Award Date
May 2019
Degree Type
Dissertation
Degree Name
Doctor of Philosophy (PhD)
Department
Chemistry and Biochemistry
First Committee Member
Kenneth Czerwinski
Second Committee Member
James Vollmer
Third Committee Member
Daniel Koury
Fourth Committee Member
Alexander Barzilov
Number of Pages
221
Abstract
Next generation fast reactor designs utilizing metallic fuel are being developed as an alternative fuel cycle option in an effort to reduce carbon emissions. Historically, oxide fuels have been the industry standard, but interest in metallic fuel systems has grown considerably due to their thermal conductivity, fissile atom density, inherent safety, and ability to reach progressively higher burnups. Chemical complexity of metallic fuel systems increase as a function of burnup from fission product ingrowth and associated fuel cladding chemical interactions (FCCI) brought on by elemental redistribution and phase formation. To date, the most extensive operational study for metallic fuel was performed at the Experimental Breeder Reactor II (EBR-II) in Idaho from the 1960’s to the early 1990’s. During its operation, thousands of U-Zr and U-Pu-Zr fuel pins with various ranges of composition, burnup, and FCCI were analyzed from post-irradiated examinations (PIE) of spent fuel. Since decommissioning EBR-II, metallic fuel chemistry and fuel cladding studies for next generation reactors have become limited due to the lack of fast neutron irradiation facilities and data to support future designs. For this purpose, an arc melting procedure was developed for surrogate U-Zr and U-Pu-Zr burnup alloys with various fission product concentrations dependent on burnup. Scanning Electron Microscopy (SEM) and X-Ray Diffraction (XRD) were used for qualitative and quantitative compositional analysis. Combined Thermogravimetric Analysis (TGA) and Differential Scanning Calorimetry (DSC) were used to determine thermal properties and phase transition temperatures. As cast alloys were implemented into diffusion couples with cladding components to determine FCCI. Targeted research aims to reach ultra-high burnups, where effects of increased burnup on fuel chemistry and FCCI must be understood to prevent eutectic formation and cladding breakdown. Data compiled in this work is compared to EBR-II for validation. Resulting data can be extrapolated to elevated burnups, yet to be studied experimentally, without the need of post-irradiated materials, thus increasing the knowledgebase to support next generation fast reactor development.
Keywords
Burnup; Metallic Fuel; Nuclear; Radiochemistry
Disciplines
Chemistry | Radiochemistry
File Format
Degree Grantor
University of Nevada, Las Vegas
Language
English
Repository Citation
Swift, Andrew Jonathan, "Preparation and Evaluation of Uranium Alloys Based on Burnup" (2019). UNLV Theses, Dissertations, Professional Papers, and Capstones. 3685.
http://dx.doi.org/10.34917/15778553
Rights
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