The design of toolhead changing manipulator is highly dependent on the specific application. The geometry, mobility of the existing system, the toolhead robot interface and the toolhead size and shape all are major factors in the development of an effective solution. The addition of other functional requirements increase the complexity of the design. The platform maintenance functions required in the BWNS problem increased the complexity to a 5 DOF feeding manipulator. This solution, while complex, is an effective and efficient solution to this specific application. The result should be a significant reduction in human radiation exposure and reduced steam generator service time. / Master of Science

The objective of this thesis is the algorithmic enhancement and initial evaluation of an underwater acoustic positioning system which is designed to determine the position and orientation of a mobile nuclear reactor vessel inspection robot. Although a great deal of research has been done in the area of underwater acoustic positioning, this work differs from previous work in three significant ways. First, most applied acoustic positioning systems have been designed for the offshore oil drilling industry, and thus their requirements and restrictions are dictated by an oceanic environment. Second, most previous work has focused only upon acquiring the position of a point from the acoustic system. The inspection robot operation requires accurate positioning and orientation. Finally, the accuracy of acoustic positioning systems is generally dependent upon an evaluation of the speed of sound. However, this parameter is highly dependent upon water temperature. As will be discussed, the reactor vessel water temperature may not be uniform or constant, which makes the design of a precise positioning system difficult. Original methods to overcome this obstacle are discussed and evaluated. Also examined are configurations and constraints of the acoustic transceivers, the numerical solution procedures utilized, and the resulting errors associated with the developed methods. / Master of Science

This study examines the parliamentary debate regarding the proposition "Ny kärnkraft i Sverige - Ett första steg" which aims to facilitate the expansion of nuclear power in Sweden. The purpose is to provide an understanding of the nuclear power debate in the Swedish Parliament since it has been revived by the energy crisis in 2021 and Russia's invasion of Ukraine. The debate is analyzed through a qualitative content analysis to identify the arguments of Tidöpartierna and the opposition for and against the proposition. The identified arguments are then interpreted through the social identity perspective to explain their different standpoints. The results show that nuclear power is a divisive issue in the Swedish Parliament. Interpretation through social identity theory reveals that the parties' historical positions, their perception of which arguments are most effective to attract voters, and confirmation bias influence their views on the nuclear power issue. The conclusions indicate that it is an issue that divides the Parliament into two sides: Tidöpartierna and the opposition parties, with each side presenting different solutions to the energy issue. Tidöpartierna argues for an energysystem where nuclear power complements renewable energy sources, while the oppositionparties favor a solution where the energy system is solely based on renewable energy sources.

The objective of the thesis is to characterize the nuclear energy in the european area with the focus on nuclear energy in France. The sector of nuclear energy is now experiencing a new period, so-called "nuclear renaissance". Many european countries decided to rebuild the present nuclear power sites or to construct new ones. Nuclear energy is the most advantageous solutions for many european countries because it decreases external energy dependence and it helps to diminish the carbon dioxide emissions. In the connection with the Czech Presidency in the European Union, it was made proposal for the "Nuclear Security Community" which has to unify the security level of member states of the EU and to intensify the mutual cooperation in the domain of nuclear energy. France represents world nuclear leader thanks to efficiently operating oragnizations, excellent results in nuclear research, realization of nuclear fuel recycling and strong government support. Nucler energy in France can serve as an example for four recommendations to other european countries: government support, efficiently working research institutions, global cooperation between all subjects participating on the formation of nuclear energy and active involvement in the international cooperation in nuclear energy. In spite of constantly high initial investment in construction of nuclear power sites, the nuclear energy seems to experience a positive future.

This diploma thesis deals with nuclear energetics and its impact to the environment. Present state of the energetics, mainly nuclear energetics, in the Czech Republic is discussed here. Also perspective of nuclear energetics is given. The thesis describes nuclear power plant waste handling and also spent nuclear fuel handling. Nuclear power plant is compared with other sources of electric energy, which are counted to the energetic mix. The author focuses on fossil fuels and also on the renewable energy sources. The amount of produced waste to the unit of produced energy, built up area, safety and economic indicators and other parameters are followed for each source of energy.

