PCA (Pool Critical Assembly) Replica Experiment. Part 1. Winfrith Measurements and Calculations

摘要

Accurate calculation of radiation penetration through the side-shield of a pressurized water reactor (PWR) is important for the estimation of nuclear heating in the thermal shields and reactor pressure vessel (RPV), displacement-rates within the RPV, and neutron leakage into the void space between the RPV and the primary shield giving rise to activation of the material in the nozzle region. A zero-energy Pool Critical Assembly (PCA) mock-up was set up at Oak Ridge to validate standard US shielding codes. This experiment has been the subject of a so-called blind test of calculational methods in which eleven laboratories (including Winfrith) calculated the neutron spectra and reaction-rates at key locations. In order to obtain additional experimental data to clarify anomalies found in the PCA analysis and to validate techniques, the REPLICA experiment was carried in NESTOR at Winfrith. This report describes the experiment and gives results of the measurements and corresponding Monte Carlo predictions made with the McBEND Code. (Atomindex citation 15:070277)