A helium cooled Li2O straight tube blanket design for cylindrical geometry

A tritium-breeding blanket design is investigated for a D-T Field-Reversed Configuration (FRC) scoping study. The thrust of our initial effort on the blanket has been to seek solutions as close to present-day technology as po ssible, and we have therefore focused on steel structure with helium coolan t. The simple FRC cylindrical geometry has allowed us reasonable success du e to the low FRC magnetic field and relatively easy maintenance. In this de sign the breeder is Li2O tubes. The design is modular with 10 modules each 2.5 m long. The inner radius of the first wall is 2.0 m and the FW/blanket/ shield thickness is about 2 m. The surface heat flux will be radiation domi nated, fairly uniform, and relatively low, because most of the charged part icles follow the magnetic flux tubes to the end walls. The neutron wall loa ding is 5 MW/m(2) In this design the surface heat flux equals 0.19 MW/m(2). The maximum Li2O tube temperature is 1003 degreesC. The helium exit temper ature from the heat exchanger is about 800 degreesC which allows a thermal efficiency of about 52%. The local tritium breeding ratio (TBR) equals 1.1 and is sufficient because in the FRC geometry the plasma has nearly full co verage. The helium pumping power is I MW. The coolant routing is optimized to limit the steel maximum temperature to 635 degreesC. The same concept wo uld be applicable to a spherical torus and spheromak.