The ongoing crisis at Japan’s Fukushima Daiichi nuclear powerplant quickly triggered demands from politicians and activists from California to New York to Germany and elsewhere to shut down aging nuclear reactors, but replacing existing nuclear generation isn’t as simple as flipping a switch.
At best, taking nuclear powerplants off line might encourage more development of renewable generation and push distributed generation, but only years or decades from now. At worst, taking a nuclear powerplant or two off line could cause spikes in wholesale electricity prices and problems with electric reliability.