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Showing 1 to 20 of 20 for “"transuranic"”.
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Transuranic Imidophosphorane Chemistry
… study the molecular and electronic structures of transuranic imidophosphorane compounds. The isolation, characterization, and redox chemistry of a large isostructural family of Ce, U, Np, and Pu complexes is presented. These compounds offer a unique opportunity to map the influence bonding has on …
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Dependence of transuranic content in spent fuel on fuel burnup
… U-235 w/o respectively. The resultant spent fuel transuranic isotopic compositions were then provided as input into ORIGEN to study the decay behavior of the spent fuel. It was found that when burnup increased from 30 MWD/kg to 100 MWD/kg, the activity more than doubled due to the decreased Pu-241 …
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TRU-ART: A cost-effective prototypical neutron imaging technique for transuranic waste certification systems
… of defense radioactive waste as either transuranic or low-level waste requires very sensitive and accurate assay instrumentation to determine the specific radioactivity within an individual waste package. The assay instruments that are currently fielded at various Department of Energy …
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The use of reduced-moderation light water reactors for transuranic isotope burning in thorium fuel
… Uranium (U)-fuelled LWRs produce long-lived transuranic (TRU) isotopes. TRUs can be recycled in LWRs or fast reactors. The thermal neutron spectrum in LWRs is less suitable for burning TRUs as this causes a build-up of TRU isotopes with low fission probability. This increases the fissile feed …
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A strategy for transition from a uranium fueled, open cycle SFR to a transuranic fueled, closed cycle sodium cooled fast reactor
Reactors utilizing a highly energetic neutron spectrum, often termed fast reactors, offer large fuel utilization improvements over the thermal reactors currently used for nuclear energy generation. Conventional fast reactor deployment has been hindered by the perceived need to use plutonium as …
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Behavior and measurement of distributed sources in a shielding matrix using gamma spectroscopy
… its mission, the Department of Energy generates transuranic waste materials. Some of these wastes are present in large waste containers. The accurate assay of these waste materials in large containers poses unique challenges. These wastes have radioactive sources that are spread throughout the …
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Actinide minimization using pressurized water reactors
Transuranic actinides dominate the long-term radiotoxity in spent LWR fuel. In an open fuel cycle, they impose a long-term burden on geologic repositories. Transmuting these materials in reactor systems is one way to ease the long-term burden on the repository. Examining the maximum possible …
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Fuel performance modeling of high burnup mixed oxide fuel for hard spectrum LWRs
… sustainability of uranium and reduction of transuranic wastes. This finding relaxes the need for sodium fast reactors (SFR) in a closed-loop nuclear fuel cycle and enables high-conversion light water reactors (HC-LWR) to be used as an alternative. HC-LWRs have two major advantages over SFRs. …
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Physics-Based 3D Multi-Directional Reloading Algorithm for Deep Burn HTR Prismatic Block Systems
… of various strategies involving utilization of Transuranic (TRU) nuclides in nuclear reactors. Due to favorable performance characteristics, multiple studies are focused on transmutation options using High Temperature Gas-cooled Reactors (HTGRs). Prismatic HTGRs allow for 3-Dimensional (3D) fuel …
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Impact of alternative nuclear fuel cycle options on infrastructure and fuel requirements, actinide and waste inventories, and economics
… in the U.S. leads to accumulation of uranium, transuranic (TRU) and fission product inventories in the spent nuclear fuel. Various separation and recycling options can be envisioned in order to reduce these inventories while extracting additional energy and sending the ultimate waste to a …
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Thermal hydraulic design and analysis of a large lead-cooled reactor with flexible conversion ratio
… was set as a desirable goal. The core employs transuranic metallic fuel. The large pool vessel contains four intermediate heat exchangers (IHX) that couple the primary system to an efficient and compact supercritical CO2 power conversion system. To prevent CO2 from entering the core in case of …
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Assessment of innovative fuel designs for high performance light water reactors
… performance light water reactors loaded with transuranic-bearing fuel for transmutation, as well as those using UO2 fuel. A proposal for using silicon carbide duplex as fuel cladding is investigated. The cladding consists of a monolithic inner layer surrounded by a tightly wound fiber-matrix …
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Sensitivity of economic performance of the nuclear fuel cycle to simulation modeling assumptions
… a nuclear fuel cycle with minimum inventory of transuranic elements. The deployment is constrained by the recycling plants construction capacity and also by the economic requirement that the recycling plants loading factor never drops below a certain level. First, through a simplified fuel cycle …
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Fuel cycle options for optimized recycling of nuclear fuel
The accumulation of transuranic inventories in spent nuclear fuel depends on both deployment of advanced reactors that can be loaded with recycled transuranics (TRU), and on availability of the facilities that separate and reprocess spent fuel. Three recycling strategies are explored in this study: …
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Innovative design of uranium startup fast reactors
… wastes. Conventional fast reactors rely on transuranic fuels from reprocessing facilities, which are not available in the U.S. Thus, deployment of fast reactors requires decoupling from reprocessing facilities. This motivates the design and deployment of Uranium Startup sodium Fast Reactors …
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Determination of actinide elements in environmental samples by ICP-MS
… the TRU-Spec resin for the determination of the transuranic actinide elements neptunium, plutonium and americium, resulted in the successful determination of 239Pu and 237Np in biological reference materials. Detection limits were 700, 850, and 600 attograms (ag) for 237Np, 233Pu, and 241Am, …
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A fundamental analysis of means of producing and storing energy
… driver and thermal transmutation of transuranic actinides.</p><p>The high energy density of liquid hydrocarbon fuels is ideal for transportation applications, but our ability to sustainably produce such fuels (i.e. biofuels) is limited by the low photosynthetic efficiency achieved by …
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Factors influencing the mobility of uranium, thorium and rare earth elements at the Steenkampskraal monazite, North Western Cape
… risk originating from an underground repository. Transuranic elements (ie. all elements with an atomic number greater than 92 (U)) do not have any non-radioactive isotopes and are very rare in natural materials. The long term geochemical behaviour of these elements must thus be derived from …
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Separation and Properties of La₂O₃ in Molten LiF-NaF-KF Salt
… a low concentration of fission products, fuel, transuranic materials and oxide impurities in the coolant. These impurities will then affect the properties of the molten salt in the long term and need to be removed without introducing new impurities. Most of the research conducted recently has …
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Used Nuclear Fuel Actinide Management in a Sodium- Cooled Heterogeneous Innovative Burner Reactor
<p>This research developed a design of an innovative sodium-cooled fast reactor (SFR) for minor actinide (MA) destruction in used nuclear fuel (UNF). The destruction of MAs would reduce the radiotoxicity of the discharged waste to less than 25% of the once-through cycle after 100 years. The design …