HOLDUP ACCOUNTABILITY AT ROCKY FLATS

At Rocky Flats Environmental Technology Site (RFETS), accountability of fissile material holdup has increased in importance as Deactivation and Decommissioning (D&D) efforts have increased. The RFETS mission change to site closure has made determining the amount of special nuclear material (SNM) holdup a major concern for safeguards, security, and safety. The site strategy is to stabilize and consolidate the SNM inventory into fewer locations, deactivate and decommission areas with no stored SNM, and transfer SNM off site. Complete and ongoing characterization of facility holdup has been an essential part of evaluating areas for compliance with Department of Energy (DOE) requirements for material control and accountability. This paper discusses the RFETS methodology for reporting and accounting for holdup and for adjusting holdup inventory values as a result of re-measurements and removals.