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Dedicated sensors are widely used throughout many industries to monitor everyday operations, maintain safety, and report performance characteristics. In order to adopt a more sustainable solution, much research is being applied to self-powered sensing, implementing solutions which harvest wasted ambient energy sources to power these dedicated sensors. The adoption of not only wireless sensor nodes, but also self-powered capabilities in the nuclear energy process is critical as it can address issues in the overall safety and longevity of nuclear power. The removal of wires for data and power transmission can greatly reduce the cost of both installation and upkeep of power plants, while self-powered capabilities can further reduce effort and money spent in replacing batteries, and importantly may enable sensors to work even in losses to power across the plant, increasing plant safety. This thesis outlines three harvesting opportunities in the nuclear energy process from: thermal, vibration, and radiation sources in the main structure of the power plant, and from thermal and radiation energy from spent fuel in dry cask storage. Thermal energy harvesters for the primary and secondary coolant loops are outlined, and experimental analysis done on their longevity in high-radiation environments is discussed. A vibrational energy harvester for large rotating plant machine vibration is designed, prototyped, and tested, and a model is produced to describe its motion and energy output. Finally, an introduction to the design of a gamma radiation and thermal energy harvester for spent nuclear fuel canisters is discussed, and further research steps are suggested. / Master of Science

This diploma thesis is based on an analysis of knowledge of inhabitants within the emergency planning zone of operations, security and behaviour in case of an accident in the Temelín Nuclear Power Plant (TNPP). Operation a nuclear equipment in connected with certain risks which can´t be utterly eliminated. From this reason, security precautions are made, which are based on an accident preparedness, or on emergency plans. Emergency planning serves to a preparedness for non-standard or emergency situations for an area which is called an emergency planning zone. The emergency preparedness, not only within this zone, has a key role for a successful performance of inhabitants´ protection in case of an emergency event. The concept of emergency preparedness includes both the emergency planning and inhabitants´ awareness and knowledge of operations, risks and following precautions in case of an accident in TNPP. The aim of this diploma thesis is to inquire about "What is knowledge of inhabitants within an emergency planning zone of the Temelín Nuclear Power Plant operations?" The theoretical part is based on consulting the employees of ČEZ Ltd. Who work in the Temelín Nuclear Power Plant as well as on a study of professional literature, articles and related legislation. The practical part is based on a questionnaire survey and it is divided into three parts: operations, risks, security, knowledge and behaviour during an accident. The results revealed some margins in respondents´ knowledge concerning issues of operations as well as knowledge and behaviour during an accident. A positive evaluation concerns respondents´ knowledge of used nuclear fuel, the meaning of containment building and the procedures in case of evacuation. On the other hand, the respondents showed insufficient knowledge of the function of a reactor, what barriers are between the active zone and environment and when to use iodine prophylaxis. I consider the present status of inhabitants´ knowledge of TNPP operations insufficient and I propose some improvements. It is important to focus on inhabitants older than 50 years, whose lack of knowledge is even alarming.

