Preliminary results from a detritiation facility dedicated to soft housekeeping waste

Nuclear waste management has to be taken into account for fusion machine in tritium experimentations. Soft housekeeping waste is produced during both operating and dismantling phases and is contaminated by tritium under reduced (HT) and oxidized (HTO) forms. At CEA Cadarache, a lab-scaled facility has been built for soft housekeeping detritiation. The tritiated gas exhausted from the process described above is foreseen to be treated by a tubular Pd–Ag membrane reactor, for gaseous tritium recovery. Since this membrane reactor uses hydrogen as swamping gas the compatibility toward explosive hazard has to be taken into account. Then, this work presents a double objective. A first study is presented in order to identify the best conditions for the declassification of soft housekeeping waste, without tritium recovery. Experiments carried out at 120 °C are not efficient enough and do not allow one to choose the most efficient carrier gas. Some other tests are being currently performed at higher temperatures (150 °C). Moreover, due to safety issues, the use of air has to be avoided during membrane reactor implementation phase. Preliminary results obtained with hydrogen hazard-free carrier gases are also presented.

► The results of the first detritiation campaign of soft housekeeping are presented. ► 120 to 150 °C increasing temperature reveals a strong rise of the detritiation yield. ► Using Ar–2%O2 declassifies the sample from ILW to LLW (UK) in 18 h. ► Carrier gas – H2 explosive risk is assessed before membrane reactor implementation. ► The optimized conditions are Ar–2%O2 at 150 °C.