CYCLE VERIFICATION USING FRESHLY DISCHARGED SPENT FUEL

There is concern that a reactor operator can divert nuclear material by incorrectly declaring the number of cycles a fuel assembly has been in a reactor core. We have examined the application of the Spent Fuel Fork Detector (FDET) to measure freshly discharged nuclear fuel assemblies. We used these data to verify the operator declaration of the number of reactor cycles an assembly has been in-core. We have determined that it is possible to determine the number of cycles a fuel assembly has been in a reactor core using simple FDET measurements and straight-forward data reduction. In the event of a loss of surveillance or suspected diversion, an entire core can be reverified quickly and with great reliability. This paper will present the results from recent measurement campaigns intended to determine the application of this approach in different reactor types.