Reuters: U.S. firm Duke Energy may be building its last two coal plants to bet instead on nuclear power, chief executive James Rogers said on Tuesday. Rogers described his company as the third largest U.S. generator of electricity from coal and the third largest from nuclear. If Duke Energy had to choose between one technology or the other Rogers said: "I’m betting on nuclear." "And I would go a step further and probably say that these two coal plants we build might well be the last two …