USING THE SHIELD FOR THERMAL-ENERGY STORAGE IN PULSAR

The PULSAR pulsed tokamak power plant design utilizes the outboard shi eld for thermal energy storage to maintain full 1000 MW(e) output duri ng the dwell period of 200 s. Thermal energy resulting from direct nuc lear heating is accumulated in the shield during the 7200 s fusion pow er production phase. The maximum shield temperature may be much higher than that for the blanket because radiation damage is significantly r educed. During the dwell period, thermal power discharged from the shi eld and coolant temperature are simultaneously regulated by controllin g the coolant mass flow rate at the shield inlet. This is facilitated by throttled coolant bypass. Design concepts using helium and lithium coolant have been developed. Two-dimensional time-dependent thermal hy draulic calculations were performed to confirm performance capabilitie s required of the design concepts. The results indicate that the syste m design and performance can accommodate uncertainties in material lim its or the length of the dwell period.