In cooperation with the Iranian Nuclear Society

Numerical Solution of Governing Thermal-Hydraulic Equations in the Core of PBMR Using the Porous Media Model

Authors

Abstract
 Numerical solution of governing thermal-hydraulic equations in the core of a pebble bed modular reactor (PBMR) is investigated using the porous media approach. By considering that there is a high temperature helium gas in the core, the NJOY code is used to generate cross sections at these temperatures. Then, the heat flux in the core is obtained in the axial and radial directions by the MCNP code and is consequently used in the computational fluid dynamics (CFD) simulation as a semi- sine and an algebraic function. The major characteristics of the flow field have been identified, whereby the thermal–hydraulic parameters such as temperature and pressure profiles have been specified and compared with the other available data. The results of the MCNP4C and CFX.12 in comparison with the other codes confirmed the present calculation to be used in this type of reactor. Other results that obtained with the use other codes and softwares prove that the inclusion of the compressibility is quite reasonable, where it leads to a slight difference between the measured temperature, pressure and velocity and the actual ones, where it enables us to improve the Darcy-Weisbach equation in this type of reactor.
 
 

Keywords


1. F. Reitsma, G. Strydom, J. De Haas, K. Ivanov, B. Tyobeka, R. Mphahlele, T. Downar, S. Seker, H. Gougar, D. Da Cru, The PBMR steady-state and coupled kinetics core thermal–hydraulics benchmark test problems, Nucl. Eng. Des. 236 (2006) 657–668.
2. B. Dudley, T. Dudley, W. Bouwer, P. De Villiers, Z. Wang, The thermal-hydraulic model for the pebble bed modular reactor (PBMR) plant operator training simulator system, Nucl. Eng. Des. 238 (2008) 3102–3113.
3. Y.A. Hassan, G. Yesilyurt, Flow distribution of pebble bed high temperature of gas cooled reactors using large eddy simulation, J. World Energy Base, ETDEWEB ID: 20265944 (2002).
4. Y.A. Hassan, Large eddy simulation in pebble bed gas cooled core reactors, Nuclear Engineering and Design, 238(3) (2008) 530-537.
5. J. Lee, G. Park, K. Kim, W. Lee, Numerical treatment of pebble contact in the flow and heat transfer analysis of a pebble bed reactor core, Nuclear Engineering and Design, 237 (2007) 2183-2196.
6. A. Acir, H. Coskun, Criticality and burn up analyses of a PBMR-400 full core using Monte Carlo calculation method, Ann. Nucl. Energy 38 (2–3) (2011) 298–301.
7. B. Boer, Optimized Core Design and Fuel Management of a Pebble-Bed Type Nuclear Reactor, IOS Press Under the Imprint Delft University Press (2008).
8. J.F. Briesmeister, MCNP-A General Monte Carlo N-particle Transport Code, Version 4C2 (1997)
9. Y.A. Hassan, G. Yesilyurt, LES simulation in pebble bed modular reactor core through randomly distributed fuel elements, Trans. Nucl. Sci., (2003) 346–348.
10. ANSYS CFX-11.0, ANSYS Inc., Canonsburg, USA, November (2006).
11. M. Kaviany, Principles of Heat Transfer in Porous Media, Springer-Verlag, New York (1995).
12. F.P Incropera, Introduction to Heat Transfer, John Wiley and Sons Inc, United States (2005).
13. K. Kugeler, R. Schulten, Hochtemperatur-reaktortechnik, Springer-Verlag (1989).