On the validation of BEPU methodologies through the simulation of integral experiments: Application to the PKL test facility

Abstract Validation is a key step in the field of thermal hydraulics and has played a crucial role in the implementation of system codes. These codes are then included in licensing methodologies being those either best estimate plus uncertainties (BEPU) or conservative approaches. However, only a small amount of efforts has been done on the validation of the methodologies as a whole. Such validation would imply the comparison of the bounding limits and the experimental data. Due to the lack of actual data of accidental situations, such validation should be carried out with data from integral test facility (ITF) experiments. The OECD/NEA PKL-4 test programme is investigating safety issues relevant for current pressurized water reactor (PWR) plants as well as for new PWR design concepts focusing on complex heat transfer mechanisms under two-phase flow. Within the project, a blind benchmark activity has been launched where an IBLOCA experiment has been simulated by 12 different organizations. The Universitat Politecnica de Catalunya (UPC) participated in the activity with a blind BEPU approach with the main objective of assessing the validity of the methodology as a whole. At first, the scalars that characterize the phenomenology of the particular scenario have been considered. Secondly, in order to broaden the extent of the validation, the results of the different participants have been interpreted as if they were blind experiments as well. Finally, different output parameters have been considered providing a matrix of results that is used to evaluate the validity of the methodology.

[2]  Hee Cheon No,et al.  Assessment of RELAP5/MOD3.2.2γ Against Flooding Database in Horizontal-to-Inclined Pipes , 2002 .

[3]  K. Jarrod Millman,et al.  Array programming with NumPy , 2020, Nat..

[4]  Francesc Reventos,et al.  Applying UPC Scaling-Up Methodology to the LSTF-PKL Counterpart Test , 2014 .

[5]  S. S. Wilks.  Determination of Sample Sizes for Setting Tolerance Limits , 1941 .

[6]  Francesco Saverio D'Auria,et al.  Development and assessment of a method for evaluating uncertainty of input parameters , 2017 .

[7]  Francesc Reventos,et al.  Testing methodologies for quantifying physical models uncertainties. A comparative exercise using CIRCE and IPREM (FFTBM) , 2016 .

[8]  Annalisa Manera,et al.  Thermal-hydraulic analysis of an intermediate LOCA test at the ROSA facility including uncertainty evaluation , 2012 .

[9]  Francesc Reventos,et al.  An analytical comparative exercise on the OECD-SETH PKL E2.2 experiment , 2008 .

[10]  Jinzhao Zhang,et al.  SAPIUM: A Generic Framework for a Practical and Transparent Quantification of Thermal-Hydraulic Code Model Input Uncertainty , 2020 .

[11]  J. Zhang.  The role of verification & validation process in best estimate plus uncertainty methodology development , 2019 .

[12]  Francesc Reventos,et al.  SBLOCA with boron dilution in pressurized water reactors. Impact on operation and safety , 2009 .

[13]  Francesc Reventos,et al.  Uncertainty and sensitivity analysis of a LBLOCA in a PWR Nuclear Power Plant: Results of the Phase V of the BEMUSE programme , 2011 .

[14]  Francesco Saverio D'Auria,et al.  The Best Estimate Plus Uncertainty (BEPU) approach in licensing of current nuclear reactors , 2012 .

[15]  Alessandro Petruzzi,et al.  Deterministic Safety Analysis for Nuclear Power Plants. IAEA Specific Safety Guide , 2009 .

[16]  Jordi Freixa,et al.  Boron Transport Model with Physical Diffusion for RELAP5 , 2007 .

[17]  Frank-Peter Weiss,et al.  Experimental and Numerical Investigation of Boron Dilution Transients in Pressurized Water Reactors , 2003 .

[18]  Francesc Reventos,et al.  Modelling guidelines for core exit temperature simulations with system codes , 2015 .

[19]  Jinzhao Zhang,et al.  Development of a Pragmatic Approach to Model Input Uncertainty Quantification for BEPU Applications , 2018, Nuclear Technology.