Where nuclear plants have been built to a safe standard, sweat them for their useful life. The costs are paid down, and the energy is cheap to produce, creating only a truckload or so of waste (which can be reprocessed into fuel) for a year’s power.

Where there aren’t usable nuclear plants, you’re probably better off building renewables and/or energy storage. The upfront costs of nuclear are steep. (Also, some nuclear plants built when the climate was cooler are having to shut down on hot days due to the temperature of water used to cool them being too high.)

In either case, I’d rather have modern nuclear power than coal.