Impact of nuclear data uncertainty on time-average models of CANDU-9

Uncertainty analysis has been performed on a time-average CANDU-9 model using the codes PARCS, SCALE and Serpent. An acceptable target exit burnup scheme was generated based on reference nuclear data, with maximum channel and bundle powers of 6.47 MW and 849 kW, respectively. Uncertainty analysis of the time-average model was then performed using 150 perturbed nuclear data sets. The largest relative standard deviation in channel power was found to be 1.8%. The distribution of uncertainty was found to be asymmetric, with significantly larger uncertainties observed in the bottom of the core. The most likely cause of the asymmetry was found to be the asymmetrical target exit burnup pattern, with lower exit burnup targets at the bottom of the core resulting in larger relative standard deviations in channel power.