Nuclear power plants are inherently complex systems. While the technology has been used to generate electrical power for many decades, process monitoring continuously evolves. There is always room for improvement in terms of maximizing the availability by reducing the risks of problems and errors. In this context, automated monitoring systems have become important tools – not least with the rapid progress being made in the field of data analytics thanks to ever increasing amounts of processing power. There are many different types of models that can be utilized for identifying anomalies. Some rely on physical properties and theoretical relations, while others rely more on the patterns of historical data. In this thesis, a data-driven approach using a hierarchical autoencoder framework has been developed for the purposes of anomaly detection at the Swedish nuclear power plant Forsmark. The model is first trained to recognize normal operating conditions. The trained model then creates reference values and calculates the deviations in relation to real data in order to identify any issues. This proof-of-concept has been evaluated and benchmarked against a currently used hybrid model with more physical modeling properties in order to identify benefits and drawbacks. Generally speaking, the created model has performed in line with expectations. The currently used tool is more flexible in its understanding of different plant states and is likely better at determining root causes thanks to its physical modeling properties. However, the created autoencoder framework does bring other advantages. For instance, it allows for a higher time resolution thanks to its relatively low calculation intensity. Additionally, thanks to its purely data-driven characteristics, it offers great opportunities for future reconfiguration and adaptation with different signal selections.

Kärnkraft är ett kontroversiellt ämne, som ofta ger upphov till två läger – de som är positivt inställda och de som är negativt inställda till kärnkraft. NIMBY (Not in My Backyard) är ett fenomen som syftar till de som är positiva till kärnkraft generellt, men som inte vill ha den i sin närhet. Utfasningen av fossila bränslen och den kommande ökningen av energibehovet ställer frågan vilken roll kärnkraften ska spela i framtidens energiproduktion. Den svenska regeringen vill satsa mer på kärnkraft och har pekat ut olika platser som möjliga lokaliseringar för kärnkraft. Säffle är en av dessa platser.  Syftet med denna uppsats är att undersöka den lokala uppfattningen i fallet Säffle kring en potentiell kärnkraftsetablering i näromgivningen, samt vilka risker som invånarna ser med kärnkraft, för att se om NIMBY föreligger. Ett vidare syfte är också att undersöka hur invånarna i Säffle anser att energifrågan ska lösas.  Metoden som använts är mixed methods där både en kvantitativ enkät och kvalitativa intervjuer genomförts. Data från 59 enkätrespondenter har analyserats med deskriptiv statistik, och sex djupintervjuer har analyserats med kvalitativ innehållsanalys.  Resultatet pekar på att det finns olika läger hos respondenterna – de som är för och de som är mot kärnkraft. NIMBY föreligger endast i några få fall bland enkätens respondenter, däremot upptäcktes flera fall av omvänd NIMBY, där positiva yttranden om att förlägga ett kärnkraftverk i Säffle uttalades. Det finns olika faktorer som påverkar människors riskperception – de som är positiva till kärnkraft medger även de att det finns risker, samtidigt som de som är negativa också anser att det råder hög säkerhet vid svenska kärnkraftverk. Säkerhet och Rädsla var två således kategorier som identifierades. Både de som är positiva och de som är negativa till kärnkraft pratar om att ta ett miljöansvar, men ur olika utgångspunkter. Alla vill att Sverige satsar på förnyelsebar energi, och vissa vill addera kärnkraft till den mixen. Ingen vill satsa på kol eller olja. Det konstaterades också en brist på kommunikation från beslutsfattare om varför Säffle är utpekat som möjlig plats för kärnkraft i framtiden. / Nuclear power is a controversial subject that often gives rise to two camps – those who are in favor and those who are opposed to nuclear power. NIMBY (Not in My Backyard) is a phenomenon that refers to those who are generally supportive of nuclear power but do not want it in their vicinity. The phasing out of fossil fuels and the upcoming increase in energy demand raise the question of what role nuclear power should play in future energy production. The Swedish government wants to invest more in nuclear power and has identified various locations as possible sites for nuclear power plants, including Säffle.  The purpose of this essay is to examine the local perception in the case of Säffle regarding a potential nuclear power establishment in the vicinity, as well as the risks that residents associate with nuclear power, to determine if NIMBY exists. Another aim is to investigate how the residents of Säffle believe the energy issue should be resolved.  The method used is mixed methods, including both a quantitative survey and qualitative interviews. Data from 59 survey respondents have been analyzed using descriptive statistics, and six in-depth interviews have been analyzed using qualitative content analysis.  The results indicate that there are different camps among the respondents - those who are in favor and those who are against nuclear power. NIMBY exists only in a few cases among the survey respondents; however, several instances of reverse NIMBY were discovered, where positive statements about locating a nuclear power plant in Säffle were expressed. Various factors influence people's risk perception – those who are in favor of nuclear power also acknowledge the existence of risks, while those who are against it believe that Swedish nuclear power plants are highly secure. Safety and Fear were thus identified as two categories. Both those in favor and those against nuclear power discuss taking environmental responsibility, but from different perspectives. Everyone wants Sweden to invest in renewable energy, and some want to add nuclear power to the mix. No one wants to rely on coal or oil. A lack of communication from decision-makers regarding why Säffle has been identified as a potential site for nuclear power in the future was also noted.

