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Assessment actions and communication of solid cancer development risk in scenarios RDD based on computational simulation
Get PDFThe complex scenario involving the disposal of radioactive material into the environment can lead to population
exposure and serious issues with its unfolding events. In this context, a methodology capable of providing useful basic information, with the least amount of scenario-specific-information, for immediate and future risk
assessment is of relevance. For this work a simulation of a Radiological Dispersal Devices involving cesium 137 will be considered, coupling the results of the Health Physics Code System for Evaluating Accidents Involving Radioactive Materials software (HotSpot 3.0.3) and the epidemiological equations of the Radiation Effects Research Foundation (RERF) to support the decision making process. The results of the simulation will be used to help quantify the number of general individuals allocated to areas of higher radiological risk and of interest to medical care by providing the scientific data to develop a more appropriate approach to risk and its
communication to the affected population
Certification of flow measurement methods and calibration of flowmeters in oil and gas industry using radioactive tracers
Get PDFOil and gas, mineral and water supply plants are the typical example of industrial facilities where they need accuracy in fluid flow measurement's procedures. In these installations, large quantities of materials are moving daily inside pipes, and one of the major problems of these industries is the safety of operations in transport of these materials. In order to monitor the transference processes many flowmeters are installed in the pipes to measure constantly the condition of the transported fluid. These flowmeters must be periodically calibrated, and one of the problems in this standardization is that these instruments need to be removed from the pipelines where they are operating and transported to the accredited laboratories to be calibrated. To remove a flowmeter from a pipe is not an easy operation, and in most of the cases, it is a very expensive operation, and in addition, any changes in the pipeline configuration can provoke leaks and when a leak occurs, it is impossible to operate the whole line and provokes accidents. Radiotracer technique is noninvasive fluid flow measure and using proper radiotracers is possible to measure organic, aqueous and gaseous flows without any disturbance in the normal operation of the pipeline. In this work, we present the ATOMUM_TRACER, a software used to determine geometrical and technical procedures to calculate the Residence Time Curves using radiotracer techniques to accurately measure flow of fluids in pipelines with uncertainties around 0.7%
Mapping data through concept maps: an auxiliary tool for decision making regarding institutional projects
Get PDFThis paper reports a data mapping construction aimed to subsidize the decision making process regarding
institutional projects, at different levels of responsibility, at the Instituto de Engenharia Nuclear. The conception
models a systemic and adaptive tool which is based on the concept mapping theory developed by Novak.
The Instituto de Engenharia Nuclear (IEN) is a research center of the Comissão de Energia Nuclear (CNEN), an autarchy attached to Ministério da Ciência, Tecnologia, Inovações e Comunicações. The main focus of IEN is research and development of nuclear science and technology. The developed tool creates a more effective and accessible way of sharing information. However, beyond project data integration into a specific instrument, it also has the intent to compensate the consequences of the continued reduction of the number of workers at IEN over recent years. The recent CNEN management report, published in 2016, showed the problematic situation caused by the loss of workers, stressing the high number of pensions granted and to be granted in the near future. The loss of labor force, besides exposing the urgent need for optimizing knowledge management efforts, also sheds light into another problem: the need for grouping responsibilities among the remaining workers. In this respect, the tool developed helps to face this challenge, enhancing autonomy at different levels but preserving the institutional guidelines. To conclude the report, and in order to exemplify the method, the paper also describes the map construction relative an innovative project proposal in a joint development towards the nuclear area
The use of the virtual reality Helmet Samsung Gear vr as interaction interface of a radioactive waste repository simulator
Get PDFRadioactive waste is all material resulting from human activity that contains elements that emit radiation that can generate risks to health and the environment. In this sense, they are very toxic also for those who perform the storage of radioactive waste in nuclear facilities. On the other hand, the virtual reality (VR) as been destined to the most diverse purposes, like simulations for educational systems, for military urposes as for diverse training. VRcan be considered as the junction of three basic principles: immersion, interaction and involvement. Bases on these principles of VR, this work aimed to develop a simulator of a repository of nuclear tailings, for mobile computing, whose interaction interface will be through the Samsung Gear VR helmet. The simulator of the nuclear waste repository was developed in the unity 3D tool and the elements that make up the scenario in the 3D MAX program. In this work we tried to put virtual reality under scrutiny in conjunction with Gear VR, to help in the sensation of immersion, as well as, the possibility of interaction with joysticks. The purpose was to provide greater insight into the operating environment
