Frågor kring kärnkraftverk har alltid varit ett omdiskuterat ämne. Kärnkraftens betydelse varierar stort mellan olika länder. Av 441 reaktorer i världen tillhör 10 av dem till Sverige. Kärnkraftverk i Oskarshamn är en av dem. Företaget OKG har beslutat att genomföra en övergripande utredning kring olika konstruktionstyper av reaktorinneslutningar med detta examensarbete. Arbetet begränsas till att göra en litteraturundersökning. En viss genomgång av både nationella och internationella rapporter har gjorts. Det primära syftet med detta examensarbete är uppdelat i två huvuddelar. Den första delen av utredningen visar olika konstruktionstyper av reaktorinneslutning i hela världen. Den andra delen visar de reaktorinneslutningarna som har en liknande konstruktion som på OKG d.v.s. betong som är förspänd med cementinjekterade spännkablar. En liknande konstruktion finns bl.a. i Finland och Frankrike. Vi har också diskuterat kontroller för andra konstruktionstyper där spännkablarna är omgivna av luft eller fettinjekterade. I utredningen redovisas en del inträffade skador och incidenter i Svenska och utländska kärnkraftverk reaktorer. Företaget har två övriga frågeställningar som undersöktes i senare skedet av arbetsgång. Spännkrafter minskar med tiden på grund av krympning och krypning i spännarmerade konstruktioner vilket påverkar säkerheten av konstruktionen negativt. Som en del av detta arbete utfördes undersökningar om det finns metoder att bestämma spännkrafter där spännkablarna inte är åtkomliga. I det slutliga skedet av utredningen undersöktes metoder som Trafikverket följer för att kontrollera sina broar d.v.s. utföra huvudinspektioner/ besiktningar. Huvudsyftet av examensarbetet har uppfyllts men vissa delar är begränsade på grund av mesta informationer av olika kärnkraftverk är konfidentiella och inte tillgängliga på nätet. Och alla våra undersökningar var webbaserade som innebär att vi hade inte möjlighet att hitta rätt informationer direkt från webben. Samtidigt kontakta de olika utländska kärnkraftverken var inte så lätt på kort varsel. Strålsäkerhetsmyndighet (SSM) hjälpte oss att få kontaktinformation av 3 olika länder. I slutet av rapporten ges analys och diskussion kring utredningen. / Questions regarding Nuclear Power Plants have always been a controversial subject. Nuclear power's importance varies between countries. Of the 441 reactors in the world 10 of them belongs to Sweden. Oskarshamn Nuclear Power Plant is one of them. OKG has decided to conduct a comprehensive investigation of this thesis work around some issues. The main purpose of this thesis work is to make a literature investigation about bracing cables in reactor containment. A specific review of national and international reports has been made and formed a collective basis with the company issues. The introductory part of this thesis is divided into two main parts. The first review of this report considers different structural types of reactor containment in the world. Most nuclear reactors are enclosed by a pre-stressed concrete containment and some have steel reactor containment. In both Sweden and Finland, the enclosure is designed as a concrete cylinder, which is pre-stressed both vertically and horizontally. The second review describes about those reactor containments, which has a similar construction to the OKG (the tendons are placed in the casing that after chucking was injected with cement mortar). A similar construction can be found in Finland and France. The investigation also reveals the damage and accidents in Swedish and foreign nuclear power reactors in recent years. Furthermore, company has two other issues, which were implemented in the later stages of the work. Due to shrinkage and creep in the concrete and relaxation in the tendons, the prestressed capacity decreases with time which affects the structure negatively. The objective of this thesis is to investigate if there are methods for determining tensile forces where the tendons are not accessible. Methods are divided into two different types: one is cement grouting method, same as OKG and another one is oil-injection method. The final review of report is to investigate about TRAFIKVERKET methods to check/inspection the bridges. It can be concluded that the main expectations of this thesis has been fulfilled but some parts are still missing due to limitation of proper information. To contact with the various foreign nuclear power plants was not so easy within this short time. All our experiments were web-based and there were many confidential matters which is unreachable. Swedish Radiation Safety authority (SSM) helped us to get contact details of 3 different countries. The discussions about the reviews are summarized at the end of the report.

