Nuclear material attractiveness: an assessment of material associated with a closed fuel cycle (original) (raw)

Nuclear material attractiveness: an assessment of used-fuel assemblies

2011

This paper examines the attractiveness of material mixtures containing special nuclear materials (SNM) associated with reprocessing and the thorium-based LWR fuel cycle. This paper expands upon the results from earlier studies [1,2] that examined the attractiveness of SNM associated with the reprocessing of spent light water reactor (LWR) fuel by various reprocessing schemes and the recycle of plutonium as a mixed oxide (MOX) fuel in LWR. This study shows that 233 U that is produced in thorium-based fuel cycles is very attractive for weapons use. Consistent with other studies, these results also show that all fuel cycles examined to date need to be rigorously safeguarded and provided moderate to high levels of physical protection. These studies were performed at the request of the United States Department of Energy (DOE), and are based on the calculation of "attractiveness levels" that has been couched in terms chosen for consistency with those normally used for nuclear materials in DOE nuclear facilities [3]. The methodology and key findings will be presented.

Nuclear Material Attractiveness: An Assessment of Material from PHWR'S in a Closed Thorium Fuel Cycle

2010

This paper examines the attractiveness of material mixtures containing special nuclear materials (SNM) associated with reprocessing and the thorium-based LWR fuel cycle. This paper expands upon the results from earlier studies that examined the attractiveness of SNM associated with the reprocessing of spent light water reactor (LWR) fuel by various reprocessing schemes and the recycle of plutonium as a mixed oxide (MOX) fuel in LWR. This study shows that {sup 233}U that is produced in thorium-based fuel cycles is very attractive for weapons use. Consistent with other studies, these results also show that all fuel cycles examined to date need to be rigorously safeguarded and provided moderate to high levels of physical protection. These studies were performed at the request of the United States Department of Energy (DOE), and are based on the calculation of 'attractiveness levels' that has been couched in terms chosen for consistency with those normally used for nuclear mater...

An assessment of the attractiveness of material associated with thorium/uranium and uranium closed fuel cycles from a safeguards perspective

2010

This paper reports the continued evaluation of the attractiveness of materials mixtures containing special nuclear materials (SNM) associated with various proposed nuclear fuel cycles. Specifically, this paper examines two closed fuel cycles. The first fuel cycle examined is a thorium fuel cycle in which a pressurized heavy water reactor (PHWR) is fueled with mixtures of plutonium/thorium and {sup 233}U/thorium. The used fuel is then reprocessed using the THOREX process and the actinides are recycled. The second fuel cycle examined consists of conventional light water reactors (LWR) whose fuel is reprocessed for actinides that are then fed to and recycled until consumed in fast-spectrum reactors: fast reactors and accelerator driven systems (ADS). As reprocessing of LWR fuel has already been examined, this paper will focus on the reprocessing of the scheme's fast-spectrum reactors' fuel. This study will indicate what is required to render these materials as having low utilit...

The Attractiveness of Materials in Advanced Nuclear Fuel Cycles for Various Proliferation and Theft Scenarios

Nuclear Technology, 2012

This paper is an extension to earlier studies J • 2 that examined the attractiveness of materials mixtures containing special nuclear materials (SNM) and alternate nuclear materials (ANM) associated with the PUREX, UREX, COEX, THOREX, and PYROX reprocessing schemes. This study extends the figure of merit (FOM) for evaluating attractiveness to cover a broad range of proliferant state and sub-national group capabilities. The primary conclusion of this study is that all fissile material needs to be rigorously safeguarded to detect diversion by a state and provided the highest levels of physical protection to prevent theft by sub-national groups; no "silver bullet" has been found that will permit the relaxation of current international safeguards or national physical security protection levels. This series of studies has been peiformed at the request of the United States Department of Energy (DOE) and is based on the calculation of "attractiveness levels" that are expressed in terms consistent with, but normally reserved for nuclear materials in DOE nuclear facilities. 3 The expanded methodology and updated findings are presented. Additionally, how these attractiveness levels relate to proliferation resistance and physical security are discussed.

An approach for evaluating the integrity of fuel applied in Innovative Nuclear Energy Systems

2014

One of the important issues in the study of Innovative Nuclear Energy Systems is evaluating the integrity of fuel applied in Innovative Nuclear Energy Systems. An approach for evaluating the integrity of the fuel is discussed here based on the procedure currently used in the integrity evaluation of fast reactor fuel. The fuel failure modes determining fuel life time were reviewed and fuel integrity was analyzed and compared with the failure criteria. Metal and nitride fuels with austenitic and ferritic stainless steel (SS) cladding tubes were examined in this study. For the purpose of representative irradiation behavior analyses of the fuel for Innovative Nuclear Energy Systems, the correlations of the cladding characteristics were modeled based on wellknown characteristics of austenitic modified 316 SS (PNC316), ferritic-martensitic steel (PNC-FMS) and oxide dispersion strengthened steel (PNC-ODS). The analysis showed that the fuel lifetime is limited by channel fracture which is a nonductile type (brittle) failure associated with a high level of irradiation-induced swelling in the case of austenitic steel cladding. In case of ferritic steel, on the other hand, the fuel lifetime is controlled by cladding creep rupture. The lifetime evaluated here is limited to 200 GW d/t, which is lower than the target burnup value of 500 GW d/t. One of the possible measures to extend the lifetime may be reducing the fuel smeared density and ventilating fission gas in the plenum for metal fuel and by reducing the maximum cladding temperature from 650 to 600°C for both metal and nitride fuel.

