Nuclear Research Emulsion Measurements and the Observation of Proportional Counter Perturbation Factors in VENUS-1

Abstract

Nuclear research emulsion (NRE) observed I-integral and J-integral reaction rates are reported for VENUS-1. Proton-recoil energy-dependent reaction rates are predicted using CEN/SCK calculated 17 group neutron energy spectra. These calculated reaction rates are compared with absolute NRE observations at seven different locations in steel and water regions of VENUS-1. The agreement between calculations and NRE observed absolute proton-recoil reaction rates depends sensitively on location in VENUS-1. Adequate agreement is attained near the center of the core. However, as one approaches the edge of the core corner at approximately 28°, the agreement deteriorates. Comparisons between theory and experiment are limited by the broad energy resolution of the 17 energy group structure used in the calculations. Nevertheless, these comparisons do suggest that difficulties arise in the calculation of neutron transport as one approaches the edge of the core corner. In the 1983 dosimetry campaign in VENUS-1, possible perturbations introduced by 4π proton-recoil gas-filled proportional counters were investigated with NRE. Preliminary I-integral and J-integral proton-recoil reaction rates from NRE irradiated in this perturbation study reveal that proportional counters do create non-negligible perturbations in LWR-PV environments.