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Desenvolvimento de uma metodologia para caracterização do filtro cuno do reator IEA-R1 utilizando o método de Monte Carlo / Development of methodology for characterization of cartridge filters from the IEA-R1 using the Monte Carlo methodPriscila Costa 28 January 2015 (has links)
O filtro cuno faz parte do circuito de tratamento de água do reator IEA-R1 que , quando saturado, é substituído, se tornando um rejeito radioativo que deve ser gerenciado. Neste trabalho foi realizada a caracterização primária do filtro cuno do reator nuclear IEA-R1 do IPEN utilizando-se espectrometria gama associada ao método de Monte Carlo. A espectrometria gama foi realizada utilizando-se um detector de germânio hiperpuro (HPGe). O cristal de germânio representa o volume ativo de detecção do detector HPGe, que possui uma região denominada camada morta ou camada inativa. Na literatura tem sido reportada uma diferença entre os valores experimentais e teóricos na obtenção da curva de eficiência desses detectores. Neste trabalho foi utilizado o código MCNP-4C para a obtenção da calibração em eficiência do detector para a geometria do filtro cuno, onde foram estudadas as influências da camada morta e do efeito de soma em cascata no detector HPGe. As correções dos valores de camada morta foram realizadas variando-se a espessura e o raio do cristal de germânio. O detector possui 75,83 cm3 de volume ativo de detecção, segundo informações fornecidas pelo fabricante. Entretanto os resultados encontrados mostraram que o valor de volume ativo real é menor do que o especificado, onde a camada morta representa 16% do volume total do cristal. A análise do filtro cuno por meio da espectrometria gama, permitiu a identificação de picos de energia. Por meio desses picos foram identificados três radionuclídeos no filtro: 108mAg, 110mAg e 60Co. A partir da calibração em eficiência obtida pelo método de Monte Carlo, o valor de atividade estimado para esses radionuclídeos está na ordem de MBq. / The Cuno filter is part of the water processing circuit of the IEA-R1 reactor and, when saturated, it is replaced and becomes a radioactive waste, which must be managed. In this work, the primary characterization of the Cuno filter of the IEA-R1 nuclear reactor at IPEN was carried out using gamma spectrometry associated with the Monte Carlo method. The gamma spectrometry was performed using a hyperpure germanium detector (HPGe). The germanium crystal represents the detection active volume of the HPGe detector, which has a region called dead layer or inactive layer. It has been reported in the literature a difference between the theoretical and experimental values when obtaining the efficiency curve of these detectors. In this study we used the MCNP-4C code to obtain the detector calibration efficiency for the geometry of the Cuno filter, and the influence of the dead layer and the effect of sum in cascade at the HPGe detector were studied. The correction of the dead layer values were made by varying the thickness and the radius of the germanium crystal. The detector has 75.83 cm3 of active volume of detection, according to information provided by the manufacturer. Nevertheless, the results showed that the actual value of active volume is less than the one specified, where the dead layer represents 16% of the total volume of the crystal. A Cuno filter analysis by gamma spectrometry has enabled identifying energy peaks. Using these peaks, three radionuclides were identified in the filter: 108mAg, 110mAg and 60Co. From the calibration efficiency obtained by the Monte Carlo method, the value of activity estimated for these radionuclides is in the order of MBq.
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A study of electrochemical precipitation as a possible method of removing radium from uranium industry liquid wastesFlausino de Paiva, Maria Isabel January 1996 (has links)
Of the various dissolved species contained in the effluents from the mining and milling of uranium ores, the one which is of particular concern for environmental protection is Radium-226. The literature shows that, in recent years, considerable efforts have been made to develop treatment systems that can achieve the stricter effluent discharge standards imposed by the regulatory bodies. There has also been a concern to treat the already existent sludges from previous treatments. The main priority is to limit, as much as possible, the arising of sludge from future treatment systems. The most common treatment used is the addition of lime and limestone to raise the pH followed by barium chloride to form a very finely divided Ba(Ra)S04 precipitate which is then settled in large ponds or basins. In spite of the high decontamination factors obtained with this technique, these may not be satisfactory in terms of environmental protection. In addition, the industry is increasingly aware of the economical benefits resulting from treatment processes that allow water reuse to the process.
