[en] The use of Monte Carlo (MC) uncertainty analysis procedures in 'Gadolinium Credit' criticality safety analysis of ≤ 5 wt.-% ²³⁵U enriched UO₂ BWR fuel loadings of CASTOR V/52 casks is described. Validation of depletion calculations is based on evaluation of several radiochemical assay data sets. Maximum Likelihood and Bayesian data analysis methods including treatment modalities for incomplete multivariate data are employed to gain bounding Isotopic Correction Factors. Validation of criticality calculations is based on calculational evaluation of several critical experiments. Correlations between the resulting neutron multiplication factors due to the uncertainties in the applied nuclear data and due to the fact, that same material components (e.g., fuel rods) are used in different experiments, are estimated by means of MC methods. (authors)