Transmutation of Massive Loadings of Cesium-137 in the Blanket of a Controlled Thermonuclear Reactor

Abstract

From joint meeting of the American Nuclear Society and the Atomic lndustrial Forum and Nuclear Energy Exhibition; San Francisco, California, USA (11 Nov 1973). Calculations have been performed that indicate the possibility of reducing below ten years the effective half-life for transmutation of massive loadings of /sup 137/Cs placed in a CTR blanket. The blanket studied is a modification of the cylindrical standard blanket'' calculational benchmark, having 1 cm of Nb wall material followed by a 20 cm target zone, 70 cm of moderator and a 6 cm absorber of Li. The standard blanket'' source yielding a wall loading of 10 MW/m/sup 2/ of 14 MeV neutrons is assumed. Neutron production by (n,2n) reactions in a Be moderator is used to increase the thermal flux. For an 80% target zone loading of /sup 137/Cs, a transmutation rate of 290 kg per year per meter of CTR length is obtained, with a half-life (including radioactive decay) of 9.9 years. At this loading, the transmutation rate is roughly one percent of the length of a CTR blanket would balance the production rate in a fission reactor of the same power. (auth)