Viability of Inert Matrix Fuel in Reducing Plutonium Amounts in Reactors


Book Description

The reactors around the world have produced more than 2000 tonnes of plutonium, contained in spent fuel or as separated forms through reprocessing. Disposition of fissile materials has become a primary concern of nuclear non-proliferation efforts worldwide. There is a significant interest in IAEA Member States to develop proliferation resistant nuclear fuel cycles for incineration of plutonium such as inert matrix fuels (IMFs). This publication reviews the status of potential IMF candidates and describes several identified candidate materials for both fast and thermal reactors: MgO, ZrO2, SiC, Zr alloy, SiAl, ZrN; some of these have undergone test irradiations and post irradiation examination. Also discussed are modelling of IMF fuel performance and safety analysis. System studies have identified strategies for both implementation of IMF fuel as homogeneous or heterogeneous phases, as assemblies or core loadings and in existing reactors in the shorter term, as well as in new reactors in the longer term.










Inert Matrix Fuel Neutronic, Thermal-Hydraulic, and Transient Behavior in a Light Water Reactor


Book Description

Currently, commercial power reactors in the United States operate on a once-through or open cycle, with the spent nuclear fuel eventually destined for long-term storage in a geologic repository. Since the fissile and transuranic (TRU) elements in the spent nuclear fuel present a proliferation risk, limit the repository capacity, and are the major contributors to the long-term toxicity and dose from the repository, methods and systems are needed to reduce the amount of TRU that will eventually require long-term storage. An option to achieve a reduction in the amount, and modify the isotopic composition of TRU requiring geological disposal is 'burning' the TRU in commercial light water reactors (LWRs) and/or fast reactors. Fuel forms under consideration for TRU destruction in light water reactors (LWRs) include mixed-oxide (MOX), advanced mixed-oxide, and inert matrix fuels. Fertile-free inert matrix fuel (IMF) has been proposed for use in many forms and studied by several researchers. IMF offers several advantages relative to MOX, principally it provides a means for reducing the TRU in the fuel cycle by burning the fissile isotopes and transmuting the minor actinides while producing no new TRU elements from fertile isotopes. This paper will present and discuss the results of a four-bundle, neutronic, thermal-hydraulic, and transient analyses of proposed inert matrix materials in comparison with the results of similar analyses for reference UOX fuel bundles. The results of this work are to be used for screening purposes to identify the general feasibility of utilizing specific inert matrix fuel compositions in existing and future light water reactors. Compositions identified as feasible using the results of these analyses still require further detailed neutronic, thermal-hydraulic, and transientanalysis study coupled with rigorous experimental testing and qualification.




The Optimum Plutonium Inert Matrix Fuel Form for Reactor-Based Plutonium Disposition


Book Description

The University of Florida has underway an ongoing research program to validate the economic, operational and performance benefits of developing an inert matrix fuel (IMF) for the disposition of the U.S. weapons plutonium (Pu) and for the recycle of reprocessed Pu. The current fuel form of choice for Pu disposition for the Department of Energy is as a mixed oxide (MOX) (PuO2/UO2). We will show analyses that demonstrate that a Silicon Carbide (SiC) IMF offers improved performance capabilities as a fuel form for Pu recycle and disposition. The reason that UF is reviewing various materials to serve as an inert matrix fuel is that an IMF fuel form can offer greatly reduced Pu and transuranic isotope (TRU) production and also improved thermal performance characteristics. Our studies showed that the Pu content is reduced by an order of magnitude while centerline fuel temperatures are reduced approximately 380 degrees centigrade compared to MOX. These reduced temperatures result in reduced stored heat and thermal stresses in the pellet. The reduced stored heat reduces the consequences of the loss of coolant accident, while the reduced temperatures and thermal stresses yield greatly improved fuel performance. Silicon Carbide is not new to the nuclear industry, being a basic fuel material in gas cooled reactors.




The Optimum Plutonium Inert Matrix Fuel Form for Reactor-Based Plutonium Disposition


Book Description

The University of Florida has underway an ongoing research program to validate the economic, operational and performance benefits of developing an inert matrix fuel (IMF) for the disposition of the U.S. weapons plutonium (Pu) and for the recycle of reprocessed Pu. The current fuel form of choice for Pu disposition for the Department of Energy is as a mixed oxide (MOX) (PuO2/UO2). We will show analyses that demonstrate that a Silicon Carbide (SiC) IMF offers improved performance capabilities as a fuel form for Pu recycle and disposition. The reason that UF is reviewing various materials to serve as an inert matrix fuel is that an IMF fuel form can offer greatly reduced Pu and transuranic isotope (TRU) production and also improved thermal performance characteristics. Our studies showed that the Pu content is reduced by an order of magnitude while centerline fuel temperatures are reduced approximately 380 degrees centigrade compared to MOX. These reduced temperatures result in reduced stored heat and thermal stresses in the pellet. The reduced stored heat reduces the consequences of the loss of coolant accident, while the reduced temperatures and thermal stresses yield greatly improved fuel performance. Silicon Carbide is not new to the nuclear industry, being a basic fuel material in gas cooled reactors.




