京都大学 / 0048 / 新制・課程博士 / 博士(農学) / 甲第21826号 / 農博第2339号 / 新制||農||1067(附属図書館) / 学位論文||H31||N5198(農学部図書室) / 京都大学大学院農学研究科地域環境科学専攻 / (主査)准教授 髙橋 知之, 教授 北山 兼弘, 准教授 刑部 正博 / 学位規則第4条第1項該当 / Doctor of Agricultural Science / Kyoto University / DFAM

The aim of this diploma work has been to work up a first study dealing with possibilities of enlargement of Slavětice substation with the new sources of Dukovany power-plant (EDU). In this work I am mentioning the linking of 400 kV Slavětice substation into the electricity system in Czech Republic and its coupling into the west-European UCTE system and I am also itemizing the basic data of neighbouring substations. Further I am describing the current state of 400 kV and 110 kV substations in Slavětice, their parameters and scheme. In this work I am mentioning basic information of nuclear reactor piles, coming into consideration for the prospective new pile construction in the premises of Dukovany substation and also reflections about possibilities of bringing out power of this new pile. In the following part of my diploma work there are stated proposals of different versions for enlarging the Slavětice 400 kV substation by a new outlet of new EDU source and the eventual overhead-line construction. I am mentioning the necessary substation arrangements for each proposed version, the scheme, eventually the proposal how to lay-out the new lines. Further there is stated here a proposal of outgoing feeder switchgear accessories for the new EDU pile and also the proposal for an entirely new substation, its description and scheme. An evaluation of all proposed versions of Slavětice substation enlargement for connecting new nuclear piles is stated in the outcome of the work.

The entire diploma thesis analyses causes, consequences and repercussions of an electricity grid network blackout and its impact to the respective consumers. Remarkable blackouts recorded since 1965 are briefly described and basic available information is considered. The grid standard fixing measures and electricity delivery priorities are characterized. The thesis also pays attention to entire Czech Republic grid availability and its blackout endurance as well as to its robustness within last several years. Indirect Fukushima event influence to the Czech Republic electricity system is mentioned. The main part of the thesis comprises of four big European grid blackouts causes and consequences, their comparison to each other and to the Dukovany nuclear power plant grid blackout drill scenario. The preventive and standard corrective measures against blackouts are pointed out.

This diploma thesis deals with a pressure suppression system containment during the loss of coolant accidents. It is focused on the containment systems of the nuclear power plants with VVER-440/V-213 reactors. There is described the process of loss of coolant accident. There was designed input model which consists of the zones representing the areas which are connected with junctions and heat structures. Were then selected input parameters for the model calculations. And finally, there have been several calculations for the selected parameters.

This thesis deals with the determination of 14C activity in liquid discharges from the Czech nuclear power plants and with the estimation of their radiological impacts on the vicinity of nuclear power plants. This work summarizes the issue of 14C liquid discharges of several nuclear power plants in the world and Czech nuclear power plants are compared to them. The sewage routs of liquid discharges from control tanks to waste water station are described in this thesis for both power plants - Dukovany and Temelín. Measured values of the 14C activity in liquid discharges from nuclear power plants Temelín and Dukovany are presented in this work. The procedure for calculating the exposure of representative persons as a result of liquid discharge of 14C activity is described in this thesis. The resulting values of annual commited effective dose for each age category of representative persons are presented in this work.

Sweden is generally considered to be a low seismicity area, but for structures within nuclear power facilities, the safety level demand with respect to seismic events are high and thus, these structures are required to be earthquake-resistant. The seismic hazard is here primarily considered to be associated with near-field earthquakes. The nuclear power plants are further founded on hard rock and the expected ground motions are dominated by high frequencies. The design earthquake considered for the nuclear facilities has an annual probability of 10-5 events, that is, the probability of occurrence is once per 100 000 years. The focus of the study is the seismic response of large concrete structures for the nuclear power industry, with regard not only to the structure itself but also to non-structural components attached to the primary structure, and with emphasis on Swedish conditions. The aim of this licentiate thesis is to summarize and demonstrate some important aspects when the seismic load is dominated by high frequencies. Additionally, an overview of laws, regulations, codes, standards, and guidelines important for seismic analysis and design of nuclear power structures is provided. The thesis includes two case studies investigating the effect of seismic high-frequency content loads. The first study investigates the influence of gaps in the piping supports on the response of a steel piping system subjected to a seismic load dominated by high amplitudes at high frequencies. The gaps are found in the joints of the strut supports or are gaps between the rigid box supports and the pipe. The piping system is assessed to be susceptible to high-frequency loads and is located within the reactor containment building of a nuclear power plant. The stress response of the pipe and the acceleration response of the valves are evaluated. The second study investigates the effect of fluid-structure interaction (FSI) on the response of an elevated rectangular water-containing concrete pool subjected to a seismic load with dominating low and high frequencies, respectively. The pool is located within the reactor containment building of a boiling water reactor at a nuclear power plant. The hydrodynamic pressure distribution is evaluated together with the stress distribution in the walls of the tank. From the two case studies, it is evident that the response due to a seismic load dominated by high frequencies and low frequencies, respectively, is different. Although the seismic high-frequency load may be considered non-damaging for the structure, the effect may not be negligible for non-structural components attached to the primary structure. Including geometrical non-linear effects such as gaps may however reduce the response. It was shown that the stress response for most of the pipe elements in the first case study was reduced due to the gaps. It may also be that the inclusion of fluid-structure interaction effects changes the dynamic properties of a structural system so that it responds significantly in the high frequency range, thus making it more vulnerable to seismic loads dominated by high frequencies. In the second case study, it was shown that even for a seismic load with small amplitudes and short duration, but with dominating high-frequency content, as the Swedish 10-5 design earthquake, the increase of the dynamic response as fluid-structure interaction is accounted for is significant. / <p>QC 20150519</p>

