Spelling suggestions: "subject:"commissioning""
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Entwicklung einer Methode zur Pre-Aktivitäts- und Dosisleistungsberechnung von reaktornahen Bauteilen auf Basis von Neutronenfluenzverteilungen – EMPRADO: Teilprojekt A: Berechnung der Neutronenfluenzverteilung in reaktornahen Bauteilen und deren Validierung an Experimenten als Basis der AktivitätsrechnungenKonheiser, J., Barkleit, A. 19 December 2024 (has links)
On the basis of an exact power history and accurate geometric modelling, plant-specific neutron fluences were calculated for in each case a pre- and convoy unit of German nuclear power plant for reactor components and for concrete and structural elements close to the reactor. These neutron fluences are the basis for determining the generated activation of the construction materials during the power operation of the plant. The calculations were supported by an extensive measurement program in the last cycles of two plants, where neutron fluence values were determined ex-perimentally with the help of activation foils (monitors). A spectral analysis was possible by using different monitor materials. The monitors were measured by gam-ma spectrometry after sampling using a high-purity germanium (HP-Ge) detector. The comparison of the calculated and measured activities shows, with a few excep-tions, good to very good agreement between the values. This means that the real ratios of neutron radiation in the elements were calculated very well and the method and model can be used to determine the activity distribution.
Due to the possibility of the accurate simulation of the resulting activities on the ba-sis of these 'best estimate' calculations, detailed planning of the decommissioning can already begin during the operation of the plant. It is not necessary to wait until extensive sampling after the shutdown.
In addition, the accurate mathematical determination of the activity distribution in the components enables improved cut planning and thus minimization of the waste volume for the final storage. A further advantage would be that the necessary exper-imental activity determinations could be reduced to a few samples thanks to the supporting experiments and thereby validated neutron fluence calculations.
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Reducing the activation of the IRIS reactor building using the SCALE/MAVRIC methodologyMcKillop, Jordan M. 20 November 2009 (has links)
The main objective of this research is: (1) to develop a model and perform numerical simulations to evaluate the radiation field and the resulting dose to personnel and activation of materials and structures throughout the IRIS nuclear power plant, and (2) to confirm that the doses are below the regulatory limit, and assess the possibility to reduce the activation of the concrete walls around the reactor vessel to below the free release limit.
IRIS is a new integral pressurized water reactor (PWR) developed by an international team led by Westinghouse with an electrical generation capacity of 335 MWe and passive safety systems. Its design differs from larger loop PWRs in that a single building houses the containment as well as all the associated equipment including the control room that must be staffed continuously. The resulting small footprint has positive safety and economic implications, and the integral layout provides additional shielding and thus the opportunity to significantly reduce the activation, but it also leads to significantly more challenging simulations.
The difficulty in modeling the entire building is the fact that the source is attenuated over 10 orders of magnitude before ever reaching the accessible areas. For an analog Monte Carlo simulation with no acceleration (variance reduction), it would take many processor-years of computation to generate results that are statistically meaningful. Instead, to generate results for this thesis, the Standardized Computer Analyses for Licensing Evaluation (SCALE) with the package Monaco with Automated Variance Reduction using Importance Calculations (MAVRIC) will be used. This package is a hybrid methodology code where the forward and adjoint deterministic calculations provide variance reduction parameters for the Monte Carlo portion to significantly reduce the computational time.
Thus, the first task will be to develop an efficient SCALE/MAVRIC model of the IRIS building. The second task will be to evaluate the dose rate and activation of materials, specifically focusing on activation of concrete walls around the reactor vessel. Finally, results and recommendations will be presented.
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A health risk assessment for the decommissioning of the Georgia Institute of Technology Research reactorKiellman, Tracy Jo 12 1900 (has links)
No description available.
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Aprimoramento da política pública ambiental da cadeia produtiva de óleo e gás offshore no Brasil: o descomissionamento das tecnologias de exploração / Improvement of environmental public policy of the supply chain of offshore oil and gas in Brazil: the decommissioning of exploration technologiesBeatriz Martins Teixeira 27 September 2013 (has links)
A Constituição Federal brasileira de 1988 elevou o meio ambiente sadio e a
qualidade de vida das presentes e futuras gerações à categoria de direito fundamental.
