Modeling and experimental validation of rotary riffling method for nuclear material input accountancy

Abstract In establishing nuclear fuel input accountancy for electrometallurgical pyroprocessing treatment of used nuclear oxide fuel, a representative sampling method has been considered as a suitable alternative of methods pursuing homogenization of used nuclear oxide fuel feed such as mixing the pulverized fuels. In principle, the representative sampling method involves random particle selection from size-classified nuclear fuel materials to give quantified and controllable sampling uncertainty. For this purpose, the rotary riffling method is known to be superior in realizing sample randomization. To qualify the rotary riffling method as a tool to establish used nuclear fuel input accountancy, this paper first derives theoretical randomization performance tailored to the rotary riffling method and used nuclear fuel feed. The performance of an off-the-shelf rotary riffler was tested and validated with mixed alumina particle feeds of different sizes.