I imagine that would render a lot of surrounding land unusable, but I'm not sure how much if the concrete encased core was exploded into particles
More than likely: nothing. The biggest effect would be the loss of power generation capacity for Ukraine.<p>Russian using nukes would more than likely cause quite a stir in NATO, EU, and would likely give the rest of the world all the political ammo it needs to get India, Brazil, China, et all to sever ties.<p>These things are enormously complicated. It's hard to look at the effects in a vacuum geopolitically and economically.