Thesis: M.S., Massachusetts Institute of Technology, Department of Nuclear Engineering, 1977 / Includes bibliographical references. / M.S. / M.S. Massachusetts Institute of Technology, Department of Nuclear Engineering

[ES] La tecnología nuclear para el uso civil genera más preocupación por la seguridad que muchas otras tecnologías que se usan a diario. La Autoridad Nuclear define las bases de cómo debe realizarse la operación segura de una Central Nuclear. De acuerdo a las directrices establecidas por la Autoridad Nuclear, una Central Nuclear debe analizar una envolvente de escenarios hipotéticos y comprobar de manera determinista que los criterios de aceptación para dicho evento se cumplen. El Análisis Determinista de Seguridad utiliza herramientas de simulación que aplican la física conocida sobre el comportamiento de la Central Nuclear para evaluar la evolución de una variable de seguridad y asegurar que los límites no se sobrepasan. El desarrollo de la tecnología informática, de los métodos matemáticos y de la física que envuelve el comportamiento de una Central Nuclear han proporcionado herra-mientas de simulación potentes que son capaces de predecir el comportamiento de las variables de seguridad con una importante precisión. Esto permite analizar escenarios de manera más realista evitando asumir condiciones conservadoras que hasta la fecha compensaban la falta de conocimiento modelado en las herramientas de simulación. Las herramientas conocidas como De Mejor Estimación son capaces de analizar even-tos transitorios en diferentes escalas. Además, emplean modelos analíticos de las dife-rentes físicas más detallados, así como correlaciones experimentales más realistas y actuales. Un paso adelante en el Análisis Determinista de Seguridad pretende combinar las diferentes herramientas de Mejor Estimación que se emplean para analizar las dis-tintas físicas de una Central Nuclear, considerando incluso la interacción entre ellas y el análisis progresivo a diferentes escalas, llegando a analizar fenómenos más locales si es necesario. Para este fin, esta tesis presenta una metodología de análisis multi-físico y multi-escala que emplea diferentes códigos de simulación analizando el escenario propuesto a dife-rentes escalas, es decir, desde un nivel de planta que incluye los distintos componentes, hasta el volumen de control que supone el refrigerante pasando entre las varillas de combustible. Esta metodología permite un flujo de información que va desde el análi-sis a mayor escala hasta el de menor escala. El desarrollo de esta metodología ha sido validado con datos de planta para poder evaluar el alcance de esta metodología y pro-porcionar nuevas líneas de trabajo futuro. Además, se han añadido los resultados de los distintos procesos de validación y verificación que han surgido a lo largo de este trabajo. / [CA] La tecnologia nuclear per a l'ús civil genera més preocupació per la seguretat que moltes altres tecnologies d'ús quotidià. L'Autoritat Nuclear defineix les bases de com ha de realitzar-se l'operació segura d'una Central Nuclear. D'acord amb les directrius establertes per l'Autoritat Nuclear, una Central Nuclear ha d'analitzar una envoltant d'escenaris hipotètics I comprovar de manera determinista que els criteris d'acceptació per a l'esdeveniment seleccionat es compleixen. L'Anàlisi Determinista de Seguretat utilitza eines de simulació que apliquen la física coneguda sobre el comportament de la Central Nuclear per avaluar l'evolució d'una variable de seguretat i assegurar que els límits no es traspassen. El desenvolupament de la tecnologia informàtica, els mètodes matemàtics i de la física que envolta el comportament d'una Central Nuclear han proporcionat eines de simulació potents amb capacitat de predir el comportament de les variables de seguretat amb una precisió significativa. Això permet analitzar escenaris de manera realista evitant assumir condicions conservadores que fins al moment compensaven la mancança de coneixement. Les eines de simulació conegudes com De Millor Estimació son capaces d'analitzar esdeveniment