URANIUM WORKING REFERENCE MATERIALS DERIVED FROM ACTUAL WASTE

摘要

Radioactive working reference materials (WRMs) traceable to a nationally recognized reference base are essential in nondestructive assay (NDA) calibration processes, measurement traceability, and the assurance of data quality. In general, WRMs are organized into two categories, WRMs derived from sampling of actual waste containers or process holdup deposits, and WRMs fabricated from highly characterized radioactive material in a radiochemical laboratory environment. The U.S. Department of Energy (DOE) Portsmouth/Paducah Project Office (PPPO) has produced three WRMs derived from sampling of actual waste for use in their NDA technical and quality programs. These WRMs are actual waste drums containing alumina trap mix produced as a byproduct of operations at the Paducah Gaseous Diffusion Plant. Alumina trap mix consists of UO_2F_2 adsorbed onto a bed of alumina pellets. The method of waste drum selection, drum sampling technique, destructive assay of sample content, and reduction of data to a National Institute of Standards and Technology (NIST) traceable radioactive material mass and uncertainty value for each drum are addressed. The use of these WRM reference drums to assure data quality in an actual PPPO NDA measurement campaign is also addressed.