For many years, thermal ionization mass spectrometry (TIMS) has represented the state of the art for the measurement of uranium and plutonium content and isotopic composition in nuclear materials. In more recent years, modifications to the conventional TIMS methodology have been developed. ASTM International and the International Organization for Standardization (ISO) have several published standards for TIMS measurements covering a variety of possible TIMS methods for analyzing a nuclear sample. The various standards cover analysis methods that are generally referred to as conventional TIMS, classical total evaporation, and modified total evaporation. Each of these methods is useful for particular situations or sample matrices; however, there are differences in the ease of use, implementation/development effort, potential uncertainty, and the length of time it takes to complete the analysis. This paper will provide review of the available TIMS standards, focusing on the advantages and disadvantages of each TIMS method in regards to the topics previously mentioned, and with a view toward customer requirements related to production, material control and accountability, and reference material characterization.
Year
2020
Abstract