TRITIUM TRAPPING BY METAL OXIDES IN RADIOACTIVE WASTES

摘要

Fusion facilities like ITER will produce radioactive waste during operation and dismantling phase. A part of those waste generated by this fusion machine are tritiated waste that have to be managed. One of the main issues in tritiated waste management is the confinement of tritium which presents a good ability to diffusion. One of the solutions is to trap the tritium degassed from waste directly in waste drums. In containers tritium is under gaseous form (HT and T2), tritiated water vapor (HTO and T2O) and some traces of organic bounded tritium species (OBT). As a hydrogen isotope, HT and T2 conversion in HTO and T2O is possible thanks to a reaction with a mix of metal oxides MnO2 and Ag2O (Chaudron et al., 1997) and tritiated water can be adsorbed on molecular sieve (Lefebvre et al., 2011). This paper aims at describing a methodology of developing a trapper, with an experimental part to obtain results on trapper efficiency and a modeling part to forecast impact of trapper on tritium release rate from waste drum.