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A critical study on best methodology to perform UQ for RIA transients and application to SPERT-III experiments

  • Dokhane, A. (Laboratory of Reactor Physics and Thermal-hydraulics (LRT), Paul Scherrer Institut) ;
  • Vasiliev, A. (Laboratory of Reactor Physics and Thermal-hydraulics (LRT), Paul Scherrer Institut) ;
  • Hursin, M. (Laboratory of Reactor Physics and Thermal-hydraulics (LRT), Paul Scherrer Institut) ;
  • Rochman, D. (Laboratory of Reactor Physics and Thermal-hydraulics (LRT), Paul Scherrer Institut) ;
  • Ferroukhi, H. (Laboratory of Reactor Physics and Thermal-hydraulics (LRT), Paul Scherrer Institut)
  • Received : 2021.07.14
  • Accepted : 2021.10.28
  • Published : 2022.05.25

Abstract

The aim of this paper is to assess the reliability and accuracy of the PSI standard method, used in many previous works, for the quantification of ND uncertainties in the SPERT-III RIA transient, by quantifying the discrepancy between the actual inserted reactivity and the original static reactivity worth and their associated uncertainties. The assessment has shown that the inherent S3K neutron source renormalization scheme, introduced before starting the transient, alters the original static reactivity worth of the transient CR and reduces the associated uncertainty due to the ND perturbation. In order to overcome these limitations, two additional methods have been developed based on CR adjustment. The comparative study performed between the three methods has showed clearly the high sensitivity of the obtained results to the selected approach and pointed out the importance of using the right procedure in order to simulate correctly the effect of ND uncertainties on the overall parameters in a RIA transient. This study has proven that the approach that allows matching the original static reactivity worth and starting the transient from criticality is the most reliable method since it conservatively preserves the effect of the ND uncertainties on the inserted reactivity during a RIA transient.

Keywords

Acknowledgement

This work was partly funded by the Swiss Nuclear Safety Inspectorate ENSI (H-101230) and conducted within the framework of the STARS program (http://www.psi.ch/stars).

References

  1. R. K. Mc Cardell, et al., "Reactivity Accident Tests Results and Analyses for the SPERT III E-Core a Small Oxide-Fueled, Pressurized Water Reactor," Ido-17281, 1969. March.
  2. G. Grandi, L. Moberg, Qualification of CASMO5/SIMULATE-3K against the SPERT III E-core cold start-up experiments, in: Proc. PHYSOR 2012, Knoxville, Tennessee, USA, April 15-20, 2012.
  3. G. Grandi, Validation of CASMO/SIMLATE-3K using the PSERT III E-core: cold start-up, hot start-up, hot standby and full power conditions, in: Proc. PHYSOR 2014, Kyoto, Japan, September 28-Oct, vol. 3, October, 2014.
  4. W. Wieselquist, T. Zhu, A. Vasiliev, H. Ferroukhi, PSI methodologies for nuclear data uncertainty propagartion with CASMO-5M and MCNPX: results for OECD/NEA UAM benchmark pahse I, Sci. Technol. Nucl. Inst 2013 (2013), 549793, https://doi.org/10.1155/2013/549793.
  5. O. Leray, H. Ferroukhi, M. Hursin, A. Vasiliev, D. Rochman, Methodology for core analyses with nuclear data uncertainty quantification and application to Swiss PWR operated cycles, Ann. Nucl. Energy 110 (2017) 547-559. https://doi.org/10.1016/j.anucene.2017.07.006
  6. A. Dokhane, G. Grandi, O. Leray, D. Rochman, H. Ferroukhi, A. Pautz, Validation of PSI best estimate plus uncertainty methodology against PSERT-III reactivity intiated accident experiments, Ann. Nucl. Energy 118 (2018) 178-184. https://doi.org/10.1016/j.anucene.2018.04.022
  7. A. Dokhane, M. Hursin, A. Vasiliev, H. Ferroukhi, Recent developments in PSI BEPU analysis for SPERT-III RIA transient: ND uncertainty breakdown and kinetic parameters uncertainty assessment, Nuclr. Energy Des. 283 (2021).