CHARACTERIZATION OF A SAFEGUARDS VERIFICATION METHODOLOGY TO DETECT PIN DIVERSION FROM PRESSURIZED WATER REACTOR (PWR) SPENT FUEL ASSEMBLIES USING MONTE CARLO TECHNIQUES

This article presents early results from Monte Carlo radiation transport calculations aimed at characterizing a novel methodology being developed to measure neutron and gamma fields inside a Pressurized Water Reactor (PWR) fuel bundle in spent fuel pools. The objective of these simulations is to evaluate the best combination of signals that can detect pin diversion from these bundles. Preliminary results from these studies indicate that the gamma-to-thermal neutron ratios at detector locations provide a useful means of detecting pin diversion. A further objective of detecting pin diversion without any prior knowledge of burnup levels of the bundle also shows promise with this methodology.