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# Study on Radial Temperature Distribution of Aluminum Dispersed Nuclear Fuels: U3O8-Al, U3Si2-Al, and UN-Al

[+] Author and Article Information
Jayangani I. Ranasinghe

Department of Physics and Engineering Physics,

Ericmoore Jossou, Linu Malakkal, Jerzy A. Szpunar

Department of Mechanical Engineering,

Barbara Szpunar

Department of Physics and Engineering Physics,

1Corresponding author.

Manuscript received December 28, 2017; final manuscript received March 23, 2018; published online May 16, 2018. Assoc. Editor: Akos Horvath.

ASME J of Nuclear Rad Sci 4(3), 031020 (May 16, 2018) (7 pages) Paper No: NERS-17-1304; doi: 10.1115/1.4039886 History: Received December 28, 2017; Revised March 23, 2018

## Abstract

The understanding of the radial distribution of temperature in a fuel pellet, under normal operation and accident conditions, is important for a safe operation of a nuclear reactor. Therefore, in this study, we have solved the steady-state heat conduction equation, to analyze the temperature profiles of a 12 mm diameter cylindrical dispersed nuclear fuels of U3O8-Al, U3Si2-Al, and UN-Al operating at 597 $°$C. Moreover, we have also derived the thermal conductivity correlations as a function of temperature for U3Si2, uranium mononitride (UN), and Al. To evaluate the thermal conductivity correlations of U3Si2, UN, and Al, we have used density functional theory (DFT) as incorporated in the Quantum ESPRESSO (QE) along with other codes such as Phonopy, ShengBTE, EPW (electron-phonon coupling adopting Wannier functions), and BoltzTraP (Boltzmann transport properties). However, for U3O8, we utilized the thermal conductivity correlation proposed by Pillai et al. Furthermore, the effective thermal conductivity of dispersed fuels with 5, 10, 15, 30, and 50 vol %, respectively of dispersed fuel particle densities over the temperature range of 27–627 °C was evaluated by Bruggman model. Additionally, the temperature profiles and temperature gradient profiles of the dispersed fuels were evaluated by solving the steady-state heat conduction equation by using Maple code. This study not only predicts a reduction in the centerline temperature and temperature gradient in dispersed fuels but also reveals the maximum concentration of fissile material (U3O8, U3Si2, and UN) that can be incorporated in the Al matrix without the centerline melting. Furthermore, these predictions enable the experimental scientists in selecting an appropriate dispersion fuel with a lower risk of fuel melting and fuel cracking.

