The need to cut back on carbon has brought attention back to nuclear as an energy source but the low cost of natural gas has caused some nuclear plants to become unprofitable. Where nuclear plants have closed carbon emissions have gone up. Nuclear advocates want support as clean energy providers. They’re also optimistic about new mini-nuclear plants and plants that would reduce nuclear waste. We’ll talk with nuclear critic Arnie Gundersen about how the changing landscape of nuclear power may affect the drive towards renewable energy. This Dec. 14, 2010 file photo shows Exelon Generation’s Braidwood nuclear power plant in Braceville, Ill. Exelon announced Wednesday (AP Photo/Charles Rex Arbogast, File)