Year
1989
Abstract
The Los Alamos Special Isotope Separation Facility produces special plutonium isotopes and converts plutonium scrap by using the molecular laser isotope separation (MLIS) process in a gaseous plutonium hexafluoride (PuFg) phase. To provide important process-development and accountability information, we have developed and installed four nondestructive assay (NDA) instruments for that facility. These instruments are (1) an in-line plutonium isotopic analysis system to measure plutonium isotopes in gaseous, solid, and liquid phases, (2) an in-line sodium iodide (Nal) monitoring system consisting of six 2-in. by 2-in., two 2-in. by 24-in., and one 2-in. by 22-in. Nal detectors at specified components (a feed bottle, a feed-transfer cold trap, a compressor, a heat exchanger, a collector, a nozzle prefilter, and a tails cold trap) in the flow loop, (3) a portable high-resolution germanium gamma-ray system for plutonium isotopic analysis, and (4) a portable Nal gamma-ray holdup monitor.This paper discusses the measurement principles, hardware and software designs, and performance associated with these NDA instruments.