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## References

Shuffler, C. , Trant, J. , Malen, J. , and Todreas, N. , 2009, “ Thermal Hydraulic Analysis for Grid Supported Pressurized Water Reactor Cores,” Nucl. Eng. Des., 239(8), pp. 1442–1460.
NEA, 2012, “Nuclear Fuel Safety Criteria Technical Review,” 2nd ed., Nuclear Energy Agency, Boulogne-Billancourt, France.
Olander, D. R. , 1976, “ Fundamental Aspects of Nuclear Reactor Fuel Elements,” National Technical Information Service, U.S. Department of Commerce, Springfield, VA, Report No. TID-26711-P1.
Allen, T. , Busby, J. , Meyer, M. , and Petti, D. , 2010, “ Materials Challenges for Nuclear Systems,” Mater. Today, 13(12), pp. 14–23.
Kim, Y. S. , 2012, “ Uranium Intermetallic Fuels (U-All, U-Si, U-Mo),” Compr. Nucl. Mater., 3, pp. 391–422.
Keiser, D. D. , Hayes, S. L. , Meyer, M. K. , and Clark, C. R. , 2003, “ High-Density, Low-Enriched Uranium Fuel for Nuclear Research Reactors,” JOM, 55(9), pp. 55–58.
Pasto, A. E. , Copeland, G. L. , and Martin, M. M. , 1980, “ Quantitative Differential Thermal Analysis Study of the U3O8-Al Thermite Reaction,” Oak Ridge National Laboratory, Oak Ridge, TN, Technical Report.
Snelgrove, J. I. , Hofman, G. L. , Meyer, M. K. , Trybus, C. L. , and Wiencek, T. C. , 1997, “ Development of Very-High-Density Low-Enriched-Uranium Fuels,” Nucl. Eng. Des., 178(1), pp. 119–126.
Wood, S. E. , White, J. T. , and Nelson, A. T. , 2017, “ Oxidation Behavior of U-Si Compounds in Air From 25 to 1000 C,” J. Nucl. Mater., 484, pp. 245–257.
Dell, R. M. , Wheeler, V. J. , and Mciver, E. J. , 1966, “ Oxidation of Uranium Mononitride and Uranium Monocarbide,” Trans. Faraday Soc., 62, pp. 3592–3606.
Paljević, M. , and Despotović, Z. , 1975, “ Oxidation of Uranium Mononitride,” J. Nucl. Mater., 57(3), pp. 253–257.
Wood, E. S. , White, J. T. , and Nelson, A. T. , 2017, “ The Effect of Aluminum Additions on the Oxidation Resistance of U3Si2,” J. Nucl. Mater., 489, pp. 84–90.
Pillai, C. G. S. , Dua, A. K. , and Raj, P. , 2001, “ Thermal Conductivity of U3O8 from 300 to 1100 K,” J. Nucl. Mater., 288(2–3), pp. 87–91.
Szpunar, B. , and Szpunar, J. A. , 2014, “ Thermal Conductivity of Uranium Nitride and Carbide,” Int. J. Nucl. Energy, 2014, p. 178360.
Poncé, S. , Margine, E. R. , Verdi, C. , and Giustino, F. , 2016, “ EPW: Electron–Phonon Coupling, Transport and Superconducting Properties Using Maximally Localized Wannier Functions,” Comput. Phys. Commun., 209, pp. 116–133.
Madsen, G. K. H. , and Singh, D. J. , 2006, “ Boltztrap. A Code for Calculating Band-Structure Dependent Quantities,” Comput. Phys. Commun., 175(1), pp. 67–71.
Li, W. , Carrete, J. , Katcho, N. A. , and Mingo, N. , 2014, “ ShengBTE: A Solver of the Boltzmann Transport Equation for Phonons,” Comput. Phys. Commun., 185(6), pp. 1747–1758.
Giannozzi, P. , Baroni, S. , Bonini, N. , Calandra, M. , Car, R. , Cavazzoni, C. , Ceresoli, D. , Chiarotti, G. L. , Cococcioni, M. , Dabo, I. , Dal Corso, A. , Fabris, S. , Fratesi, G. , de Gironcoli, S. , Gebauer, R. , Gerstmann, U. , Gougoussis, C. , Kokalj, A. , Lazzeri, M. , Martin-Samos, L. , Marzari, N. , Mauri, F. , Mazzarello, R. , Paolini, S. , Pasquarello, A. , Paulatto, L. , Sbraccia, C. , Scandolo, S. , Sclauzero, G. , Seitsonen, A. P. , Smogunov, A. , Umari, P. , and Wentzcovitch, R. M. , 2009, “ QUANTUM ESPRESSO: A Modular and Open-Source Software Project for Quantum Simulations of Materials,” J. Phys. Condens. Matter, 21(39), p. 395502. [PubMed]
Miller, V. J. , 1967, “ Estimating Thermal Conductivity of Cermet Fuel Materials for Nuclear Reactor Application,” National Aeronautics and Space Administration, Washington, DC, Report No. NASA-TN-D-3898.
Barbara, S. , Linu, M. , Ericmoore, J. , Ranasinghe, J. , Rossland, I. , and Szpunar, J. A. , 2016, “ First-Principles Studies of Thermal Conductivity of Nuclear Fuel Materials,” 13th International Conference on CANDU Fuel, Kingston, ON, Canada, Aug. 15–18.
Szpunar, B. , and Szpunar, J. A. , 2013, “ Thoria Enhancement of Nuclear Reactor Safety,” Phys. Int., 4(2), pp. 110–119.
Lewis, B. J. , Szpunar, B. , and Iglesias, F. C. , 2002, “ Fuel Oxidation and Thermal Conductivity Model for Operating Defective Fuel Rods,” J. Nucl. Mater., 306(1), pp. 30–43.
Abu-eishah, S. I. , 2000, “ Correlations for the Thermal Conductivity of Metals as a Function of Temperature,” Int. J. Thermophys., 22(6), pp. 1855–1868.
Jain, A. , and McGaughey, J. H. , 2016, “ Thermal Transport by Phonons and Electrons in Aluminum, Silver, and Gold From First Principles,” Phys. Rev. B, 93(8), pp. 1–5.
Togo, A. , and Tanaka, I. , 2015, “ First Principles Phonon Calculations in Materials Science,” Scr. Mater., 108, pp. 1–5.
Kurosaki, K. , Yano, K. , Yamada, K. , Uno, M. , and Yamanaka, S. , 2000, “ A Molecular Dynamics Study of the Heat Capacity of Uranium Mononitride,” J. Alloys Compd., 297(1–2), pp. 1–4.
Hayes, S. L. , Thomas, J. K. , and Peddicord, K. L. , 1990, “ Material Property Correlations for Uranium Mononitride,” J. Nucl. Mater., 171(2–3), pp. 262–270.
Powell, R. W. , Ho, C. Y. , and Liley, P. E. , 1966, “ Thermal Conductivity of Selected Materials,” National Bureau of Standards, Washington, DC, Standard No. 8.
Muta, H. , Kurosaki, K. , Uno, M. , and Yamanaka, S. , 2008, “ Thermal and Mechanical Properties of Uranium Nitride Prepared by SPS Technique,” J. Mater. Sci., 43(19), pp. 6429–6434.
White, J. T. , Nelson, A. T. , Dunwoody, J. T. , Byler, D. D. , Safarik, D. J. , and McClellan, K. J. , 2015, “ Thermophysical Properties of U3Si2 to 1773 K,” J. Nucl. Mater., 464, pp. 275–280.
Shimizu, H. , 1965, “ The Properties and Irradiation Behavior of U3Si2,” Atomics International, Canoga Park, CA, Report No. NAA-SR-10621.
Williams, R. K. , Domagala, R. F. , Wiencek, T.,C. , and Graves, R. S. , 1986, “ Thermal Conductivities of U3Si and U3Si2-Al Dispersion Fuels,” Argonne National Laboratory, Argonne, IL, Report No. CONF-851021–1.
Matos, J. E. , and Snelgrove, J. L. , 1992, “Selected Thermal Properties and Uranium Density Relations for Alloy, Aluminide, Oxide, and Silicide Fuels,” International Atomic Energy Agency, Vienna, Austria, Technical Report No. IAEA-TECDOC–643(V.4).

