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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.
1

Techno-economic factors in uranium enrichment

Basar, Cengiz 22 November 2010 (has links)
M.Phil. / In the pricing of nuclear fuel, the cost of the uranium enrichment has the biggest portion. In addition, characteristics of enrichment technologies, the structure of the international market, and the balance of supply and demand are considered to be three main determinant factors for the cost of uranium enrichment. This study attempts to examine the determinant factors of uranium enrichment costs and to try to forecast the future trends of the price of uranium enrichment by examining the current market situation and present projections of uranium enrichment prices. The analysis indicates that while the development of the enrichment techniques allows the enrichers to produce with a lower cost, the structure of the market causes the prices to rise. Moreover, the supply and demand balance of the present market is very fragile and there is a need for an expansion in the market to make and sustain a stronger balance. It is the prediction of this study that the enrichment prices are likely to increase because of the reflection of the constructions of the new enrichment facilities and new ventures in the market.
2

Time-dependent fission product cross sections for ²³⁵U fuels

Stankiewicz, Gayle J. January 1981 (has links)
Thesis (M.S.)--University of Michigan, 1981.
3

A POTENTIAL CONSEQUENCE OF EXCLUDING WORK-REQUIRED X-RAY EXPOSURES WHEN COMPUTING CUMULATIVE OCCUPATIONAL RADIATION DOSE AT A URANIUM ENRICHMENT PLANT

Cardarelli, John Joseph, II January 2000 (has links)
No description available.
4

Determination of a calculation bias in the MCNP model of the OSTR

Kitto, Allyson K. 05 December 2012 (has links)
Oregon State University is home to a TRIGA® Mark II reactor. In October of 2008, the reactor began operating on low enriched uranium fuel. A model of the facility exists in MCNP, a Monte Carlo code that can be used for criticality calculations. Until now, a bias in the calculation of the neutron multiplication factor has been carried forward from outdated core models. This work involves updating various aspects of the model, including the geometry of the facility as well as materials and their properties, in order to arrive at a more accurate representation of the facility as it is today. The individual effect that each change has on the results of MCNP calculations of the core is documented. Following the updates to the model, the model can emulate records that describe the startup of the reactor in October of 2008. The results of these calculations can be compared to actual data in order to establish a foundation for benchmarking the model and characterizing the reactor core. The deviation between calculated and expected results can be used to determine a single reactivity bias in the model. The bias determined as a result of this work can be applied to future calculations using the model developed as a part of this work. / Graduation date: 2013
5

Development of the fundamental attributes and inputs for proliferation resistance assessments of nuclear fuel cycles

Giannangeli, Donald D. J., III 17 September 2007 (has links)
Robust and reliable quantitative proliferation resistance assessment tools are critical to a strengthened nonproliferation regime and to the future deployment of nuclear fuel cycle technologies. Efforts to quantify proliferation resistance have thus far met with limited success due to the inherent subjectivity of the problem and interdependencies between attributes that contribute to proliferation resistance. This work focuses on the diversion of nuclear material by a state and defers other threats such as theft or terrorism to future work. A new approach is presented that assesses the problem through four stages of proliferation: the diversion of nuclear material, the transportation of nuclear material from an internationally safeguarded nuclear facility to an undeclared facility, the transformation of material into a weapons-usable metal, and weapon fabrication. A complete and concise set of intrinsic and extrinsic attributes of the nation, facility and material that could impede proliferation are identified. Quantifiable inputs for each of these attributes are defined. For example, the difficulty of handling the diverted material is captured with inputs like mass and bulk, radiation dose, heating rate and others. Aggregating these measurements into an overall value for proliferation resistance can be done in multiple ways based on well-developed decision theory. A preliminary aggregation scheme is provided along with results obtained from analyzing a small spent fuel reprocessing plant to demonstrate quantification of the attributes and inputs. This quantification effort shows that the majority of the inputs presented are relatively straightforward to work with while a few are not. These few difficult inputs will only be useful in special cases where the analyst has access to privileged, detailed or classified information. The stages, attributes and inputs of proliferation presented in this work provide a foundation for proliferation resistance assessments which may use multiple types of aggregation schemes. The overall results of these assessments are useful in comparing nuclear technologies and aiding decisions about development and deployment of that technology.
6

Comparison of HEU and LEU neutron spectra in irradiation facilities at the Oregon State TRIGA�� reactor

