In light water reactor (LWR) transient analyses using deterministic simulation codes, best-estimate plus uncertainty (BEPU) approaches complement the results obtained from simulation codes with uncertainty quantification. In this study, a stochastic sampling–based uncertainty analysis function was developed under the framework of BEPU, enabling uncertainty quantification of important parameters in LWR steady-state and transient analyses using SIMULATE5 and SIMULATE5-K. In the uncertainty quantification of the dynamic behavior of nuclear reactors, the uncertainty knowledge of thermal-hydraulic parameters was highlighted; however, the nuclear data uncertainty propagation to dynamic behavior was insufficient.

To bridge the knowledge gap, the uncertainties of interest parameters in the Organisation for Economic Co-operation and Development/Nuclear Energy Agency and the U.S. Nuclear Regulatory Commission PWR MOX/UO2 Core Transient Benchmark were quantified considering cross-section and kinetics data uncertainties. Consequently, the uncertainties of the maximum fuel enthalpy important for rod ejection transient analyses evaluated on the basis of the generalized extreme value distribution were equally contributed by cross-section and kinetics data uncertainties.