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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.
71

Definition and characterization of non high-level waste in the thorium fuel cycle

Parker, Steven Ray January 1979 (has links)
No description available.
72

An economic evaluation of the recovery of krypton and xenon from nuclear fuels reprocessing plants

Boyum, Bruce Montgomery, 1947- January 1971 (has links)
No description available.
73

Proliferation resistances of Generation IV recycling facilities for nuclear fuel

Åberg Lindell, Matilda January 2013 (has links)
The effects of global warming raise demands for reduced CO2 emissions, whereas at the same time the world’s need for energy increases. With the aim to resolve some of the difficulties facing today’s nuclear power, striving for safety, sustainability and waste minimization, a new generation of nuclear energy systems is being pursued: Generation IV. New reactor concepts and new nuclear facilities should be at least as resistant to diversion of nuclear material for weapons production, as were the previous ones. However, the emerging generation of nuclear power will give rise to new challenges to the international safeguards community, due to new and increased flows of nuclear material in the nuclear fuel cycle. Before a wide implementation of Generation IV nuclear power facilities takes place, there lies still an opportunity to formulate safeguards requirements for the next generation of nuclear energy systems. In this context, this thesis constitutes one contribution to the global efforts to make future nuclear energy systems increasingly resistant to nuclear material diversion attempts. This thesis comprises three papers, all of which concern safeguards and proliferation resistance in Generation IV nuclear energy systems and especially recycling facilities: In Paper I, proliferation resistances of three fuel cycles, comprising different reprocessing techniques, are investigated. The results highlight the importance of making group actinide extraction techniques commercial, due to the inherently less vulnerable isotopic and radiological properties of the materials in such processes. Paper II covers the schematic design and safeguards instrumentation of a Generation IV recycling facility. The identification of the safeguards needs of planned facilities can act as a guide towards the development of new instrumentation suitable for Generation IV nuclear energy systems. Finally, Paper III describes a mode of procedure for assessing proliferation resistance of a recycling facility for fast reactor fuel. The assessments may be used, as in this case, as an aid to maintain or increase the inherent proliferation resistance when performing facility design changes and upgrades.
74

Acidic high-level liquid waste processing for improved management, actinide product utilization and fuel safeguards

Hubert, Richard Gregory 12 1900 (has links)
No description available.
75

Safeguards Envelope Methodology

Metcalf, Richard 2011 December 1900 (has links)
Nuclear safeguards are intrinsic and extrinsic features of a facility which reduce probability of the successful acquisition of special nuclear material (SNM) by hostile actors. Future bulk handling facilities in the United States will include both domestic and international safeguards as part of a voluntary agreement with the International Atomic Energy Agency. A new framework for safeguards, the Safeguards Envelope Methodology, is presented. A safeguards envelope is a set of operational and safeguards parameters that define a range, or “envelope,” of operating conditions that increases confidence as to the location and assay of nuclear material without increasing costs from security or safety. Facilities operating within safeguards envelopes developed by this methodology will operate with a higher confidence, a lower false alarm rate, and reduced safeguards impact on the operator. Creating a safeguards envelope requires bringing together security, safety, and safeguards best practices. This methodology is applied to an example facility, the Idaho Chemical Processing Plant. An example diversion scenario in the front-end of this nuclear reprocessing facility, using actual operating data, shows that the diversion could have been detected more easily by changing operational parameters, and these changed operational parameters would not sacrifice the operational efficiency of the facility, introduce security vulnerabilities, or create a safety hazard.
76

