Nuclear reactors aren't fundamentally incompatible with load following: you can stick some control rods in or out and get more or less heat energy distributed t

Nuclear reactors aren't fundamentally incompatible with load following: you can stick some control rods in or out and get more or less heat energy distributed to your turbines. Nuclear power plants are generally used for base load for economic reasons: they are really expensive to build and have close to fixed hourly costs to operate, compared to say natural gas plants which are cheap to build and have operating costs proportional to the amount of gas they burn. Consequently we only build nuclear where we expect it can be utilized pretty much all the time, and we don't optimize nuclear plants for quick scaling up and down.