Conversor DSB-SSB a capacitores chaveados por Transformador de Hilbert em tecnologia CMOS de 180 nm/
Get PDFThe realization of an analog integrated circuit for conversion of Double-Sideband (DSB) amplitude-modulated signals into Single-Sideband (SSB) is presented. Implemented by discrete-time switched-capacitor circuits, it adopts an Infinite Impulse Response (IIR) filter to realize a Hilbert transformer as alternative to digital implementations which take advantage of high processing capacity from parallel digital circuits to obtain the Hilbert transformer by means of high-order Finite Impulse Response (FIR) filters. Fabricated in a 180 nm CMOS technology with metal-metal (MiM) capacitors, the use of structurally all-pass filters greatly reduces the converter’s sensitivity to capacitor mismatch. For 1.8 V power supply and 1 V differential input/output signals, experimental results show the converter achieves Image Rejection Ratio (IRR) greater than 39.5 dB for Lower-Sideband (LSB) modulation and 38.0 dB for Upper-Sideband (USB) modulation for input signals ranging from 25% to 75% of the carrier frequency. These figures are higher than previous analog circuit proposals and comparable to digital implementations of state-of-the-art integrated circuits. Its silicon area is 1.09 mm2 and the converter consumes only 17.7 mW for 1 MHz sampling frequency while its IRR presents standard deviation of only 0.5 dB among 20 chip samples.Este trabalho trata da realização de um circuito integrado analógico para a conversão de sinais com modulação em amplitude de banda dupla (Double Sideband ou DSB) para modulação de banda simples (Single Sideband ou SSB). Implementado por circuitos de tempo discreto a capacitores chaveados, utiliza-se de um filtro com resposta infinita ao impulso (Infinite Input Response ou IIR) para compor um transformador de Hilbert como alternativa a implementações digitais, que se aproveitam da grande capacidade de processamento paralelo dos circuitos digitais para a obtenção do transformador de Hilbert por meio de filtros com resposta finita ao impulso (Finite Impulse Response ou FIR) de ordem elevada. Fabricado em tecnologia CMOS de 180 nm com capacitores do tipo metal-metal (MiM), a adoção de filtros estruturalmente passa-tudo reduz significativamente a sensibilidade do conversor ao descasamento de capacitores. Para alimentação de 1,8 V e sinais diferenciais de até 1 V, resultados experimentais mostram que o conversor atinge taxa de rejeição de imagem (Image Rejection Ratio ou IRR) maior que 39,5 dB para modulação Lower Sideband (LSB) e 38,0 dB para modulação Upper Sideband (USB) para sinais de entrada na faixa de 25% a 75% da frequência da portadora, valores estes superiores a propostas analógicas anteriores e comparáveis a propostas digitais do estado da arte em circuitos integrados. Com área de silício de 1,09 mm2, o conversor consome apenas 17,7 mW para frequência de amostragem de 1 MHz enquanto sua IRR apresentou desvio padrão de apenas 0,5 dB dentre 20 amostras avaliadas
Dinâmica das águas subterrâneas e mecanismos de recarga em uma área de mineração de urânio empregando técnicas isotópicas
Get PDFIn arid and semi-arid regions, where surface water is not available on fixed basis, groundwater provides in most cases the only permanent and safe source of water. This situation is particularly true in the Caetité Experimental Basin (CEB), located in the semi-arid region of Northeastern Brazil, where the local community depends heavily on groundwater availability. The water issue has been aggravated since 1999 when a
nuclear facility, the Uranium Concentrate Unit (URA), started operations and the local community had to face not only the challenges associated with water scarcity but also the potential contamination processes due to mining activity. This scenario caused an increasing debate over competing water interests between the local community and the uranium production center. Although several studies have been conducted to characterize the hydrological system of the region, the groundwater flow regime in this watershed remains poorly understood. This study aims to investigate the groundwater dynamics and recharge mechanisms in this basin, as part of initial efforts to characterize the hydrogeology of this area for future contamination studies. Measurements of δ2H, δ18O, total dissolved solids (TDS), pH, and electrical conductivity (EC) were carried out in a total of 181 samples (122 groundwater, 36 surface water and 23 rainfall samples), collected during the dry and wet seasons from 2012 to 2014. The chemical, physicochemical and Isotope results suggest that the recharge is spatially variable, occurring by direct and indirect mechanism, by local precipitation and surface water contribution, respectively. These results point to a fast dynamic of this system, which makes this aquifer more