Esse fato jurídico modifica todas as propostas normativas e de execução de políticas
públicas até então vigentes, e exige uma adequaçãodas atividades produtivas para
atender a esse novo ideal voltado para uma sociedade sustentável. A presente tese
analisa a atividade petrolífera offshore, dando ênfase à fase do descomissionamento da
exploração do petróleo, a fim de estudar os mecanismos legais regulatórios incidentes
sobre a desativação do sistema de produção, momento em que se constata uma
grande vulnerabilidade ambiental. Trata-se de demonstrar a tese de que o sistema legal
brasileiro sobre o descomissionamento é inconsistente em relação às normas de direito
ambiental e do modelo de desenvolvimento sustentável constitucionalmente instituído.
O objetivo central é contribuir para o aprimoramento das políticas públicas de
exploração do petróleo, visando consolidar o sistema legal brasileiro sobre o tema, bem
como valorizar as questões ambientais no processo de descomissionamento. Através
de uma metodologia qualitativa, é identificado, inicialmente, o cenário da indústria
petrolífera para discutir o conceito de desenvolvimento sustentável, verificando como
ele está sendo incorporado pelas políticas energética e ambiental do país. Em seguida,
é descrita e analisada a estruturação e quais são as experiências internacional e
brasileira sobre o descomissionamento. Após essa etapa cognitiva, passa-se a
detalhar: o arcabouço institucional-legal do descomissionamento da indústria do
petróleo no Brasil, com base nos princípios de direito ambiental; a infraestrutura estatal
para a consolidação de um novo marco regulatório para essa etapa da produção; a
política nacional de resíduos sólidos e o instrumento do licenciamento ambiental. Ao
término desse processo, são formuladas duas propostas complementares de
instrumentos legais, voltados para a consolidação da regulamentação do
descomissionamento da indústria do petróleo offshore, baseado nas orientações do
direito ambiental. A tese é concluída com considerações gerais sobre as propostas
formuladas, a fim de aprimorar o arcabouço jurídico da indústria do petróleo, visando à
proteção ambiental e ao fortalecimento do modelo de desenvolvimento sustentável
instituído com a Constituição Brasileira de 1988. / The Federal Constitution of 1988 raised the healthy environment and quality of life of
present and future generations to a fundamental right . This legal fact modifies all the
policy proposals and implementation of public policies in force hitherto, and requires an
adjustment of production activities to meet this new ideal toward a sustainable society.
This thesis analyzes the offshore oil activity, emphasizing the decommissioning phase of
oil exploration in order to study the legal regulatory mechanisms incidents on disabling
the production system, at which time it turns out great environmental vulnerability. This
is to demonstrate the thesis that the Brazilian legal system on decommissioning is
inconsistent with the norms of environmental law and sustainable development model
constitutionally established. The main objective is to contribute to the improvement of
public policy oil exploration, aiming to consolidate the Brazilian legal system on the
topic, as well as valuing environmental issues in the process of decommissioning.
Through a qualitative methodology is identified, initially, the scenario of the oil industry to
discuss the concept of sustainable development, seeing how it is being built by the
energy and environmental policies of the country. Is then described and analyzed the
structure and what are the international and Brazilian experiences on decommissioning.
After this stage cognitive passes to detail: the institutional and legal framework of the
decommissioning of the oil industry in Brazil, based on the principles of environmental
law, the state infrastructure for the consolidation of a new regulatory framework for this
stage of production; national policy on solid waste and the instrument of environmental
licensing . At the end of this process, two proposals are formulated supplementary legal
instruments aimed at consolidating the regulation of decommissioning offshore oil
industry, based on the guidelines of environmental law. The thesis concludes with
general comments on the proposals in order to improve the legal framework of the oil
industry, environmental protection and aimed at strengthening the sustainable
development model introduced with the 1988 Brazilian Constitution
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Estimativa do inventário de material radioativo para centrais nucleares PWR no descomissionamentoBusse, Alexander Lucas January 2016 (has links)
Orientador: Prof. Dr. João Manoel Losada Moreira / Dissertação (mestrado) - Universidade Federal do ABC. Programa de Pós-Graduação em Energia, 2016. / Este trabalho faz uma estimativa do inventário de material radioativo oriundo do descomissionamento de reatores nucleares a água pressurizada (PWR). Os volumes e atividades dos resíduos radioativos provenientes do descomissionamento de reatores do tipo PWR semelhantes aos reatores da Central Nuclear Álvaro Alberto - BR foram compilados a partir de dados do reator Trojan. As atividades do vaso, internos e barreira de concreto do reator foram calculados com auxílio dos programas KENO V.a e SERPENT. Os fluxos de nêutrons calculados para os reatores de Angra 2 e Trojan foram utilizados para calcular a ativação do barril, vaso e barreira de concreto dos reatores. Os resultados evidenciaram
a contribuição de nêutrons térmicos no vaso do reator devida a reflexão na barreira de concreto.
