Nuclear Engineering and Technology

Korean Nuclear Society (한국원자력학회)
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Modelling of multidimensional effects in thermal-hydraulic system codes under asymmetric flow conditions - Simulation of ROCOM tests 1.1 and 2.1 with ATHLET 3D-Module

  • Pescador, E. Diaz (Helmholtz Zentrum Dresden Rossendorf (HZDR)) ;
  • Schafer, F. (Helmholtz Zentrum Dresden Rossendorf (HZDR)) ;
  • Kliem, S. (Helmholtz Zentrum Dresden Rossendorf (HZDR))
  • Received : 2020.11.17
  • Accepted : 2021.04.09
  • Published : 2021.10.25
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Abstract

The implementation and validation of multi-dimensional (multi-D) features in thermal-hydraulic system codes aims to extend the application of these codes towards multi-scale simulations. The main goal is the simulation of large-scale three-dimensional effects inside large volumes such as piping or vessel. This novel approach becomes especially relevant during the simulation of accidents with strongly asymmetric flow conditions entailing density gradients. Under such conditions, coolant mixing is a key phenomenon on the eventual variation of the coolant temperature and/or boron concentration at the core inlet and on the extent of a local re-criticality based on the reactivity feedback effects. This approach presents several advantages compared to CFD calculations, mainly concerning the model size and computational efforts. However, the range of applicability and accuracy of the newly implemented physical models at this point is still limited and needs to be further extended. This paper aims at contributing to the validation of the multi-D features of the system code ATHLET based on the simulation of the Tests 1.1 and 2.1, conducted at the test facility ROCOM. Overall, the multi-D features of ATHLET predict reasonably well the evolution from both experiments, despite an observed overprediction of coolant mixing at the vessel during both experiments.

Keywords

Acknowledgement

This work is funded by the German Federal Ministry for Economic Affairs and Energy (BMWi) with the grant number 1501540 on the basis of a decision by the German Bundestag.