A Practical Strategy for Reducing the Future Security Risk of United States Spent Nuclear Fuel


Book Description

Depletion calculations show that advanced oxide (AOX) fuels can be used in existing light water reactors (LWRs) to achieve and maintain virtually any desired level of US (US) reactor-grade plutonium (R-Pu) inventory. AOX fuels are composed of a neutronically inert matrix loaded with R-Pu and erbium. A 1/2 core load of 100% nonfertile, 7w% R-Pu AOX and 3.9 w% UO2 has a net total plutonium ({sup TOT}Pu) destruction rate of 310 kg/yr. The 20% residual {sup TOT}Pu in discharged AOX contains> 55% 242Pu making it unattractive for nuclear explosive use. A three-phase fuel-cycle development program sequentially loading 60 LWRs with 100% mixed oxide, 50% AOX with a nonfertile component displacing only some of the 238U, and 50% AOX, which is 100% nonfertile, could reduce the US plutonium inventory to near zero by 2050.




Plutonium


Book Description

This book provides a readable and thought-provoking analysis of the issues surrounding nuclear fuel reprocessing and fast-neutron reactors, including discussion of resources, economics, radiological risk and resistance to nuclear proliferation. It describes the history and science behind reprocessing, and gives an overview of the status of reprocessing programmes around the world. It concludes that such programs should be discontinued. While nuclear power is seen by many as the only realistic solution to the carbon emission problem, some national nuclear establishments have been pursuing development and deployment of sodium-cooled plutonium breeder reactors, and plutonium recycling. Its proponents argue that this system would offer significant advantages relative to current light water reactor technology in terms of greater uranium utilization efficiency, and that separating out the long-lived plutonium and other transuranics from spent fuel and fissioning them in fast reactors would greatly reduce the duration of the toxicity of radioactive waste. However, the history of efforts to deploy this system commercially in a number of countries over the last six decades has been one of economic and technical failure and, in some cases, was used to mask clandestine nuclear weapon development programs. Covering topics of significant public interest including nuclear safety, fuel storage, environmental impact and the spectre of nuclear terrorism, this book presents a comprehensive analysis of the issue for nuclear engineers, policy analysts, government officials and the general public. "Frank von Hippel, Jungmin Kang, and Masafumi Takubo, three internationally renowned nuclear experts, have done a valuable service to the global community in putting together this book, which both historically and comprehensively covers the “plutonium age” as we know it today. They articulate in a succinct and clear manner their views on the dangers of a plutonium economy and advocate a ban on the separation of plutonium for use in the civilian fuel cycle in view of the high proliferation and nuclear-security risks and lack of economic justification." (Mohamed ElBaradei, Director General, International Atomic Energy Agency (1997-2009), Nobel Peace Prize (2005)) "The 1960s dream of a ‘plutonium economy’ has not delivered abundant low-cost energy, but instead has left the world a radioactive legacy of nuclear weapons proliferation and the real potential for nuclear terrorism. Kang, Takubo, and von Hippel explain with power and clarity what can be done to reduce these dangers. The governments of the remaining countries whose nuclear research and development establishments are still pursuing the plutonium dream should pay attention.” (Senator Edward Markey, a leader in the US nuclear-disarmament movement as a member of Congress since 1976) "The authors have done an invaluable service by putting together in one place the most coherent analysis of the risks associated with plutonium, and the most compelling argument for ending the practice of separating plutonium from spent fuel for any purpose. They have given us an easily accessible history of the evolution of thinking about the nuclear fuel cycle, the current realities of nuclear power around the world and, arguably most important, a clear alternative path to deal with the spent fuel arising from nuclear reactors for decades to centuries to come." (Robert Gallucci, Chief US negotiator with North Korea (1994); Dean, Georgetown University School of Foreign Service (1996-2009); President, MacArthur Foundation (2009-2014))




Technical Approaches for the Management of Separated Civilian Plutonium


Book Description

This publication aims to outline credible technical options for managing separated plutonium. There is no attempt to rank or rate any of the options, instead the intent is to inform the reader of the technical merits of the various options and the state of their development. It is primarily focused on Member States that have adopted a closed fuel cycle policy but can also be of value to other Member States, specifically their decision makers and other stakeholders involved in potential future nuclear fuel cycles, by informing them on life cycle options and energy policy.




AECL/U.S. INERI - Development of Inert Matrix Fuels for Plutonium and Minor Actinide Management in Power Reactors Fuel Requirements and Down-Select Report


Book Description

This report documents the first milestone of the International Nuclear Energy Research Initiative (INERI) U.S./Euratom Joint Proposal 1.8 entitled "Development of Inert Matrix Fuels for Plutonium and Minor Actinide Management in Light-Water Reactors." The milestone represents the assessment and preliminary study of a variety of fuels that hold promise as transmutation and minor actinide burning fuel compositions for light-water reactors. The most promising fuels of interest to the participants on this INERI program have been selected for further study. These fuel compositions are discussed in this report.