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  • 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.
11

Development of a nuclear accident health/eclogical consequence model for Hong Kong /

Lui, Wai-sing. January 1996 (has links)
Thesis (M. Phil.)--University of Hong Kong, 1996. / Includes bibliographical references (leaf 245-252).
12

The feasibility of modern technologies for reinforced concrete containment structures of nuclear power plants

Czerniewski, Sarah January 1900 (has links)
Master of Science / Department of Architectural Engineering and Construction Science / Kimberly W. Kramer / This report explores the requirements for the design and analysis of concrete containment and shows how newer material technologies such as self-consolidating concrete (SCC) and fiber reinforcement could assist in the constructability and durability of new nuclear power plant facilities. SCC for example, enables concrete to flow in the forms around the reinforcement and provides a more uniform adhesion with the reinforcement. Additionally, fiber reinforcement in the concrete mix increases bonding capability, thus making the concrete less likely to fracture. In particular, the ease of constructability benefits offshore floating nuclear power plants and preapproved modular power plants. To differentiate, the offshore plant would employ the assembly line to make all the plants the same while the modular plant, designed to be used anywhere, is not site specific and is typically smaller. Regarding research method, the report starts with the history of the nuclear industry in the United States, including the last nuclear power plant constructed, clarifying that nuclear energy was first harnessed for a submarine propulsion system before being employed to generate electricity. After these early endeavors, two major accidents, Three Mile Island (March 28, 1979) and Chernobyl (April 26, 1986), provided information regarding the lack of safety of nuclear power plant design and operation. Since the containment building is the focus of this report, recognizing the loads and the load combinations for design was the next step in research. Following that, the next step was to determine the design considerations and analyze the containment structure. New material technologies clearly have opened the door to new construction techniques, and the combination of new materials and methods offers structural engineers opportunity to build inherently safer nuclear power plants.
13

Laminar cracking in post-tensioned concrete nuclear containment buildings

Dolphyn, Bradley P. 27 May 2016 (has links)
As a critical public safety-related structure, the long-term integrity of post-tensioned concrete containment buildings (PCCs) is necessary for continued operation of the reactors they house. In 2009, during preparations for a steam generator replacement, extensive subsurface laminar cracking was identified in a portion of the Crystal River 3 (CR3) PCC in Florida, and the plant was permanently shut down in 2013. This study investigates potential contributing factors to the identified cracking with particular focus on the effects of high early-age temperatures on the cracking risk of the concrete, on the development of the concrete properties, and on the late-age structural behavior of the concrete. Two planar, full-scale mock-ups of a portion of the CR3 PCC were constructed and instrumented with temperature and strain gauges to monitor the thermal and mechanical behavior during representative concrete curing and post-tensioning loading. Standard- and match-cured concrete specimens were tested for determination of the time- and temperature-dependent development of thermal and mechanical concrete properties, and hydration parameters were determined for the mock-up cement paste for modeling the heat generation in the concrete. These properties and parameters were utilized in 3D finite element analysis of the mock-ups in COMSOL Multiphysics and compared with experimental results. Non-destructive evaluation via shear wave tomography was conducted on the mock-ups to identify flaws and determine the effectiveness of the methods for identifying delaminations between post-tensioning ducts approximately 10 inches beneath the concrete surface. Though early-age thermal stresses were determined not to have caused cracking in the mock-ups, the high early-age concrete temperatures resulted in decreased late-age mechanical properties that were shown to contribute to greater concrete cracking risk when the mock-up was post-tensioned. Tensile stresses exceeding the tensile strength of the concrete were identified along the post-tensioning ducts when biaxial post-tensioning loads were applied in finite element analysis, but the stresses decreased rapidly with increased distance from the ducts. Through parametric modeling, increasing the tensile strength of the concrete was identified as an effective means of reducing the cracking risk in PCCs. Additionally, relationships between the mechanical properties for the standard- and match-cured specimens were identified that could enable prediction of in-place or match-cured concrete properties based only on the results of tests on fog-cured specimens.
14

