Cross-Section Sensitivity Analysis of ²³⁵U and ²³⁸U Fission Rates Measured in a Graphite-Reflected Lithium Assembly

In a spherical lithium metal assembly with a graphite reflector, the changes in the fission rates of ²³⁵U and ²³⁸U due to changes in the cross-section sets of the constituent elements of the assembly are calculated. The results are discussed on the basis of experimental data. The fission rate of ²³⁵U is found to be most sensitive to changes in the cross-section set of ⁶Li in the lithium region, while in the graphite reflector, it is most sensitive to that of ¹²C. The fission rate of ²³⁸U is found to be more sensitive to changes in the cross-section sets of the elements in the stainless-steel structure rather than to those of lithium or graphite.