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Full-Text Articles in Engineering
The Advancement Of Experimental And Computation Tools For The Study Of Molten Salt Chemistry To Facilitate The Extraction Of Strategic Elements In Nuclear Applications, Michael Stoddard
Theses and Dissertations
Nuclear energy presents environmental benefits, yet the challenge of radioactive waste management persists. Advanced solutions, such as Molten Salt Reactors (MSRs), require a more profound understanding of molten salt chemistry. This research aims to develop tools, including a depletion simulator, molten salt electrochemical simulator, and a fluoride-based thermodynamic reference electrode for electrochemical purification. The computationally inexpensive depletion simulator allows for exploration into extraction and processing strategies for molten salt reactors. An illustrative case study on Mo-99 production from MSRs demonstrates the practical application of the theoretical framework, emphasizing the need for optimization in extraction effectiveness and separation difficulty. The electrochemical …
Modeling Pa-233 Generation In Thorium-Fueled Reactors For Safeguards, Victoria Davis
Modeling Pa-233 Generation In Thorium-Fueled Reactors For Safeguards, Victoria Davis
Theses and Dissertations
Thorium has been researched for many decades as a possible alternative to uranium nuclear fuel. Thorium can be implemented in many different reactor designs including pressurized water reactors (PWRs), pressurized heavy water reactors (PHWRs), and molten salt reactors (MSRs). Its abundance in the earth, decreased long-lived transuranic waste, and claims that there are fewer proliferation concerns contribute to the attractiveness of using thorium as alternative nuclear fuel. However, possible proliferation pathways have been noted and must be investigated, particularly the potential diversion of 233Pa which can then decay to 233U – special fissionable material that should be under …
Equations Of State For Warm Dense Carbon From Quantum Espresso, Derek J. Schauss
Equations Of State For Warm Dense Carbon From Quantum Espresso, Derek J. Schauss
Theses and Dissertations
Warm dense plasma is the matter that exists, roughly, in the range of 10,000 to 10,000,000 Kelvin and has solid-like densities, typically between 0.1 and 10 grams per centimeter. Warm dense fluids like hydrogen, helium, and carbon are believed to make up the interiors of many planets, white dwarfs, and other stars in our universe. The existence of warm dense matter (WDM) on Earth, however, is very rare, as it can only be created with high-energy sources like a nuclear explosion. In such an event, theoretical and computational models that accurately predict the response of certain materials are thus very …
Reducing Material Attractiveness Utilizing Pu-238 And U-232, Cody Lloyd
Reducing Material Attractiveness Utilizing Pu-238 And U-232, Cody Lloyd
Theses and Dissertations
Decreasing the material attractiveness of uranium and plutonium materials is crucial to nuclear nonproliferation. The International Atomic Energy Agency (IAEA) implements safeguards across the world on a limited budget. Not only does decreasing material attractiveness reduce the possibility of proliferation, but also may lighten the financial burden on the IAEA if safeguards can be reduced. Two particular isotopes that have negative material attractiveness traits are 238Pu and 232U. Without isotopic separation technology, these isotopes cannot be removed from plutonium and uranium materials respectively. Both 238Pu and 232U produce large quantities of heat by alpha decay. High …
Electrochemical Separation Of Multivalent Species On A Liquid Bismuth Cathode In Licl-Kcl Eutectic For Used Nuclear Fuel Reprocessing, Michael Woods
Electrochemical Separation Of Multivalent Species On A Liquid Bismuth Cathode In Licl-Kcl Eutectic For Used Nuclear Fuel Reprocessing, Michael Woods
Theses and Dissertations
The presence of group I/II fission products (Cs-137, Sr-90, and Ba-137) within molten salt nuclear processes degrades operational efficiencies by contributing to increased radiation levels in the case of material handling processes or to loss of criticality in the case of a reactor. While methods such as zone freezing and ion exchange have been proven for the separation of these fission products in LiCl-KCl salts, they require extra equipment and processing steps. Addition of a liquid metal electrode to molten salt media, such as the electrorefiner of a pyroprocessing scheme or the salt cleaning stage of a molten salt fast …
Suitability Of The Kalina Cycle For Power Conversion From Pressurized Water Reactors, Jack Ryan Webster
Suitability Of The Kalina Cycle For Power Conversion From Pressurized Water Reactors, Jack Ryan Webster
Theses and Dissertations
The primary objective of this work is to determine the Kalina cycle's suitability for thermal power conversion from a pressurized water reactor. Several previous papers have examined this application, but these either lack proof of concept or make unfeasible assumptions. This work expands current knowledge by simulating the Kalina cycle and comparing it to current pressurized water reactor Rankine cycles in order to identify which is more efficient. Prerequisite to the modeling is a simulation tool capable of modeling the thermodynamics of ammonia/water mixtures. Instead of using an existing program, a new one called Clearwater is used. This tool is …
Innovative Fuel Design To Improve Proliferation Management, Taylor C. Britt
Innovative Fuel Design To Improve Proliferation Management, Taylor C. Britt
Theses and Dissertations
This research uses an existing innovative fuel design (IFD) that has intrinsic safety features and enhanced economics over the current uranium dioxide (UO2) light water fuel design and evaluates promising methods to improve the waste management and proliferation resistance of the IFD by doping the fresh fuel with select actinides.The most robust approach for proliferation resistance is to denature these materials by adding a uranium or plutonium isotope that hampers the usability of the materials in weapons. The proposed modifications to the IFD use this approach through elevated fractions of 238Pu. 238Pu generates large quantities of …