transitoris a diferent escales. A més, utilitzen models analítics per a les diferents físiques amb més detall així com correlacions experimentals més actualitzades i realistes. Un pas més endavant en l'Anàlisi Determinista de Seguretat pretén combinar les diferents eines de Millor Estimació que se utilitzen per analitzar les distintes físiques d'una Central Nuclear, considerant inclús la interacció entre ells i l'anàlisi progressiu a diferents escales, amb la finalitat de poder analitzar fenòmens locals. Per a aquest fi, esta tesi presenta una metodologia d'anàlisi multi-física i multi-escala que utilitza diferents codis de simulació analitzant l'escenari proposat a diferents escales, és a dir, des d'un nivell de planta que inclou els distints components, fins al volum de control que suposa el refrigerant passant entre les varetes de combustible. Esta metodologia permet un flux de informació que va des de l'anàlisi d'una escala major a una menor. El desenvolupament d'aquesta metodologia ha sigut validada i verificada amb dades de planta i els resultats han sigut analitzats a fi d'avaluar la capacitat de la metodologia i les possibles línies de treball futur. A més s'han afegit els principals resultats de verificació i validació que han sorgit en les distintes etapes d'aquest treball. / [EN] The nuclear technology for civil use has generated more concerns for the safety than several other technologies applied to the daily life. The Nuclear Regulators define the basis of how the Safety Operation of Nuclear Power Plants is to be done. According to these guidelines, a Nuclear Power Plant must analyze an envelope of hypothetical events and deterministically define if the acceptance criteria for these events is met. The Deterministic Safety Analysis uses simulation tools that apply the physics known in the behavior of the Nuclear Power Plant to evaluate the evolution of a safety varia-ble and assure that the safety limits will not be exceeded. The development of the computer science, the numerical methods and the physics involved in the behavior of a Nuclear Power Plant have yield powerful simulation tools that are capable to predict the evolution of safety variables which significant accuracy. This allows to consider more realistic simulation scenarios instead of con-servative approaches in order to compensate the lack of knowledge in the applied prediction methods. The so called Best Estimate simulation tools are capable to analyze the transient events in different scales. Furthermore, they account more detailed analytical models and experimental correlations. A step forward in the Deterministic Safety Analysis intends to combine the Best Estimate simulation tools of the different physics considering the interaction among them and analyzing the different scales, considering more local approaches if necessary. For this purpose, this thesis work presents a multi-scale and multi-physics methodology that uses different physics codes and has the aim of modeling postulated scenarios in different scales, i.e. from system models representing the components of the plants to the subchannel models that analyze the behavior of the coolant between the fuel rods. This methodology allows a flow of information where the output of one scale is used as input in a more detailed scale to predict a more local analysis of parameters, such as the Critical Power Ratio, which are of great importance for the estimation of safety margins. The development of this methodology has been validated against plant data with the aim of evaluating the scope of this methodology and in order to provide future lines of development. In addition, different results of the validation and verifi-cation yielded in the development of the parts of this methodology are presented. / Hidalga García-Bermejo, P. (2020). Development and validation of a multi-scale and multi-physics methodology for the safety analysis of fast transients in Light Water Reactors [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/160135

Typescript (photocopy). / Digitized by Kansas Correctional Industries