The function of safety reviews (here understood as expert judgements on proposals for design modifications and redesign of technical systems in commercial Nuclear Power Plants, supported by formalised safety review processes) plays a fundamental role for safety in nuclear installations. The primary aims of the presented case studies includes: critically examining and identifying the main areas for improvement of the existing technical safety review process as it is conducted at a Swedish nuclear power plant, developing a new process, and evaluating whether any improvements were accomplished. By using qualitative methods, observation/participation and interviews, data has been gathered on how the safety review process is perceived and conducted by experts involved in the safety review process, and ways to improve this process have been developed. This area is neglected in the larger safety literature. The novel approach here is to gather data directly from those involved in the safety review process, analysis of safety review reports as well as from inspection reports by the regulatory authority. The study presented in paper I shows that the partition between primary and independent review is positive, having supplementary roles with different focus and staff with different skills and perspectives making the reviews. The study identifies a number of areas for improvement, such as: - a tendency to put too much resource on minor assignments - a clearer prioritization would improve focus on the most critical projects - there is a need for improved guidance and direction for how to structure the work It is argued that future applications of safety review processes should focus more on communicating and clarifying the process and its adherent requirements, and improve the feedback system within the process. It is also recommended that the NPPs create introductory training for new reviewers The study presented in paper II concluded that grading of the primary safety review reports facilitates improved experience feedback by providing easier access to good examples for reviewers. Improvements identified by implementing the revised process are primarily linked to the independent safety review function, including better planning and means for resource allocation as well as clearer and more unambiguous supporting instructions. Introduction of formalized independent review meetings provides increased exchange of knowledge and strengthened the independent safety review function in the organization. / <p>QC 20130305</p>

From 1976 to 1992 Portland General Electric (PGE) -- a private utility based in Portland, Oregon -- operated the Trojan Nuclear Plant near Rainier, Oregon, on the bank of the Columbia River. Trojan was the first commercial nuclear facility in the Pacific Northwest and was the largest such facility in U.S. history. From its origins, Trojan was the focus of growing conflict over atomic energy facilities and their environmental effects, risks, and costs. This thesis traces the history of Trojan, including the conditions in which PGE decided to build the plant as well as the changing conditions in which the environmental movement in Oregon worked to impact the operation of Trojan and the development of further atomic energy facilities in the region. Two sets of values, largely endemic to the region, came into conflict in the debate over Trojan: one which valued preservation of vital natural systems over all else, and another that elevated technological progress to supreme importance in achieving the ultimate social good. Supporters of Trojan and anti-nuclear activists both viewed misinformation about nuclear power as one of the central problems in the way that Oregon residents viewed nuclear power. Although there were many loyal supporters of Trojan, particularly in Columbia County, there were also a great number who viewed the technology cautiously. While both PGE and nuclear opponents worked diligently to sway public opinion, many activists did so by attempting to uncover and publicize hidden information about the design and operation of Trojan, and the nuclear fuel cycle in general. This included efforts throughout the plant's lifetime to develop opportunities for intervention in administrative proceedings, government hearings, and other arenas which often discourage citizen involvement. Related to the public debate over Trojan were ongoing operational difficulties and changing economic conditions, which contributed to the decision PGE announced in 1993 that Trojan would be permanently shut down. This study is based primarily on coverage from newspapers and periodicals, new and extant oral history interviews, documents from the personal files of activists, as well as various archival materials associated with PGE, activist groups, and government agencies.

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Nuclear Engineering, 1975. / Vita. / Bibliography: leaves 460-462. / by Raymond Eng. / Ph.D.

Diploma thesis is focused on comparison of small punch test results and tensile test results. For experiments were chosen steel P91, 10Ch2MFA, 20CrNi2MoV, 11 416 and 42 2707. These steel are used in nuclear power engineering, or they were developed for this purpose. Basic mechanical characteristics, namely ultimate tensile stress and yield stress, were evaluated from small punch test records of observed materials. This is done via convenient correlation relationships. Obtained values were compared with values obtained by conventional tensile tests. There are mentioned own suggested correlation relationships and comparison of temperature curves gained from small punch test and tensile test in the thesis. Assessment of microstructure of observed materials and analysis of fracture surfaces was provided as well. It was found out, that for assessing basic mechanical characteristics (ultimate tensile stress and yield stress) is the best to suggest own correlation relationships, instead of using universal relationships from literature. The fracture mechanism of all types of assessed steel was ductile in entire temperature range (up to -40 °C).

