UWFDM-1372 Need for Online Adjustment of Tritium Bred in Blanket and Implications for ARIES Power Plants

For many researchers involved in fusion power plant development, the issue of tritium selfsufficiency is of particular concern because of the danger of placing the plant fuelling at risk. The tritium (T) bred in the blanket should be estimated fairly accurately as an uncertainty as small as 1% translates into 1-2 kg of T per FPY for 2-3 GW fusion power. This has a significant impact that is important not only for a shortage of T, but also for a surplus of T. The real question is not whether any blanket design could eliminate the danger of a T shortage or surplus – it should – but whether it offers a practical solution for breeding adjustment (up or down) during plant operation in order to precisely control the narrow T operating window. To mitigate concerns about T fuelling, it is less risky to produce more T during operation with the understanding that an online adjustment of the breeding level is necessary. This adjustment is feasible for power plants employing liquid breeders through fine-tuning of the Li enrichment while difficult to envision for solid breeder blankets.