Entergy’s decision Monday to nix plans to spin off six nuclear reactors, including Vermont Yankee, into a separate company that would be overburdened with debt is a welcome step forward in the state’s discussion about extending Vermont Yankee’s permit in 2012 by another 20 years. The spin-off proposal was widely criticized as a ploy to create an under-funded corporation (Enexus) that would have been more likely to default on decommissioning costs, while allowing Entergy to dodge those expenses at plants in New York, Massachusetts, Vermont and Michigan.