Também foram estimados o volume de elementos combustíveis irradiados para 40 anos de operação de um dos reatores do sítio de Angra. Quase a totalidade da atividade induzida nos sistemas, estruturas e equipamentos do sítio encontra-se no combustível irradiado. Esses, classificados como resíduos de alto nível, totalizam um volume de 591 m3 ou 5,8 % do total de resíduos radioativos incluindo aqueles provenientes do descomissionamento. Os grandes equipamentos do circuito primário representam 2298 m3 ou 22,4% do total de resíduos e contribuem com 99,994 % da atividade dos resíduos de baixo e médio nível. O restante, 71 % do volume ou 7351 m3 são resíduos de nível muito baixo. O espaço total requerido para os resíduos radioativos oriundos do descomissionamento das três usinas nucleares do sítio de Angra seria em torno de 30.000 m3. Esses resíduos requerem armazenamento por aproximadamente 150 anos. / This work estimates the radioactive inventory resulting from the decommissioning process of
pressurized water reactors (PWR). The volumes and activities of radioactive waste from the
decommissioning of PWR reactors similar to those in the Angra site have been appraised out of data of the Trojan nuclear power plant and correlated to the plant thermal power level. The activities from the reactor vessel, internals and bioshield were estimated with the KENO V.a and SERPENT codes. The neutron fluxes calculated for the Angra 2 and Trojan reactors were used to estimate the activation of the barrel, vessel and bioshield. The total volume of spent fuel elements for 40 years of a 1300 MWPWR was also estimated. Most of activity induced in systems, structures and equipment of the site comes from the spent fuel. The total fuel volume, classified as high-level waste amounted to 591 m3 or 5.8 % of the total radioactive residues including those from the decommissioning. The major equipment of the nuclear steam supply system amounted 2298 m3, or 22.4 % of total waste, and contributed with 99.994 % of the total activity from low and medium level waste. The remaining 71 % of the volume, or 7351 m3, were classified as very low level waste. The total space required for the radioactive waste arising from the decommissioning of the three nuclear power plants of the Angra site was estimated as 30,000 m3. This total waste requires storage for approximately 150 years.
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Effects of IFRS adoption on the financial statements of Nigerian listed entities : the case of oil and gas companiesBala, Masud January 2015 (has links)
On 28 July 2010, the Nigerian Federal Executive Council approved January 1, 2012 as the effective date for the convergence of Nigerian Statement of Accounting Standards (SAS) or Nigerian GAAP (NG-GAAP) with International Financial Reporting Standards (IFRS). By this pronouncement, all publicly listed companies and significant public interest entities in Nigeria were statutorily required to issue IFRS based financial statements for the year ended December, 2012. This study investigates the impact of the adoption of IFRS on the financial statements of Nigerian listed Oil and Gas entities using six years of data which covers three years before and three years after IFRS adoption in Nigeria and other African countries. First, the study evaluates the impact of IFRS adoption on the Exploration and Evaluation (E&E) expenditures of listed Oil and Gas companies. Second, it examines the impact of IFRS adoption on the provision for decommissioning of Oil and Gas installations and environmental rehabilitation expenditures. Third, the study analyses the impact of the adoption of IFRS on the average daily Crude Oil production cost per Barrel. Fourth, it examines the extent to which the adoption and implementation of IFRS affects the Key Performance Indicators (KPIs) of listed Oil and Gas companies. The study further explores the impact of IFRS adoption on the contractual relationships between Nigerian Government and Oil and Gas companies in terms of Joint Ventures (JVs) and Production Sharing Contracts (PSCs) as it relates to taxes, royalties, bonuses and Profit Oil Split. A Paired Samples t-test, Wilcoxon Signed Rank test and Gray’s (Gray, 1980) Index of Conservatism analyses were conducted simultaneously where the accounting numbers, financial ratios and industry specific performance measures of GAAP and IFRS were computed and analysed and the significance of the differences of the mean, median and Conservatism Index values were compared before and after IFRS adoption. Questionnaires were then administered to the key stakeholders in the adoption and implementation of IFRS and the responses collated and analysed. The results of the analyses reveal that most of the accounting numbers, financial ratios and industry specific performance measures examined changed significantly as a result of the transition from GAAP to IFRS. The E&E expenditures and the mean cost of Crude Oil production per barrel of Oil and Gas companies increased significantly. The GAAP values of inventories, GPM, ROA, Equity and TA were also significantly different from the IFRS values. However, the differences in the provision for decommissioning expenditures were not statistically significant. Gray’s (Gray, 1980) Conservatism Index shows that Oil and Gas companies were more conservative under GAAP when compared to the IFRS regime. The Questionnaire analyses reveal that IFRS based financial statements are of higher quality, easier to prepare and present to management and easier to compare among competitors across the Oil and Gas sector but slightly more difficult to audit compared to GAAP based financial statements. To my knowledge, this is the first empirical research to investigate the impact of IFRS adoption on the financial statements of listed Oil and Gas companies. The study will therefore make an enormous contribution to academic literature and body of knowledge and void the existing knowledge gap regarding the impact and implications of IFRS adoption on the financial statements of Oil and Gas companies.
