| dc.description.abstract | Nuclear forensics is a scientific discipline that focuses on nuclear or radioactive material and
aims to provide information on the intended use, history, and even origin of the material. It
examines and evaluates the signatures in nuclear and other radioactive materials to assist in
criminal investigations involving these materials. The information obtained from forensic
investigations needs to be accurate and precise for the evidence to be accepted in court. By
using inductively coupled plasma mass spectrometry (ICP-MS), a new and straightforward
analytical method has been created for the detection of lanthanides (rare-earth elements) in
uranium ore and Uranium Ore Concentration. Rare earth elements (REE), called lanthanides,
show consistent patterns under a variety of geochemical conditions. The aim of this project was
to determine REE in uranium bearing material for nuclear forensics purposes using ICP-MS.
The TRUTM resin was used for a selective extraction chromatographic separation of
lanthanides, which was followed by ICP-MS analysis. To improve ionization efficiencies for
determining REE concentrations, the chemical separation strategy was intended to limit matrix
effects. Four (4) UOC and two (2) uranium ore samples from Witwatersrand basin in South
Africa were subjected to the technique to measure REE abundances. Ce/Ce*, Eu/Eu*, LaN/YbN,
LaN/GdN, and GdN/YbN were the few element ratios that seem to contain substantial
information regarding sources. According to the findings, the total REEs (ΣREE)
concentrations in several UOC samples were in the following order: UOC4 (15634,541 ppb) >
UOC2 (983,972 ppb) > UOC1 (390,182 ppb) > UOC3 (182,968 ppb). For uranium ore samples,
the ΣREE concentrations were: U ore1 (12486,420 ppb) > U ore2 (8413,640 ppb). While
UOC1, UOC2, and UOC3 of the normalized REE/Cl chondrites pattern of UOC exhibited light
rare earth elements (LREE) enrichment and heavy rare earth elements (HREE) depletion with
positive Cerium anomalies and negative Europium anomalies, UOC4 demonstrated the
opposite, with depletion LREE and HREE enrichment with a large negative Europium
anomaly. The enrichment of the medium REEs was more pronounced than that of the LREEs and HREEs. U ore1 and U ore2 indicated positive Ce anomalies and negative Eu anomalies, as
shown in the normalized REE/Cl chondrites pattern and their ratios of (LaN/GdN) and
(GdN/YbN), ranged from 0.932 to 3.665 and 1.383 to 3.919 respectively. To evaluate their
statistical significance in the observed variations, REEs for UOC and uranium ore samples
were determined from the acquired data and subjected to ANOVA. The findings showed that
among the analysed mining sites, REEs used to determine origin location, exhibited significant
variation. It has been proven that these techniques can precisely measure the REE concentration
of well-characterized UOC and uranium ore samples. The REE pattern was utilized for the
identification and origin assessment of UOC and uranium ore samples. By doing so, it is simple
to confirm the source of an unknown substance by comparing the pattern to that of a known
sample. The provenance of the material can also be determined in numerous circumstances
even when there is no reference sample available due to characteristic patterns, in contrast to
other indicators utilized for nuclear forensic research. Finally, the findings provided in this dissertation can be a helpful tool for forensic nuclear investigations, supporting the fight against
the illicit trafficking of nuclear materials. | en_US |
