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Assessment of CATHARE code against DEC-A upper head SBLOCA experiments

  • Anis Bousbia Salah (Bel V (Subsidiary of the Belgian Federal Agency for Nuclear Control))
  • Received : 2023.05.17
  • Accepted : 2023.10.16
  • Published : 2024.03.25

Abstract

Design Extension Conditions (DEC)-A assessments of the operating nuclear power plants are generally considered for the purpose of getting additional safety demonstrations of their capability to undergo conditions that are generally more severe than DBAs by features implemented in the design and accident management measures. The pursued methodology is generally based upon Best Estimate approaches aiming at verifying that the safety limits in terms of integrity of the barriers against eventual large or early releases of radioactive material are fulfilled. These aspects are nowadays being experimentally and analytically addressed within the OECD/NEA experimental projects like the ATLAS and PKL series where a set of DEC-A experiments are considered. In this paper, experiments related to SBLOCA at the vessel upper head of the pressurized vessel of ATLAS and PKL are analytically assessed using the CATHARE code. These experiments includes issues related to common cause failure of the safety injection system and operator actions for preventing core excessive overheating. It is shown that, on the one hand, the safety features embedded in the design together with the operator actions are capable to prevent the progression towards a severe accident state and on the other hand, the code prediction capabilities for such scenario are generally good but still to be enhanced.

Keywords

Acknowledgement

Special thanks to the ATLAS and PKL experimental teams and the respective OECD/NEA ATLAS3 and ETHARINUS projects.

References

  1. WENRA, RHWG guidance document, issue F: design extension of existing reactors, in: Guidance for the WENRA Safety Reference Levels for Existing Reactors in Their Update in Relation to Lessons Learned from the TEPCO Fukushima Dai-Ichi Accident, 2014, p. 2014.
  2. SSR-2/1, Safety of Nuclear Power Plants: Design, Specific Safety Requirements, vol. 1, IAEA, 2016. Revision.
  3. C. Queral, J. Gonzalez-Cadelo, G. Jimenez, E. Villalba, Accident management actions in an upper-head small-break loss-of-coolant accident with high-pressure safety injection failed, Nuclear Technology 175 (2011).
  4. T. Takeda, Summary data report of ROSA/LSTF experiment SB-PV-07 - 1% pressure vessel top break LOCA with accident management actions and gas inflow, in: JAEA-Data/Code 2018, JAEA, 2018, 003.
  5. T. Takeda, Summary Data Report of ROSA/LSTF Experiment SB-PV-09 on PWR 1.9% Pressure Vessel Top Small Break LOCA with SG Depressurization and Gas Inflow, JAEA, 2021.
  6. Description Report of ATLAS Facility and Instrumentation, Korea Atomic Energy Research Institute, 2018. KAERI/TR-7218/2018.
  7. R. Guneysu, H. Kremin, Description of the PKL Test Facility, NTCTP-G/2007/en/0010, 2007.
  8. Y. Park, Quick-look report on the OECD-ATLAS2 B5.1 test: counterpart test for 1% SBLOCA at reactor pressure vessel top of LSTF with accident management actions and gas inflow, in: OECD-ATLAS2-QLR-20-03, KAERI, 2020.
  9. L. Dennhardt, S. Schollenberger, PKL III J1.1 - SB-LOCA of 1.9 % in the Upper Head, D02-ARV-01-192-258, 2022.
  10. Equipe CATHARE, CATHARE V2.5_3/mod8.1, SMTH/LMDS/EM/2002_067, 2018.
  11. A. Kovtonyuk1, M. Havet, T. de Laet, J. Nam, A. Bousbia Salah, R. Leung, N. Alyammahi, H. Austregesilo, S. Buchholz, Zh. Li, K.-H. Kang, S.W. Bae, Y. Park, M.K. Cho, P. Hellings, V. Corda, E. Cascioli, V. Jammot, J. Freixa, C. Berna Escriche, M. Lorduy, S. Gallardo, G. Verdu, D. Blanco, J.L. Munoz-Cobo, A. Escriva, R. Harrington, Analytical benchmark on OECD/NEA ATLAS-2 test B5.1, in: The 19th International Topical Meeting on Nuclear Reactor Thermal Hydraulics, NURETH-19, Brussels, Belgium, March 6 - 11, 2022.
  12. A. Bousbia Salah, J. Vlassenbroeck, H. Austregesilo, Experimental and analytical assessment of natural circulation interruption phenomenon in the LSTF and PKL test facilities, Nuclear Technology journal 192 (2015).