References

  1. OECD, Proceedings of the OECD/NEA/CSNI Specialist Meeting on Boron Dilution Reactivity Transients. Comitee on the Safety of Nuclear Installations OECD Nuclear Energy Agency, vol. 96, NEA/CSNI/R, State College, PA, USA, 1995, p. 3.
  2. S. Kliem, U. Rohde, F. Weiss, Core response of a PWR to a slug of under-borated water, Nucl. Eng. Des. 230 (2004) 121-132, https://doi.org/10.1016/j.nucengdes.2003.11.021.
  3. S. Kliem, R. Franz, OECD PKL2 Project - Final Report on the ROCOM Tests, Insitute Report HZDR\FWO\2012\03, 2012.
  4. S. Kliem, R. Franz, OECD PKL3 Project - Final Report on the ROCOM Tests, Insitute Report HZDR\FWO\2016\01, 2016.
  5. U. Rohde, S. Kliem, B. Hemstrom, T. Toppila, Y. Bezrukov, The European project FLOMIX-R: description of the slug mixing and buoyancy related experimens at the different test facilities, Final report on WP2. Technical Report FZR-430, http://www.fzd.de/publications/007459/7459.pdf, 2005.
  6. S. Kliem, H.M. Prasser, T. Suhnel, F.P. Weiss, A. Hansen, Experimental determination of the boron concentration distribution in the primary circuit of a PWR after a postulated cold leg small break loss-of-coolant-accident with cold leg safety injection, Nucl. Eng. Des. 238 (2008) 1788-1801, https://doi.org/10.1016/j.nucengdes.2007.10.016.
  7. H. Prasser, G. Grunwald, T. Hohne, S. Kliem, U. Rohde, F. Weiss, Coolant mixing in a pressurized water Reactor : deboration transients, steam-line breaks, and emergency core cooling injection, Nucl. Technol. 143 (2003) 37-56, https://doi.org/10.13182/NT03-A3396.
  8. T. Hohne, S. Kliem, U. Rohde, F.P. Weiss, Boron dilution transients during natural circulation flow in PWR-Experiments and CFD simulations, Nucl. Eng. Des. 238 (2008) 1987-1995, https://doi.org/10.1016/j.nucengdes.2007.10.032.
  9. T. Hohne, S. Kliem, U. Bieder, Modeling of a buoyancy-driven flow experiment at the ROCOM test facility using the CFD codes CFX-5 and Trio_U, Nucl. Eng. Des. 236 (2006) 1309-1325, https://doi.org/10.1016/j.nucengdes.2005.12.005.
  10. A. Schaffrath, K.C. Fischer, T. Hahm, S. Wussow, Validation of the CFD code fluent by post-test calculation of a density-driven ROCOM experiment, Nucl. Eng. Des. 237 (2007) 1899-1908, https://doi.org/10.1016/j.nucengdes.2007.02.029.
  11. A. Grahn, E. Diaz Pescador, S. Kliem, F. Schafer, T. Hohne, Modelling of complex boron dilution transients in PWRs - validation of CFD simulation with ANSYS CFX against the ROCOM E2 . 3 experiment, Nucl. Eng. Des. 372 (2021) 110938, https://doi.org/10.1016/j.nucengdes.2020.110938.
  12. B.L. Smith, M. Andreani, U. Bieder, F. Ducros, E. Graffard, M. Heitsch, M. Henriksson, T. Hohne, M. Houkema, E. Komen, J. Mahaffy, F. Menter, F. Moretti, T. Morii, P. Muhlbauer, U. Rohde, M. Scheuerer, C.-H. Song, T. Watanabe, G. Zigh, Assessment of CFD Codes for Nuclear Reactor Safety Problems, vol. 12, NEA/CSNI/R, 2014, pp. 1-226, 2014.
  13. J. Mahaffy, B. Chung, F. Dubois, F. Ducros, E. Graffard, M. Heitsch, M. Henriksson, E. Komen, F. Moretti, T. Morii, P. Muhlbauer, U. Rohde, M. Scheuerer, B.L. Smith, C. Song, T. Watanabe, G. Zigh, Best Practice Guidelines for the Use of CFD in Nuclear Reactor Safety Applications, vol. 11, NEA/CSNI/R, 2014, pp. 1-176, 2014.
  14. H. Austregesilo, C. Bals, A. Hora, G. Lerchl, P. Romstedt, P. Schoffel, D. Von der Cron, F. Weyermann, ATHLET Mod. 3.1 cycle A, models and methods, GRS-P-13 (2016), https://doi.org/10.1007/978-4-431-55663-3_2. Rev. 4.
  15. D. Bestion, System thermalhydraulics for design basis accident analysis and simulation : status of tools and methods and direction for future R & D, Nucl. Eng. Des. 312 (2017) 12-29, https://doi.org/10.1016/j.nucengdes.2016.11.010.
  16. P. Pandazis, S.C. Ceuca, P.J. Schoeffel, H.V. Hristov, Investigation of Multidimensional flow mixing phenomena in the reactor pressure vessel with the system code ATHLET, Nureth-16 (2015) 3378-3391.
  17. A. Bousbia Salah, J. Vlassenbroeck, Assessment of the CATHARE 3D capabilities in predicting the temperature mixing under asymmetric buoyant driven flow conditions, Nucl. Eng. Des. 265 (2013) 469-483, https://doi.org/10.1016/j.nucengdes.2013.09.016.
  18. E. Diaz Pescador, F. Schafer, S. Kliem, Thermal-hydraulic insights during a main steam line break in a generic PWR KONVOI reactor with ATHLET 3.1A, Kerntechnik 84 (2019) 367-374, https://doi.org/10.3139/124.190008.
  19. E. Diaz Pescador, A. Grahn, S. Kliem, F. Schafer, T. Hohne, Advanced modelling of complex boron dilution transients in PWRs - validation of ATHLET 3D-Module against the experiment ROCOM E2 . 3, Nucl. Eng. Des. 367 (2020) 110776, https://doi.org/10.1016/j.nucengdes.2020.110776.
  20. OECD/NEA, Assessment of Computational Fluid Dynamics (CFD) for Nuclear Reactor Safety Problems, vol. 13, NEA/CSNI/R, 2007, p. 2008.
  21. A. Bousbia Salah, S.C. Ceuca, R. Puragliesi, R. Mukin, A. Grahn, S. Kliem, J. Vlassenbroeck, H. Austregesilo, Unsteady single-phase natural-circulation flow mixing prediction using 3-D thermal-hydraulic system and CFD codes, Nucl. Technol. 203 (2018) 293-314, https://doi.org/10.1080/00295450.2018.1461517.
  22. C. Demaziere, V.H. Sanchez-Espinoza, B. Chanaron, Advanced numerical simulation and modelling for reactor safety - contributions from the CORTEX, HPMC, McSAFE and NURESAFE projects, EPJ Nucl. Sci. Technol. 6 (2020) 42, https://doi.org/10.1051/epjn/2019006.
  23. L. Dennhardt, PKL III G3.1 Test Report, Areva NP GmbH, 2011. PTCTP-G/2011/En/0009, Rev. A.
  24. K. Umminger, R. Mandl, R. Wegner, Restart of natural circulation in a PWR - PKL test results and S-RELAP 5 calculations, Nucl. Eng. Des. 215 (2002) 39-50. https://doi.org/10.1016/S0029-5493(02)00040-7