Ventures of Bellevue, WA.
Many reasonable Kossaks view any form of nuclear energy as anathema, but faced with the imminent dangers of global warming, I believe it is necessary to look at options like this.