Roles for Process Monitoring in Nuclear Safeguards at Aqueous Reprocessing Plants

Process monitoring (PM) is increasingly important in nuclearsafeguards as a supplement to mass-balance based nuclear materialsaccounting (NMA). The main goal for using PM in additionto NMA is to improve the ability to detect off-normal plantoperation, which could indicate intent to divert special nuclearmaterial. With this main goal in mind, programs within the U.S.Department of Energy and the National Nuclear Security Administrationaim to advance the use of PM.This paper reviews traditional PM roles, describes possiblenew roles, and then illustrates new PM roles using two diversionscenarios. Particular focus is on safeguards at aqueous reprocessingplants where in the particular case of solution monitoring, PMtracks frequent measurements of bulk solution mass and volume.