vulnerable to contamination from activities in the land surface, as the contaminants could move and quickly reach the aquifer.Em regiões áridas e semiáridas, a água superficial não está disponível de forma perene, e as águas subterrâneas proporcionam, na maioria dos casos, a única fonte de água permanente e segura. Esta situação é particularmente verdadeira na Bacia Experimental Caetité (BEC), localizada na região semiárida do Nordeste do Brasil, onde a comunidade local é fortemente dependente da disponibilidade de águas subterrâneas. A questão da água se agravou em 1999, com o início das operações de uma instalação nuclear, a Unidade de Concentrado de Urânio (URA), e a comunidade local teve que enfrentar não apenas os desafios associados à escassez de água, mas também os potenciais processos de contaminação decorrentes da atividade de mineração. Este cenário provocou um debate crescente entre a comunidade local e o centro de produção de urânio. Embora vários estudos venham sendo conduzidos na região, o regime de fluxo de águas subterrâneas nesta bacia hidrográfica permanece mal compreendido. Este
estudo tem como objetivo investigar a dinâmica das águas subterrâneas e mecanismos de recarga nesta bacia, como parte dos esforços iniciais para caracterizar a hidrogeologia desta área afim de subsidiar futuros estudos de contaminação. Medidas de δ2H, δ 18O, total de sólidos dissolvidos (TSD), pH e condutividade elétrica (EC) foram realizadas em um total de 181 amostras (122 águas subterrâneas, 36 águas superficiais e 23 amostras de precipitação) coletadas durante as estações secas e chuvosas de 2012 a 2014. Os resultados químicos, físico-químicos e isotópicos sugerem que a recarga é espacialmente variável, correndo por mecanismo direto e indireto, por precipitação local e contribuição da água superficial, respectivamente. Estes resultados apontam para uma dinâmica rápida deste sistema, tornando-o mais vulnerável à contaminação por atividades na superfície do terreno, uma vez que os contaminantes podem rapidamente atingir o aquífero
STUDIES OF SIMULATIONS OF TWO-PHASE WATER-AIR FLOWS USING ANSYS CFX.
Get PDFNormally in all simulations of flows in computational fluid dynamics, CFD, it is common to use characteristic planes to visualize the profiles of the parameters of interest, mainly in 3D simulations.
The present work proposes a standard form of visualization that shows, mainly in two-phase flows, in a more realistic way, the dynamics of the development of the phase flow. This visualization is present within the CFX program in the post-processing module, in the option of representing volumes using sub option, isovolumes. Through this representation, the program highlights the volumes of the finite element mesh corresponding to the selected values of the parameter to be analyzed such as pressure, velocity, volumetric fraction, etc.
By means of the volume-isovolume representation, a well representative effect of the current flow pattern is obtained, especially when the volumetric fraction of the air or the gas phase of the flow is emphasized.
This form of visualization is being applied to the study of inclined two-phase flows, which will be tested in a new experiment currently under construction at the Laboratory of Experimental Thermal-Hydraulics – LTE of the Institute of Nuclear Engineering - IEN in Rio de Janeiro
THE USE OF VIRTUAL REALITY FOR TRAINING PROFESSIONALS OF NUCLEAR MEDICINE
Get PDFThe use of virtual reality has becoming an important tool for training purposes, with emphasis to those procedures that involve risk to professionals, as those associated with occupational exposure to ionizing radiation in nuclear medicine services. According to the basic safety standards (BSS), published by International Atomic Energy Agency (IAEA), the qualification and training of all personnel of a nuclear medicine service should be performed periodically in order to ensure its understanding and better performance of their respective duties. In face of that, this work consists in research, analysis and unification of requirements and specifications for the radiological protection of nuclear medicine workers, specifically those of radiopharmacy. To this end, a detailed study of the radiological safety and workflow related to radiopharmacy procedures is under development considering the radiological recommendations and safety standards of nuclear medicine services. As a result, it is expected a set of information that will enable the development of a virtual training environment in radiological protection for such professionals aiming the development of skills and the improvement of competencies by means of the simulation with lower cost, unlimited number of repetitions of training, without interference in the laboratory routine and the primary purpose of this work: in safe conditions
Análise probabilística de segurança e os guias de gerenciamento de acidentes severos - um estudo de caso para uma usina similar à Angra 1
Get PDFProbabilistic Safety Assessment (PSA) plays an important role in the nuclear industry contributing for an increase in the plant safety. Their results are reference for improvements in design, process and procedures. When analyzing the accident progression with the reactor core fusion, it provides many insights that collaborated for the elaboration of the Severe Accident Management Guidance (SAMG).
