Year
2001
Abstract
On June 21, 2000, the United States Enrichment Corporation (USEC) announced that it would cease enrichment operations at the Portsmouth Gaseous Diffusion Plant (PORTS) located near Piketon, Ohio. As a result of this announcement, USEC is conducting activities necessary to place the process equipment and facilities at the Portsmouth plant in a cold standby mode. One of the requirements that USEC must meet prior to turning the equipment and facilities back to the Department of Energy (DOE) is to remove solid deposits of UO2F2 and UF6 to the extent necessary to prevent a criticality. The Applied Nuclear Technology (ANT) group at PORTS is responsible for providing the facility with nondestructive assay (NDA) support. The ANT group has conducted NDA measurements to locate and quantify several deposits in the LEU cascade to support criticality safety requirements. However, the NDA measurement techniques used to date have typically been for individual process components except for process cells located in the high-enriched portion of the cascade. Therefore, it was necessary to develop NDA methods and procedures to support deposit remediation efforts for LEU process cells. Tests were conducted that compared the UF6 gas inventory for individual cells to the quantitative estimate determined using NDA techniques. The test was conducted on various sized process equipment and at various enrichments that ranged from approximately 0.7% to 4% by weight 235U. This paper discusses the results of the comparative tests in addition to other technical, administrative and programmatic issues related to NDA support for cessation of enrichment activities at PORTS.