• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 192
  • 76
  • 44
  • 23
  • 19
  • 8
  • 7
  • 7
  • 6
  • 4
  • 3
  • 3
  • 2
  • 1
  • 1
  • Tagged with
  • 515
  • 515
  • 248
  • 142
  • 69
  • 69
  • 68
  • 61
  • 57
  • 52
  • 52
  • 47
  • 38
  • 36
  • 33
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
91

Loss of normal feedwater ATWS for Vogtle Electric Generating Plant using RETRAN-02

Rader, Jordan D. 16 October 2009 (has links)
With the ever advancing state of computer systems, it is imperative to maintain the most up-to-date and reliable safety evaluation data for nuclear power systems. Commonplace now is the practice of updating old accident simulation results with more advanced models and codes using today's faster computer systems. Though it may be quite an undertaking, the benefits of using a more advanced model and code can be significant especially if the result of the new analysis provides increased safety margin for any plant component or system. A series of parametric and sensitivity studies for the Loss of Normal Feedwater Anticipated Transient without Scram (LONF ATWS) for Southern Company's Vogtle Electric Generating Plant (VEGP) Units 1&2 located near Waynesboro, GA was performed using the best-estimate thermal-hydraulics transient analysis code RETRAN-02w. This thesis includes comparison to the results of a generic plant study published by Westinghouse Electric Corporation in 1974 using an earlier code, LOFTRAN, as well as Vogtle-specific analysis. The comparative analysis exposes and seeks to explain differences between the two codes whereas the Vogtle analysis utilizes data from the Vogtle FSAR to generate plant-specific data. The purpose of this study is to validate and update the previous analysis and gather more information about the plant actions taken in response to a LONF ATWS. As a result, now there is a new and updated evaluation of the LONF ATWS for both a generic 4-loop Westinghouse plant and VEGP using a more advanced code. Beyond the reference case analysis, a series of sensitivity and parametric studies have been performed to show how well each type of plant is designed for handling an ATWS situation. These studies cover a wide range of operating conditions to demonstrate the dependability of the model. It was found that both the generic 4-loop Westinghouse PWR system and VEGP can successfully mitigate a LONF ATWS throughout the core's operating cycle.
92

SPECIFICATION ERRORS IN ESTIMATING COST FUNCTIONS: THE CASE OF THE NUCLEAR ELECTRIC GENERATING INDUSTRY.

JORGENSEN, EDWARD JOHN. January 1987 (has links)
This study is an application of production-cost duality theory. Duality theory is reviewed for the competitive and rate-of-return regulated firm. The cost function is developed for the nuclear electric power generating industry of the United States using capital, fuel and labor factor inputs. A comparison is made between the Generalized Box-Cox (GBC) and Fourier Flexible (FF) functional forms. The GBC functional form nests the Generalized Leontief, Generalized Square Root Quadratic and Translog functional forms, and is based upon a second-order Taylor-series expansion. The FF form follows from a Fourier-series expansion in sine and cosine terms using the Sobolev norm as the goodness of fit measure. The Sobolev norm takes into account first and second derivatives. The cost function and two factor shares are estimated as a system of equations using maximum likehood techniques, with Additive Standard Normal and Logistic Normal error distributions. In summary, none of the special cases of the GBC function form are accepted. Homotheticity of the underlying production technology can be rejected for both the GBC and FF forms, leaving only the unrestricted versions supported by the data. Residual analysis indicates a slight improvement in skewness and kurtosis for univariate and multivariate cases when the Logistic Normal distribution is used.
93

From inquiry to consultation : contested spaces of public engagement with nuclear power