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Diverging flow tracer tests in fractured granite: equipment design and data collectionBarackman, Martin Lee, 1953-, Barackman, Martin Lee, 1953- January 1986 (has links)
Down-hole injection and sampling equipment was designed and constructed in order to perform diverging-flow tracer tests. The tests were conducted at a field site about 8 km southeast of Oracle, Arizona, as part of a project sponsored by the U. S. Nuclear Regulatory Commission to study mass transport of fluids in saturated, fractured granite. The tracer injection system was designed to provide a steady flow of water or tracer solution to a packed off interval of the borehole and allow for monitoring of down-hole tracer concentration and pressure in the injection interval. The sampling system was designed to collect small volume samples from multiple points in an adjacent borehole. Field operation of the equipment demonstrated the importance of prior knowledge of the location of interconnecting fractures before tracer testing and the need for down-hole mixing of the tracer solution in the injection interval. The field tests were designed to provide data that could me analyzed to provide estimates of dispersivity and porosity of the fractured rock. Although analysis of the data is beyond the scope of this thesis, the detailed data are presented in four appendices.
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Critical evaluation of medical waste management policies, processes and practices in selected rural hospitals in the Eastern CapeMaseko, Qondile January 2014 (has links)
This thesis critically evaluates the policies, processes and practices of medical waste management in selected rural hospitals in the Eastern Cape. Medical Waste Management is a growing public health and environmental issue worldwide. Research shows large scale incapacity in dealing with medical waste in an efficient and sustainable fashion globally, which demonstrates that it is not merely a developing world problem alone. This study is conducted against the backdrop of an increasing medical waste crisis in South Africa. Although there are an abundance of studies on solid waste management, there is a lack of data and research particularly on medical waste management in rural hospitals. The crisis of medical waste management in South Africa is closely intertwined with the collapsing health care system and an overburdened natural environment. It is an undisputable fact that South Africa’s generation of medical waste far exceeds its capacity to handle it effectively. This thesis argues that the neglect of medical waste as an environmental-health issue and the absence of an integrated national medical waste management plan aggravate the medical waste problem in the country. In explaining the medical waste crisis, this thesis adopts a Marxist perspective which is based on the premise that industrial capitalist societies place economic growth and production at high priority at the expense of the natural environment; creating a society that is engulfed by high health risk due to the generation of hazardous and toxic waste. Industrial societies view themselves as superior and separate from the natural environment, whereas one cannot separate nature from society as they are interlinked. As society attempts to adopt a sustainable environmental approach towards environmental management, science and technology are enforced as a solution to environmental problems in order to continue developing countries’ economies whilst sustainably managing and protecting the environment, which is contradictory. This thesis emphasises that medical waste management is a socio-political problem as much as it is an environmental problem, hence the need to focus on power relations and issues of environmental and social justice. The results of the study identified gaps in policy framework nationally and institutionally on medical waste management. In addition, there were poor waste management practices due to poor training, inadequate infrastructure and resources as well as poor budget support.
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The Study of Sonar for Imaging of the Solid-Liquid Interface Inside Large TanksSood, Nitin 04 August 2005 (has links)
Retrieval, treatment, and disposal of high-level radioactive waste (HLW) is expected to cost between 100 and 300 billion dollars. The risk to workers, public health, and the environment are also a major area of concern for HLW. Visualization of the interface between settled solids and the optically opaque liquid is needed for retrieval of the waste from underground storage tanks. A Profiling sonar selected for this research generates 2-D image of the interface. Multiple experiments were performed to demonstrate the effectiveness of sonar in real-time monitoring the interface inside HLW tanks. First set of experiments demonstrated that objects shapes could be identified even when 30% of solids entrained in liquid, thereby mapping the interface. Simulation of sonar system validated these results. Second set of experiments confirmed the sonar’s ability in detecting the solids with density similar to the immersed liquid. Third set of experiments determined the affects of near by objects on image resolution. Final set of experiments proved the functional and chemical capabilities of sonar in caustic solution.
