Sensitivity and uncertainty analyses of reactivities for PWR cells with UO2 and MOX fuels

•The improved method has been used to calculate sensitivity coefficients relative to infinite dilution cross-sections.•Two types of reactivities are considered: Doppler reactivity and coolant void reactivity.•The reactivity uncertainty is larger than the eigenvalue uncertainty.•The uncertainty of coolant void reactivity is much greater than Doppler reactivity.•The verification was performed by comparing our results SCALE code.