Energiöverenskommelsen 2016 innefattade ett flertal mål och implikationer för utformningenav det svenska el- och energisystemet. Sveriges energisystem ska vara ekologiskt hållbart,konkurrenskraftigt och försörjningstryggt. Utöver detta så omfattas överenskommelsen av enmålsättning om 100% förnyelsebar elproduktion år 2040, som analyserats i rapporten. Syftetmed rapporten är att belysa problematiken som kan uppkomma vid ett obalanserat elsystemmed avseende på försörjningstrygghet, ekologisk hållbarhet och konkurrenskraft. Här ämnarrapporten även att öka medvetenheten bland aktörer inom det svenska energisystemet ochsynliggöra problematik som kan uppkomma efter år 2040. Den huvudsakliga vetenskapligametoden är en formativ undersökning där intervjuer med kraftbolag genomförts för att få endjupare förståelse för det framtida kraftsystemet. Sedan har även en explorativ undersökninggenomförts genom litteraturstudier. Dessa två undersökningar har tillsammans möjliggjortförklaringar av orsakssamband. Det främsta källmaterialet i rapporten är vetenskapliga artiklarkopplade till el- och energiområdet, där KTH:s Databas Primo samt Google scholar använtssom främsta medium för sökningar. Myndigheter och organisationer som KungligaIngenjörsvetenskapsakademien (IVA) samt North European Energy Perspectives Project(NEPP) har bidragit med information. Resultaten visar att det finns problematik kopplade tilleffektbrist, svängmassa och planerbarhet i och med en nedläggning av kärnkraften, där ensamtida beskattning av avfallsbaserad kraftvärme ytterligare försämrar tillgången på effekt.Resultaten visar även att introducering av vindkraft till systemet ökar det svenskaimportberoendet av el från Tyskland med högre andel fossila inslag, men samtidigt bidrar tillen ökad export där svensk el kan trycka bort smutsig el i andra länder. Vidare beskrivslångsiktighet och ett ökat samarbete mellan systemets aktörer som av stor vikt för utvecklingenav det framtida elsystemet samt ett ökat fokus på implementering av systemtjänster somförsvinner från systemet framöver. Andelen vindkraft beräknas öka till år 2030 samtidigt somkärnkraft och värmekraft, som båda är planerbara kraftslag, beräknas minska. Att målet omförnyelsebar elproduktion införlivas 2040 är inte troligt, då kärnkraftsreaktorerna beräknasdrivas hela deras ekonomiska livslängd vilket löper ut 2045. / The Energy Agreement from 2016 is comprised of several goals for the forming of the Swedishpower system. The Swedish power system should be ecologically sustainable, competitive andbe able to supply power without interruption. Furthermore, this agreement also involves a goalof a 100% renewable power generation in 2040, which has been analyzed in this report. Theaim with his report is to highlight problems that might occur in the case of an unbalanced powersystem with respect to ecological sustainability, competitiveness and safe supply. The reportalso aims to raise awareness amongst the actors in the Swedish energy system and highlightproblems in the future. The main scientific method used in this report is a formativeexamination where interviews with the power company representatives gave a deeperunderstanding of the power system as of now, but also in the future. Another scientific methodused has been an explorative examination throughout the literature studies, where these twomethods combined has enabled explanations and causations. The foremost source ofinformation are scientific studies connected to the power system, where KTH’s database Primoand Google Scholar has been used as a primary medium for searches. Authorities and NGOs,such as the Royal Swedish Academy of Engineering Sciences (IVA) and North EuropeanEnergy Perspectives Project (NEPP), has also been used as a primary source of information.The results show problems connected to lack of effect, inertia as well as a decrease of plannablepower through the closure of nuclear power plants and thermal power plants due to newtaxation. The result also shows that an introduction of wind power to the Swedish power systemalso decrease the national independence and rely more on import of power, mainly fromGermany which have a higher share of fossil elements. In other situations, it also leads to ahigher export where Swedish power removes fossil elements in other countries. Furthermore,a long-term strategy and increased cooperation between the systems actors is crucial for thedevelopment of the future energy system with focus on implementing system services whichare decreasing with the decrease of plannable power. The share of wind power is expected torise to 2030, at the same time the plannable power, nuclear and thermal power, is expected todrop. The national goal of a renewable power generation is reached by the year 2040 is notlikely, where the current nuclear power reactors will remain their entire economic life spanwhich spans to 2045, with chance of life span extension.

