19 research outputs found
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Status Report on Fast Reactor Recycle and Impact on Geologic Disposal
The GNEP program envisions continuing the use of light-water reactors (LWRs), with the addition of processing the discharged, or spent, LWR fuel to recover actinide and fission product elements, and then recycling the actinide elements in sodium-cooled fast reactors. Previous work has established the relationship between the processing efficiencies of spent LWR fuel, as represented by spent PWR fuel, and the potential increase in repository utilization for the resulting processing waste. The purpose of this current study is to determine a similar relationship for the waste from processing spent fast reactor fuel, and then to examine the wastes from the combination of LWRs and fast reactors as would be deployed with the GNEP approach
Sodium fast reactor safety and licensing research plan. Volume I.
This report proposes potential research priorities for the Department of Energy (DOE) with the intent of improving the licensability of the Sodium Fast Reactor (SFR). In support of this project, five panels were tasked with identifying potential safety-related gaps in available information, data, and models needed to support the licensing of a SFR. The areas examined were sodium technology, accident sequences and initiators, source term characterization, codes and methods, and fuels and materials. It is the intent of this report to utilize a structured and transparent process that incorporates feedback from all interested stakeholders to suggest future funding priorities for the SFR research and development. While numerous gaps were identified, two cross-cutting gaps related to knowledge preservation were agreed upon by all panels and should be addressed in the near future. The first gap is a need to re-evaluate the current procedures for removing the Applied Technology designation from old documents. The second cross-cutting gap is the need for a robust Knowledge Management and Preservation system in all SFR research areas. Closure of these and the other identified gaps will require both a reprioritization of funding within DOE as well as a re-evaluation of existing bureaucratic procedures within the DOE associated with Applied Technology and Knowledge Management
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Sodium fast reactor safety and licensing research plan. Volume I.
This report proposes potential research priorities for the Department of Energy (DOE) with the intent of improving the licensability of the Sodium Fast Reactor (SFR). In support of this project, five panels were tasked with identifying potential safety-related gaps in available information, data, and models needed to support the licensing of a SFR. The areas examined were sodium technology, accident sequences and initiators, source term characterization, codes and methods, and fuels and materials. It is the intent of this report to utilize a structured and transparent process that incorporates feedback from all interested stakeholders to suggest future funding priorities for the SFR research and development. While numerous gaps were identified, two cross-cutting gaps related to knowledge preservation were agreed upon by all panels and should be addressed in the near future. The first gap is a need to re-evaluate the current procedures for removing the Applied Technology designation from old documents. The second cross-cutting gap is the need for a robust Knowledge Management and Preservation system in all SFR research areas. Closure of these and the other identified gaps will require both a reprioritization of funding within DOE as well as a re-evaluation of existing bureaucratic procedures within the DOE associated with Applied Technology and Knowledge Management
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Objectives, Strategies, and Challenges for the Advanced Fuel Cycle Initiative
This paper will summarize the objectives, strategies, and key chemical separation challenges for the Advanced Fuel Cycle Initiative (AFCI). The major objectives are as follows: Waste management - defer the need for a second geologic repository for a century or more, Proliferation resistance - be more resistant than the existing PUREX separation technology or uranium enrichment, Energy sustainability - turn waste management liabilities into energy source assets to ensure that uranium ore resources do not become a constraint on nuclear power, and Systematic, safe, and economic management of the entire fuel cycle. There are four major strategies for the disposal of civilian spent fuel: Once-through - direct disposal of all discharged nuclear fuel, Limited recycle - recycle transuranic elements once and then direct disposal, Continuous recycle - recycle transuranic elements repeatedly, and Sustained recycle - same as continuous except previously discarded depleted uranium is also recycled. The key chemical separation challenges stem from the fact that the components of spent nuclear fuel vary greatly in their influence on achieving program objectives. Most options separate uranium to reduce the weight and volume of waste and the number and cost of waste packages that require geologic disposal. Separated uranium can also be used as reactor fuel. Most options provide means to recycle transuranic (TRU) elements - plutonium (Pu), neptunium (Np), americium (Am), curium (Cm). Plutonium must be recycled to obtain repository, proliferation, and energy recovery benefits. U.S. non-proliferation policy forbids separation of plutonium by