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Desenvolvimento do plano preliminar de descomissionamento do reator IPEN/MB-01 / Preliminary decommissioning plan of the reactor IPEN/MB-01VIVAS, ARY de S. 20 February 2015 (has links)
Submitted by Maria Eneide de Souza Araujo (mearaujo@ipen.br) on 2015-02-20T15:58:48Z
No. of bitstreams: 0 / Made available in DSpace on 2015-02-20T15:58:48Z (GMT). No. of bitstreams: 0 / Dissertação (Mestrado em Tecnologia Nuclear) / IPEN/D / Instituto de Pesquisas Energéticas e Nucleares - IPEN-CNEN/SP
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Considerações sobre o descomissionamento do reator de pesquisa IEA-R1 e futuro de suas instalações após o seu desligamento / Considerations about decommissioning of the IEA-R1 research reactor and the future of its instalations after shutdownFRAJNDLICH, ROBERTO 25 February 2015 (has links)
Submitted by Maria Eneide de Souza Araujo (mearaujo@ipen.br) on 2015-02-25T13:57:02Z
No. of bitstreams: 0 / Made available in DSpace on 2015-02-25T13:57:02Z (GMT). No. of bitstreams: 0 / Tese (Doutorado em Tecnologia Nuclear) / IPEN/T / Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP
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Aprimoramento da política pública ambiental da cadeia produtiva de óleo e gás offshore no Brasil: o descomissionamento das tecnologias de exploração / Improvement of environmental public policy of the supply chain of offshore oil and gas in Brazil: the decommissioning of exploration technologiesBeatriz Martins Teixeira 27 September 2013 (has links)
A Constituição Federal brasileira de 1988 elevou o meio ambiente sadio e a
qualidade de vida das presentes e futuras gerações à categoria de direito fundamental.
Esse fato jurídico modifica todas as propostas normativas e de execução de políticas
públicas até então vigentes, e exige uma adequaçãodas atividades produtivas para
atender a esse novo ideal voltado para uma sociedade sustentável. A presente tese
analisa a atividade petrolífera offshore, dando ênfase à fase do descomissionamento da
exploração do petróleo, a fim de estudar os mecanismos legais regulatórios incidentes
sobre a desativação do sistema de produção, momento em que se constata uma
grande vulnerabilidade ambiental. Trata-se de demonstrar a tese de que o sistema legal
brasileiro sobre o descomissionamento é inconsistente em relação às normas de direito
ambiental e do modelo de desenvolvimento sustentável constitucionalmente instituído.
O objetivo central é contribuir para o aprimoramento das políticas públicas de
exploração do petróleo, visando consolidar o sistema legal brasileiro sobre o tema, bem
como valorizar as questões ambientais no processo de descomissionamento. Através
de uma metodologia qualitativa, é identificado, inicialmente, o cenário da indústria
petrolífera para discutir o conceito de desenvolvimento sustentável, verificando como
ele está sendo incorporado pelas políticas energética e ambiental do país. Em seguida,
é descrita e analisada a estruturação e quais são as experiências internacional e
brasileira sobre o descomissionamento. Após essa etapa cognitiva, passa-se a
detalhar: o arcabouço institucional-legal do descomissionamento da indústria do
petróleo no Brasil, com base nos princípios de direito ambiental; a infraestrutura estatal
para a consolidação de um novo marco regulatório para essa etapa da produção; a
política nacional de resíduos sólidos e o instrumento do licenciamento ambiental. Ao
término desse processo, são formuladas duas propostas complementares de
instrumentos legais, voltados para a consolidação da regulamentação do
descomissionamento da indústria do petróleo offshore, baseado nas orientações do
direito ambiental. A tese é concluída com considerações gerais sobre as propostas
formuladas, a fim de aprimorar o arcabouço jurídico da indústria do petróleo, visando à
proteção ambiental e ao fortalecimento do modelo de desenvolvimento sustentável
instituído com a Constituição Brasileira de 1988. / The Federal Constitution of 1988 raised the healthy environment and quality of life of
present and future generations to a fundamental right . This legal fact modifies all the
policy proposals and implementation of public policies in force hitherto, and requires an
adjustment of production activities to meet this new ideal toward a sustainable society.