Large, ever more complex, technological systems surround us and provide products and services that both construct and define much of what we consider as modern society. Our societal bargain is the trade-off between the benefits of our technologies and our constant vigilance over the safe workings and the occasional failures of these often hazardous sociotechnical systems during their operating life. Failure of a system's infrastructure, whether a complex subsystem or a single component, can cause planes to crash, oil rigs to burn, or the release of radioactivity from a nuclear power plant. To prevent catastrophes, much depends not only on skilled and safe operations, but upon the effective maintenance of these systems. Using the commercial nuclear power industry, of the United States, as a case study, this dissertation examines how nuclear power plant maintenance functions to ensure the plants are reliable and can safely operate for, potentially, eighty years; the current, government regulation defined limit, of their functional life. This study explores the history of U.S. nuclear maintenance regulatory policy from its early Cold War political precursors, the effect of the 1979 Three Mile Island reactor melt-down accident, through its long development, and finally its implementation by nuclear power licensees as formal maintenance programs. By investigating the maintenance of nuclear power plants this research also intends to expand the conceptual framework of large- technological-system (LTS) theory, in general, by adding a recognizable, and practically achievable, end-of-life (EOL) phase to the heuristic structure. The dissertation argues that maintenance is a knowledge producing technology that not only keeps a sociotechnical system operating through comprehension, but can be a surveillance instrument to make system end-of-life legible; that is both visible and understandable. With a discernible and legible view of system end-of-life, operators, policy makers, and the public can make more informed decisions concerning a system's safety and its continued usefulness in society. / Doctor of Philosophy / Large, ever more complicated, technical systems surround us and provide products and services that define much of what we consider as modern society. Our societal bargain is the trade-off between the benefits of our technologies and our constant vigilance over the safe workings and the occasional failures of these often hazardous systems during their operating life. Failure of a system's infrastructure, whether a complex subsystem or a single component, can cause planes to crash, oil rigs to burn, or the release of radioactivity from a nuclear power plant. To prevent catastrophes, much depends not only on skilled and safe operations, but upon the effective maintenance of these systems. Using the commercial nuclear power industry, of the United States, as a case study, this dissertation examines how nuclear power plant maintenance functions to ensure the plants are reliable and can safely operate for, potentially, eighty years; the current, government regulation defined limit, of their functional life. This study explores the history of U.S. nuclear maintenance regulatory policy from its early Cold War political precursors, the effect of the 1979 Three Mile Island reactor melt-down accident, through its long development, and finally its implementation by nuclear power licensees as formal maintenance programs. By investigating the maintenance of nuclear power plants this research also intends to develop a method to determine when a nuclear power plant, or other large technological system, is approaching or has reached the end of its reliable and safe operational life. The dissertation presents maintenance as a technology of knowledge that not only keeps a system operating through understanding of its components, but can be a general surveillance instrument to make system end-of- life legible. With a discernible and understandable view of end-of-life, operators, policy makers, and the public can make more informed decisions concerning a system's safety and its continued usefulness to society.

