FYI, there is an interesting webcast about uranium enrichment - particularly centrifuges - at http://digitalmedia.utk.edu:8080/ramgen/11424.rm

The info is posted at http://www.engr.utk.edu/nuclear/colloquia/Archive/

The American Centrifuge: The Future of Uranium Enrichment

Mr. Ronald F. Green

Senior Vice President, U.S. Enrichment Corporation, Inc., Bethesda, MD

Presented January 12, 2005

......its got a teriffic punch line at the end, about the megatons-to-megawatts program, BTW, which USEC is also involved in.