Establishing a volumetric measurement control program

At the Savannah River Site (SRS), several facilities have nearly all their special nuclear material in solution and therefore, volume measurements play a key role in the accountability of these materials. Normally, facilities rely on frequent instrument calibrations, periodic tank calibrations and proper instrument configuration to ensure measurement control. At SRS, methods have been employed that go beyond these basic steps to monitor the volume measurement systems and provide real time indication of measurement control. These methods can be used to indicate if a tank requires recalibration, if there is a sampling problem, or if there is an instrument problem. The methods include: sample density comparison, in-tank to laboratory density comparison, redundant instrument comparison and tank to tank transfer comparison. This paper describes these methods and the generation of control charts to track these comparisons in real time.