I'm not sure why you're bringing up hydro so much. Yes, it's a component in storage but so are batteries and many other forms of storage.
Furthermore, switching completely to renewables and utility-scale batteries shifts the bottleneck from building reactors to digging mines & building factories.
They already exist. A new nuclear plant, by definition, does not.
To overbuild that much infrastructure requires an astronomical amount of copper, lithium, and rare earth metals. Spinning up a single new large-scale mine from exploration to production takes 10 to 15 years due to regulatory and engineering hurdles.
Sodium ion batteries are perfect for grid storage applications with no rare earth components. Panels and wind turbines are being recycled.
It's obvious you've made an emotional decision that nuclear = fucking awesome, and now you're trying and failing to justify your stance.