För att företag idag ska vara konkurrenskraftiga krävs hög kvalitet, leveransförmåga och flexibilitet. Olhager (2013) menar att ständiga förbättringar av företagsstrategier, produkter och processer är nödvändigt. Lean verktyget värdeflödesanalys kan användas för att identifiera slöserier och förbättra produktiviteten (Rahani &amp; al-Ashraf, 2012). I denna studie undersöks det hur ett globalt industriföretag som tillverkar till kärnkraftsindustrin kan öka sin effektivitet trots regleringar från standarder och kundkrav. För att undersöka detta har observationer gjorts på företagets produktionsflöde, sedan har fyra intervjuer utförts för att få en god bild över företagets produktionsflöde och administrativa flöde samt deras nuläge. Dessutom har relevant litteratur ifrån vetenskapliga artiklar, böcker, myndigheter samlats in. Fallföretagets produkter måste uppfylla produktstandarden ASME Boiler and Pressure Vessel Code och andra krav i kundspecifikationen, som täcker tillverkning, inspektion, kvalitetssäkring, testning och frakt. För att tillverka till kärnkraftsindustrin behöver företag följa strikta kvalitetskrav samt att det förekommer omfattande mängd dokumentation och provtagningar. Företaget i denna studie har tidigare använt värdeflödesanalys för att analysera mindre delar av flödet, men företaget ser potential för bredare användning. Slutsatserna för denna studie är att standarder som ASME Boiler and Pressure Vessel Code är viktiga för kärnkraftssäkerheten. Standarden ställer höga krav för tillverkningen där det måste utföras flera kvalitetskontroller för att förhindra defekter. Detta kan göra tillverkningsprocessen mer komplex och tidskrävande i jämförelse med andra industrier. Då företaget i denna studie har ett omfattande administrativt flöde som följer längs med materialflödet är det många delar att ha kontroll på. Att använda värdeflödesanalys och analysera en större del av flödet ger en helhetsbild och möjlighet till gemensam förståelse över flödets begränsningar. För att utföra effektiva förbättringar är det viktigt att vara eniga om hur flödet ser ut och vart flaskhalsarna finns som begränsar flödet. Utifrån företaget i denna studies behov är värdeflödesanalys enligt teorin ett lämpligt verktyg att använda för att navigera i deras förbättringsarbete och öka effektiviteten. / For companies today to be competitive, high quality, delivery capability and flexibility are required. Olhager (2013) believes that continuous improvement of company strategies, products and processes becomes necessary. The Lean tool value stream mapping can be used to identify waste and improve productivity (Rahani &amp; al-Ashraf, 2012). This study analyzes how a global industrial company that manufactures for the nuclear power industry can increase its efficiency despite regulations from standards and customer requirements. To study this, observations have been made on the company's production flow, then four interviews have been carried out to get a good picture of the company's material and administrative flow and current situation. In addition, have relevant literature from scientific articles, books, authorities been collected. The case company's products must meet the ASME Boiler and Pressure Vessel Code product standard and other customer specification requirements, covering manufacturing, inspection, quality assurance, testing and shipping. In order to manufacture for the nuclear power industry, companies need to follow strict quality requirements and there is an extensive amount of documentation and sampling. The company in this study has previously used value flow analysis to analyze smaller parts of the flow, but the company sees potential for wider use. The conclusions of this study are that standards such as the ASME Boiler and Pressure Vessel Code are important for nuclear safety. The standard places high demands on the manufacturing, where several quality controls must be carried out to prevent defects. This can make the manufacturing process more complex and time-consuming compared to other industries. As the company in this study has an extensive administrative flow that follows along with the material flow, there are many parts to have control over. Using value flow analysis and analyzing a larger part of the flow provides an overall picture and the opportunity for a common understanding of the flow's limitations. To carry out effective improvements, it is important to agree on what the flow looks like and where the bottlenecks are that limit the flow. Based on the needs of the company in this study, value flow analysis is, according to the theory, an appropriate tool to use to navigate their improvement efforts and increase efficiency.

Prior to this work, MASSVAC (MASS eVACuation) had evolved as a micro-computer simulation model for analysis and evaluation of areas facing natural disasters (hurricanes and floods). Conceptual and technical enhancements have been made to procedures within MASSVAC to deal with the special problems of evacuating around nuclear power stations. Its incorporation into TEDSS-3 (Transportation-Evacuation Decision Support System) has resulted in a powerful tool to assist development of evacuation plans for nuclear power plants. The computer package comprehensively provides for all functions related to evacuation planning such as development of a socioeconomic and highway network database, estimation of evacuation time and development/evaluation of traffic management strategies to reduce network clearance times and to improve highway network performance during evacuation. Primary focus is on the new features incorporated into MASSVAC, especially in the trip distribution and traffic assignment procedures. Significant improvements have been made to the software implementations of the Dial traffic assignment and other key algorithms used in MASSVAC. The information content of the model's output has been enhanced for better understanding of the evacuation process and presentation of results. / Master of Science

This thesis investigates the circumstances under which parties change their positions, with Swedish nuclear power policy as a case to adress the purpose. The thesis employed qualitative text analysis and the theoretical framework Advocacy Coalition Framework (ACF) to examine and adress the the thesis's research questions and purpose. ACF was used to formulate the research questions, focusing on wether there had been changes in the Swedish parliamentary parties' policy core belifes regardning nuclear power policy and, if so, wether external subsystem events and or\changes in coalition formation could explain these changes. The study found that three out of eight Swedish parliamentary parties had changed their policy core belifes regarding the nuclear power issue:the Social Democrats, the Green Party, and the Center party.  At least one of the examined external subsystem events could either explain the changes or reinforce previous changes. Furthermore, the sudy showed that changes in coalition formation could potentially explain the Social Democrats' and the Green Party's altered policy core belifes. Other potential explanations included the influence of the Janaury Agreement, where the Liberals, as a strongly pro-nuclear party, may have influenced the Green party and the Social Democrats to become more positive towards nuclear power. In summary, the sudy demonstrated that changes in coalition formation and\or external subsystem evenets are circumstances that can explain why parties change their positions. Additionally, the thesis suggested that ACF should include two additional external subsystem events, which this sudy has shown to have an impact on parties' changed policy core belifes:war and economic changes.