This is not an intrinsic limitation. Naval nuclear reactors can power up to meet demand very rapidly. Civilian nuclear reactors aren't built like this for various reasons, including gas turbines just being cheaper for this purpose.
Additionally when your capital and fixed O&M costs are higher than renewables with the same net power + batteries, then the costs of your peaking energy skyrocket even further.
Far better to build less nuclear + storage. And then realise that the generation doesn't need to be nuclear in most places.