With the aim of targeting low-carbon energy mixes, variable renewable energy sources, i.e. wind and solar, are broadly promoted worldwide. In France, nuclear is the first contributor to today's low-carbon power mix and it will, tomorrow, be challenged by the increase of variable renewable energy sources. This paper develops a prospective approach to examine the solicitations that nuclear will have to face, for several scenarios. Results show that, with the penetration of renewable energy sources, the number of extreme nuclear power ramps and amplitudes variations increase, as well as the number of annually required shut-downs/start-ups events per reactor, even if the nuclear capacity was to be lowered. Beyond 30% wind and solar penetration, complementary flexibility options will have to be leveraged. (C) 2018 Elsevier Ltd. All rights reserved.