Design and analysis of mixed bed solid breeder blanket with titanium berrylide as neutron multiplier

• Published in: Applied thermal engineering 2024-12, Vol.257, p.124375, Article 124375
• Main Authors: Sharma, Deepak, Chaudhuri, Paritosh, Swami, H.L., Abhangi, Mitul R., Bhattacharya, S.
• Format: Article
• Language: English
• Subjects: Be12Ti; Blanket; CFD; Flow; Thermal; Tritium
• ISSN: 1359-4311
• DOI: 10.1016/j.applthermaleng.2024.124375

•Proposed modification in design concept of Indian Solid breeder Blanket for fusion reactors replacing Be with titanium berrylide as neutron multiplier.•Separate breeder and multiplier pebble bed replaced with mixed bed and introduction of cooling tubes instead of plates.•Reduction in structural material increased volume of functional material and hence improved tritium production.•Thermo-hydraulics analysis of breeding unit performed for designing cooling tubes.•Flow distribution, thermal analysis and design optimization of blanket using CFD. Solid Breeder blankets are promising candidates being proposed worldwide as a source of tritium production and heat extraction in a fusion reactor. In many of these concepts including the Indian HCSB (Helium Cooled Solid Breeder) concept, Lithium meta- titanate (Li2TiO3) pebbles are used as tritium breeder whereas beryllium (Be) also in pebble form is used as neutron multiplier for increasing the tritium breeding ratio. The paper proposes replacing Be with titanium berrylide (Be12Ti) in the present blanket concept, its design modification, optimization and thermal hydraulics to accommodate the new material. Be12Ti shows effective performance compared to Be regarding high temperature operation, irradiation effects, tritium retention, swelling etc. The similar limiting temperatures for Li2TiO3 and Be12Ti complemented by lower swelling in Be12Ti makes it possible for these two materials to be used in mixed pebble bed form which in the case of the present concept is not feasible. The paper investigates cooling tube concept instead of plates by replacing the separate zones of breeder and neutron multiplier with a mixed pebble bed of Li2TiO3 and Be12Ti which resulted in an increase of 13 % by volume of functional material compared to the present concept with same size of blanket. The calculated TPR (Tritium production Rate) for the proposed concept is 78 mg per full power day compared to 62.4 mg in the present concept for the same blanket size which shows that TBR can be improved through design modifications in case of Be12Ti. The paper discusses details of blanket thermal –hydraulics, flow distribution in cooling tubes from blanket manifolds and also the neutronic analysis of the modified concept. ANSYS thermal and ANSYS CFX simulation tools are used for the finite element and CFD analysis. The results show that temperatures are within the operating limits with some design modifications. The new concept features easy desi