Year
1998
Abstract
We describe the piping nondestructive assay monitor for the Portsmouth Gaseous Diffusion Plant and present some measurement results. The United States government has offered excess fissile material that is no longer needed for defense purposes for the International Atomic Energy Agency (IAEA) inspection. This transparency technology is being used by the IAEA in a verification experiment to provide confidence that the US is blending down highly enriched uranium (HEU). The monitor measures the uranium enrichment in two cascade pipes, the HEU pipe and the product low-enriched uranium pipe. The monitor determines the amount of 235U from the 185.7-keV peak and the total amount of uranium by x-ray fluorescence (XRF) of the 98.4-keV x-ray from uranium with a 57Co XRF source. The ratio yields the enrichment. The detector is an electromechanically cooled germanium detector. A rack-mounted personal computer controls commercial and customized software for operation of the monitor. The monitor was installed in December 1997 and is scheduled to be used by the IAEA inspectors for short notice random inspections through August 1998. The equipment is sealed with tamper-indicating enclosures when the inspectors are not present.