Year
2006
Abstract
Safeguards systems employing multiple measurement approaches provide complimentary assurances of safeguards integrity. Laser-induced breakdown spectroscopy (LIBS), a laser based optical method for the elemental characterization of liquids and solids, has previously been considered in safeguarding a UREX reprocessing facility that separates uranium and removes the transuranic elements together. LIBS capabilities that support the safeguards goals include (1) real-time or near real-time automated analysis, (2) essentially non-destructive analysis with little or no sample preparation or handling, (3) on-line or at-line capabilities, (4) remote operation in multiple sites via fiber optics, and (6) isotopic analysis. In LIBS, a focused pulsed laser beam impinges a sample (solid, liquid, or gas) to create a short-lived high-temperature plasma consisting of microgram quantities of the sample. The plasma emits light that is characteristic of the elements within the plasma and is analyzed spectroscopically. LIBS application to four specific points in a UREX flowsheet will be illustrated: 1) U and Np, Pu, Am and Cm (TRU) quantitation in the head end accountability tank, 2) ratios of TRU elements in solutions following uranium separation to assure proper process operation, 3) Np and Pu quantitation in the final product oxide and 4) U and TRU threshold measurements in liquid and solid waste streams to exclude diversion possibilities. The sensitivity of LIBS is approximately the same for all of the actinide elements and is on the order of hundreds of parts per million and ratios of these elements can readily be obtained. Potential safeguards applications and limitations will be addressed.