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Development of a mobile gamma-ray LaBr3(Ce) detector for in-situ radionuclide analysis at TENORM contamination sites
Thesis (PhD)--Stellenbosch University, 2025.
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| Format: | Thesis |
| Language: | English |
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Stellenbosch : Stellenbosch University
2025
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| _version_ | 1867613806714159104 |
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| access_status_str | Open Access |
| author | Van Niekerk, Ferdinand |
| author2 | Jones, Peter Michael |
| author_browse | Jones, Peter Michael Van Niekerk, Ferdinand |
| author_facet | Jones, Peter Michael Van Niekerk, Ferdinand |
| author_sort | Van Niekerk, Ferdinand |
| collection | Thesis |
| dc_rights_str_mv | Stellenbosch University |
| description | Thesis (PhD)--Stellenbosch University, 2025. |
| format | Thesis |
| id | oai:scholar.sun.ac.za:10019.1/132290 |
| institution | Stellenbosch University (South Africa) |
| language | English |
| last_indexed | 2026-06-10T12:42:00.137Z |
| license_str | Other — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from SUNScholar — Stellenbosch University Repository |
| publishDate | 2025 |
| publishDateRange | 2025 |
| publishDateSort | 2025 |
| publisher | Stellenbosch : Stellenbosch University |
| publisherStr | Stellenbosch : Stellenbosch University |
| record_format | dspace |
| source_str | SUNScholar — Stellenbosch University Repository |
| spelling | oai:scholar.sun.ac.za:10019.1/132290 Development of a mobile gamma-ray LaBr3(Ce) detector for in-situ radionuclide analysis at TENORM contamination sites Van Niekerk, Ferdinand Jones, Peter Michael Newman, Richard Thomas Stellenbosch University. Faculty of Science. Dept. of Physics. Gamma ray spectrometry Radiation -- Measurement Soils -- Radioactive contamination -- South Africa -- Kruger National Park -- Measurement Soils -- Radioactive contamination -- South Africa -- Welverdiend AH -- Measurement Uranium -- Environmental aspects -- South Africa Mineral industries -- South Africa Environmental monitoring -- South Africa -- Instruments Technologically Enhanced Naturally Occurring Radioactive Material UCTD Thesis (PhD)--Stellenbosch University, 2025. van Niekerk, F. 2025. Development of a mobile gamma-ray LaBr3(Ce) detector for in-situ radionuclide analysis at TENORM contamination sites. Unpublished doctoral dissertation. Stellenbosch: Stellenbosch University [online]. Available: https://scholar.sun.ac.za/items/319eca66-35f3-4f02-961e-17095f02bf43 ENGLISH ABSTRACT: The activity concentration of naturally occurring radioactive materials (NORMs) in terrestrial environments is typically measured using a gamma-ray spectrometer equipped with a NaI(Tl) detector. If higher spectral resolution is required, samples must be collected on-site and analysed with an HPGe instrument in a laboratory. In this study, a mobile radiation detection unit (MRDU) equipped with a 2”×2” LaBr3(Ce) detector was designed to measure NORMs in terrestrial environments. Measurement sites were chosen to represent various NORM distribution scenarios: natural radionuclide distribution at iThemba LABS and Mamba Weir in the Kruger National Park (KNP); a rehabilitated site following a contamination spill at the Selati River in the KNP; and a site with elevated radiation levels due to technologically enhanced contamination from mining activities at Welverdiend AH. Soil samples were collected from the KNP and Welverdiend AH sites and analysed chemically using ICP-OES to determine the presence or absence of uranium disequilibrium at the contaminated site. At the iThemba and KNP sites, the activity concentrations were below the minimum detectable activity (MDA), which was confirmed by chemical analysis showing results below the detection limit. At the Welverdiend site, elevated uranium levels were detected with the MRDU, and these elevated levels were confirmed through chemical analysis. Additionally, the comparison of radiation and chemical data revealed the presence of uranium disequilibrium at the Welverdiend AH site. The MRDU equipped with the LaBr3(Ce) yielded satisfactory results when carried in hostile terrestrial environments. Also, a residential soil sample was collected and measured for 40K using both LaBr₃(Ce) and HPGe detectors. Additionally, an ICP-OES chemical analysis was performed to determine the total potassium content in the sample. The aim was to evaluate the difference in resolution between the two detectors, and to compare the radiation data with the chemical analysis results. As expected, the data obtained demonstrated the superior resolution of the HPGe detector compared to the LaBr₃(Ce) detector. Nevertheless, the 40K activity results showed a very good