Establishing a High-Precision Titrimetric Laboratory at Oak Ridge National Laboratory to Support the NBL Program Office's Mission

摘要

The NBL Program Office (NBL-PO) is a federally-staffed Office of Science program responsible for ensuring the production, certification and distribution of nuclear reference materials for a wide variety of users. The NBL Program is the U.S. Government's certifying authority for nuclear reference materials and measurement calibration standards. The NBL PO's primary mission elements are to; provide nuclear reference materials and conduct proficiency testing campaigns. The Nuclear Analytical Chemistry and Isotopics Laboratory (NACIL) group is a specialized nuclear analytical organization at Oak Ridge National Laboratory. The group's expertise is in the development and advancement of cutting-edge measurement methodologies for elemental and isotopic characterizations in environmental and nuclear matrices. The NBL-PO has tasked the NACIL group to establish the NBL High-Precision Titrimetric (HPT) method at ORNL to help maintain the US capability for the certification of uranium assay reference materials. The HPT method is the current gold standard in the uranium assay evaluation of certified reference materials. Based on the more commonly known Davies and Gray titration, the HPT method achieves uranium assay measurements to within 0.012% uncertainty. In this paper we will discuss the HPT method with the differences from the Davies and Gray titration together with the NBL-PO"s expectations for a laboratory dedicated to the HPT method. The establishment, maintenance, and proceduralization of the ORNL HPT laboratory, together with staff training and qualification with be presented. A brief overview of the HPT section of the newly established '"OakLimbs", an in-house laboratory data management software, which will be used to record and maintain all HPT laboratory observations and measurements, together with results from the initial laboratory training and certification, will also be reported.