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Irradiated graphite waste : analysis and modelling of radionuclide production with a view to long term disposalBlack, Greg January 2014 (has links)
The University of Manchester Greg BlackThesis submitted for the degree of Doctor of EngineeringIrradiated Graphite Waste: Analysis and Modelling of Radionuclide Production with a View to Long Term Disposal23rd June 2014The UK has predominantly used graphite moderator reactor designs in both its research and civil nuclear programmes. This material will become activated during operation and, once all reactors are shutdown, will represent a waste legacy of 96,000 tonnes [1]. The safe and effective management of this material will require a full understanding of the final radiological inventory. The activity is known to arise from impurities present in the graphite at start of life as well as from contamination products transported from other components in the reactor circuit. The process is further complicated by radiolytic oxidation which leads to considerable weightloss of the graphite components. A comprehensive modelling methodology has been developed and validated to estimate the activity of the principle radionuclides of concern, 3H, 14C, 36Cl and 60Co. This methodology involves the simulation of neutron flux using the reactor physics code WIMS, and radiation transport code MCBEND. Activation calculations have been performed using the neutron activation software FISPACT. The final methodology developed allows full consideration of all processes which may contribute to the final radiological inventory of the material. The final activity and production pathway of each radionuclide has been researched in depth, as well as operational parameters such as the effect of changes in flux, fuel burnup, graphite weightloss and irradiation time. Methods to experimentally determine the activity, and distribution of key radionuclides within irradiated graphite samples have been developed in this research using a combination of both gamma spectroscopy and autoradiography. This work has been externally validated and provides confidence in the accuracy of the final modelling predictions. This work has been undertaken as part of the EU FP7 EURATOM Project: CARBOWASTE, and was funded by the Office for Nuclear Regulation.
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Desenvolvimento de uma metodologia para caracterização do filtro cuno do reator IEA-R1 utilizando o método de Monte Carlo / Development of methodology for characterization of cartridge filters from the IEA-R1 using the Monte Carlo methodCosta, Priscila 28 January 2015 (has links)
O filtro cuno faz parte do circuito de tratamento de água do reator IEA-R1 que , quando saturado, é substituído, se tornando um rejeito radioativo que deve ser gerenciado. Neste trabalho foi realizada a caracterização primária do filtro cuno do reator nuclear IEA-R1 do IPEN utilizando-se espectrometria gama associada ao método de Monte Carlo. A espectrometria gama foi realizada utilizando-se um detector de germânio hiperpuro (HPGe). O cristal de germânio representa o volume ativo de detecção do detector HPGe, que possui uma região denominada camada morta ou camada inativa. Na literatura tem sido reportada uma diferença entre os valores experimentais e teóricos na obtenção da curva de eficiência desses detectores. Neste trabalho foi utilizado o código MCNP-4C para a obtenção da calibração em eficiência do detector para a geometria do filtro cuno, onde foram estudadas as influências da camada morta e do efeito de soma em cascata no detector HPGe. As correções dos valores de camada morta foram realizadas variando-se a espessura e o raio do cristal de germânio. O detector possui 75,83 cm3 de volume ativo de detecção, segundo informações fornecidas pelo fabricante. Entretanto os resultados encontrados mostraram que o valor de volume ativo real é menor do que o especificado, onde a camada morta representa 16% do volume total do cristal. A análise do filtro cuno por meio da espectrometria gama, permitiu a identificação de picos de energia. Por meio desses picos foram identificados três radionuclídeos no filtro: 108mAg, 