itself; therefore, one or more of the other transuranic elements must be kept with the plutonium; neptunium is considered the easiest option. Recycling neptunium also provides repository benefits. Americium recycling is also required to obtain repository benefits. At the present time, curium recycle provides relatively little benefit; indeed, recycling curium in thermal reactors would significantly increase the hazard (hence cost) of the resulting fuel. Most options separate short-lived fission products cesium and strontium to allow them to decay in separate storage facilities tailored to that need, rather than complicate long-term geologic disposal. This can also reduce the number and cost of waste packages requiring geologic disposal. These savings are balanced by costs for separation and recycle systems. Several long-lived fission products, such as technetium-99 and iodine-129 go to geologic disposal in improved waste forms, recognizing that transmutation of these isotopes would be a slow process; however, the program has not precluded their transmutation as a future alternative
Overview of the Facility Safeguardability Analysis (FSA) Process
The safeguards system of the International Atomic Energy Agency (IAEA) provides the international community with credible assurance that a State is fulfilling its nonproliferation obligations. The IAEA draws such conclusions from the evaluation of all available information. Effective and cost-efficient IAEA safeguards at the facility level are, and will remain, an important element of this “State-level” approach. Efficiently used, the Safeguards by Design (SBD) methodologies , , , now being developed can contribute to effective and cost-efficient facility-level safeguards. The Facility Safeguardability Assessment (FSA) introduced here supports SBD in three areas. 1. It describes necessary interactions between the IAEA, the State regulator, and the owner / designer of a new or modified facility to determine where SBD efforts can be productively applied, 2. It presents a screening approach intended to identify potential safeguard issues for; a) design changes to existing facilities; b) new facilities similar to existing facilities with approved safeguards approaches, and c) new designs, 3. It identifies resources (the FSA toolkit), such as good practice guides, design guidance, and safeguardability evaluation methods that can be used by the owner/designer to develop solutions for potential safeguards issues during the interactions with the State regulator and IAEA. FSA presents a structured framework for the application of the SBD tools developed in other efforts. The more a design evolves, the greater the probability that new safeguards issues could be introduced. Likewise, for first-of-a-kind facilities or research facilities that involve previously unused processes or technologies, it is reasonable to expect that a number of possible safeguards issues might exist. Accordingly, FSA is intended to help the designer and its safeguards experts identify early in the design process: • Areas where elements of previous accepted safeguards approach(es) may be applied to facility modifications or new designs • Modifications of the design that could mitigate a potential safeguards issue or facilitate a more efficient application of the safeguards approach • Possible innovative ideas for more efficient application of safeguards • The potential for changes in elements of the safeguard approach that may be required by IAEA as a result of facility design features and characteristics • Other potential concerns These issues will then be presented to the IAEA and the state regulator to be resolved in a timely manner, ensuring that the planned safeguards approach is acceptable and compatible with the facility design. The proposed approach should be validated by application to suitable facilities to assess its utility, comprehensiveness, and cost-effectiveness. The approach and example application should also be reviewed by industry to confirm the conclusions reached in the DOE review
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Which Elements Should be Recycled for a Comprehensive Fuel Cycle?
Uranium recovery can reduce the mass of waste and possibly the number of waste packages that require geologic disposal. Separated uranium can be managed with the same method (near-surface burial) as used for the larger quantities of depleted uranium or recycled into new fuel. Recycle of all transuranics reduces long-term environmental burden, reduces heat load to repositories, extracts more energy from the original uranium ore, and may have significant proliferation resistance and physical security advantages. Recovery of short-lived fission products cesium and strontium can allow them to decay to low-level waste in facilities tailored to that need, rather than geologic disposal. This could also reduce the number and cost of waste packages requiring geologic disposal. These savings are offset by costs for separation, recycle, and storage systems. Recovery of technetium-99 and iodine-129 can allow them to be sent to geologic disposal in improved waste forms. Such separation avoids contamination of the other products (uranium) and waste (cesium-strontium) streams with long-lived radioisotopes so the material might be disposed as low-level waste. Transmutation of technetium and iodine is a possible future alternative
Categorization of Used Nuclear Fuel Inventory in Support of a Comprehensive National Nuclear Fuel Cycle Strategy
Sodium fast reactor gaps analysis of computer codes and models for accident analysis and reactor safety.
