Year
2003
Abstract
As the Deactivation and Decommissioning (D&D) programs, at sites such as Rocky Flats Environmental Technology Site (RFETS) progresses, the focus is moving from assay of 55 gallon (208 liter) drums towards larger systems capable of assaying boxed waste forms. In the absence of specific regulatory performance criteria for boxes, non-destructive assay (NDA) data quality objectives (DQOs) are essentially independent of container size. Thus the box assay systems are required to meet DQOs originally promulgated for 55- gallon drum assays. Two new box assay systems have been deployed at RFETS. The Super High Efficiency Neutron Coincidence Counting System (SuperHENC) was designed and fabricated as a collaborative effort between RFETS, Los Alamos National Laboratory (LANL) and BNFL Instruments Inc (BII). The Multi- Purpose Crate Counter (MPCC) designed and built by BII is based on the Imaging Passive Active Neutron IPAN?? technology. The latter was designed to provide diverse capacity for assay of Standard Waste Boxes (SWBs) and for the larger B25 LLW crates. Both systems have been calibrated and validated in accordance with the requirements for RFETS Material Control and Accountability (MC&A) and WIPP disposal. The systems have achieved the matrix specific qualification criteria for precision and accuracy for safeguards termination limit assays over their calibrated range, including the new RFETS mixed D&D materials waste streams. These systems were the first, and at this time the only, waste box assay systems that have achieved both MC&A qualification and WIPP certification. They are now fully operational at RFETS and continue to support the site closure mission. This represents a significant milestone in both waste management at RFETS and in the U.S. Department of Energy’s D&D program as a whole. This paper discusses the calibration and validation process undertaken to achieve the goal of MC&A qualification for the systems within the framework of the site’s safeguards requirements.