Schickler, Robert 01 October 2012 (has links)
In 2008, the Oregon State TRIGA�� Reactor (OSTR) was converted from highly-enriched uranium (HEU) fuel lifetime improvement plan (FLIP) fuel to low-enriched uranium (LEU) fuel. This effort was driven and supported by the Department of Energy's (DoE's) Reduced Enrichment for Research and Test Reactors (RERTR) program. The basis behind the RERTR program's ongoing conversion effort is to reduce the nuclear proliferation risk of civilian research and test reactors. The original intent of the HEU FLIP fuel was to provide fuel to research reactors that could be utilized for many years before a necessary refueling cycle. As a research reactor, the OSTR provides irradiation facilities for a variety of applications, such as: activation analysis, fission-track dating, commercial isotope production, neutron radiography, prompt gamma characterization, and many others. In order to accurately perform these research functions, several studies have been conducted on the HEU FLIP fuel core to characterize the neutron spectra in various experimental facilities of the OSTR. As useful as these analyses were, they are no longer valid due to the change in fuel composition and the resulting alteration of core performance characteristics. The purpose of this study is to characterize the neutron spectra in various experimental facilities within the new LEU core so as to provide data that is representative of the OSTR's current state. / Graduation date: 2013
7

[en] IMPLICATIONS OF THE ARTICLE IV OF THE NON-PROLIFERATION TREATY / [pt] A APLICAÇÃO DO ARTIGO QUARTO DO TRATADO DE NÃO-PROLIFERAÇÃO NUCLEAR

MARIANA OLIVEIRA DO NASCIMENTO 12 July 2016 (has links)
[pt] Os bombardeios nucleares contra Hiroshima e Nagasaki alteraram profundamente o conceito de guerra entre os Estados nacionais. A partir do momento em que os dois cogumelos atômicos espalharam-se as cidades japonesas, a inclusão da ameaça nuclear em conflitos interestatais passou a ser preocupação obrigatória das nações que disputariam áreas de influência diante a Guerra Fria. Estimulada por essa preocupação, a comunidade internacional tomou diversas medidas durante os últimos 50 anos para restringir o uso dos armamentos nucleares. O Tratado de não-Proliferação Nuclear (TNP) foi uma das principais iniciativas para atingir esse fim. Seus artigos determinaram a proibição do desenvolvimento e da aquisição de armamentos nucleares após 1967, além de incentivar o desenvolvimento da tecnologia nuclear civil e o encorajamento do progressivo desarmamento dos Estados.Os acordos firmados no final da década de 60, entretanto, não foram capazes de prever o avanço da tecnologia nuclear. Se o uso pacífico do átomo era permitido em 1968, hoje o desenvolvimento de tecnologias de duplo uso - tais como o enriquecimento de urânio, ainda que para fins pacíficos - não é visto com bons olhos.As dificuldades para verificar a boa-fé do desenvolvimento e do uso dessas tecnologias tornaram a possibilidade de sua proliferação um problema ainda mais temido. O surgimento de programas nucleares clandestinos e, consequentemente, de novos Estados nucleares, além da cada vez mais presente possibilidade de terrorismo nuclear, abalaram a credibilidade do Regime de Não-Proliferação. Para tentar controlar os danos causados por esse problema, diversas reuniões de revisão do TNP vêm tentando preencher as brechas que desafiam o regime.Esta dissertação mostra quais são as principais tensões existentes dentro do regime e como a comunidade internacional e a Agência Internacional de Energia Atômica estão atuando para lidar com essas dificuldades. A análise do artigo IV do TNP parece demonstrar que, se as cláusulas do contrato não forem cumpridas de forma igualitária por todos os Estados-parte, será muito difícil resolver os problemas da não-proliferação. / [en] The nuclear bombings over hiroshima and Nagasaki have deeply changed the concept of war among national States. From the moment the two atomic mushroom clouds spread in the sky over the Japanese cities, the inclusion of the nuclear threat in interstate conflicts has become a mandatory worry to the nations that would struggle for influence areas during the Cold War.Stimulated by these worries, the international community has taken several measures over last 50 years in order to curb the use of nuclear weapons. The Non-Proliferation Treaty (NPT) has been one of the main initiatives aimed at this purpose. Its articles instituted the proscription of developing and acquiring nuclear weapons after 1967, besides motivating the expasion of civil nuclear technology and heartening the progressive disarmament of states. The agreements signed by the end of the 60s, however, were not able to predict the advance of nuclear technology. If the peaceful use of the atom was allowed back in 1968, today the development of dual-use technology- such as uranium enrichment, even for peaceful reasons - is still frowned upon.The difficulties to examine the true intentions behind developing and using this technology have changed the possibility of its proliferation into a truly fearsome problem. The blossoming of rogue nuclear programs, and, therefore, of new nuclear states, allied to the growing threat of nuclear terrorism, has shaken the credibility of the non-proliferation regime. In order to control the damages induced by this problem, several review conferences have been trying to mend the gaps that challenge the regime.This paper tries to show which are the main tensions inside the regime and how the international community and the Internatonal Atomic Energy Agency are trying to cope with these matters. The analysis of Articles IV of the NPT seems to demonstrate that if the treaty provisions are not equally observed by all member states, it will be extremely hard to overcome the problems of non-proliferation.

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