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[en] Owing to the diverse nuclear fuel cycle options available, including direct disposal, it is necessary to select the optimum nuclear fuel cycles in consideration of the political and social environments as well as the technical stability and economic efficiency of each country. Economic efficiency is therefore one of the significant evaluation standards. In particular, because nuclear fuel cycle cost may vary in each country, and the estimated cost usually prevails over the real cost, when evaluating the economic efficiency, any existing uncertainty needs to be removed when possible to produce reliable cost information. Many countries still do not have reprocessing facilities, and no globally commercialized HLW (High-level waste) repository is available. A nuclear fuel cycle cost estimation model is therefore inevitably subject to uncertainty. This paper analyzes the uncertainty arising out of a nuclear fuel cycle cost evaluation from the viewpoint of a cost estimation model. Compared to the same discount rate model, the nuclear fuel cycle cost of a different discount rate model is reduced because the generation quantity as denominator in Equation has been discounted. Namely, if the discount rate reduces in the back-end process of the nuclear fuel cycle, the nuclear fuel cycle cost is also reduced. Further, it was found that the cost of the same discount rate model is overestimated compared with the different discount rate model as a whole
[en] The development of a systematic approach to protection of the environment has required a number of basic steps to be taken, including a discussion of what objectives could reasonably be set, together with an examination of how existing knowledge could best be used in order to achieve them. It has required bold decisions to be made, new modelling to be undertaken, and new data sets to be compiled. Equally challenging, however, has been the need to fold the entire subject area into an expanded system originally developed for the protection of human beings. There are, inevitably, a number of data gaps, and further decisions need to be made. However, the priority now is to examine how this approach to protection of the environment can be used in practice. With an intensifying worldwide debate about the environmental merits of different forms of energy production, it would seem imperative that the various practices involved in the nuclear fuel cycle are able to demonstrate, clearly and independently, their own actual or potential impact on the environment. The International Commission on Radiological Protection now has the basic means for such evaluations to be made, and further developments in this system will reflect the experience of its practical application.
[en] Previous PNNL work has shown the existing nuclear fuel markets to provide a high degree of supply security, including the ability to respond to supply disruptions that occur for technical and non-technical reasons. It is in the context of new reactor designs - that is, reactors likely to be licensed and market ready over the next several decades - that fuel supply security is most relevant. Whereas the fuel design and fabrication technology for existing reactors are well known, the construction of a new set of reactors could stress the ability of the existing market to provide adequate supply redundancy. This study shows this is unlikely to occur for at least thirty years, as most reactors likely to be built in the next three decades will be evolutions of current designs, with similar fuel designs to existing reactors.
[en] This report contains a technical summary package in response to a Level 2 milestone in the transmutation fuel campaign (TFC) management work-package calling for input to the Secretarial decision. At present, the form of the Secretarial decision package is not fully defined, and it is not clear exactly what will be required from the TFC as a final input. However, it is anticipated that a series of technical and programmatic documents will need to be provided in support of a wider encompassing document on GNEP technology development activities. The TFC technical leadership team provides this report as initial input to the secretarial decision package which is being developed by the Technical Integration Office (TIO) in support of Secretarial decision. This report contains a summary of the TFC execution plan with a work breakdown structure, high level schedule, major milestones, and summary description of critical activities in support of campaign objectives. Supporting documents referenced in this report but provided under separate cover include: (1) An updated review of the state-of-the art for transmutation fuel development activities considering national as well as international fuel research and development testing activities. (2) A definition of the Technology Readiness Level (TRL) used to systematically define and execute the transmutation fuel development activities
[en] The rare occurrence of sheath defects may lead to contact between the fuel and coolant, which may lead to fuel hyperstoichiometry, thus degrading fuel thermal performance and raising the potential for centreline melting. By simplifying a published mechanistic model, a semi-empirical model has been developed to predict fuel hyperstoichiometry using a one-dimensional oxygen transport equation coupled to a two-dimensional temperature equation, improving numerical robustness for possible implementation into fuel performance codes. The model has been validated against experimental measurements from commercial defective elements for normal operation, and has been used to predict the response of defective fuel under accident conditions. (author)
[en] This document was prepared as part of an independent review to explain design verification activities already completed, and to define the remaining design verification actions for the Fuel Retrieval System. The Fuel Retrieval Subproject was established as part of the Spent Nuclear Fuel Project (SNF Project) to retrieve and repackage the SNF located in the K Basins. The Fuel Retrieval System (FRS) construction work is complete in the KW Basin, and start-up testing is underway Design modifications and construction planning are also underway for the KE Basin. An independent review of the design verification process as applied to the K Basin projects was initiated in support of preparation for the SNF Project operational readiness review (ORR)
[en] This report describes the impact that waste stream parameters have on repository design, including surface, subsurface and waste package designs. Two design basis waste streams and corresponding design levels are established for two documented inventories of wastes: (a) Mined Geologic Design System (MGDS) Baseline (Viability Assessment) (VA) and (b) Extended Baseline. The MGDS Baseline VA inventory is currently used as the basis for the VA design of the repository, and is limited by statutes to a total of 70,000 MTU. The Extended Baseline includes the total documented inventories of commercial spent nuclear fuel, high-level waste and US Department of Energy spent nuclear fuel. Impacts of the two design bases on surface, subsurface and waste package designs are projected. The impact of potential disposal of additional commercial and Department of Energy miscellaneous wastes on design is assessed qualitatively
[en] This document provides the Operations Manual for the Cold Vacuum Drying Facility (CVDF). The Manual was developed in conjunction with HNF-SD-SNF-SAR-002, Safety Analysis Report for the Cold Vacuum Drying Facility, Phase 2, Supporting Installation of the Processing Systems (Garvin 1998) and, the HNF-SD-SNF-DRD-002, 1997, Cold Vacuum Drying Facility Design Requirements, Rev. 3a. The Operations Manual contains general descriptions of all the process, safety and facility systems in the CVDF, a general CVD operations sequence, and has been developed for the spent nuclear fuel project (SNFP) Operations Organization and shall be updated, expanded, and revised in accordance with future design, construction and startup phases of the CVDF until the CVDF final ORR is approved