Introducing the nuclear material challenges

Journal of Nuclear Materials, 2006

Introducing the nuclear material challenges Nuclear power currently accounts for about 20% of the worldwide electricity. And the demand should increase steadily. Since this is based on a relatively restricted number of production plants, the enhancement of production will require more performing materials utilised as structural components or as fuels. In addition the waste stock pile increases and ecological solutions are required. This Symposium compares and contrasts the material performance requirements. The Symposium also discusses candidate materials in various existing and proposed nuclear power plant components. A common theme for all of these proposed future nuclear power systems is the aiming toward higher operation temperatures and burn-up. An additional key challenge to the successful development of materials for fission and fusion systems is the harsh neutron irradiation environment. Several examples are given to illustrate how multiscale modelling and advanced experimental testing techniques are used to investigate and to resolve key material issues. Through the last 20 years of material science, Europe is a leader in nuclear material science with strong cooperation's with American, Asiatic and other organisations. The Symposium has been structured on the production unit structural materials, the fuels and the waste forms. These materials are component materials for future generation units such as advanced fission/fusion systems, followed by structural materials for thermal reactor units. The fuel materials including fuel matrices and targets for transmutation are considered prior, during and after irradiation as well as the waste form materials for intermediate and geological disposal. These nuclear materials are studied for their high thermal stress capacity, good resistance to radiation damage, compatibility with coolant or fluid phase, compatibility with other materials (cladding, backfield, fluids,. . .), long lifetime in the system, high reliability, adequate resources and easy fabrication, and good safety and environmental behavior.

Technology Insights and Perspectives for Nuclear Fuel Cycle Concepts

2010

This report characterizes fuel cycle options in four areas-resource utilization, radioactive waste, fuel cycle safety, and proliferation resistance and physical protection. Graphs and tables provide insights regarding which features of a fuel cycle option most impact performance for a given characteristic. For example, some characteristics are insensitive to reactor technology but very sensitive to whether and what is recycled. Sometimes it is variations within a class of options that matter. For still other characteristics, the pattern is that a feature impacts performance only under certain situations and is irrelevant in others. Resource utilization: The utilization of uranium ranges from <1% for all thermal reactor concepts, up to ~10% for fast reactors with no fuel recycle, and approaching 100% for sustained recycle with fast reactors. The patterns for utilization of thorium are less clear due to less study of option space. Radioactive waste: There are many possible ways to reduce radiotoxicity and/or the mass of waste streams having both high-heat and high long-term radiotoxicity. The combination of decay heat and radiotoxicity complicates waste disposal and there is no international precedent for disposal of waste that has both high decay heat and high long-term radiotoxicity. The value of a given improvement method can range from very little to orders of magnitude depending on which other improvement methods are also used in a fuel cycle. For example, low processing loss of transuranic material to waste has little value in a single-recycle strategy but can have orders of magnitude impact in sustained recycle. Fuel cycle safety: Safety is too important to ignore during concept selection and development. Historical experience suggests that some types of safety issues are easier to resolve in concept development, detailed design, and/or operation than others. "Easier" can mean lower design cost to add safety systems as a design goes from concept to details, fewer iterations and delays with regulators, easier operation, a more transparent safety case engendering higher trust, less chance for expensive changes during construction, less chance of expensive retrofitting during operation, etc. Co-location of facilities, e.g., separation and fuel fabrication, is one of the ways that the potential risk of future fuel cycles may be reduced. Although the radiological risk from transportation has been shown to be low, public concerns are high and any industrial transport involves common daily transportation risks. Proliferation resistance and physical protection: There are many perspectives in this area, but there is no tool and no single indicator that covers the entire area and all four stages from material acquisition, transportation, transformation of material, and weapon fabrication. Conflicting claims can be often be better understood if it is realized that each claim can be valid within its subset of the entire area.

An Assessment of the Attractiveness of Material Associated with a MOX Fuel Cycle from a Safeguards Perspective

2009

This paper is an extension to earlier studies that examined the attractiveness of materials mixtures containing special nuclear materials (SNM) and alternate nuclear materials (ANM) associated with the PUREX, UREX, coextraction, THOREX, and PYROX reprocessing schemes. This study extends the figure of merit (FOM) for evaluating attractiveness to cover a broad range of proliferant State and sub-national group capabilities. This study also considers those materials that will be recycled and burned, possibly multiple times, in LWRs [e.g., plutonium in the form of mixed oxide (MOX) fuel]. The primary conclusion of this study is that all fissile material needs to be rigorously safeguarded to detect diversion by a State and provided the highest levels of physical protection to prevent theft by sub-national groups; no 'silver bullet' has been found that will permit the relaxation of current international safeguards or national physical security protection levels. This series of stud...

Development of New Reactor Fuel Materials

Journal of Nuclear Science and Technology, 1995

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