Johnstone, Philip Calum Jamil January 2013 (has links)
This doctoral thesis examines the political and democratic implications of transformations in nuclear power policy, with a focus on the formalised spaces of public engagement situated in three ‘eras’ of nuclear power development. The research is particularly focussed upon the Planning Act 2008, designed to speed up the planning process around large-scale infrastructure including nuclear power. To date the political consequences of the Act have received little academic attention. Building upon key debates in Geography and Planning situated around notions of ‘post-politics’ as well as other conceptualisations of ‘contentious’ political and democratic interventions including STS and state-theoretical perspectives, this thesis examines the consequences for political contestation around nuclear power, in relation to spaces of consultation. These new forms of public engagement are based around a ‘rescaled and segmented’ policy framework created by the Planning Act. A central argument of this is thesis is that the Planning Act cannot be viewed in isolation however. Rather it should be understood in relation to tensions regarding the spatial politics and political opportunities present in previous forms of public engagement around nuclear power, as well as the contradictions created between particular ideological underpinnings of government, and simultaneous commitments to certain ‘objects of governance’, in this instance, nuclear power. Three eras of nuclear power development form the foci of the research. Firstly, an examination of the ‘forgotten inquiry’ between 1988-1989 into the construction of Hinkley C nuclear power station, which was never built due to the collapse of the economic case for nuclear due to privatisation. Through archival research and interviews, this chapter traces empirically how ‘political opportunities’ were enacted and created by campaign groups within the inquiry setting, and how various spatial strategies were utilised to politicise the inquiry. The second empirical chapter addresses the participatory era of New Labour, where new collaborative experiments were developed to negotiate nuclear issues. Through analysis of policy documents and interview data, the ways in which the enthusiasm towards participatory governance was problematised through the return of new nuclear power onto the policy agenda is explored, with particular attention to ‘object-focussed’ state theory. Thirdly, the effects of the ‘rescaled’ consultative framework of the Planning Act are explored through interviews, policy documents, and ethnographic research. Situated within the context of the second attempt to construct Hinkley C, this chapter provides fertile ground for comparative analysis with the 1980’s Inquiry. I argue that the Act attempts to solve some of the key tensions of previous policy, attempting to speed up the planning process whilst maintaining commitments to collaborative forms of public engagement through consensus-based decision-making. The spatial framing of the Act is seen as key to processes of post-politicisation however, where substantial concerns regarding the profound uncertainties of the UK nuclear revival are displaced to other forms of engagement beyond planning. This attempt to ‘solve political dissensus through space’ has ‘unintended consequences’ however which are explored in the conclusion. This thesis brings empirical attention to the’ where’ of politics in different policy settings. Theoretical discussions regarding the relationship between spatial politics, and more nuanced understandings of post-politics and the political are developed through this thesis.
94

From Fish to Fission : Changing sense of place and risk perception in a power plant host community

Messa, Sebastian January 2016 (has links)
Prior studies suggest that proximity to nuclear power plants do not affect concerns regarding perceived risks of nuclear power. This thesis applies and compare Swedish plant Ringhals with prior studies but with the added intent of addressing the relationship between plant and population. The host community Bua is positive towards Ringhals and the changes it has brought. To some degree more so than results of prior studies with a higher than national average percent of study respondents being in favor of nuclear power. When Ringhals was established, Bua was small and had little power to impact the decision. Today, the population is bigger and have a better chance to affect future pathways for their community. While positive towards nuclear power the population expresses concerns over possible future changes. A large scale change like the construction of a power plant is less likely to happen again.
95

Public opinion and nuclear power : a West Cumbrian case study

Wainwright, Paul Francis January 1995 (has links)
This work investigates the factors which might influence public opinion regarding the nuclear power industry, and the accuracy of existing theories about that opinion. West Cumbrian opinion is of particular interest, because the area has the highest concentration of the nuclear power industry in the UK, and might thereby represent a potentially 'nuclear-friendly' area which would contrast with the increasing scepticism reported in the rest of the country, and indeed across much of the industrialised world. The factors which may influence public opinion are analyzed in three ways. Firstly, historical factors are presented in an account of the development of the nuclear power industry. Next, the socio-economic situation and traditions of West Cumbria are examined, in order to assess particular local influences on public opinion. Thirdly, the public relations methods of important local and national groups are examined in the light of public relations theories, in order to assess the ability of such groups to influence public opinion (a new avenue of research related to nuclear power). In order to discover the state of West Cumbrian opinion in 1994, and to assess the impact of the above factors upon that opinion, a survey was conducted using a representative sample of the population of Cockermouth, chosen as a typical Cumbrian town. The scope of questions employed in previous studies was broadened to analyze attitudes towards antinuclear groups as well as towards the industry. Great attention was paid to the methodology of the new survey, the findings of which were analyzed in the light of a comparative analysis of existing research and theories related to West Cumbrian opinion. Local opinion was contrasted with that of a national 'public' consisting of political, environmental and energy orientated organizations. This study confirmed some previously held ideas about public opinion, but also found several differences which suggest flaws in the methodology of previous research. One very important finding was that it is important not to overstate the existence of controversy surrounding the nuclear industry in West Cumbria. Overall, the West Cumbrian population appeared to be relatively nuclear friendly, but not as strongly pro-nuclear as might have been thought. A surprisingly large number of people displayed a lack of knowledge about the subject, and many showed feelings of apathy and alienation. Nuclear power and coal were found to be controversial choices of fuel supply. Wind power received more support and less opposition. Environmental groups were seen to perform a watchdog role, for which they were welcomed in West Cumbria by more people than supported the presence of either BNFL or NIREX. Levels of pOlitical activity amongst local people were low. The particular socio-economic situation in West Cumbria appeared to have had an impact upon local opinion. Support extended to the local industry, and to BNFL in particular, far more than it did to the nuclear industry in general. The insular aspect of West Cumbrian culture has affected attitudes towards those groups perceived as 'outsiders', including the national media and environmental groups. It has also affected attitudes to the industry where public relations campaigns have been targeted at a national rather than a specifically West Cumbrian audience.
96

Comparative analysis of electricity generating technologies with regards to environmental burdens

