[en] The MUSE-4 experimental programme in the zero power fast facility MASURCA at CEA Cadarache aims at studying accelerator-driven-systems (ADS). One of the main objectives is the qualification of measuring and monitoring sub-critical reactivities. Rossi α and Feynman α and pulsed neutron source techniques based on the use of the GENEPI deuteron accelerator are investigated to assess the prompt neutron decay constant a and to deduce the reactivity. Reactivity reference levels are determined using a revised rod drop technique and static source multiplication methods for comparison with values extracted from dynamic measurements. This article focuses on the determination of the inherent source and the reactivity sensitivity to kinetic constants and counting rate in the rod drop technique using the point kinetic model. (author)