As the article you linked also states, this feature is largely theoretical and for operational and economic reasons utility companies do not use it unless forced to. In France specifically, the high percentage of nuclear power makes it look like you can regulate it quite well, but that is an artifact of looking at total numbers that does not transfer to other grid situations where nuclear is only a small percentage of the overall production capacity. Generally speaking, nuclear and renewables are a bad match, and if you have to chose between them, renewables clearly win on both economics and scalability.
No, already existing nuclear plants can regulate, as it’s needed for places with lots of nuclear power like France.
https://www.powermag.com/flexible-operation-of-nuclear-power-plants-ramps-up/
As the article you linked also states, this feature is largely theoretical and for operational and economic reasons utility companies do not use it unless forced to. In France specifically, the high percentage of nuclear power makes it look like you can regulate it quite well, but that is an artifact of looking at total numbers that does not transfer to other grid situations where nuclear is only a small percentage of the overall production capacity. Generally speaking, nuclear and renewables are a bad match, and if you have to chose between them, renewables clearly win on both economics and scalability.