Separation of radionuclides from nuclear waste by a plasma mass filter

Summary form only given, as follows. The tank waste at the Hanford Nuclear Reservation is the worst environmental cleanup problem in the United States. Separation of radionuclides from the waste has proved intractable by standard chemical means. Low pressure plasmas offer a way around this problem since the waste molecules are fully dissociated and consequently the rate of chemical reactions is small. Archimedes Technology Group in San Diego, CA is developing a patented new plasma technology that separates the radionuclides from the waste by mass. This technique has the potential to greatly reduce the amount of waste since 99.9% of the radioactivity comes from atoms above mass 89 while 95% of the total atoms are below mass 60. The technique is fundamentally different than the plasma centrifuge concept developed for isotope separation. Rather than relying on an equilibrium mass distribution, it works by establishing a "low-pass filter". Ions heavier than a certain "cut-off mass" are expelled from the plasma. This talk will focus on the plasma physics bases for establishing the cut-off mass and the fundamental constraints on the plasma parameters.