Neutronics features of a high power density first wall/blanket with lithium evaporation cooling

Two-dimensional neutronics analysis has been performed for the Evaporation of Lithium and Vapor Extraction (EVOLVE) FW/blanket concept. The concept utilizes a refractory alloy (W-5Re) structure. The overall tritium breeding ratio is 1.37 at a lithium enrichment of 40% 6Li. The amount of nuclear heat deposited in the different regions was determined. About 76% of the total thermal energy is carried by the Li vapor to the heat exchanger. Since this heat is extracted at a temperature of 1200°C, a power conversion efficiency >60% can be achieved. No significant poloidal peaking is observed in the nuclear heating and damage profiles. Shielding requirements for the vacuum vessel and magnet are satisfied.