Other commenters also pointed it out, but ramping down a nuclear reactor is not an easily reversed process. After a ramp down the fuel needs a certain amount of

Other commenters also pointed it out, but ramping down a nuclear reactor is not an easily reversed process. After a ramp down the fuel needs a certain amount of time before it can be ramped back up again. The output can be modulated, but it's a process that must be performed over a long period of time.