Sistemas de transmissão de energia elétrica em corrente contínua e alta tensão baseados em tecnologia de conversores a fonte de tensão (VSC-HVDC), ao contrário de linhas de transmissão em corrente alternada, operam como elementos de controle de variáveis elétricas, podendo ser úteis na estabilidade do sistema de potência. Mas apesar desta vantagem, sistemas VSC-HVDC possuem limitações no desempenho estável, o que enseja o desenvolvimento de uma metodologia para mapeamento de suas zonas de operação estável e possíveis regiões de instabilidade. Inicialmente estudou-se os detalhes da tecnologia VSC-HVDC tais como o funcionamento da eletrônica de potência e estratégias de controle utilizadas. Em seguida, investigou-se os modelos de geradores síncronos para interconexão com o lado CA das estações conversoras do VSC-HVDC. E, finalmente, aplicou-se a tecnologia VSC-HVDC sobre um modelo de sistema de potência com uma estação conversora localizada em um porto offshore e uma outra no continente, próxima à rede de alta tensão em corrente alternada. Simulações e análise deste sistema foram executadas considerando várias condições operacionais. O gráfico de potência gerada e consumida, obtido pela aplicação da metodologia, apresenta grande potencial de uso prático como por exemplo sua implementação na interface homem-máquina da estação de operação do porto offshore, provendo informação em tempo real de alto nível ao operador do sistema elétrico do porto offshore e consequentemente aumentando sua consciência situacional quanto a proximidade dos limites de instabilidade. / High voltage direct current power transmission systems based on voltage source converters (VSC-HVDC), as opposed to alternating current ones, operates as elements of control of electrical variables, being useful for stability of power system. Besides this advantage, VSC-HVDC systems have limitations in stable performance, which instigates the development of a methodology for mapping its operational zones of stability and possible regions of instability. The author initially studied the details of the VSC-HVDC technology such as the power electronic principles and the control strategies used on this research. Subsequently, the author investigated synchronous generator models for interconnection on the AC side of the VSC-HVDC converter stations. Finally, the author applied the VSC-HVDC technology on a model of power system with two converter stations, one located on an offshore port and the other on the shore, next to an alternating current high voltage power grid. Simulations and analysis of this system were carried out considering various operational conditions. The graphic of generated and consumed power on offshore port, obtained by the application of the methodology for mapping operational zones, presents a great potential of being implemented in the man-machine interface of an operation workstation, thus providing high level online information for the operator of the offshore port electrical system and consequently improving its situational awareness of the proximity to instability limits.

Sistemas de transmissão de energia elétrica em corrente contínua e alta tensão baseados em tecnologia de conversores a fonte de tensão (VSC-HVDC), ao contrário de linhas de transmissão em corrente alternada, operam como elementos de controle de variáveis elétricas, podendo ser úteis na estabilidade do sistema de potência. Mas apesar desta vantagem, sistemas VSC-HVDC possuem limitações no desempenho estável, o que enseja o desenvolvimento de uma metodologia para mapeamento de suas zonas de operação estável e possíveis regiões de instabilidade. Inicialmente estudou-se os detalhes da tecnologia VSC-HVDC tais como o funcionamento da eletrônica de potência e estratégias de controle utilizadas. Em seguida, investigou-se os modelos de geradores síncronos para interconexão com o lado CA das estações conversoras do VSC-HVDC. E, finalmente, aplicou-se a tecnologia VSC-HVDC sobre um modelo de sistema de potência com uma estação conversora localizada em um porto offshore e uma outra no continente, próxima à rede de alta tensão em corrente alternada. Simulações e análise deste sistema foram executadas considerando várias condições operacionais. O gráfico de potência gerada e consumida, obtido pela aplicação da metodologia, apresenta grande potencial de uso prático como por exemplo sua implementação na interface homem-máquina da estação de operação do porto offshore, provendo informação em tempo real de alto nível ao operador do sistema elétrico do porto offshore e consequentemente aumentando sua consciência situacional quanto a proximidade dos limites de instabilidade. / High voltage direct current power transmission systems based on voltage source converters (VSC-HVDC), as opposed to alternating current ones, operates as elements of control of electrical variables, being useful for stability of power system. Besides this advantage, VSC-HVDC systems have limitations in stable performance, which instigates the development of a methodology for mapping its operational zones of stability and possible regions of instability. The author initially studied the details of the VSC-HVDC technology such as the power electronic principles and the control strategies used on this research. Subsequently, the author investigated synchronous generator models for interconnection on the AC side of the VSC-HVDC converter stations. Finally, the author applied the VSC-HVDC technology on a model of power system with two converter stations, one located on an offshore port and the other on the shore, next to an alternating current high voltage power grid. Simulations and analysis of this system were carried out considering various operational conditions. The graphic of generated and consumed power on offshore port, obtained by the application of the methodology for mapping operational zones, presents a great potential of being implemented in the man-machine interface of an operation workstation, thus providing high level online information for the operator of the offshore port electrical system and consequently improving its situational awareness of the proximity to instability limits.

