Consistent set of transplutonium multigroup cross sections

A consistent set of multigroup neutron cross sections was developed for nuclides in the chain from 242Pu to 253Es. Evaluated multigroup cross section data were combined with experimental test measurements and production yields from long-term reactor irradiations in flux spectra of varying hardness. Thus 37- and 84-group data were derived in part from ENDF/B and existing Savannah River Laboratory evaluated libraries. Where differential data were lacking, resonance-region model calculations and integral cross section values were combined to form the multigroup data. The data were tested with the JOSHUA system to calculate the reactor environment as a function of time and to predict the concentration of actinide nuclides in the chain. Cross section data were modified within experimental uncertainties until predicted nuclide concentrations matched experimental results within reasonable limits over the range of neutron flux spectra. 2 figures, 3 tables