Investigation of the isotopic composition of lead and of trace elements concentrations in natural uranium materials as a signature in nuclear forensics

Abstract

Lead is contained as trace element in uranium ores and propagates throughout the production process to intermediate products like yellow cake or uranium oxide. The lead isotopes in such material originate from two sources: natural lead and radiogenic lead. The variability of the isotopic composition of lead in ores and yellow cakes was studied and the applicability of this parameter for nuclear forensic investigations was investigated. Furthermore, the chemical impurities contained in these materials were measured in order to identify characteristic differences between materials from different mines. For the samples investigated, it could be shown, that the lead isotopic composition varies largely from mine to mine and it may be used as one of the parameters to distinguish between materials of different origins. Some of the chemical impurities show a similar pattern and support the conclusions drawn from the lead isotope data.

Isotope ratio analysis of actinides, fission products, and geolocators by high-efficiency multi-collector thermal ionization mass spectrometry

“…For strontium isotope ratio analysis using multiple Faraday cups, a value of 86 Sr/ 88 Sr = 0.1194 (atom ratio) was used for internal mass fractionation correction, and Rb-87/Rb-85 = 0.3860 (atom ratio) to correct for Rb-87 interferences. An average 87 Sr/ 86 Sr atom ratio of 0.71028 ± 0.00006 (1 , n > 50) for NBS 987 was found over a period of more than 18 months and multiple operators, an average 84 Sr/ 86 Sr atom ratio of 0.05649 ± 0.00005 (1 , n > 50).…”

“…In the nuclear forensic context, isotopic composition [1,2,4,[68][69][70][71][72][73][74][75][76][77] is of primary concern, in addition to the determination of physical parameters (including roughness, microstructure, geometry) [2][3][4][78][79][80], chemical structure (e.g., mineralogical structure, metallurgical information, oxidation states) [81][82][83], impurity and analyte content [2,3,77,78,[84][85][86][87], geolocation signatures (e.g., host rock, climate) [3,[88][89][90][91], or age since last chemical treatment [3,90,[92][93][94][95][96]. Isotope ratio analysis can be particularly useful in revealing the origin and history of nuclear materials.…”

Developing Nuclear Forensics Signatures and National Nuclear Forensics Libraries for the African Continent: A Case Review for South Africa

“…The results presented here demonstrate that South Africa and all other African countries have the capability to develop their own nuclear forensic signatures to account for nuclear materials [27,28].…”

Rapid paper spray mass spectrometry characterization of uranium and exemplar molecular species

“…The chemical speciation of actinides or concurrent organic species can provide clues about the geological origin of a material, and the intent or history of the material, and offer an additional axis for forensic fingerprinting . For example, the presence of uranyl tri‐ n ‐butylphosphate (uranyl–TBP) complexes may indicate concurrent reprocessing efforts, or the state of hydrolysis could be used to determine the age or history of a material .…”