Recovery of REE's using Laser Ablation (LIBS), page-4

https://www.osti.gov/servlets/purl/1261279

1. Introduction
In nuclear fuel fission reactions, each uranium or plutonium atom will split into two
lighter elements. Rare earth elements are a major component of these fission products. Since
fission product content in nuclear fuels is proportional to the fraction of “burned” fuel, it can be
used to estimate actinide masses (U, Pu, etc.) for nonproliferation “safeguards” monitoring. The
reprocessing of irradiated fuel must remove most fission products prior to reuse as fuel.
Therefore, it is important to monitor the presence of mixed actinide, rare earths, and other fission
product elements throughout the separation process. Challenges in monitoring fission product
content using conventional analytical techniques can be significant, such as in electrochemical
recycling processes [1]. The emission spectra of rare earths are very complex and spectral
interferences must be known, so a detailed and comprehensive study of the predominant rare
earths using LIBS has been undertaken in this research and reported here. There are a number of
detailed research articles that have shown the LIBS measurements on actinides, their surrogates,
[2-7, 27] and rare earth elements [8-26]. This study is the most comprehensive LIBS analysis of
rare earth elements individually and in a mixture.