RADIATION-DAMAGE IN LIQUID-PROTECTED FIRST-WALL MATERIALS FOR IFE-REACTORS

Material damage through displacements per atom (DPA) and helium gas pr oduction, as well as the tritium breeding and energy absorption in an IFE (Inertial Fusion Energy) reactor chamber have been investigated wi th variable coolant zone thickness using different liquids. Examples a re given for HYLIFE-II (an IFE reactor design) energy conversion chamb ers using Flibe (Li2BeF4), natural lithium and Li17Pb83 eutectic as bo th coolant and wall protection. To achieve a useful energy density for energy conversion purposes with sufficient tritium breeding (TBR = 1. 1), material protection (DPA < 100 and He < 500 appm in 30 years of op eration) and shallow burial criteria, coolant zone thickness values ar e found to be 56 cm for Flibe, 160 cm for natural lithium and 170 cm f or Li17Pb83 with SS-304 as structural material. Material damage invest igations are extended to structural materials made of SiC and graphite for the same blanket. DPA values and He production rates in graphite turn out to be comparable to those in SS-304. However, they are higher in SiC, as compared to SS-304 and graphite.