Fabrication and test of thin double-layered annulus metal hydride bed

Metal hydride bed for the storage and delivery of tritium is one of the essential components of tokamak fuel cycle. For the development of metal hydride bed, rapid delivery/recovery rate according to the tokamak operation scenario and accurate and rapid measurement of tritium inventory are major concerns. It has to store the tritium safely and satisfy the requirements of the facility where metal hydride bed is installed. To fulfill these requirements, we developed a thin double-layered annulus metal hydride bed. A mock-up with the capacity of 70 g tritium storage (1250 g ZrCo) is fabricated. Using hydrogen gas, the recovery and delivery performance during absorption or desorption process is tested. With 7.5 mole of H2 gas, the recovery rate of 72.5 Pa m3/s for 90% absorption and the delivery rate of 15.6 Pa m3/s for 90% desorption is achieved. The thermal insulation test and tritium inventory measurement test using in-bed gas flowing calorimetry are also performed. It took less than 24 h for the in-bed calorimetry procedure to reach the steady state.