台灣海岸地帶土地資源規劃與管理之研究

陳炎基, CHEN, YAN-JI Unknown Date (has links)
海岸地帶係位處陸地與海洋交會之帶狀區域,自然孕育了珍貴且富變化的資源,能提 供高經濟、遊憩、教育、研究、生態保護及國土保安等多樣化使用。惟此等資源甚為 脆弱且不具復原性,一旦遭受破壞,將難以恢復,而遠失去其效用。 台灣土地資源極為有限,近二十年來,因為人口增加,產業結構轉型,對於不同型態 土地的需求日益殷切,而海岸土地具無主資源之特性,遂成為公、私部門競相使用的 對象。由於缺乏一套整體性的規劃與管理制度,致使海岸土地利用所衍生的問題方興 未艾,而這些問題正是以往海岸土地利用不當所累聚的環境惡果。 本研究承續上述問題,首先探討土地資源規劃與管理相關理論及美、日、荷等國海岸 土地資源規劃與管理的理念與精神,以作為本研究的理論基礎。 其次,透過實地訪問調查(使用者、管理者)並選擇彰濱工業區與核能四廠預定廠址 作為實例分析,分析重點為海岸土地資源競用與衝突之根源、政府所扮演的角色以及 規劃與管理之功能。根據分析結果,進一步檢視海岸地帶現行規劃與管理體制之缺失 。 從規劃與管理的角度來看,海岸地帶牽涉到陸域與水域二個方面,所以管轄機關職權 的複雜與重疊,法規的零散以及基於政治層面的考量,都構成規劃與管理的困難,而 海岸地帶規劃與管理的功能在於如何配置資源?建立使用的優先次序、整合法規以及 管理策略等。在這種思想結構下,本研究提出「動態的系統規劃與管理架構」,就政 策、法規、土地使用分派計畫、管理機構等作一詳盡的改革建議。整個架構力求與現 行體制相互配合,俾作為未來台灣地區海岸地帶長期發展規劃與管理之參考。
15

Sorpce radionuklidu85Sr na zeminy z areálu jaderné elektrárny Temelín / Sorption of radionuclid 85Sr to soils from area nuclear power plant Temelín

Reidingerová, Markéta January 2012 (has links)
This thesis is focused on the study of sorption of radionuclide 85 Sr in soil collected in the area of a nuclear power plant Temelín. A single-batch method experiment was used when a solution of radionuclide 85 Sr of known activity was added to the soil. The experiments focussed on the influence of pH with the size of the sorption and the influence of the time of the contact of the solution with the sorption. During the experiment with the value of pH closest to the pH of underground water from the nuclear power plant Temelín, the sorption of soil was somewhere between 31 to 44 %. When the time influence on the sorption was examined, radionuclide 85 Sr was sorbed very quickly. For the comparison of the sorption size in connection with the time, for which it was chosen 120 minutes, the sorption was almost constant, reaching 40 to 48 %. Key words Radioactivity, radionuclide 85 Sr, sorption, nuclear power plant Temelín
16

Determination of Failure Criteria for Electric Cables Exposed to Fire for Use in a Nuclear Power Plant Risk Analysis

Murphy, Jill E. 14 January 2004 (has links)
The vulnerability of electrical cables exposed to a fire environment is of particular concern to the nuclear power plant community. The community is interested in data that could be used for predicting cable failures during a fire situation. For this reason, a cable test program was conducted using two different types of cable insulation. Several different exposure heat fluxes were tested, as well as different test arrangements such as cable trays and conduits. The program revealed that a single failure temperature for all cable types is not recommended, but if it is necessary a reasonable temperature could be chosen for the thermosets tested in this project.
17

The phenomenon of Living Close to Nuclear power Plants

Miles, Jacquelynn Isabel 01 January 2019 (has links)
Communities near nuclear power plants are at potential risk from natural and man-made failures at the nuclear power plants located within those communities. This study explored the concerns and rationalizations of residents of a community who live within a 10-mile evacuation zone of the nuclear power plant located there. Using the general theory of deliberative democracy, the purpose of this qualitative study was to understand and explore why individuals continue to live close to nuclear power plants. Data were collected through semi-structured interviews with 15 individuals who live within a 10- mile radius of a nuclear power plant in the western US. These interviews were transcribed, coded, and analyzed using a modified Van Kaam procedure. Findings indicated that members of the community had concerns that natural or man-made disasters could lead to catastrophic failure of the nuclear power plant but rationalized living in proximity. Another key finding was that the community itself was supported by the revenue generated from the plant which led many of the participants to live in the community and this contributed to their rationalizing for why they should live close to the plant. The social change implications of this study included recommendations to mayors, city councils, and regulatory bodies to provide more information about nuclear power plants to communities to help them cope with fear and feelings of helplessness. Residents living near nuclear power plants would benefit from the recommendations made in this study because it would help them understand the risks of living near nuclear power plants.
18

A knowledge-based approach for monitoring and situation assessment at nuclear power plants

