@article{takasugi_aly_holler_abarca_beeler_avramova_ivanov_2023, title={Development of an efficient and improved core thermal-hydraulics predictive capability for fast reactors: Summary of research and development activities at the North Carolina state University}, volume={412}, ISSN={["1872-759X"]}, DOI={10.1016/j.nucengdes.2023.112474}, abstractNote={The improved understanding of the safety, technical gaps, and major uncertainties of advanced fast reactors will result in designing their safe and economical operation. This paper focuses on the development of efficient and improved core thermal-hydraulics predictive capabilities for fast reactor modeling and simulation at the North Carolina State University. The described research and development activities include applying results of high-fidelity thermal-hydraulic simulations to inform the improved use of lower-order models within fast-running design and safety analysis tools to predict improved estimates of local safety parameters for efficient evaluation of realistic safety margins for fast reactors. The above-described high-to-low model information improvements are being verified and validated using benchmarks such as the OECD/NRC Liquid Metal Fast Reactor Core Thermal-Hydraulic Benchmark and code-to-code comparisons.}, journal={NUCLEAR ENGINEERING AND DESIGN}, author={Takasugi, C. and Aly, A. and Holler, D. and Abarca, A. and Beeler, B. and Avramova, M. and Ivanov, K.}, year={2023}, month={Oct} }
 @article{aly_beeler_avramova_2022, title={Ab initio molecular dynamics investigation of gamma-(U,Zr) structural and thermal properties as a function of temperature and composition}, volume={561}, ISSN={["1873-4820"]}, DOI={10.1016/j.jnucmat.2022.153523}, abstractNote={Uranium in its metallic form is considered as a fuel for sodium fast reactors due to its higher thermal conductivity and high fissile material density relative to UO 2 fuel. The metal is alloyed with zirconium to increase its stability at high temperatures and increase its solidus temperature . This work uses ab initio molecular dynamics to perform an evaluation of the mechanical and thermophysical properties of the γ -(U,Zr) system at temperatures between 1000 K and 1400 K. Among these properties are the equilibrium volume, bulk modulus , molar heat capacity , heat of formation , and the surface energy. The obtained results are compared to experimental data and previous computational work available in the literature. This is the first study of γ -(U,Zr) utilizing ab initio molecular dynamics, and reduces thermophysical property knowledge gaps that are currently present in the literature.}, journal={JOURNAL OF NUCLEAR MATERIALS}, author={Aly, Ahmed and Beeler, Benjamin and Avramova, Maria}, year={2022}, month={Apr} }
 @article{aly_beeler_avramova_2022, title={Investigation of ?-(U, Zr) structural properties and its interfacial properties with liquid sodium using ab initio molecular dynamics}, volume={567}, ISSN={["1873-4820"]}, url={https://doi.org/10.1016/j.jnucmat.2022.153835}, DOI={10.1016/j.jnucmat.2022.153835}, abstractNote={In this study, the elastic properties, structural parameters, sound velocity, and Debye temperature of γ−(U,Zr) were computed using ab initio molecular dynamics (AIMD) at temperatures between 1000 K and 1400 K and for Zr content between 0 at.% and 100 at.%. UZr is used as a metallic fuel for Sodium Fast Reactors (SFRs). The study of the mechanical and thermal behavior of these alloys leads to a better data-informed fuel design. The bulk modulus, shear modulus, Young’s modulus, and Poisson’s ratio were calculated from the elastic constants and their dependence on Zr content and temperature was investigated, comparing the results with previous computational work and the available experimental data in the literature. Interfacial properties between UZr (up to 32 at.% which typically exists in nuclear fuel) and liquid sodium are also of interest due to the presence of a sodium bond between the fuel and the cladding in metallic nuclear fuel. The interfacial energy between γ−(U,Zr) and liquid sodium, the surface tension of liquid sodium, and the work of adhesion were computed at different temperatures and Zr concentrations. It was demonstrated that γ−(U,Zr) is completely wetted by liquid sodium at all the investigated temperatures and Zr concentrations. This work provides the basis for the determination of interfacial resistances in SFRs and their implementation into heat transfer fuel performance simulations, which will be the subject of future work.}, journal={JOURNAL OF NUCLEAR MATERIALS}, publisher={Elsevier BV}, author={Aly, Ahmed and Beeler, Benjamin and Avramova, Maria}, year={2022}, month={Aug} }