Papadopoulos, Ioannis January 2010 (has links)
In the last couple of decades, there has been an increased awareness of the effects that electricity generation has on the environment through the emission of greenhouse gases and the depletion of natural resources. This realisation, coupled with an increased drive towards ensuring the sustainability of the energy supply system, has lead many, including the United Kingdom government to investigate the options for moving away from traditional fossil fuel-burning generation methods towards “lowcarbon” generators, such as renewables and nuclear power. Specifically, wind power, the more mature systems (with the exception of hydro power) of the available renewable energy supply, and nuclear power, a technology seen as producing large amounts of electricity with very few associated greenhouse emissions, have been promoted but also pitted against each other by analysts and policy makers. This work aims to provide a balanced analysis of wind power and nuclear power with respect to their effects on the natural environment. As such, modeling has been undertaken of a Generation III+ nuclear reactor, an onshore wind farm located in southern Scotland and an offshore wind farm near the Thames estuary while environmental indicators have been created to permit the comparative assessment of these three electricity generation technologies, in a U.K. context. These indicators thus facilitate an assessment of the energy requirements, the associated greenhouse gas emissions, the natural resource requirements, as well as the displaced carbon dioxide emissions from operation of each power plant. A parametric analysis has also been conducted to show the range of likely variations in each indicator’s values. The results of this research show that all three technologies demonstrate similar performance with respect to their energetic and environmental impacts. More specifically, the wind farms demonstrate better energy gain ratios than the nuclear power plant when they are credited for not depleting non-renewable fuel sources. The wind farms also are shown to pay back their energy investments faster than the nuclear power plant. On the other hand, the nuclear power plant is found to produce slightly lower greenhouse gas emissions than either onshore or offshore wind farms. With respect to the assessment of natural resource depletion, it is estimated that both wind farms need more land per unit of electricity produced than the nuclear power plant, but all three power plants permanently sequester similar amounts of water. The wind farms and the nuclear power plant are found to have similar performance with respect to their material requirements, while the calculation of the avoided emissions factors for all technologies are of similar orders of magnitude. All results are shown to be highly sensitive to the assumptions made about the prospective lifecycles, and as such caution should be exercised when drawing conclusions about any comparative advantages. Nethertheless both technologies are clearly shown to have lower environmental impacts than traditional electricity generation technologies.
97

A market shock : the effect of the nuclear accident at Three Mile Island upon the prices of electric utility securities

Laslavic, Thomas J January 1981 (has links)
Thesis (M.S.)--Massachusetts Institute of Technology, Alfred P. Sloan School of Management, 1981. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND DEWEY. / Bibliography: leaves 58-59. / by Thomas J. Laslavic. / M.S.
98

Detection of outliers in failure data

Gallup, Donald Robert January 2011 (has links)
Typescript (photocopy). / Digitized by Kansas Correctional Industries
99

MCNP model of Sierra Nuclear Corporation dry spent fuel storage containers at Trojan Nuclear Power Plant

Brice, Derek J. 20 February 1998 (has links)
Graduation date: 1998
100

Investigation of the IRWST flow patterns during a simulated station blackout experiment on the OSU APEX facility

Strohecker, Mark F. 21 April 1998 (has links)
The OSU/APEX thermal hydraulic test facility models the passive safety systems of the Westinghouse AP600 advanced light water reactor design. Numerous experiments have been performed to test these systems, the one of focus here is the station blackout scenario. This experiment simulated the complete loss of AC power to all plant systems. One of the objectives of this experiment was to determine the effectiveness of the Passive Residual Heat Removal (PRHR) system. The PRHR system removes heat by rejecting it into the In-containment Refueling Water Storage Tank (IRWST). The IRWST houses the PRHR and is used as a heat sink for the decay heat. The PRHR is a C-type tube heat exchanger. Heat is removed through two mechanisms: natural convection and nucleate boiling from the surface of the PRHR. As the experiment progressed, a large degree of thermal stratification was observed in the IRWST with no significant thermal mixing. A thermal layer developed in the top of the tank and as the thermal layer approached saturation the rate of heat removal from the sections of the PRHR engulfed by this layer decreased. The effectiveness of these sections of the PRHR continued to decrease until unexpected flow patterns developed at the same time that the thermal layer reached saturation. The IRWST fluid exhibited a bulk azimuthal flow pattern that increased the effectiveness of the PRHR. This increase allowed for more heat to be injected into the IRWST. However, the bulk fluid motion still did not mix the thermal layers. A three-dimensional computational fluid dynamic model using the CFX-4.2 software was developed to study the PRHR/IRWST system. The model uses the RPI method to account for the sub-cooled boiling that is present on the PRHR surface. The model successfully predicted the thermal stratification in the IRWST to within 4 K of experimental data. A counter-current flow was shown to occur along the interface of the thermal layers. This caused an enhancement of the heat transfer and turbulent mixing occurring across the interface of the thermal layers. / Graduation date: 1998

Page generated in 0.0493 seconds