Uranium mill tailings from the Ranger mine, located in the Alligator Rivers Region of the Northern Territory, Australia, were examined to assess the effects of weathering and diagenesis on their long-term geochemical stability. Run of mill uranium tailings are a complex heterogeneous mixture of lithogenic ( primary gangue minerals and weathering products ) and secondary ( components that form during milling ) minerals, residual process chemicals and biogenic ( products of biological activity ) phases. Following transfer to the tailings storage facility, post depositional reactions alter the mineralogical and hydrochemical characteristics of the tailings solids and pore waters in accordance with weathering and diagenetic processes. In this thesis, a detailed examination of tailings cores and pore waters, kinetic column test work and geochemical modelling was combined with results from earlier studies to examine the key processes governing the geochemical stability of the Ranger tailings. Conclusions drawn from the work clearly demonstrates that the solid state speciation and mobility of metals and radionuclides in the tailings pile are governed by the processes of oxidative dissolution of sulfide minerals, weathering of phyllosilicates and organic matter diagenesis. The processes are spatially dependent, evolve over time and are influenced by the following key factors : 1. Tailings water content or degree of saturation ; 2. The nature and content of organic matter in the tailings ; 3. Redox potential of the tailings solid - pore water interface ; and 4. The specific reactivity of precursor minerals ( primary / secondary ) from the milling process and pore water solutes. Combined, these processes lead to the formation of authigenic minerals, which control the solubility of pore water constituents. These mechanisms will also have a profound impact on the long-term geochemical stability of the tailings pile and, as such, will need to be taken into account in the design, management and closure of the final tailings repositories at the Ranger site. / Thesis (Ph.D.)--School of Earth and Environmental Sciences, 2004.

Thesis (MBA)--Stellenbosch University, 2001. / New technologies have the ability to enable radical new business strategies, new value propositions and at least transform the manner in which we conduct our day-to-day business. This not only transforms our business but also the speed at which it occurs is nothing short of phenomenal. In the 1990's the advent of the Enterprise Resource Planning (ERP) tools brought about a previously unknown capability of integration and business processes as opposed to functional management. This brought about the capability to reengineer business processes and subsequent work practices. This opportunity presented itself at Rossing Uranium Limited and based on a sound business case this organisation went ahead to implement an ERP along with reengineered work processes. This study project has examined the role of information technology in a modern organisation and its ability to transform business processes. The theory of information technology as a key enabler is explored and documented. The human factor and change management is a critical success factor in any of these major technology or business improvement initiatives. This study has therefore examined the need for change management in organisations and the change management process in some detail. Further to this the topic of improvisational change was introduced, as a recognition that change management within a bounded project initiative is not always sufficient to support ongoing sustainable business improvements. The theoretical aspects of systems implementation, reengineering and change management are extrapolated into a real life case study, Rossing Uranium. Within this case study the external market environment is described along with the internal organisational dynamics. The case study goes on to describe the implementation of the ERP, the reengineering effort and the change management program. The final chapters deal with the evaluation of the Rossing business case within the context of the change management process and focusing particularly on business outcomes and the strengths and weaknesses of the change management program. This is followed up by some key recommendations to address shortcomings.

Thesis (MBA)--Stellenbosch University, 2006. / ENGLISH ABSTRACT: The International Energy Agency will for the first time in its 32 years history urge governments to speed up the construction of nuclear power plants. According to Fatih Birol, lEA chief economist, "the decision almost needs to be made tomorrow if we are going to act before we reach a point of no return in climate and security of supply." Nuclear energy, through the conversion and enrichment of uranium oxide, is one of the energy sources with the potential to make an immediate and substantial difference in the emission of greenhouse gasses. Uranium Oxide currently provides a cost effective and sustainable source of clean energy through nuclear power generation, directly comparable in price to gas and coal. With the growth of the world economy, comes a requirement for more energy. This can only be sustained through a number of sources, of which uranium and renewable sources of energy i.e. wind power generation, is part of. The supply of uranium oxide from production to conversion is key to the success of the uranium industry. The high energy potential of relative small quantities of uranium makes rt ideal to transport as the cost and handling is reduced. The transportation of uranium oxide is continuously increasing in complexity. This combined with a high price scenario, increased demand and supply shortages increases the risk associated with denial and delays of shipments. / AFRIKAANSE OPSOMMING: Die Internasionale Energie Agentskap gaan vir die eerste keer in die organisasie se 32-jaar geskiedenis' regerings aanspoor om die konstruksie van kemkragsentrales te bespoedig. Volgens Fatih Birol, IEA se hoof-ekonoom, "moet die besluit amper more geneem word as ons gaan reageer voor ons 'n punt van geen omdraai bereik het ten opsigte van die klimaat en sekuriteit van aanbod." Kernkrag, deur die omskakeling en verryking van uraanoksied, is een van die energie bronne met die potensiaal om 'n onmiddelike en substansiele verskil in die vrylating van groenhuis-gasse te maak. Uraanoksied verskaf huidiglik 'n koste effektiewe en volhoudbare bron van skoon energie deur kernkrag opwekking, direk vergelykbaar met steenkool en gas. Met die groei in die wereld ekonomie, kom die vraag na meer energie. Dit kan slegs volhoudbaar wees uit 'n aantal bronne waarvan uraan en hernubare bronne soos windkrag-opwekking, deel is. Die verskaffing van uraanoksied van produksie tot verryking is die sleutel tot die sukses van die uraan industrie. Die hoe energie potensiaal van relatiewe klein hoeveelhede uraan, maak dit geskik vir vervoer omdat die koste van vervoer en hantering verminder word. Die transportering van uraan oksied is voortdurend besig om in kompleksiteit toe te neem. Gekombineerd met 'n hoe prys senario, verhoogde vraag na en aanbodtekorte, verhoog die risiko verbind met wyering en vertragings in verskeping.

