Application of neodymium isotope ratio measurements for the origin assessment of uranium ore concentrates

Abstract

A novel procedure has been developed for the measurement of (143)Nd/(144)Nd isotope ratio in various uranium-bearing materials, such as uranium ores and ore concentrates (UOC) in order to evaluate the usefulness and applicability of variations of (143)Nd/(144)Nd isotope ratio for provenance assessment in nuclear forensics. Neodymium was separated and pre-concentrated by extraction chromatography and then the isotope ratios were measured by multi-collector inductively coupled plasma mass spectrometry (MC-ICP-MS). The method was validated by the measurement of standard reference materials (La Jolla, JB-2 and BCR-2) and the applicability of the procedure was demonstrated by the analysis of uranium samples of world-wide origin. The investigated samples show distinct (143)Nd/(144)Nd ratio depending on the ore type, deposit age and Sm/Nd ratio. Together with other characteristics of the material in question, the Nd isotope ratio is a promising signature for nuclear forensics and suggests being indicative of the source material, the uranium ore.

Nuclear Forensic Science: Analysis of Nuclear Material Out of Regulatory Control

“…The 143 Nd/ 144 Nd ratio in UOCs varies over an extremely wide range [from 0.510 to 0.515, ± ∼40 epsilon units (Krajkó et al 2014)]. In addition, the 143 Nd/ 144 Nd ratio and Sm/Nd can be used as combined signatures to distinguish UOCs of different origins (Krajkó et al 2014).…”

“…The 143 Nd/ 144 Nd ratio in UOCs varies over an extremely wide range [from 0.510 to 0.515, ± ∼40 epsilon units (Krajkó et al 2014)]. In addition, the 143 Nd/ 144 Nd ratio and Sm/Nd can be used as combined signatures to distinguish UOCs of different origins (Krajkó et al 2014). Although neodymium isotopic ratios vary on the order of 10-20 epsilon units between paired U ores and UOCs, the 143 Nd/ 144 Nd ratio for a series of samples from a given mine remains more consistent than other isotope ratios [e.g., Pb, Sr (Krajkó et al 2014)].…”

“…In addition, the 143 Nd/ 144 Nd ratio and Sm/Nd can be used as combined signatures to distinguish UOCs of different origins (Krajkó et al 2014). Although neodymium isotopic ratios vary on the order of 10-20 epsilon units between paired U ores and UOCs, the 143 Nd/ 144 Nd ratio for a series of samples from a given mine remains more consistent than other isotope ratios [e.g., Pb, Sr (Krajkó et al 2014)]. The consistency of neodymium isotopic signatures appears to make them one of the most promising signatures for UOC provenance yet developed.…”

LA-ICP-MS of rare earth elements concentrated in cation-exchange resin particles for origin attribution of uranium ore concentrate

“…Impurities in UOCs, such as, Fe [2], Sr [3], Pb [3], and rare earth elements (REE) [4][5][6], which exhibit inherent characteristics of UOC have been determined for origin attribution of UOCs.…”

“…To eliminate the above described interferences, coexisting elements are chemically separated by solid phase extraction in column packed with commercial resins such as TRU s [4][5][6], UTEVA s [2], Ln s [10] or TODGA s [11]. These resins lead to the effective removal of U along with the coexisting elements in UOCs and sufficiently low limits of detection (LoD) in the pg per g range.…”