Year
2000
Abstract
The Radionuclide Assay System – Photon (RAS-P) is a near-field, transmission-corrected assay system developed for measurement of the actinide content of relatively homogeneous waste generated by facility operations. It is intended for use by facility operations personnel, and has features to enhance its usefulness and efficiency. These include multinuclide assay capability, automatic (off-shift) collection of background and straight-through transmission source data, enforcement of measurement control requirements, Go-NoGo or Assay modes, password protection, and reporting of total fissile gram equivalent values. System hardware consists of a shielded high-resolution germanium detector, a turntable, a shielded transmission source and shutter assembly, and a desktop computer and laser printer mounted on a compact frame. RAS-P was designed to assay the contents of cylindrical containers up to 30 inches diameter by 32 inches high, boxes up to 30 inches diagonal by 32 inches high, and HEPA filters up to 2 x 2 x 1 feet. Prior to installation at the Savannah River Site (SRS), code validation, system performance, and assurance against Y2K effects all were confirmed. Code validation was accomplished using spreadsheet calculations that were independent of the original code to calculate intermediate and final result produced by RAS-P. System testing was performed by repeated operation of the instrument under all required circumstances. Y2K testing was performed simultaneously with code validation following a protocol prescribed by the SRS Y2K subcommittee that required assays with dates varying thought the expected useful life of the RAS-P, particularly those bracketing Y2K boundaries. Performance history has been compiled demonstrating reliability (system availability), diversiability (the ability to alter assay parameters and obtain results quickly), and measurement control characteristics.