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Human Reliability analysis as an evaluation tool of the emergency evacuation process on industrial installation
Get PDFHuman reliability is the probability that a person correctly performs some required activity by the system in a
required time period and performs no extraneous activity that can degrade the system. Human reliability
analysis (HRA) is the analysis, prediction and evaluation of work-oriented human performance using some
indices as human error likelihood and probability of task accomplishment. The human error concept must not
have connotation of guilt and punishment, having to be treated as a natural consequence, that emerges due to the not continuity between the human capacity and the system demand. The majority of the human error is a
consequence of the work situation and not of the responsibility lack of the worker. The anticipation and the
control of potentially adverse impacts of human action or interactions between the humans and the system are
integral parts of the process safety, where the factors that influence the human performance must be recognized and managed. The aim of this paper is to propose a methodology to evaluate the emergency evacuation process on industrial installations including SLIM-MAUD, a HRA first-generation method, and using virtual reality and simulation software to build and to simulate the chosen emergency scenes
Estudo de viabilidade de rotas para produção de 124I
Get PDFEste relatório visa pesquisar as reações de produção do 124I utilizando o Sb (3He e α) ou Te (próton e dêuteron) como alvos a fim de escolher uma rota para implementação de uma metodologia de irradiação e processamento químico do 124I utilizando o Cíclotron CV-28 do Instituto de Engenharia Nuclear, considerando o compromisso com o rendimento e com as impurezas do processo, custo de produção, além de manter o índice de confiabilidade atual obtido na produção do 123I e 18F
Preliminary study for a nuclear multi-cycle reaload optimization system
No full textFuel assemblies in a reactor are discharged normally after several fuel cycles. This happens because of the concentration of fissile material existing in the fuel assemblies in the core decreases to values such that it is not more possible to keep the reactor operating producing energy at normal rated power. Therefore, the refueling optimization for a nuclear power plant is in fact a multi-cycle problem. A typical multi-cycle reload optimization depends on several kinds of relationships: one is the relationship between the locations where the fuel assemblies are placed for a specified fuel cycle; another is the relationship between fuel loading patterns for the subsequent fuel cycles. This makes the problem very complex and difficult to solve. Until the moment, all the presented proposals for solution are far from solving the multi-cycle optimization problems in reactor fuel management. In this work, we will show preliminary studies of possible solutions for a typical multi-cycle reload optimization problem trying to consider most important restrictions of a real model. In the initial comparisons, the optimization results will be compared with those obtained by the successive single cycle optimizations
Groundwater management and nuclear applications for the northeast: how they can improve life quality in urban environment?
No full textThe groundwater has earned more importance in the last decades, due to growing demands, contamination,
wasteful use and depletion of superficial sources. In Brazil, one of the regions with more intensive use of
groundwater for urban populations supply is the North-eastern Coast. The hydrogeological province of
Northeast Coast is formed by three aquifer systems located in sedimentary basins: Potiguar-Recife, Alagoas-
Sergipe and Jatobá-Tucano-Recôncavo. Coastal aquifers are usually very sensitive to changes in hydraulic head and fluxes. The overexploitation, above the levels of natural recharge, cause risk of aquifer salinization by
marine intrusion. Several wells have showed increasing values of dissolved salts along the last few years, and in some cases they were closed. In that context, some nuclear techniques have been used with great success. Like mentioned above, the use of isotopes (e.g. 2H, 3H, 3He, 18O, 13C, 14C, 15N, 34S, 36Cl, 222Rn, 234U) allow to determine recharge and discharge rates, the ionic strength flux and map the salinization path, giving valuable information for water use management. Other contribution from nuclear technology to coastal urban centres is the seawater desalination. The contracted capacity of nuclear desalination plants has increased steadily since 1965 and is now about 32.4 million m3/d worldwide. In Brazil, the nuclear desalination has begun to be evaluated by studies leaded by government companies and agencies. So, these nuclear applications together with a public system for water management can contribute to solve the main problems of the region, i.e. costly water supply, energy lack and environmental degradation
The users centered design of a new digital fluorometer
