Deep penetration integral experiment for a thorium blanket mockup

An integral experiment has been performed for verification of radiation transport methods and nuclear data used for design of the radial shield for the gas-cooled fast breeder reactor (GCFR). The experiment included a thorium oxide blanket mockup and several shield configurations. The blanket measurements were needed to reduce uncertainties in the cross-section data used for calculating neutron transmission through a thorium blanket and to bound the uncertainties in calculated gamma-ray heating rates within the blanket. Measured neutron spectra and integral flux data are compared to 1D calculations of the transmitted flux. Calculations using ENDF/B-IV and ENDF/B-V data for thorium are compared and show the version V data to be superior above 1 MeV. The experiment, which is primarily sensitive to the total removal cross section, also showed V to be an improvement below 1 MeV, but still discrepant from the measurements