The so-called nuclear "Renaissance" is starting to look less like a marble David and more like a collapsing cooling tower as U.S. utility, Constellation, becomes the next to run for the exits. According to a Bloomberg article, Constellation and French partner, EDF, are in frantic talks to try to save their joint U.S. venture - a third reactor at the Calvert Cliffs nuclear power plant site on the shores of  the Chesapeake Bay.