An operator's performance and mental workload when interacting with a complex system, such as the main control room (MCR) of a nuclear power plant (NPP), are major concerns when seeking to accomplish safe and successful operations. The impact of performance on operator workload is one of the most widely researched areas in human factors science with over five hundred workload articles published since the 1960s (Brannick, Salas, & Prince, 1997; Meshkati & Hancock, 2011). Researchers have used specific workload measures across domains to assess the effects of taskload. However, research has not sufficiently assessed the psychometric properties, such as reliability, validity, and sensitivity, which delineates and limits the roles of these measures in workload assessment (Nygren, 1991). As a result, there is no sufficiently effective measure for indicating changes in workload for distinct tasks across multiple domains (Abich, 2013). Abich (2013) was the most recent to systematically test the subjective and objective workload measures for determining the universality and sensitivity of each alone or in combination. This systematic approach assessed taskload changes within three tasks in the context of a military intelligence, surveillance, and reconnaissance (ISR) missions. The purpose for the present experiment was to determine if certain workload measures are sufficiently effective across domains by taking the findings from one domain (military) and testing whether those results hold true in a different domain, that of nuclear. Results showed that only two measures (NASA-TLX frustration and fNIR) were sufficiently effective at indicating workload changes between the three task types in the nuclear domain, but many measures were statistically significant. The results of this research effort combined with the results from Abich (2013) highlight an alarming problem. The ability of subjective and physiological measures to indicate changes in workload varies across tasks (Abich, 2013) and across domain. A single measure is not able to measure the complex construct of workload across different tasks within the same domain or across domains. This research effort highlights the importance of proper methodology. As researchers, we have to identify the appropriate workload measure for all tasks regardless of the domain by investigating the effectiveness of each measure. The findings of the present study suggest that responsible science include evaluating workload measures before use, not relying on prior research or theory. In other words, results indicate that it is only acceptable to use a measure based on prior findings if research has tested that measure on the exact task and manipulations within that specific domain.

Nuclear Power Plants (NPP) undergo fault and sensitivity analysis with scenario modelling to predict catastrophic events, specifically releases of Cesium 137 (Cs-137). The purpose of this thesis is to find which of 108 input-features from Modular Accident Analysis Program (MAAP)simulation code are important, when there is large release of Cs-137 emissions. The features are tested all together and in their groupings. To find important features, the Machine learning (ML) model Random Forest (RF) has a built-in attribute which identifies important features. The results of RF model classification are corroborated with Support Vector Machines (SVM), K-Nearest Neighbor (KNN) and use k-folds cross validation to improve and validate the results, resulting in a near 90% accuracy for the three ML models. RF is successful at identifying important features related to Cs-137 emissions, by using the classification model to first identify top features, to further train the models at identifying important input-features. The discovered input-features are important both within their individual groups, but also when including all features simultaneously. The large number of features included did not disrupt RF much, but the skewed dataset with few classified extreme events caused the accuracy to be lower at near 90%.

