Should Exelon close some reactors, the decision will be another hit to an industry already struggling from plant closures and prospects for anemic growth. Dominion closed its Kewaunee plant in Wisconsin last year; Entergy ( ETR -0.07% ) is closing its Vermont Yankee plant at the end of 2014; and Exelon will close its Oyster Creek unit in 2019. The San Onofre power plant in California also closed because of safety issues. There are only five new reactors under construction in U.S. – two in South Carolina, two in Georgia, and one in Tennessee – with little prospect for more.