Passive Decay Heat Removal in Liquid-Metal Cooled Reactors

The response of liquid metal self-cooled fusion reactors to a loss of flow accident (LOFA) has been investigated. Coolant temperature rise through the blanket was determined for conditions where decay heat is removed solely by natural convection. It was found that lithium-lead (Li17-Pb83) coolant provides sufficient natural convection to remove decay heat in both tokamak and TMR designs with a reasonable temperature rise. With pure lithium coolant, however, decay heat removal by natural convection proves difficult without excessive temperature rise. A transient analysis reveals that there should be ample time to respond to a LOFA if the plasma is shut down promptly.