A MODIFIED MONTE CARLO PROGRAM FOR SAND-II WITH SOLUTION WEIGHTING AND ERROR ANALYSIS

摘要

In previous versions of the SAND-II and Monte Carlo codes, uncertainty data for both measured activities and cross sections were used only in a statistical sense for error propagation studies. These versions used an equal uncertainty procedure for weighting each foil. This re-port describes an in-depth study of different weighting procedures utilizing available uncertainty data to obtain a "most appropriate" SAND-II solution flux spectrum.nBased on this study, an improved and modified SAND-II Monte Carlo code has been developed. Development of the new code was based on extensive computer runs involving data from 21 foils irradiated in CFRMF as a part of the Interlaboratory LMFBR Reaction Rate (ILRB) program. This report also provides an up-to-date listing of the new Modified SAND-II Monte Carlo code, and a set of operating instructions.