Heaberlin, Joan Oylear 21 July 1994 (has links)
An approach for developing a computer-based aid to assist in monitoring and assessing nuclear power plant status during situations requiring emergency response has been developed. It is based on the representation of regulatory requirements and plant-specific systems and instrumentation in the form of hierarchical rules. Making use of inferencing techniques from the field of artificial intelligence, the rules are combined with dynamic state data to determine appropriate emergency response actions. In a joint project with Portland General Electric Company, a prototype system, called EM-CLASS, was been created to demonstrate the knowledge-based approach for use at the Trojan Nuclear Power Plant. The knowledge domain selected for implementation addresses the emergency classification process chat is used to communicate the severity of the emergency and the extent of response actions required. EM-CLASS was developed using Personal Consultant Plus (PCPlus), a knowledge-based system development shell from Texas Instruments which runs on IBM-PC compatible computers. The knowledge base in EM-CLASS contains over 200 rules. The regulatory basis, as defined in 10 CFR 50, calls for categorization of emergencies into four emergency action level classes: (1) notification of unusual event, (2) alert, (3) site area emergency, and (4) general emergency. Each class is broadly defined by expected frequency and the potential for release of radioactive materials to the environment. In a functional sense, however, each class must be ultimately defined by a complex combination of in- plant conditions, plant instrumentation and sensors, and radiation monitoring information from stations located both on- and off-site. The complexity of this classification process and the importance of accurate and timely classification in emergency response make this particular application amenable to an automated, knowledge-based approach. EM-CLASS has been tested with a simulation of a 1988 Trojan Nuclear Power Plant emergency exercise and was found to produce accurate classification of the emergency using manual entry of the data into the program. / Graduation date: 1997
19

Nonintrusive intelligent monitoring for nuclear power plant emergency classification

Greene, Kenneth R. (Kenneth Ray), 1958- 13 May 1991 (has links)
A prototype real-time process monitoring emergency classification expert system, RT/EM-CLASS, has been developed for use at the Trojan Nuclear Power Plant. This knowledge-based system features the integration of electronically sensed plant data with the menu selection data representation of its predecessor, EM-CLASS. This prototype demonstrates the techniques required to acquire plant process data from another computer and use that data in an expert system to determine the proper Emergency Action Level. Several benefits are realized by the RT/EM-CLASS application. These include: The resources required to make a classification are reduced thereby freeing the responsible person to devote time to other important tasks. The classification may be completed more often and with better data than the current system allows. The human user is less likely to make an erroneous Emergency Action Level classification. Prototype implementation required resolution of an efficiency problem of relating plant process data to the expert system data forms. This was achieved through the development of multi-conditional rules that significantly reduce the size of the rule set. The development of RT/EM-CLASS presents a methodology for building knowledge based applications that perform nonintrusive real-time monitoring of dynamic systems. This methodology features Use of existing analytical and Al tools where possible Monitoring of a dynamic system Non-intrusive acquisition of data from the system This technology might be applied to portions of the nuclear engineering design process (control rod programming in Boiling Water Reactors, for example) to emulate the guidance and activities of an expert. A substantial portion of the effort by the expert engineer involves preparation of the code input, running the computer code, analyzing the results, and based on the results, deciding what case to submit next. A suitably designed expert system could act in the place of the engineer in this dynamic design process. This methodology has been tested against the 1988 emergency exercise at the Trojan Nuclear Power Plant. / Graduation date: 1992
20

Ecological Interface Design for Turbine Secondary Systems in a Nuclear Power Plant: Effects on Operator Situation Awareness

Kwok, Jordanna January 2007 (has links)
Investigations into past accidents at nuclear power generating facilities such as that of Three Mile Island have identified human factors as one of the foremost critical aspects in plant safety. Errors resulting from limitations in human information processing are of particular concern for human-machine interfaces (HMI) in plant control rooms. This project examines the application of Ecological Interface Design (EID) in HMI information displays and the effects on operator situation awareness (SA) for turbine secondary systems based on the Swedish Forsmark 3 boiling-water reactor nuclear power plant. A work domain analysis was performed on the turbine secondary systems yielding part-whole decomposition and abstraction hierarchy models. Information display requirements were subsequently extracted from the models. The resulting EID information displays were implemented in a full-scope simulator and evaluated with six licensed operating crews from the Forsmark 3 plant. Three measures were used to examine SA: self-rated bias, Halden Open Probe Elicitation (HOPE), and Situation Awareness Control Room Inventory (SACRI). The data analysis revealed that operators achieved moderate to good SA; operators unfamiliar with EID information displays were able to develop and maintain comparable levels of SA to operators using traditional forms of single sensor-single indicator (SS-SI) information displays. With sufficient training and experience, operator SA is expected to benefit from the knowledge-based visual elements in the EID information displays. This project was researched in conjunction with the Cognitive Engineering Laboratory at the University of Toronto and the Institute for Energy Technology (IFE) in Halden, Norway.

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