Helium cooled dual breeder blanket-preliminary design analyses of a candidate breeding blanket concept for near term Indian DEMO fusion reactor

Helium cooled dual breeder (HCDB) blanket concept is designed for Indian DEMO fusion reactor and it is made of two tritium breeder materials PbLi and Li2TiO3. It has helium as a coolant and the India specific RAFMS as a structural material. High-pressure helium first cools the plasma facing first-wall and after that, it will extract heat from PbLi and ceramic breeder. Since PbLi is not used as a coolant, it therefore circulates with a low flow rate. It will overcome the corrosion and MHD issues associated with high temperature and high flow rate of PbLi. The idea behind the concept is to make a design which can be made using the existing blanket materials, extract high-grade heat from the reactor and also enhance the availability. In HCDB blanket the role of neutron multiplier is done by PbLi, an alternative to the beryllium and it eliminates the issue associated with high toxic beryllium handling. It can be a potential tritium breeding blanket concept along with lead lithium cooled ceramic breeder (LLCB) and helium cooled ceramic breeder (HCCB) for near term Indian demonstration nuclear fusion power plant. In order to realize the HCDB conceptual design, preliminary estimations of tritium production, nuclear heat density have been carried out. The thermal behaviors of the HCDB blanket in Indian DEMO conditions have been also assessed and reported here. The assessment establishes the proof of HCDB blanket concept and supports it to be a good alternate blanket candidate for the Indian DEMO. The paper describes the HCDB concept along with analysis to verify the tritium self-sufficiency and materials temperature limits.