Abstract
The U.S. Department of Energy’s Next Generation Safeguards Initiative Spent Fuel (NGSI-SF) project is nearing the final phase of developing several advanced nondestructive assay (NDA) instruments designed to measure spent nuclear fuel assemblies for the purpose of improving nuclear safeguards. Current efforts are focusing on calibrating several of these instruments with realistic spent fuel assemblies at two international spent fuel facilities. Modelling and simulation are expected to play important roles in predicting nuclide compositions, neutron and gamma source terms, and instrument responses in order to assist instrument calibrations. As part of NGSI-SF project, the purpose of this work is to assess the impacts of nuclear data uncertainties on the calculations of both spent fuel content and instrument responses.
Nuclear data is an essential part of many modern nuclear codes, including nuclear burnup codes and nuclear transport codes. Such codes are routinely used for analysis of spent fuel and NDA instruments. Hence, the uncertainties existing in the nuclear data used in these codes affect the accuracies of such analysis. In addition, nuclear data uncertainties represent the limiting (smallest) uncertainties that can be expected from the nuclear code predictions, and therefore define the highest attainable accuracy of the NDA instrument. This work studies the impacts of nuclear data uncertainties on calculated spent fuel nuclide inventories and the associated NDA instrument response. Recently developed methods within the SCALE code system are applied in this study. The Californium Interrogation with Prompt Neutron instrument was selected to illustrate the impact of these uncertainties on NDA instrument response.
