A common myth is that nuclear power plants have two positions: on or off.This myth is one of the reasons many think renewables and nuclear are incompatible.
However France produces easily available output data for all of its nuclear power plants. Available at the link below.
For example Cattentom 1 ran at around 300 MW throughout most of last Sunday and then in the space of a couple of hours ramped up to 1200 MW. If you believe what many people say then this is technically impossible, but the French do it.
Strangely the same myth is believed by many regarding coal plants. Odd given how some countries run their entire grid on coal.