correlation not only between the two detectors but also between the radiation measurements and the chemical analysis results. AFRIKAANSE OPSOMMING: Die aktiwiteitskonsentrasie van natuurlik radioaktiewe materiale (NORMs) in natuurlike omgewings word gewoonlik gemeet met behulp van 'n gammastraal-spektrometer wat toegerus is met 'n NaI(Tl)-detektor. Indien 'n hoër spektrale resolusie egter benodig word, moet monsters op die terrein versamel en in 'n laboratorium met 'n HPGe-instrument ontleed word. In hierdie studie is 'n mobiele stralingsdeteksie-eenheid (MRDU) toegerus met 'n 2”×2” LaBr3(Ce)-detektor ontwerp om NORMs in natuurlike omgewings te meet. Meetterreine is gekies om verskeie NORM-verspreidingscenario's te verteenwoordig: natuurlike radionukliedverspreiding by iThemba LABS, en Mamba Weir in die Krugerwildtuin (KNP); 'n gerehabiliteerde terrein na 'n besoedelingslekkasie by die Selatirivier in die KNP; en 'n terrein met verhoogde stralingsvlakke as gevolg van tegnologiese besoedeling afkomstig vanaf mynbou-aktiwiteite by Welverdiend AH. Grondmonsters is versamel van die KNP en Welverdiend AH terreine en chemies ontleed met behulp van IGP-OES om die teenwoordigheid of afwesigheid van uraan-disekwilibrium by die besoedelde terrein te bepaal. By die iThemba en KNP terreine was die aktiwiteitskonsentrasies onder die minimum opspoorbare aktiwiteit (MDA), wat deur chemiese analise bevestig is deurdat resultate onder die deteksielimiet getoon is. By die Welverdiend-terrein is verhoogde uraanvlakke met die MRDU opgespoor, en hierdie verhoogde vlakke is deur chemiese analise bevestig. Daarbenewens het die vergelyking van stralings- en chemiese data die teenwoordigheid van uraan-disekilibrium by die Welverdiend AH-terrein bevestig. Die MRDU toegerus met die LaBr3(Ce) detektor het bevredigende resultate gelewer wanneer dit in moeilik bereikbare natuurlike omgewings gebruik is. ‘n Residensiele grondmonster is ook versamel en gemeet vir 40K met behulp van beide LaBr₃(Ce) en HPGe detektors. Daarbenewens is 'n IGP-OES chemiese analise uitgevoer om die totale kaliuminhoud in die monster te bepaal. Die doel was om die verskil in resolusie tussen die twee detektors te evalueer en om die stralingsdata met die chemiese analise te vergelyk. Soos verwag, het die data die beter resolusie van die HPGe- detektor in vergelyking met die LaBr₃(Ce) detektor bevestig. Nietemin, het die 40K aktiwiteitresultate 'n baie goeie korrelasie getoon, nie net tussen die twee detektors nie, maar ook tussen die stralingsmetings en die chemiese analise. Doctoral 2025-06-02T14:09:48Z 2025-06-02T14:09:48Z 2025-03 Thesis https://scholar.sun.ac.za/handle/10019.1/132290 en Stellenbosch University xiv, 119 pages, (21 pages articles) : illustrations, maps application/pdf Stellenbosch : Stellenbosch University |
| spellingShingle | Gamma ray spectrometry Radiation -- Measurement Soils -- Radioactive contamination -- South Africa -- Kruger National Park -- Measurement Soils -- Radioactive contamination -- South Africa -- Welverdiend AH -- Measurement Uranium -- Environmental aspects -- South Africa Mineral industries -- South Africa Environmental monitoring -- South Africa -- Instruments Technologically Enhanced Naturally Occurring Radioactive Material UCTD Van Niekerk, Ferdinand Development of a mobile gamma-ray LaBr3(Ce) detector for in-situ radionuclide analysis at TENORM contamination sites |
| title | Development of a mobile gamma-ray LaBr3(Ce) detector for in-situ radionuclide analysis at TENORM contamination sites |
| title_full | Development of a mobile gamma-ray LaBr3(Ce) detector for in-situ radionuclide analysis at TENORM contamination sites |
| title_fullStr | Development of a mobile gamma-ray LaBr3(Ce) detector for in-situ radionuclide analysis at TENORM contamination sites |
| title_full_unstemmed | Development of a mobile gamma-ray LaBr3(Ce) detector for in-situ radionuclide analysis at TENORM contamination sites |
| title_short | Development of a mobile gamma-ray LaBr3(Ce) detector for in-situ radionuclide analysis at TENORM contamination sites |
| title_sort | development of a mobile gamma ray labr3 ce detector for in situ radionuclide analysis at tenorm contamination sites |
| topic | Gamma ray spectrometry Radiation -- Measurement Soils -- Radioactive contamination -- South Africa -- Kruger National Park -- Measurement Soils -- Radioactive contamination -- South Africa -- Welverdiend AH -- Measurement Uranium -- Environmental aspects -- South Africa Mineral industries -- South Africa Environmental monitoring -- South Africa -- Instruments Technologically Enhanced Naturally Occurring Radioactive Material UCTD |
| url | https://scholar.sun.ac.za/handle/10019.1/132290 |
| work_keys_str_mv | AT vanniekerkferdinand developmentofamobilegammaraylabr3cedetectorforinsituradionuclideanalysisattenormcontaminationsites |