Five years ago, no self-respecting American utility executive would have dared to even think out loud about building a new nuclear power plant. Today, with the U.S. fleet sporting a nearly flawless safety record and a 90% average capacity factor, and with global warming a growing concern, nearly a dozen utilities are on record as seriously considering adding nuclear generation. The question is no longer if-but when-the next U.S. nuclear plant will be built.