Sensitivity and uncertainty analysis for coolant void reactivity in a Candu fuel lattice cell model

This paper proposes the Monte Carlo (MC) second-order perturbation methodology to estimate the uncertainty for the reactivity worth and presents the uncertainty for Coolant Void Reactivity (CVR) of the Candu fuel lattice cell problem. The Eigenvalue Perturbation Based Method (EPBM) which utilizes the first-order perturbation technique is presented as well. They are applied to predict the cross-section sensitivity of the reactivity change due to the density perturbation. The prediction accuracy of estimated sensitivities is evaluated by comparing with the ones estimated by direct subtraction method. The results show both EPBM and second-order perturbation method agree well with the reference. With those sensitivities, the uncertainty analysis is performed for the Candu fuel lattice cell problem with the 44- energy group ENDF/B-VII.1 covariance data. (authors)