Coupled Analysis of Thorium-based Fuels in the High-Performance Light Water Reactor Fuel Assembly

Y. Pérez, C. R. García, F. L. Mena, L. Castro


One of the six selected concepts to be part of Generation IV nuclear reactors is the Supercritical Light Water Cooled Reactor. The High-Performance Light Water Reactor (HPLWR) is the European version and it is a very promising design. In recent years, interest in the study of thorium-based fuel cycles has been renewed and its possibilities for current LWRs have been evaluated. The use of thorium-based fuels will be fundamental in the future sustainability of nuclear energy, since in addition to its abundance in nature, thorium has an important group of advantages. In this paper, performance of thorium-based fuels in the typical fuel assembly of the HPLWR reactor is evaluated, using a computational model based on CFD and Monte Carlo codes for the neutronic/thermal-hydraulic coupled analysis. The volumetric power density profiles, coolant temperature profiles, fuel temperature profiles and others are compared with those obtained for standard UO2 fuel. When the thorium-based fuels are used, the obtained infinite multiplication coefficients are smaller than the value obtained when UO2 is used, since the 232Th isotope has a lower contribution to the multiplicative properties of the medium than 238U. As a result, a difference of approximately 12 000 pcm was observed. The results verified that the HPLWR is a thermal reactor with a hard spectrum. There are no notable changes in the neutron spectrum if the mass fraction of thorium is slightly varied.  With coupled analysis, the potential benefits of the utilization of thorium-based fuels were verified. Moreover, a significant temperature decrease by 136 K on the center line of the fuel elements was observed. When the mass fraction of thorium increases in the oxides mixture, the weighted average temperature on the fuel elements decreases.


Supercritical water; HPLWR; CFD; Thorium-based fuels; Neutronic/thermal-hydraulic coupled analysis

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L. Pioro, Handbook of Generation IV Nuclear Reactors, Woodhead Publishing Series in Energy (2016) 103.

L. Castro, J-L. François and C. García, Prog. Nucl. Energy 124 (2020) 103342.

J. R. Maiorino, F. D’Auria and R. Akbari-Jeyhouni, An Overview of Thorium Utilization in Nuclear Reactors and Fuel Cycles, Proceedings of the 12th International Conference of the Croatian Nuclear Society, Croatia (2018).

S. Krahn, A. Worrall, T. Ault et al., Development of Fuel Cycle Data Packages for Thorium Fuel Cycle Options, Project No. 13-5220, Nuclear Energy University Programs, US Departement Energy (2017).

K. S. Chaudri, W. Tian, G. Su et al., Prog. Nucl. Energy 68 (2013) 55.

G. Csom, T. Reiss, S. Fehér et al., Ann. Nucl. Energy 41 (2012) 67.

L. Castro, R. Alfonso, C. García et al., Int. J. Nucl. Energy Sci. Technol. 11 (2017) 229.

L. Castro, J-L François and C. García, Ann. Nucl. Energy (2020) 107312.

J. T. Goorley, M. R. James, T. E. Booth et al., Initial MCNP6 Release Overview - MCNP6 version 1.0, U.S. Department of Energy (2016).

Anonymous, Release ANSYS 19.0 Release Notes 1-132, ANSYS (2018).

Anonymous, The International Association for the Properties of Water and Steam, IAPWS.

Retrieved in March (2020).

L. Castro, G. Delgado, C. García et al., Ann. Nucl. Energy 127 (2019) 227.

Anonymous, Thermophysical Properties of Materials for Nuclear Engineering: A Tutorial and Collection of Data, IAEA. PDF/IAEA-THPH_web.pdf.

Retrieved in December (2019).


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