Advanced computational tools are applied to simulate a nuclear power plant (NPP) control rod assembly ejection (CRE) accident. The impact of these reactivity-initiated accidents (RIAs) on core reactivity behavior, 3D power distribution and stochastic reactivity estimation are evaluated. The three tools used are: the thermal-hydraulic (TH) RELAP5 (R5) code, the neutronic (NK) PARCS (P3D) code, and the coupled version P3D/R5, with specially developed linkage using the environment code MATLAB. This study considers three different-size cores: NPP1 (2772 MWt); NPP2 (530 MWt); and NPP3 (1061 MWt). The three cores have the same general design and control rod assembly (CRA) positions, and the ejected CRA has similar worth and at the same rod ejection pace. The CRE is assessed under both hot zero power (HZP) and hot full power (HFP) conditions. The analyses indicate that RIA modeling and simulation should be carried out through a systematic coding and configuration approaches, otherwise the results will not capture the true transient behavior of the core under analysis. The simulation of one code depends on the appropriate configuration of parameters generated by the other code and on the correct determination of the TH/NK mapping weight factors for the various mesh regions in each of the models. From the design point of view, the standalone codes predict milder magnitude of power and reactivity increase compared to the coupled P3D/R5 simulation. The magnitudes of reduced peak power and reactivity become larger as the core size shrinks. The HFP simulation shows that the three NPPs have the same transient peak value, but the post-transient steady power is lower for a smaller core. The HZP analysis indicates that the transient peak is lower for the smaller core, but the post-transient power occurs at the same level. The three-dimensional (3D) power distributions are different among the HFP and HZP cases, but do not depend on the size of the core. The results indicate: i) HFP: core power increases in the area surrounding the ejected rod/bank assembly, and this increase becomes lower as the NPPs shrinks however, the power is well-distributed after the transient; and ii) HZP: the area surrounding the CRA stays hotter, but the 3D peak assembly factor becomes lower, during and after the transients, as the NPPs shrinks. These features confirm that the smaller cores yield a safer response to a given inserted reactivity compared to larger cores. A stochastic extended Kalman filter (EKF) algorithm is implemented to estimate the reactivity based on the reactor power profile, after the addition of random noise. The inverse point kinetics (IPK) deterministic method is also implemented and the results of the application of EKF and IPK are compared to the P3D/R5 simulation. The following sophisticated strategies made the EKF algorithm robust and accurate: the system is modeled by a set of continuous time nonlinear stochastic differential equations; the code uses a time step directly based on the power measured and applies that to the model for online discretization and linearization; filter tuning goes automatically up from the first time step; and the state noise covariance matrix is updated online at each time step. It was found that the IPK reactivity has higher noise content compared to the EKF reactivity for all cases. Thus, the EKF presents superior and more accurate results. Furthermore, under a small reactivity insertion, the IPK reactivity varies widely from positive to negative values: this variation is not observed within the EKF. A sensitivity analysis for three distinct standard deviation (SD) noise measurements suggests that EKF is superior to IPK method, independent of the noise load magnitude. As the noise content increases, the error between the IPK and P3D/R5 reactivity also increases. A sensitivity analysis for five distinct carry-over effects of different random noise loads indicates that the random addition of different noise loads to the reactor power does not change the overall performance of both algorithms. / Este trabalho aplica métodos computacionais avançados para simular a ejeção de barras de controle (CRE) em uma planta térmica nuclear (NPP). São avaliados o impacto da ocorrência de acidentes iniciados por reatividade (RIAs) na reatividade total, na distribuição da potência em três dimensões (3D) e na determinação da reatividade. As ferramentas utilizadas são: o código termo-hidráulico (TH) RELAP5 (R5), o código neutrônico (NK) PARCS (P3D), a versão acoplada P3D/R5, e o ambiente computacional MATLAB. Este estudo considera três reatores nucleares de diferentes tamanhos: NPP1 (2772 MWT); NPP2 (530 MWt); e NPP3 (1061 MWt). Os três núcleos possuem projeto similar e idêntica posição dos grupos das barras de controle (CRA), além do mesmo valor de reatividade diferencial das CRA ejetadas e idêntica velocidade de ejeção. A ocorrência da CRE é avaliada sob condições de hot zero power (HZP) e de hot full power (HFP). As análises indicam que a modelagem e a simulação de RIAs devem ser realizadas sistematicamente, caso contrário os resultados não irão refletir o comportamento em regime transitório do núcleo. A simulação de um modelo em um código depende da apropriada configuração de parâmetros gerados pelo outro código e da determinação adequada do mapeamento TH/NK para as várias malhas dos modelos. Do ponto de vista de projeto, a utilização de códigos independentes resulta em cálculos de potência e reatividade conservadores em comparação com os resultados utilizando-se P3D/R5. Os picos de potência e de reatividade são menores à medida que o núcleo encolhe. A simulação em condições de HFP resulta em valores de pico de potência similares durante transitório para as três NPPs, mas a potência de pós-transitórios é menor para o menor núcleo. A análise em condições de HZP também indica que o valor máximo durante o transitório é menor para o menor núcleo, mas o pós-transitórios ocorre aos mesmos níveis de potência das demais NPPS. A distribuição de potência em 3D também apresenta resultados distintos para condições de HFP e HZP, mas tais resultados são independentes do tamanho do núcleo: i) HFP: há um aumento da potência do núcleo em torno da CRE, mas tal comportamento diminui para núcleos menores - no entanto, a potência é bem distribuída após o transitório; e ii) HZP: há aumento de potência na área do CRE, mas o pico de potência em 3D é menor durante e depois dos transitórios para núcleos menores. Tais características indicam que os núcleos menores respondem de forma mais segura quando da inserção de reatividade em comparação a reatores de maiores dimensões. O método estocástico de filtragem de Kalman estendido (EKF) foi codificado para estimar a reatividade com base no perfil de potência da NPP, após a adição de ruído aleatório. O método determinístico da cinética pontual inversa (IPK) também foi implementado e os resultados da aplicação dos algoritmos do EKF e IPK foram comparados com os resultados da simulação do P3D/R5. As seguintes estratégias, implementadas neste trabalho, possibilitaram a aplicação robusta e precisa do EKF: o sistema foi modelado por um conjunto de equações diferenciais não-lineares estocásticas de tempo contínuo; o algoritmo obtém o passo de tempo diretamente da potência medida e aplica-o ao modelo para a discretização e linearização online; o ajuste do filtro ocorre automaticamente a partir do primeiro passo de tempo; e a matriz de covariância do ruído no estado é atualizada online. Verificou-se que a reatividade calculada pelo método IPK possui maior nível de ruído quando comparada ao EKF para todos os casos estudados. Portanto, o EKF apresenta resultados superiores e mais precisos. Além disso, sob uma pequena inserção de reatividade, a reatividade calculada pelo método IPK varia consideravelmente de valores positivos para negativos: esta variação não é observada com o EKF. Uma análise de sensibilidade para três desvios padrão (SD) sugere que o algoritmo EKF é superior ao método IPK, independente da magnitude do ruído. Com o aumento da magnitude do ruído, o erro entre as reatividades calculadas pelo IPK e pelo P3D/R5 aumenta. A análise de sensibilidade para cinco ruídos aleatórios indica que a adição de ruído na potência do reator não altera o desempenho global de ambos os algoritmos.

