Yucca Mountain is Dead! Long Live Fast Breeders?!
The Obama administration's new budget essentially kills the Yucca mountain radioactive waste repository project. The original goal was to build a facility in which to safely store high level radioactive wastes from America's 104 nuclear power reactors. Anti-nuke environmentalist ideologues have long opposed the Yucca mountain facility. Their goal is make nuclear power impractical by blocking the waste disposal stream. But perhaps they've outfoxed themselves.
The new budget promises that the Obama administration will "devise a new strategy toward nuclear waste disposal." Well, there is already a strategy that will work, using fast breeder reactors to burn up waste and simultaneously produce more reactor fuel. At the nuclearinfo site, a group of Australian physicists explains:
Natural Uranium consists of 0.7% 235U and 99.3% 238U. All commercial Power reactors used in the world today utilize the 235U component in natural Uranium as the primary means of maintaining a chain reaction. The most troublesome component of nuclear waste are the tran-Uranic elements that occur when 238U captures a neutron and transmutes to 239Pu. Further neutron captures on this element lead to a buildup of long-lived transuranic nuclei. However 239Pu is also fertile and undergoes fission like 235U. Advanced reactor designs exploit this to convert the 238U to 239Pu. If the reactor avoids the slowing down, "thermalization" of neutrons, there are sufficient excess neutrons that it is possible to convert more 238U to 239Pu than 235U is consumed. These reactors use the unmoderated "fast" neutrons directly produced via the fission process.
Thus these reactors "breed" 239Pu from 238U and so produce more fuel than they consume. The use of fast-breeder technology makes it possible to increase the efficiency of Uranium use by over a factor of 50. It is then possible to exploit the vast quantities of depleted Uranium stockpiled around the world to generate electricity. In addition the excess neutrons can be used to transmute the long-lived transuranic waste from current Nuclear Power reactors to ever-heavier isotopes until they eventually fission. Thus these reactors can be used to "burn" the most troublesome component of nuclear waste.
And there's more—thorium breeder reactors:
Thorium is an element that is 3 times more abundant than Uranium on earth. It has a single stable isotope 232Th. In a nuclear reactor this isotope can capture a neutron and be converted to 233U. 233U undergoes fission like 235U and 239Pu. However when 233U fissions it releases more neutrons than either 235U or 239Pu. Consequently it is possible to to construct a breeder reactor that utilizes thermal neutrons to both generate energy and to breed 233U from Thorium given sufficient initial quantities of 233U mixed with 232Th.
A further advantage of Thorium breeders is that the amount of transuranic waste is vastly decreased compared to a Uranium or Plutonium based reactor.
If the Obama administration believes that it can persuade reactionary environmentalists into accepting thousands of miles of new high voltage power lines strung across the countryside, surely it will have no trouble talking them into fast breeder reactors.
Hat tip to Steve Skutnik.