110mAg e 60Co. A partir da calibração em eficiência obtida pelo método de Monte Carlo, o valor de atividade estimado para esses radionuclídeos está na ordem de MBq. / The Cuno filter is part of the water processing circuit of the IEA-R1 reactor and, when saturated, it is replaced and becomes a radioactive waste, which must be managed. In this work, the primary characterization of the Cuno filter of the IEA-R1 nuclear reactor at IPEN was carried out using gamma spectrometry associated with the Monte Carlo method. The gamma spectrometry was performed using a hyperpure germanium detector (HPGe). The germanium crystal represents the detection active volume of the HPGe detector, which has a region called dead layer or inactive layer. It has been reported in the literature a difference between the theoretical and experimental values when obtaining the efficiency curve of these detectors. In this study we used the MCNP-4C code to obtain the detector calibration efficiency for the geometry of the Cuno filter, and the influence of the dead layer and the effect of sum in cascade at the HPGe detector were studied. The correction of the dead layer values were made by varying the thickness and the radius of the germanium crystal. The detector has 75.83 cm3 of active volume of detection, according to information provided by the manufacturer. Nevertheless, the results showed that the actual value of active volume is less than the one specified, where the dead layer represents 16% of the total volume of the crystal. A Cuno filter analysis by gamma spectrometry has enabled identifying energy peaks. Using these peaks, three radionuclides were identified in the filter: 108mAg, 110mAg and 60Co. From the calibration efficiency obtained by the Monte Carlo method, the value of activity estimated for these radionuclides is in the order of MBq.
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Pollution in Africa : a new toxic waste colonialism? An assessment of compliance of the Bamako Convention in Cote d’IvoireKone, Lassana January 2009 (has links)
While exploring the new forms of pollution in Africa, this study also focuses on the 2006 toxic dumping incident in Cote d’Ivoire viewed by commentators as the biggest scandal of the 21st century. Looks at the incident from a human rights approach considering the linkages between the human rights suffering and the environment and also the right to enjoy the best attainable state of physical and mental health. / A Dissertation submitted to the Faculty of Law University of Pretoria, in partial fulfilment of the requirements for the degree Masters of Law (LLM in Human Rights and Democratisation in Africa). Prepared under the supervision of Mr Imeru Tamirat, Faculty of Law, Addis Ababa University / Thesis (LLM (Human Rights and Democratisation in Africa))--University of Pretoria, 2009. / http://www.chr.up.ac.za/ / Centre for Human Rights / LLM
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Selection of disposal method for nuclear spent fuel: a plan for the application of the systems engineering processMin, Bryan B. 16 February 2010 (has links)
Master of Science
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Aktuelle Entwicklung in der EndlagerbrancheLautsch, Thomas 28 September 2017 (has links)
Die Endlagerbranche steht vor einem tiefgreifenden Wechsel. Die bisherigen Organisationseinheiten DBE mbH, ASSE GmbH, Bundesamt für Strahlenschutz (BfS) werden neu sortiert und in der neugegründeten Bundes-Gesellschaft für Endlagerung verschmolzen. Eine neue Genehmigungsbehörde, das Bundesamt für Kerntechnische Entsorgungssicherheit (BfE) wird geschaffen. Im Ergebnis dieser Neustrukturierung gibt es eine klare Aufgabentrennung zwischen Regulator und Operator. Darüber hinaus führt die Zusammenlegung der bisher verteilten Aufgaben vom Bauherr und ausführender Baufirma zu Synergieeffekten und einer größeren Umsetzungskompetenz in den Endlagerprojekten. Die neue Bundes-Gesellschaft für Endlagerung (BGE) wird sowohl in der Tiefe als auch in der Breite ihre Aktivitäten jede der bisher bestehenden Organisationen übertreffen und daher eine höhere Schlagkraft haben.
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