Application of the best-estimate plus uncertainty approach on a BWR ATWS transient using the NURESIM European code platform

One objective of the NURESAFE project was to develop and execute simulation schemes using the NURESAFE codes for the analysis of a BWR ATWS transient supplemented with Uncertainty Quantification (UQ). The OECD/NEA Boiling Water Reactor (BWR) Turbine Trip (TT) Benchmark is selected for the simulation and evaluation of the BWR ATWS. The selected transient is the Turbine Trip (TT) without SCRAM which is also part of the OECD/NEA Benchmark (Extreme Scenario #2). The Peach Bottom power plant is modelled with the thermal-hydraulics/neutron-kinetics coupled code ATHLET-DYN3D. The URANIE tool for uncertainty analysis is applied to the random sampling of the uncertain parameters and the statistical treatment of the results. Using the two sided Wilks' formula, 100 coupled simulations were run on the NURESIM platform using the developed coupling within the NURESAFE EU project. The results confirm that the NURESIM platform is applicable for the simulation of challenging coupled transients in BWR and shows the compatibility of the NURESIM simulation tools with the URANIE platform for uncertainty and sensitivity analysis. (C) 2017 Elsevier B.V. All rights reserved.