A method of calculating the neutron-kinetics parameters with and without the aid of the value function implemented in the MCU program code and the computational results are presented. Calculations of nineteen critical experiments from the ICSBEP Handbook were performed in order to investigate the influence of the neutron-value function on the accuracy of the calculation of the effective delayed-neutron fraction βeff and the prompt neutron generation time Λ. Analysis showed that the neutron-kinetics parameters are determined with greater precision if the value function is taken into account.