This issue represents contribution to discussion of the population protection within the emergency planning zone of Temelín Nuclear Power Plant (NNP). My intention was to evaluate the actual system of public protection measures in the case of potential appearance of the radiation accident. As a part of this evaluation the analysis of correlation between emergency classification system of emergency events severity, valid for Temelín NPP, and system of immediate protective measures for population was done. The introductory parts of my work describes the basic information about Temelín Nuclear Power Plan. The main attention was given to nuclear safety, radiation protection, principles of emergency preparedness and types of NPP operating modes. Further system of public protection measures for the case of radiation accident appearance is described. Emergency classification system of potential extraordinary events at Temelín NPP and principles of announcements and public warning is also explained in this part. Part of this information represents description of potential implementation of immediate protective actions. One of the outputs is in the form of simple educational software program useful especially for children education. They can received information how to behave in the case of radiation accident declaration. Software is enclosed in the form of compact disk and gain knowledge can be verified by a short test.

La thèse s’intéresse au travail de conduite d’une industrie de process à risques,les centrales nucléaires, et aux marges de manoeuvre dont disposent les équipes dans l’application des procédures techniques. Celles-ci doivent en effet être adaptées aux situations rencontrées dans la réalité, qui sont toujours nouvelles et finalement uniques. En effet, la technologie concernée est si complexe que les situations ambiguës sont fréquentes. Les exploitants sont souvent confrontés à des décisions techniques qui cristallisent en elles la pluralité d’exigences auxquelles sont soumises les industries à risques : sûreté nucléaire, disponibilité et productivité, sécurité des travailleurs, respect de l’environnement, etc.Exploiter une centrale nucléaire implique donc d’arbitrer entre des exigences qui devraient en théorie être conciliables mais qui ne le sont pas en pratique, ou difficilement. En effet, chaque terme de la décision concrète comporte des avantages vis-à-vis de l’un des critères et des inconvénients vis-à-vis des autres critères en présence. Ainsi, décider revient toujours à renoncer, et la décision technique dans les organisations à risques implique une prise de risque professionnelle et personnelle pour les acteurs de terrain. La thèse s’interroge alors sur les facteurs qui participent de l’engagement des opérationnels dans l’action. Les théories utilitaristes et culturalistes ne parvenant pas à épuiser toute la complexité des cas rencontrés (implication d’agents pourtant peu carriéristes, disparités individuelles fortes au sein de groupes socio-professionnels supposés homogènes. . .), la recherche s’intéresse aux théories de la reconnaissance sociale et du don/contre-don comme explication première de la motivation et de la coopération au travail. / This doctoral dissertation describes the running of a high-risk process industry,nuclear power plants, and the operators’ autonomy to apply technical procedures.The chosen procedures must fit the "real-life" situations, which are always new, andultimately unique. Nuclear power technology is so complex that ambiguous situations often arise. The operators have to make technical decisions that encompassall the demanding issues of high-risk industries : nuclear safety, plant availabilityand generation output, workers’ safety, environmental protection, etc.Operating a nuclear power plant thus involves trade-offs between theoretically compatible concerns that in practice are incompatible or difficult to reconcile.Each option in the actual decision will have advantages for certain criteria anddisadvantages for others. Deciding thus always means forgoing something, andtechnical decision-making in high-risk organizations forces the field workers totake professional and personal risks. The dissertation thus examines the factors explaining why operators are still interested in getting involved in the action.Self-interest and cultural theories cannot explain all the cases encountered in thefield (workers with high commitment but paradoxically little interest in career advancement, strong differences between individuals in a supposedly homogenoussocio-professional groups, etc.). The research focuses on social recognition andgift/countergift theories as the primary explanation for motivation and cooperation at work.

