IN-LINE X-RAY FLUORESCENCE ANALYSIS OF SPECIAL NUCLEAR MATERIALS IN DISSOLVER SOLUTION: MATERIALS DEVELOPMENT, LABORATORY SIMULATION AND PARAMETERIZATION

An automated x-ray fluorescence (XRF) analysis apparatus and sampling system have been used for a proof-of-principle test of on-line x-ray fluorescence assay of special nuclear materials (SNM) in dissolver solutions. A \"total sampling\" technique gives total mass assays with no need for solution density or tank volume measurements. Error propagation equations control the accumulation of high-precision data, and are also used for calculating parameters of x-ray fluorescence analysis equipment that will meet specified requirements. Short dwell times at each spectrometer setting significantly compensate for long-term instrumental drift. Sample cells that have survived prolonged exposure to dissolver solution are described.