European helium cooled pebble bed blanket: Design of blanket: module to be tested in ITER

Abstract

The helium-cooled pebble bed (HCPB) blanket for a fusion DEMO reactor is based on the use of separate small lithium orthosilicate and beryllium pebble beds placed between radial toroidal cooling plates. The cooling is provided by helium at 8 MPa. The tritium produced in the pebble beds is purged by the flow of helium at 0.1 MPa. The structural material is martensitic steel. It is foreseen, after extensive R&D, to test in ITER a blanket module based on the HCPB design which is one of the two European proposals for the ITER Test Blanket Programme. To facilitate the handling operations, the blanket test module (BTM) is bolted to a surrounding water cooled frame fixed to the ITER shield blanket back plate. For the design of the test module, 3D Monte Carlo neutronic calculations and thermo-hydraulic and stress analyses for the operation during the basic performance phase (BPP) and during the extended performance phase (EPP) of ITER have been performed. The behaviour of the test modules during LOCA, LOFA and electromagnetic transients has been investigated. Conceptual designs of the required ancillary loops have been performed.