Measured average reaction cross sections for the Big Ten central flux spectrum are given together with calculated values based on the US Evaluated Nuclear Data File ENDF/B-IV. Central reactivity coefficients for /sup 233/U, /sup 235/U, /sup 239/Pu, /sup 6/Li, and /sup 10/B are given to check consistency of bias between measured and calculated reaction cross sections for these isotopes. Spectral indexes for the Los Alamos /sup 233/U, /sup 235/U, and /sup 239/Pu metal critical assemblies are updated, utilizing the Big Ten measurements and interassembly calibrations, and their implications for inelastic scattering are reiterated