## Figures

Fig. 1

(a) Calculated phonon contribution, electron contribution and total thermal conductivity of aluminum. The blue solid line shows the experimental thermal conductivity taken from Powell et al. [28] while red crosses give DFT calculation for phonon contribution in Jian et al. [24]. (b) Calculated lattice, electronic and total thermal conductivities of UN. Experimental results for the total thermal conductivity from Hayes et al. [27] and lattice contribution from Muta et al. [29] also shown. (c) Comparison of thermal conductivity of U3Si2 calculated in our work with experimental results in White et al. [30] (see color figure online).

Fig. 2

Calculated effective thermal conductivities of (a) U3Si2-Al, (b) UN-Al, and (c) U3O8-Al dispersion fuels for 5 vol %, 10 vol %, 15 vol %, 30 vol %, and 50 vol % (see color figure online)

Fig. 3

Predicted temperatures along the radial direction (R) of cylindrical fuel pellets of (a) U3Si2, (b) UN, and (c) U3O8 dispersed in Al. For U3Si2 and U3O8 dispersions of 5 vol %, 15vol %, and 30 vol % are considered while for UN dispersions 5 vol %, 15 vol %, 30 vol %, and 35 vol % are considered. R(m) is distance from the centerline measured along the radial direction (see color figure online).

Fig. 4

Temperature gradients of 30 vol % of U3Si2, UN, and U3O8 dispersions. R(m) is the distance from the centerline along the radial direction (see color figure online).

Fig. 5

Temperature profiles of 5 vol %, 10 vol %, and 15 vol % of BeO in (a) UO2 and (b) ThO2. R (m) is the distance from the centerline along the radial direction (see color figure online).

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