Thus nuclear power becomes forced into ever more marginalized peaking roles.
Try calculate the cost for a kWh of electricity from a peaking nuclear power plant.
That depends on the market setup of the grid; if generator and retailer bypass the various market arrangements (as is the case in the UK since NETA) the price on the market is irrelevant. EDF can choose to have their own power transported to their consumers, leaving intermittent generators to be constrained away. Hence the CfD for Hinkley Point C is a relatively assured revenue stream, unlike for offshore wind merchant generators who are increasingly at risk from being constrained away (at the loss of their CfD payments, in exchange for a smaller constraint payment).