This report summarizes the results of an expert-opinion elicitation activity designed to qualitatively assess the status and capabilities of currently available computer codes and models for accident analysis and reactor safety calculations of advanced sodium fast reactors, and identify important gaps. The twelve-member panel consisted of representatives from five U.S. National Laboratories (SNL, ANL, INL, ORNL, and BNL), the University of Wisconsin, the KAERI, the JAEA, and the CEA. The major portion of this elicitation activity occurred during a two-day meeting held on Aug. 10-11, 2010 at Argonne National Laboratory. There were two primary objectives of this work: (1) Identify computer codes currently available for SFR accident analysis and reactor safety calculations; and (2) Assess the status and capability of current US computer codes to adequately model the required accident scenarios and associated phenomena, and identify important gaps. During the review, panel members identified over 60 computer codes that are currently available in the international community to perform different aspects of SFR safety analysis for various event scenarios and accident categories. A brief description of each of these codes together with references (when available) is provided. An adaptation of the Predictive Capability Maturity Model (PCMM) for computational modeling and simulation is described for use in this work. The panel's assessment of the available US codes is presented in the form of nine tables, organized into groups of three for each of three risk categories considered: anticipated operational occurrences (AOOs), design basis accidents (DBA), and beyond design basis accidents (BDBA). A set of summary conclusions are drawn from the results obtained. At the highest level, the panel judged that current US code capabilities are adequate for licensing given reasonable margins, but expressed concern that US code development activities had stagnated and that the experienced user-base and the experimental validation base was decaying away quickly
Sodium fast reactor safety and licensing research plan. Volume II.
Expert panels comprised of subject matter experts identified at the U.S. National Laboratories (SNL, ANL, INL, ORNL, LBL, and BNL), universities (University of Wisconsin and Ohio State University), international agencies (IRSN, CEA, JAEA, KAERI, and JRC-IE) and private consultation companies (Radiation Effects Consulting) were assembled to perform a gap analysis for sodium fast reactor licensing. Expert-opinion elicitation was performed to qualitatively assess the current state of sodium fast reactor technologies. Five independent gap analyses were performed resulting in the following topical reports: (1) Accident Initiators and Sequences (i.e., Initiators/Sequences Technology Gap Analysis), (2) Sodium Technology Phenomena (i.e., Advanced Burner Reactor Sodium Technology Gap Analysis), (3) Fuels and Materials (i.e., Sodium Fast Reactor Fuels and Materials: Research Needs), (4) Source Term Characterization (i.e., Advanced Sodium Fast Reactor Accident Source Terms: Research Needs), and (5) Computer Codes and Models (i.e., Sodium Fast Reactor Gaps Analysis of Computer Codes and Models for Accident Analysis and Reactor Safety). Volume II of the Sodium Research Plan consolidates the five gap analysis reports produced by each expert panel, wherein the importance of the identified phenomena and necessities of further experimental research and code development were addressed. The findings from these five reports comprised the basis for the analysis in Sodium Fast Reactor Research Plan Volume I
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Advanced Nuclear Fuel Cycle Options
A systematic evaluation has been conducted of the potential for advanced nuclear fuel cycle strategies and options to address the issues ascribed to the use of nuclear power. Issues included nuclear waste management, proliferation risk, safety, security, economics and affordability, and sustainability. The two basic strategies, once-through and recycle, and the range of possibilities within each strategy, are considered for all aspects of the fuel cycle including options for nuclear material irradiation, separations if needed, and disposal. Options range from incremental changes to today’s implementation to revolutionary concepts that would require the development of advanced nuclear technologies