Good point. I am not opposed to pumped hydro or other such schemes for storing energy. Nuclear itself tends to be employed for base load power generation and is not especially good at following demand variability. Having supply side variability (from solar, wind, etc.) makes matters worse, of course, and necessitates even more storage. But one way or another, it will be needed, and pumped hydro tends to scale better than say battery farms.

I wonder about option B. As it stands where I live at least, there is not much wiggle room in terms of getting people to use less power in the event of a shortage. For example, the local utility has offered free programmable thermostats in exchange for giving them the ability to control power usage in the event of a shortage, but I understand uptake of the program has been low thus far. I suspect in that scenario, they would have to bring fossil fuel power generation online.

Where I live is not in a drought-prone area at least, but it is also not suitable for pumped hydro given the geography. There was talk in the local news recently about a compressed air storage system that may get built nearby our natural gas plant. This juxtaposition makes some sense when you think about it, since it is a site that already features well-established grid hookups, so they can piggyback on that. The province as a whole is generating something like 60% nuclear, 32% renewables (mostly hydro), and 8% fuels. Recently, there was a major refurbishment of some of the nuclear reactors and it came in on budget and ahead of schedule, so the argument that anything nuclear must automatically involve cost overruns is perhaps no longer true, though good lord we have seen some epic ones in the past, particularly after the utility was privatized.