Dans le cadre des activités de maintenance des centrales nucléaires, les personnes intervenant sur des chantiers en zone contrôlée doivent effectuer des mesures de contamination surfacique sur leurs outils, gants, sur tenue de travail et sur les parties de leur corps susceptible d’être contaminées (cou et tête par exemple). Or, les mesures de contamination surfacique bêta ne peuvent pas toujours être réalisées au plus près des chantiers. Le bruit de fond gamma présent à ces endroits étant élevé et fluctuant, ce dernier perturbe les appareils utilisés habituellement pour la mesure de contamination surfacique. L’objectif principal de ce travail était de concevoir un appareil de mesure adapté à la détection de contamination surfacique bêta de quelques Bq/cm2 (typiquement < 4 Bq/cm2), dans une ambiance gamma de quelques dizaines de µSv/h (typiquement < 100 µSv/h) et fluctuante (typiquement de l’ordre de 30% en 1 seconde). / In the framework of the nuclear power plants maintenance, the onsite workers incontrolled areas must performed some surface contamination controls of their tools, gloves, workingsuits and over their body parts which may be contaminated (neck and head for instance). However,surface beta contamination measurements can’t always been done as close as possible of the working location. The onsite ambient gamma background, being high and fluctuating, may disturb the radiation protection devices commonly used for surface contamination measurements.The main goal of this work was to conceive a radiation protection device adapted to the betasurface contamination of about a few Bq/cm2 (< 4Bq/cm2 typicaly) in a fluctuating (typicaly 30%variation per second) ambient gamma background of a few μSv/h (typicaly <100 μSv/h).

The theme of the dissertation is a change in an approach to securing fire protection in the Temelín Nuclear Power Plant after the accident in the Fukushima Nuclear Power Plant. The theoretical part is an introduction to fire protection. It especially points out the statutory obligations applicable for both the public and the private sector, which are transferred to the companys fire rescue corps too. At the same time, fire protection is interconnected with legislation and specified in greater detail in EU countries. The theoretical part describes the process of building a uniform information system, safety-related issues and prevention of dangerous situations. The theoretical part summarizes the history of the nuclear energy industry, from the discovery of the disintegration of the uranium nucleus in 1938 and the first controlled reaction of uranium liberation by splitting a nucleus in 1942, when, at the same time, the first reactor was built. Unfortunately, this discovery did not only familiarize mankind with positive aspects associated with a controlled reaction, but it also showed the dark side of nuclear energy in the form of atomic bombs used mainly in the course of the World War II. After the World War II, civil defence organizations were gradually founded in the world. The main goal of all these organizations was to prevent nuclear weapons, nuclear power plants and nuclear fuel from being spread. At the present time there are three strong international organizations dealing with nuclear fission. Despite all the efforts to build a system of radiation protection, environmental protection and impacts on living organisms were not elaborated fully. First, passive attitudes aimed at protective equipment were the central theme, and these passive attitudes have been reflecting in an active approach to environmental protection in the past few years, the goal being to eliminate phenomena giving rise to threats to the environment and life as such. The actual history of nuclear power plants is very complex and complicated. The principle of all these power plants, no matter what type of reactor their operation is based on, is always nuclear fission the trouble is that in this case any wrong handling or storage has immense consequences for the whole world's population. The development of the nuclear energy industry in the Czech Republic was slow, which was caused by the occupation of the Jáchymov uranium mines by the Soviet Army after the World War II. Based on an agreement with Czechoslovakia, the Soviet Army exported the uranium extracted to the Soviet Union and left just 10% of it in the territory of Czechoslovakia. At that time, nuclear power plants began to be built in Czechoslovakia, such as the Jaslovské Bohunice Nuclear Power Plant, Dukovany Nuclear Power Plant and the Temelín Nuclear Power Plant as the last one, whose construction was started in times of Czechoslovakia, but which was completed and put into operation in times of the existence of the Czech Republic. The research is focused on emergency events which were the cause of the accident in the Fukushima Nuclear Power Plant. Based on an FMEA (failure mode and effects analysis), the issues related to the activities of the company's fire rescue corps were specified. Another analysis is focused on the evaluation of outside and inside factors and evaluation of strengths, weaknesses, opportunities and threats to the company's fire rescue corps. Utilizing an FMEA, possible risks and failures are detected. The goal of this analysis is to eliminate risks and increase safety. The result is objective evaluation and increase in safety within the Temelín Nuclear Power Plant. A considerable negative aspect of this analysis is that it is very time consuming and varies in time due to the changeability of the factors monitored. The result of all the work is the evaluation of the existing state of the company's fire rescue corps through a SWOT analysiS.