Implementing marine pollution policy : proposals for change

Richards, Jonathan Peter January 2001 (has links)
This study aims to determine the factors that affect the implementation of marine pollution policy, especially with regard to regulation of the hazardous substances which contaminate the marine environment- The purpose is to identify weaknesses in the current regulatory regime and to propose improvements. The study also aims to develop a new strategic framework for the implementation of the recent international policy commitments, which call for the complete cessation of discharges of hazardous substances into the marine environment by the year 2020. Furthermore, the study seeks to provide evidence to support or challenge current theories relating to regulation and policy implementation. Examination was made of the attitudes of environmental managers from the UK chemical industry and inspectors from the environmental agencies towards the regulatory system. These are the key personnel who operate at the regulatory interface where the policy outcome is determined. The methodology combined both qualitative and quantitative techniques. Structured interviews helped define the issues for subsequent investigation using a questionnaire survey which was sent to over 700 key personnel. Focus groups were then used to explain the survey findings and develop solutions to key regulatory problems. Statistical analysis of the survey response data revealed similarities and significant differences between the views of industry and the regulator on the effectiveness of the current Integrated Pollution Control regime. The strength of the system was perceived as its practical and pragmatic approach, coupled with a convenient and familiar bureaucracy. The weaknesses identified related to the derivation and enforcement of standards. The Environmental Quality Standards system, which underpins the regime, was acknowledged to be flawed by both operators and regulators who agreed it should be improved by the expansion in the number of priority listed chemicals, the introduction of sediment Environmental Quality Standards and Direct Toxicity Assessment of effluents. Focus groups supported the expansion of the system, but recognised that it would create a regime that was both complex and impractical. The findings were used to construct a revised model of the existing regime. Multivariate analysis of the industry response data identified 3 cluster types and significant differences were revealed between their knowledge of policy developments, their implications and the need for changes to the current system of hazardous chemical control. Operators and regulators acknowledged the existence of the mutual interdependency which has created and maintained a tight policy network (community) at the regulatory interface. Further evidence to support the existence of this community and of regulatory capture, was provided by the study data. Focus group discussions also identified the requirement for a more fundamental reappraisal of the regulatory system in order to deliver the OSPAR strategy. A new regulatory model, which incorporates process and product substitution, is proposed as a strategic framework to ensure that future policy commitments are implemented. This approach may lead to the opening up of the current tight policy network with resultant benefits for policy implementation and reduced regulatory capture. The new model could be applied by other countries within the OSPAR region and in other regions of the world, in order to improve environmental protection.
77

Safety characteristics of a suspended-pellet fission reactor system /

Kingdon, David Ross. January 1998 (has links)
Thesis (Ph.D.) -- McMaster University, 1998. / Includes bibliographical references (p. 185-197). Also available via World Wide Web.
78

EMDR Eye movement desensitization and reprocessing ; a new method in the treatment of performance anxiety for singers /

Feener, Raymond Scott. Fisher, Douglas. January 2004 (has links)
Treatise (D.M.A.) -- Florida State University, 2004. / Advisor: Douglas Fisher, Florida State University, School of Music. Title and description from treatise home page (viewed 9-29-04). Document formatted into pages; contains 73 pages. Includes biographical sketch. Includes bibliographical references.
79

Aqueous complexation of citric acid and DTPA with selected trivalent and tetravalent f-elements

Brown, M. Alex 03 July 2013 (has links)
Carboxylic acids have played an important role in the field of actinide (An) and lanthanide (Ln) separations and the reprocessing of irradiated nuclear fuel. Recent bench-scale experiments have demonstrated that 3-carboxy-3-hydroxypentanedioic acid (citric acid) is a promising aqueous complexant that can effectively aid in the separation of transition metals from f-element mixtures. Furthermore, citric acid was found to be a suitable buffer for the nitrogen donating ligand diethylenetriamine-N,N,N',N'',N''-pentaacetic acid (DTPA) which has a higher complexation affinity for An over Ln. The complexation of Ln and An with anions of citric acid and DTPA have been previously studied with conflicting results regarding the coordination of metal ions between carboxylic groups, the feasibility of protonated metal complexes, and the formation constants themselves. Using potentiometry, spectrophotometry,microcalorimetry, and specific ion interaction modeling, we investigated metal complexes of citric acid and DTPA with selected trivalent and tetravalent Ln and An ions. The complexes were investigated with respects to stability constants, thermodynamics of complexation, oxidation states, the concentration of electrolyte, ligand size, thermodynamics of complexation, oxidation states, the concentration of electrolyte, ligand size, and metal ionic radius. / Graduation date: 2013 / Access restricted to the OSU Community at author's request from Jan. 3, 2013 - July 3, 2013
80

Contribuição ao estudo da nova filosofia internacional de segurança radiológica no processamento químico do urânio natural

SILVA, TERESINHA de M. da 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:32:40Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:08:42Z (GMT). No. of bitstreams: 1 03371.pdf: 3959885 bytes, checksum: 92c5eafe280381862d70e980bb9322c9 (MD5) / Dissertacao (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP

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