[pt] Os princípios de gerenciamento de projetos têm alcançado nos últimos anos um grande interesse por parte das organizações, com objetivos de foco operacional em realizações eficazes dentro do custo, prazo e qualidade planejadas. No entanto, muito pouco se fez para reconhecer a disciplina gerenciamento de projetos como uma das core competencies para a composição do diferencial competitivo na estratégia empresarial selecionada. Esta pesquisa tem como objetivo principal o desenvolvimento de um estudo para averiguar se existe adequação entre os processos da disciplina gerenciamento de projetos e a estratégia da empresa pesquisada. A pesquisa foi desenvolvida por meio de estudo de caso único, para o qual foi selecionada como unidade de análise uma empresa governamental: a Eletrobrás Termonuclear S.A. - Eletronuclear. A coleta de dados foi realizada de acordo com o princípio de triangulação de diferentes métodos (YIN, 2003), e: 1) investigação documental (impressa, telematizada, eletrônica); 2) levantamento de percepções com auxílio de questionário estruturado de pesquisa; 3) levantamento de percepções complementares por meio de entrevistas. As interpretações e análises efetuadas dos dados coletados foram fundamentadas no referencial teórico utilizando-se o modelo genérico-integrativo de Macedo-Soares (2001b). Os resultados evidenciaram algumas inconsistências entre os processos da disciplina gerenciamento de projetos e a estratégia da empresa. Permitiram identificar fatores organizacionais que contribuem e outros que não contribuem para a adequação estratégica de projetos. Na conclusão do trabalho, são compartilhadas lições que a pesquisa focada na Eletronuclear trouxe para outras empresas. / [en] In recent years, organizations have become increasingly interested in the principles of project management in order to enhance the operational effectiveness of their undertakings in terms of planned cost, schedule and quality. However, little has been done in the way of recognizing the discipline of project management as one of the core competencies constituting the competitive differential of the business strategy selected. The main objective of this study is to ascertain whether the processes of the project management discipline fit the strategy of the firm at issue. The study adopted the single case study method, focusing on the government firm Eletrobrás Termonuclear S.A. - Eletronuclear. Data collection was performed in accordance with the method triangulation principle (YIN, 2003), together with 1) documental investigation (printed, telematic, electronic); 2) a perceptions survey using a structured research questionnaire; 3) a complementary perceptions survey through interviews. The data collected was analyzed and interpreted using Macedo-Soares` (2001b) generic integrative model. The results evidenced some inconsistencies between the processes of the project management discipline and the firm´s strategy. They permitted the identification of organizational factors that did or did not contribute to projects´ strategic fit. The study concludes by sharing the lessons for other firms that could be drawn from the Electronuclear case.

The complete design process for a new nuclear power plant concept is costly, long, complicated, and the work is generally split between several specialized groups. These design groups separately do their best to design the portion of the reactor that falls in their expertise according to the design criteria before passing the design to the subsequent design group. Ultimately, the work of each design group is combined, with significant iteration between groups striving to facilitate the integration of each of the heavily interdependent systems. Such complex interaction between experts leads to three significant problems: (1) the issues associated with knowledge management, (2) the lack of design optimization, and (3) the failure to discover the hidden interdependencies between different design parameters that may exist. Some prior work has been accomplished in both developing common frame of reference (CFR) support systems to aid in the design process and applying optimization to nuclear system design.The purpose of this work is to use multi-objective optimization to address the second and third problems above on a small subset of reactor design scenarios. Multi-objective optimization generates several design optima in the form of a Pareto front, which portrays the optimal trade-off between design objectives. As a major part of this work, a system design optimization tool is created, namely the Optimization and Preference Tool for the Improvement of Nuclear Systems (OPTIONS). The OPTIONS tool is initially applied to several individual nuclear systems: the power conversion system (PCS) of the Integral, Inherently Safe Light Water Reactor (I²S-LWR), the Kalina cycle being proposed as the PCS for a LWR, the PERCS (or Passive Endothermic Reaction Cooling System), and the core loop of the Zion plant. Initial sensitivity analysis work and the application of the Non-dominated Sorting Particle Swarm Optimization (NSPSO) method provides a Pareto front of design optima for the PCS of the I²S-LWR, while bringing to light some hidden pressure interdependencies for generating steam using a flash drum. A desire to try many new PCS configurations leads to the development of an original multi-objective optimization method, namely the Mixed-Integer Non-dominated Sorting Genetic Algorithm (MI-NSGA). With this method, the OPTIONS tool provides a novel and improved Pareto front with additional optimal PCS configurations. Then, the simpler NSGA method is used to optimize the Kalina cycle, the PERCS, and the Zion core loop, providing each problem with improved designs and important objective trade-off information. Finally, the OPTIONS tool uses the MI-NSGA method to optimize the integration of three systems (Zion core loop, PERCS, and Rankine cycle PCS) while increasing efficiency, decreasing costs, and improving performance. In addition, the tool is outfitted to receive user preference input to improve the convergence of the optimization to a Pareto front.