Tritium measurement techniques for a metal tritide bed in hydrogen isotope storage and delivery system

Tritium accounting technologies have been continuously studied and developed for an SDS bed. The pressure, volume, temperature, and concentration method (PVT-c) is a standard tritium accounting procedure. It requires tritium in a gaseous form. It is necessary to heat the SDS bed to keep the tritium in a gaseous form. The tritium release and penetration probabilities might increase if the tritium is kept in a gaseous form. It has been applied to some tritium facilities, providing robust and reasonable results. However, it is difficult to apply typical calorimetry into the SDS bed for ITER because the technique requires an additional SDS bed attaching/detaching system and a thermal measurement facility with large thermal insulation. In this paper, as the tritium measurement techniques without any heating processes, static calorimetry, flowing gas calorimetry, and a radiation measurement were introduced and evaluated to employ into the SDS bed. In addition, our progress on tritium accountability and thermal-hydraulic code application into the SDS is presented. We designed and fabricated an SDS bed to measure the amount of tritium using two calorimetry techniques. The tritium accountability tests are progressing. The calorimetry techniques are thought to be useful and give a reasonable value based on our test results. We were unable to find a good radiation measurement method because the physicochemical conditions inside the SDS bed are quite harsh and most of the radiation measurement devices need a sampling of radioactive nuclides in the form of various phases.