Orientador: Daniel Marcos Bonotto / Banca: Jorge Luis Mialhe / Banca: Nelson Angeli / Resumo: Este trabalho mostra eventos que influenciaram a indústria mundial do urânio tomando como países selecionados a Alemanha, a Austrália, o Canadá, os Estados Unidos da América, a França e o Brasil. Os eventos destacados para cada país são: a implantação das agências reguladoras ao longo dos anos; a evolução das políticas de proteção do público e do meio ambiente contra os possíveis danos da radiação ionizante. Um levantamento histórico desses fatos foi realizado e é organizado em ordem cronológica, dividindo as legislações de cada país em seus âmbitos: federal, estadual e ambiental, bem como é tratado da produção de urânio de cada nação. Deste modo é apresentada a evolução das legislações no campo da indústria de urânio, com o propósito de demonstrar como a legislação sobre esta indústria e a agência reguladora nacional podem ser aperfeiçoadas e melhoradas. / Abstract: This study shows events that have influenced the worldwide uranium industry, taking into account the countries: Germany, Australia, Canada, the United States of America, France and Brazil. The highlighted events for every country will be: the installations of the regulatory agencies along the years, the evolution of the political concepts concerning the public health and the environment against the possible effects of the ionizing radiation. A historical study of these facts was accomplished and will be set in chronological order, so that dividing the legislation of every country in its federal, state and environmental scopes. Uranium production for every nation is also treated herein. Therefore the legislation evolution in the uranium industry field is shown with the aim to demonstrate how the legislation of this industry and the Brazilian regulatory agency can be improved. / Mestre

The importance of possible consequences of radiation, possible health hazard of people and the radionuclide contamination of the environment requires securing radiation protection from the very start of any operation, where radioactive substances are being handled with. One of these fields is the uranium industry in which DIAMO, state enterprise, takes an important position, dealing with the extraction and treatment of uranium, effacing the impacts of mining, remediation and disposal. Findings in the field of uranium industry are primarily won in form of research of professional information sources. In the theoretical part of the work, historical data about the founding and development of the organisation DIAMO, state enterprise, about carried out operations and the affect on the environment are being listed. Furthermore, information concerning radiation protection, its history, principles and measures are being elaborated. On the basis of carried out analysis and gauging results the level of secured radiation protection in DIAMO, state enterprise, is being assessed. Comparing the analysis of currently valid legal regulations to the analysis of safety documentation worked out in DIAMO, state enterprise, the fulfilment of requirements of legal standards is being assessed. In areas affected with uranium industry (Příbram, Stráž pod Ralskem, Mydlovary) gauging the dose equivalent power consupmtion of gama radiation has been carried out. In selected sites water and soil samples have been taken to assess the concentration of radionuclides. The results of the research are being compared to the measuremet results from other sources. In conclusion it is possible to state that the results in the carried out research are comparable to the results of similar researches carried out in other countries.

Made available in DSpace on 2014-06-11T19:26:14Z (GMT). No. of bitstreams: 0 Previous issue date: 2008-01-23Bitstream added on 2014-06-13T19:54:20Z : No. of bitstreams: 1 barros_df_me_rcla.pdf: 4822584 bytes, checksum: fd3df8fb03e1be9a4566668c777c0a5a (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Este trabalho mostra eventos que influenciaram a indústria mundial do urânio tomando como países selecionados a Alemanha, a Austrália, o Canadá, os Estados Unidos da América, a França e o Brasil. Os eventos destacados para cada país são: a implantação das agências reguladoras ao longo dos anos; a evolução das políticas de proteção do público e do meio ambiente contra os possíveis danos da radiação ionizante. Um levantamento histórico desses fatos foi realizado e é organizado em ordem cronológica, dividindo as legislações de cada país em seus âmbitos: federal, estadual e ambiental, bem como é tratado da produção de urânio de cada nação. Deste modo é apresentada a evolução das legislações no campo da indústria de urânio, com o propósito de demonstrar como a legislação sobre esta indústria e a agência reguladora nacional podem ser aperfeiçoadas e melhoradas. / This study shows events that have influenced the worldwide uranium industry, taking into account the countries: Germany, Australia, Canada, the United States of America, France and Brazil. The highlighted events for every country will be: the installations of the regulatory agencies along the years, the evolution of the political concepts concerning the public health and the environment against the possible effects of the ionizing radiation. A historical study of these facts was accomplished and will be set in chronological order, so that dividing the legislation of every country in its federal, state and environmental scopes. Uranium production for every nation is also treated herein. Therefore the legislation evolution in the uranium industry field is shown with the aim to demonstrate how the legislation of this industry and the Brazilian regulatory agency can be improved.