Title: Determination of /sup 232/U daughter products released from HTGR fuel during refabrication. Part 2
Abstract: During the.heat treatment step of High Temperature Gas-Cooled Reactor (HTGR) fuel beads, the 233 U-loaded f ue ] beads are exposed to temperatures as high as 1700 C C. 9 $ince 233y f ue ] beads unavoid ably contain a small percentage of 232 U, decay products of 232 U might be released during the heat treatment step.To avoid shield ing requirements, experiments were conducted using 232jh-loaded fuel beads rather than 232 U-loaded fuel beads.Decay products of 232 U and 232 Th are the same after " 3 Th.Experimental data were obtained by monitoring the 583 and 2614 keV gamma emissions of 2 0°T1.Computer simulations of the decay pro cess and experimental data were used to infer what relative amount of the daughter products was removed.The carbonization step (300 -500°C) has an effect on the loss of daughter products in the conversion step.Using uncarbonized fuel beads, approximately 50% of 2 ™Rn was removed at 300°C and approxi mately 20% of 220 Rn was removed at 200 C C. At most, 5% of 22D Rn was removed from uncarbonized beads at 25°C.Marginal 22 ^Rn loss was »H<: At. iann°f_ Q?I 21 detected at 100°C using pre-cirbonized beads 70-90% 212 6i, and 0% 224 Ra losse 212 Pb, 80-100% 212 Bi 'i\\ 21 100% *'«Pb, 80-100% 1800°C, 100% 212 Pb, 80-100% At 1400°C, 92% "^Pb, were observed.At 1600°C, 100% nd 3-7% 224 Ra losses were observed.At 1750°C, Bi, and"62% 224 Ra losses were observed.At 'lis;2 Bi, and 86% * 2 ^Ra losses were observed.