Fast reactor technology aimed on improved safety and sustainability as in accord to the goals of Generation IV candidates, places specific requirements on the validating the codes which are used for evaluation of the performance and behaviour of such systems. A new calculation benchmark has been proposed for the startup core of the Superphénix reactor. The paper gives an overview of the benchmark content, provides the core model definition for static neutronics calculations and presents preliminary results on core performance and comparisons with some experimental data, obtained during startup trials. The calculation results allowed concluding that the developed model can serve as an appropriate basis for benchmark activity.