Uncertainty analysis of HPR-1000 LOCA with probabilistic and deterministic methods

The HPR-1000 is an advanced Gen III pressurized water reactor (PWR) in China. For the purpose of carrying out uncertainty analysis of the LOCA scenario, two different types of best estimate plus uncertainty (BEPU) method were utilized, namely the DRM of the deterministic method and a typical input-driven probabilistic method. The DRM is carried out by introducing a penalization mode to envelop the input uncertainties, while the probabilistic input-driven method is implemented by performing the uncertainty propagation after the uncertainty sources are identified and quantified. The peak cladding temperature (PCT) was selected to be the figure of merit, and the 95% confidence limit as well as the tolerance limit of the PCT in the LOCA scenario were obtained. Results show that even though there are some phenomenal differences exist, the uncertainty limit obtained through the two methods are similar and both fall below the acceptance criterion.