Year
1989
Abstract
The Savannah River Site (SRS) has completed an experimental evaluation of the application of an active well (neutron) coincidence counter (AWCC) to the assay of 235U in U-A1 coextrusion billets of the Savannah River Site fuel fabrication area. Using U-A1 coextrusion core standards for the experimental measurements, the AWCC was tested in several different source/sample configurations. As a result of this work, a new configuration was identified for billet assay. This configuration, using a moderated ArnLi source placed in the central hole of the billet, yielded a twostandard- deviation precision of 0.6-1.0% for a twentyminute assay. This precision is a factor of 2-3 better than that obtained from the operation of the AWCC in the standard configuration, i.e., with the interrogation sources located above and below the billet. A dedicated Billet AWCC, using the new center-source configuration and custom-built to accommodate coextrusion billets, is being acquired for use in the fuel fabrication area of SRS. This paper will present details of the experimental work, as well as a description of the resulting AWCC design.