It depends, I believe the area around can be hit, but yes "busting" is a no no. Not something I can say with 100% certainty
Attack of facilities, works, or installations containing dangerous forces, such as dams, nuclear power plants, or facilities producing weapons of mass destruction, is permissible so long as it is conducted in accordance with other applicable rules, including the rules of discrimination and proportionality
https://lieber.westpoint.edu/attacking-dams-part-i-customary-international-law/
@UKDslayer ran into this post WW1 Soviet history video. A very general overview of event.