Uncertainty propagation and sensitivity analysis of coupled thermalhydraulic-neutronic nuclear power plant simulations: Influence of uncertainty in neutronic data

This paper presents a study of the influence of the uncertainty in the macroscopic neutronic information for a three-dimensional PWR core model on the core power and reactivity during a Reactivity Induced Accident (RIA). The analysis uses a coupled thermal-hydraulic and neutronic model for RELAP5-PARCS. The SIMTAB methodology provides neutronic information. The statistical methodology assumes uncertainty in the macroscopic cross sections, whose pdfs are sampled and the Noether-Wilks formulas for Tolerance Intervals determine the sample size. Non-parametric statistical methods determine the intervals of tolerance and sensitivities of the sample for core power, fuel enthalpy, fuel temperatures and reactivity values.