Synroc for Immobilising Excess Weapons Plutonium

Abstract

AbstractThe immobilisation of excess weapons plutonium into Synroc can meet all of the important criteria discussed by the U.S. National Academy of Sciences (NAS)(1)for disposal, if the disposal option is pursued rather than options that exploit the energy value of plutonium. This paper summarises the relevant background of Pu incorporation into Synroc, the durability of Pu-containing Synroc and outlines a process flowsheet based on the experience with the 10 kg/hr Synroc Demonstration Plant at ANSTO. The extensive solid solubility of Pu in Synroc, coupled with a very high degree of chemical durability under hydrothermal conditions, makes Synroc ideal as a waste matrix for Pu disposal in deep boreholes to minimise diversion and proliferation risks.