No open-access location is known for this record yet.
No open-access location is known for this record yet.
In the past few decades, there has been an increasing interest in the use of Best Estimate Plus Uncertainty (BEPU) methodologies for the safety analyses of nuclear reactors. One of the crucial issues is to quantify the input uncertainties associated to the physical models in the thermal-hydraulic codes. Such a quantification can be performed by comparison with experimental data, and it is usually referred to as Inverse Uncertainty Quantification (IUQ). Focusing on discussing IUQ methodologies, the OECD/NEA SAPIUM (Development of a Systematic APproach for Input Uncertainty quantification of the physical Models in thermal-hydraulic codes) good practice guidance led to the definition of a new systematic approach for transparent and rigorous IUQ. It highlighted that IUQ should be performed as a global process involving a clear identification of the transient to be simulated and the uncertainties of key phenomena to be quantified, an efficient strategy to construct adequate experimental database and an assessment of the simulation models. The uncertainty ranges and distributions can then be quantified with adequate IUQ methods and finally validated. However, no full application of the guidelines was performed within the SAPIUM project.In this paper, the new OECD/NEA project ATRIUM (Application Tests for Realization of Inverse Uncertainty quantification and validation Methodologies in thermal-hydraulics) is presented. The goal is to perform practical IUQ exercises to bring new insights on the applicability of the SAPIUM best-practices and on the possible improvements necessary when quantifying model input uncertainties. Two IUQ exercises with increasing complexity are planned to quantify the uncertainties associated to the critical/chocked flow and post-Critical Heat Flux (CHF) heat transfer phenomena, which are important during a Loss Of Coolant Accident (LOCA). A particular attention will be dedicated to the evaluation of the adequacy of the experimental databases. The final step of the project consists in the propagation of the quantified uncertainties on the Hot Leg Intermediate Break LOCA IB-HL-01 Integral Effect Test performed in the framework of the OECD/NEA ROSA-2 (Rig-of-Safety Assessment) joint experimental project in the LSTF (Large Scale Test Facility), to validate their application in LOCA type experiments at larger scale.
Loading…
Imported from OpenAlex (CC0) — nothing here is generated.