Candidate Measurement Technique Application as a Method for Materials Accountancy in Electrochemical Reprocessing

Electrochemical reprocessing is a promising method to recover useful fissile material from spent nuclear fuel. Due to the recent attention surrounding electrochemical reprocessing as a complement or alternative to aqueous methods, necessary safeguards must be developed. However, the process requires high temperatures and an inert atmosphere thus complicating the prospect of making material accountancy measurements. Thus, to be deployed commercially, viable material accountancy and process monitoring methods must be designed and tested to meet safeguard standards. This work focuses on gamma spectroscopy and total neutron counting methods, which have previously been applied to aqueous reprocessing. These signatures are simulated in a previously developed flowsheet model. By tracking the isotopic mass concentrations at a given time and location, proper emission rates can be calculated that yield accurate representations of the material. Furthermore, notional diversion scenarios were simulated to evaluate the sensitivity of the measurement simulations to slight changes in material mass. Confirmatory measurements at key locations allowed for identification and differentiation of normal and off-normal operating conditions.