Nuclear Material Estimation and Uncertainties for the Spent Treatment at FCF

Spent fuel from the Experimental Breeder Reactor-II (EBR-II) is treated at the Fuel Conditioning Facility (FCF) located at Argonne National Laboratory-West (ANL-W). A number of sensitive nuclear material streams are present in the facility, which mainly include material in the input spent fuel, the element chopper, the electrorefiner, the cathode processor, and the casting furnace. Different types of measurements and calculations are performed in order to estimate the amount of material in those streams. There are three basic types of measurements: weight, elemental and isotopic fractions, and liquid level measurements. Materials in some streams are determined using validated models, which include the mass and composition of the input spent fuel. This paper describes the different streams of sensitive nuclear material for the facility, and the methods for their measurements or estimation as part of the MC&A system at FCF. It also describes the analytical and sampling uncertainties associated with those measurements and estimates, which are required for the facility variances propagation calculations.