Sensitivity analysis of input uncertain parameters on BWR stability using TRACE/PARCS

•Study focused on understanding of parameters that affect BWR Stability.•Two TRACE/PARCS models of Ringhals-1 and Oskarshamn-2 BWRs were used.•An attempt has been made to identify the most influential parameters.•The spearman rank has been used to identify the most influential parameters.•Sensitivity calculations were shown for better understanding of the BWR stability.

The unstable behavior of Boiling Water Reactors (BWR), which is known to occur at certain power and flow conditions, could cause SCRAM and decrease the economic performance of the plant. For better prediction of BWR stability and understanding of influential parameters, two TRACE/PARCS models of Ringhals-1 and Oskarshamn-2 BWRs were employed to perform a sensitivity study. Using the propagation of input errors uncertainty method’s results, an attempt has been made to identify the most influential parameters affecting the stability. Furthermore, a methodology using the spearman rank correlation coefficient has been used to identify the most influential parameters on the stability parameters (decay ratio and frequency).