Technical bases for the use of CIF{sub 3} in the MSRE reactive gas removal project at Oak Ridge National Laboratory, Oak Ridge, Tennessee

Nearly impermeable, non-volatile deposits in the Molten Salt Reactor Experiment (MSRE) off-gas piping are impeding the removal of reactive gases from that system. The deposits almost certainly consist of reduced uranium fluorides or of uranium oxyfluorides. Treatment with ClF{sub 3} is a non-intrusive method capable of chemically converting these compounds back to UF{sub 6}, which can then be removed as a gas. This report discusses the technical bases for the use of ClF{sub 3} treatments in this system. A variety of issues are examined, and where the necessary information exists or has been developed, the resolution discussed. The more important of these issues include the efficacy of ClF{sub 3} at deposit removal under the conditions imposed by the MSRE system, materials compatibility of ClF{sub 3} and its reaction products, and operational differences in the Reactive Gas Removal System imposed by the presence of ClF{sub 3} and its products