In-Situ Measurements of Low Enrichment Uranium Holdup Process Gas Piping at K-25-Paper for Waste Management Symposia 2010 East Tennessee Technology Park, Oak Ridge, Tennessee

摘要

This document is the final version of a paper submitted to the Waste Management Symposia, Phoenix, 2010, abstract BJC/OR-3280. The primary document from which this paper was condensed is In-Situ Measurement of Low Enrichment Uranium Holdup in Process Gas Piping at K-25 Using NaI/HMS4 Gamma Detection Systems, BJC/OR-3355. This work explores the sufficiency and limitations of the Holdup Measurement System 4 (HJVIS4) software algorithms applied to measurements of low enriched uranium holdup in gaseous diffusion process gas piping. HMS4 has been used extensively during the decommissioning and demolition project of the K-25 building for U-235 holdup quantification. The HMS4 software is an integral part of one of the primary nondestructive assay (NDA) systems which was successfully tested and qualified for holdup deposit quantification in the process gas piping of the K-25 building. The initial qualification focused on the measurement of highly enriched UO(sub 2)F(sub 2) deposits. The purpose of this work was to determine if that qualification could be extended to include the quantification of holdup in UO(sub 2)F(sub 2) deposits of lower enrichment. Sample field data are presented to provide evidence in support of the theoretical foundation. The HMS4 algorithms were investigated in detail and found to sufficiently compensate for UO(sub 2)F(sub 2) source self-attenuation effects, over the range of expected enrichment (4-40%), in the North and East Wings of the K-25 building. The limitations of the HMS4 algorithms were explored for a described set of conditions with respect to area source measurements of low enriched UO(sub 2)F(sub 2) deposits when used in conjunction with a 1 inch by 1/2 inch sodium iodide (NaI) scintillation detector.