WIPP AND PLUTONIUM DISPOSITION: END OF THE SPENT FUEL STANDARD?

The Department of Energy (DOE) is constructing a MOX fuel fabrication facility (MFFF) at the Savannah River Site (SRS) in order to convert at least 34 metric tons of surplus weapon-grade plutonium into fuel for light-water reactors, in accordance with the 2000 Plutonium Management and Disposition Agreement. In addition, DOE is currently evaluating approaches for the disposal of an additional 13.1 metric tons of surplus plutonium. One option DOE is considering for 6 metric tons of non-pit plutonium from this additional inventory is direct disposal at the Waste Isolation Pilot Plant (WIPP) in New Mexico. DOE has already disposed of several tons of plutonium residues in WIPP, so this proposal is nothing new. However, it does add new weight to concerns about the security of plutonium disposal at WIPP. One of the original objectives of plutonium disposition was to meet the \"spent fuel standard\" - to convert plutonium to a form from which it would be as difficult to separate as the plutonium in power reactor spent fuel. An integral feature of the spent fuel standard is the combination of plutonium with fission products so that separation would require use of a heavily shielded, remotely operated reprocessing plant. But the plutonium disposed of in WIPP was not mixed with fission products; instead, it was blended down to less than 10 weight percent with a non-radioactive diluent with classified characteristics known as \"stardust.\" DOE asserts that the arrangements for WIPP disposal \"provide protection from theft, diversion or future reuse akin to that afforded by the Spent Fuel Standard.\" However, given the classified aspects, it is difficult for the public to have confidence in these measures. In the early days of the plutonium disposition program, the spent fuel standard was developed in part because of the arguments that chemical mixtures alone would be insufficient to provide a sufficient barrier to separation of plutonium by either national or sub-national groups. What has changed since then? In order to have a broader debate about the most cost-effective means for plutonium disposition, a review of the purpose of the spent fuel standard is in order.