Thermal Analysis of a Solid Breeder TBM Under ITER Operational Conditions

The Quarter Port Submodule (QPS) was proposed as a Solid Breeder (SB) Test Blanket Module under the US program of the SB blankets. The QPS features layer configuration, in its left half, where the SB pebble beds are parallel to the first wall and edge-on configuration, in its right half, where the SB pebble beds are perpendicular to the first wall. The objective of this study is to investigate: (i) the QPS thermal profile under steady state conditions and ITER transient loads, and (ii) the impact of the interface conductance h on the QPS thermal profile. In addition the effect of lack of contact, at the SB pebbles/structure interface, on the QPS thermal profile is presented. The results of the steady state cases showed that h has a significant impact on the QPS thermal profile. The QPS transient analysis provided results on: (i) QPS thermal profile under a pulse length of 400s, (ii) burning time required for reaching the equilibrium temperatures, and (iii) time needed to cool the QPS. In the cases of lack of contact, the maximum temperature of the SB pebble beds exceeded the SB temperature limit, which may cause sintering of the pebbles and consequently inhibit the tritium release.