Every time nuclear power comes up someone blames environmentalists for the industry's problems -- in this case before the problems have manifested. It's an article of faith.
So far as I can see there's only ever been one plant in the US that's ever been cancelled for environmental concerns is the proposed plant at Bodega Harbor, which as you can see on the map would have been right on top of the San Andreas fault. In every other case projects have been shut down after serious miscalculations in the industry's economic forecasting (e.g. lower energy prices in the 80s than anticipated in the 70s), often exacerbated by poor project management performance. In those cases environmentalists were just a convenient scapegoat for management screw-ups.
You can see that because after the very largest anti-nuclear protests in history -- against Seabrook in NH and Diablo Canyon -- the plants were built and put into operation anyway. If a company had a plant under construction that it could make money operating, that plant would get built, even if thirty thousand people turned out to protest.