Rig design development for in situ tritium release studies of EU reference ceramic breeders (ACB-TREND)

• Introduction to the ACB-TREND irradiation campaign. • Preparatory work for first neutron irradiation of highly Li-6 enriched ACB pebbles. • Development of rig design for in situ tritium release under neutron irradiation. • Mock-up test at irradiation temperatures of 400–900 °C. Advanced Ceramic Breeder (ACB) material is the European reference material for the ITER Test Blanket Module (TBM) and the DEMO Helium Cooled Pebble Bed (HCPB) blanket concept. The biphasic ACB material (Li 4 SiO 4 + Li 2 TiO 3 ) has been extensively characterised and evaluated in the past. However, the ACB's in situ performance under neutron irradiation still has to be investigated in detail. Therefore, the “Advanced Ceramic Breeder's in situ Tritium Release Experiment under Neutron irraDiation” (ACB-TREND) campaign was launched. For the irradiation taking place in the WWR-K research reactor, an irradiation rig (IR) design was developed that is presented here. The IR design needs to meet certain criteria that allows more fusion-like irradiation conditions. A cadmium shielding will be used to reduce the thermal neutrons to decrease the lithium burn-up significantly. The IR design was evaluated in a mock-up test. Small adaptions were made to completely cover the desired temperature range of 400–900 °C.