This thesis analyzes the offshore oil activity, emphasizing the decommissioning phase of
oil exploration in order to study the legal regulatory mechanisms incidents on disabling
the production system, at which time it turns out great environmental vulnerability. This
is to demonstrate the thesis that the Brazilian legal system on decommissioning is
inconsistent with the norms of environmental law and sustainable development model
constitutionally established. The main objective is to contribute to the improvement of
public policy oil exploration, aiming to consolidate the Brazilian legal system on the
topic, as well as valuing environmental issues in the process of decommissioning.
Through a qualitative methodology is identified, initially, the scenario of the oil industry to
discuss the concept of sustainable development, seeing how it is being built by the
energy and environmental policies of the country. Is then described and analyzed the
structure and what are the international and Brazilian experiences on decommissioning.
After this stage cognitive passes to detail: the institutional and legal framework of the
decommissioning of the oil industry in Brazil, based on the principles of environmental
law, the state infrastructure for the consolidation of a new regulatory framework for this
stage of production; national policy on solid waste and the instrument of environmental
licensing . At the end of this process, two proposals are formulated supplementary legal
instruments aimed at consolidating the regulation of decommissioning offshore oil
industry, based on the guidelines of environmental law. The thesis concludes with
general comments on the proposals in order to improve the legal framework of the oil
industry, environmental protection and aimed at strengthening the sustainable
development model introduced with the 1988 Brazilian Constitution
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Desenvolvimento do plano preliminar de descomissionamento do reator IPEN/MB-01 / Preliminary decommissioning plan of the reactor IPEN/MB-01VIVAS, ARY de S. 20 February 2015 (has links)
Submitted by Maria Eneide de Souza Araujo (mearaujo@ipen.br) on 2015-02-20T15:58:48Z
No. of bitstreams: 0 / Made available in DSpace on 2015-02-20T15:58:48Z (GMT). No. of bitstreams: 0 / Em todo mundo, muitas instalações nucleares foram construídas e necessitarão serem desligadas em um determinado momento por estarem próximas do seu tempo recomendado de utilização que é de aproximadamente 40 anos. A AIEA (Agência Internacional de Energia Atômica) busca orientar e recomendar uma série de diretrizes para a realização de atividades de descomissionamento de instalações nucleares, com atenção especial aos países que não possuem um quadro regulatório legal que ampare as atividades de descomissionamento. O Brasil, até o momento, não possui uma norma específica que oriente as etapas de descomissionamento de reatores de pesquisa. Entretanto, em março de 2011 foi constituída uma comissão de estudo com a atribuição principal voltada às questões de descomissionamento das instalações nucleares brasileiras, culminando na resolução 133, de 8 de novembro de 2012, um projeto de norma que dispõe sobre o Descomissionamento de Usinas Nucleoelétricas. O Instituto de Pesquisas Energéticas e Nucleares (IPEN) possui dois reatores de pesquisa sendo um deles o reator IPEN/MB-01. O objetivo dessa dissertação de mestrado é elaborar um plano preliminar de descomissionamento desse reator de pesquisa, considerando a documentação técnica da instalação (RAS-Relatório de Análise de Segurança), as normas existentes da CNEN (Comissão Nacional de Energia Nuclear), assim como as recomendações da AIEA. Em termos de procedimentos de descomissionamento para reatores de pesquisa, este trabalho se baseou no que existe de mais moderno em experiências, estratégias e lições aprendidas realizadas e documentadas nas publicações da AIEA que abrangem técnicas e tecnologias de descomissionamento. Considerando estes conhecimentos técnicos e às peculiaridades da instalação, foi selecionada a estratégia de desmantelamento imediato, que corresponde ao inicio das atividades de descomissionamento assim que a instalação for desligada, dividindo-a em setores de trabalho. Como recurso de gerenciamento e acompanhamento do projeto de descomissionamento do reator e manutenção de registros, foi desenvolvido um banco de dados utilizando o programa Microsoft Access 2007, no qual contêm todos os itens e informações referentes ao plano preliminar de descomissionamento. O trabalho aqui descrito busca atender os requisitos, critérios técnicos e institucionais, incorporando o que se tem de mais atual em procedimentos de descomissionamento, podendo servir como guia para as demais instalações brasileiras. / Dissertação (Mestrado em Tecnologia Nuclear) / IPEN/D / Instituto de Pesquisas Energéticas e Nucleares - IPEN-CNEN/SP
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