No full textThe fluorometer is an equipment used in chemical analysis laboratories, research institutes and nuclear fuel
cycle companies. This equipment measures an unknown amount of uranium in ores, rivers, etc. The fluorometer functioning is based on the uranium fluorescence when submitted to the ultraviolet radiation incidence. The fluorescence is measured by an electronic optic system with optics filters, photomultiplier tube, and a current amplifier. The user centered design involvers the user in the product development in all phases of the design process. Users are not simply consulted at the beginning of the design process and evaluated the system at the end; they are treated as partners throughout the design process. The user centered design emphasizes the needs and abilities of the users and improves the usability of the equipment. The activity centered design emphasizes the development of the equipment with a deep understanding of the users activities and of the current work practices of the users. The aim of this paper is to present a methodological framework that contributes to the design and evaluation of a new digital fluorometer towards an approach related to the users and their activities. This methodological framework includes users-based testing, interviews, questionnaires, human factors standards and guidelines, the users activity analysis and users satisfaction questionnaire
Preliminary study for a nuclear multi-cycle reload optimization system
Get PDFFuel assemblies in a reactor are discharged normally after several fuel cycles. This happens because of the concentration of fissile material existing in the fuel assemblies in the core decreases to values such that it is not more possible to keep the reactor operating producing energy at normal rated power. Therefore, the refueling optimization for a nuclear power plant is in fact a multi-cycle problem. A typical multi-cycle reload optimization depends on several kinds of relationships: one is the relationship between the locations where the fuel assemblies are placed for a specified fuel cycle; another is the relationship between fuel loading patterns for the subsequent fuel cycles. This makes the problem very complex and difficult to solve. Until the moment, all the presented proposals for solution are far from solving the multi-cycle optimization problems in reactor fuel management. In this work, we will show preliminary studies of possible solutions for a typical multi-cycle reload optimization problem trying to consider most important restrictions of a real model. In the initial comparisons, the optimization results will be compared with those obtained by the successive single cycle optimizations
A reduced scale two loop PWR Core Design with Particle Swarm Optimization Technique
No full textReduced scale experiments are often employed in engineering projects because they are much cheaper
than real scale testing. Unfortunately, designing reduced scale thermal-hydraulic circuit or equipment,
with the capability of reproducing, both accurately and simultaneously, all physical phenomena that occur
in real scale and at operating conditions, is a difficult task. To solve this problem, advanced optimization
techniques, such as Genetic Algorithms, have been applied. Following this research line, we have
performed investigations, using the Particle Swarm Optimization (PSO) Technique, to design a reduced
scale two loop Pressurized Water Reactor (PWR) core, considering 100% of nominal power and nonaccidental operating conditions. Obtained results show that the proposed methodology is a promising
approach for forced flow reduced scale experiments
Aplicação do Método dos Pseudo-Harmônicos à Cinética Multidimensional
No full textNeste trabalho propomos a aplicação dos pseudo-harmônicos nos métodos modais em cinética espacial. Os pseudo-harmônicos, ou os pseudo-modos, são as autofunções associadas ao operador de fuga+remoção em cada grupo de energia da equação de difusão estacionária. Este operador é auto-adjunto e não se tem a necessidade de calcular as autofunções adjuntas. No presente trabalho os pseudo-harmônicos, serão obtidos a partir da equação de difusão discretizada pelo Método de Diferenças Finitas de Malha Grossa (DFMG). Os métodos modais aproximam o fluxo dependente do tempo por uma expansão em funções predeterminadas, que incluem a dependência espacial, com coeficientes de expansão incógnitos, que inclue toda a parte dependente do tempo. A obtenção de sistema cuja soluções são os coeficientes da expansão modal é feita com auxílio de uma função peso. Usando os pseudo-modos, obtidos no cálculo estacionário, na expansão modal como sendo as funções dependentes do espaço, mostraremos que a função peso pode ser escolhida como sendo os próprios pseudo-modos adjuntos. Este cálculo conduz a um sistema linear de equações diferenciais ordinárias com a dimensão definida pelo número de pseudo-harmônicos empregados. A solução das equações é constituída por meio da integração analítica da equação dos precursores de nêutrons retardados. O método proposto foi testado e apresentou bons resultados, quando comparado com o método direto