AN INVESTIGATION OF PLASMA-FACING COMPONENT MATERIAL EFFECTS ON TRITIUM REPROCESSING SYSTEMS

Plasma-facing component (PFC) materials directly affect tritium invent ories by the creation of a characteristic set of volatile impurities i nside the torus. Impurity creation processes were modeled and incorpor ated into the TritiUm Fusion Fuel cycLE dynamic Simulation, TRUFFLES, which simulates dynamic inventories in the tritium reprocessing system s.(1) These surface processes include net erosion and ''outgassing''. The estimated impurity outflow is coupled with the tritium reprocessin g models in TRUFFLES to calculate inventories. Be and C were evaluated as examples of plasma-facing materials. It is found that for C a cons traint limiting its net erosion rate is necessary in order to keep the tritium inventory in the cryopumps below a specified value. In contra st, Be may present no problem because of its non-production of volatil e species when eroded during reactor power operation. ''Outgassing'' o f H2O and the DT reflection coefficient were also investigated.