In order to study this interaction between PSA and SAMG, the proposed work consisted in the development a preliminary Level 2 PSA analysis for a plant similar to Angra 1.
During this work it was found the following relevant steps of a PSA: the grouping of the Level 1 accident sequences into Plant Damage States (PDS), defining all combinations of events that could lead to the fusion of the reactor core in a small number of scenarios; the study of the accident evolution through the Accident Progression Event Trees (APET), evaluating the associated phenomena; and the perception that actions proposed to prevent core fusion in some cases could worsen the conditions after the core is damaged. So they have to be evaluated and balanced their positives and negatives impacts before being used.A Análise Probabilística de Segurança (APS) tem mostrado papel relevante na indústria nuclear contribuindo para o aumento da segurança das plantas. Seus resultados servem de referência para melhoria de projeto, processos e procedimentos. Ao analisar a progressão de acidente com a fusão do núcleo do reator, ela acaba por fornecer diversos resultados que colaboraram para a elaboração dos Guias de Gerenciamento de Acidentes Severos (SAMG). A fim de estudar esta interação entre a APS e o SAMG, o trabalho proposto consistiu no desenvolvimento de uma análise preliminar de uma APS Nível 2 para uma usina similar à Angra 1. Durante este desenvolvimento foram verificados os seguintes pontos relevantes da APS: o agrupamento das sequências de acidentes em Estados de Dano à Planta (EDP), sintetizando todas as possíveis combinações de eventos que levam à fusão do núcleo do reator em um pequeno número de cenários; o estudo da evolução do acidente através das Árvores de Progressão de Acidente, avaliando os fenômenos associados; e a percepção de que ações propostas para a prevenção da fusão do núcleo podem ser prejudiciais após a sua ocorrência, de modo que devem ser avaliados e balanceados seus impactos positivos e negativos antes de sua utilização
Utilização de um ambiente virtual de aprendizagem com realidade virtual interativa
Get PDFNas últimas décadas foram desenvolvidos diversos estudos a respeito da efetividade do uso da realidade virtual como ferramenta de ensino. Também foram desenvolvidas novas e cada vez mais complexas ferramentas de TIC (Tecnologias da Informação e Comunicação). Nesse contexto surgiram as AVA (Ambientes Virtuais de Aprendizagem) que são mídias que utilizam o ciberespaço para veicular conteúdo didático oferecendo aos discentes uma ferramenta de ensino alternativa antagonizando o problema da complexidade do tema da engenharia de reatores. Esse trabalho trata do desenvolvimento e da utilização de um Ambiente Virtual de Aprendizagem para auxílio do ensino do funcionamento do primeiro e segundo ciclo de um reator nuclear de água pressurizada, possibilitando ao discente uma melhor visualização dos componentes, através da realidade virtual interativa, a engenharia básica de uma usina nuclear geradora de potência. Além de dessa plataforma ser usada como ferramenta de ensino, outra funcionalidade apresentada, é a utilização da mesma pelos desenvolvedores de ambientes ou objetos virtuais como repositório online dos mesmos modelados pelos pesquisadores. Então, com esses objetos virtuais alocados em categoria, os discentes poderiam utilizar esse AVA em sala de aula como ferramenta de auxílio no ensino em matérias relacionadas a engenharia de reatores. Desse modo também, é possível que os pesquisadores utilizem a plataforma como uma alternativa prática para exibir seus modelos para outros pesquisadores e assim contribuir com a difusão do conhecimento sobre a energia nuclear dentro e fora de sua comunidade de pesquisa