One of the country’s oldest and most controversial nuclear plants has announced it will close late next year. Citing financial reasons, the nuclear plant operator Entergy said Tuesday it will decommission the Vermont Yankee nuclear power station in Vernon, Vermont. The site has been the target of protests for decades and has had a series of radioactive tritium leaks. In 2010, the Vermont State Senate voted against a measure that would have authorized a state board to grant Vermont Yankee a permit to operate for an additional 20 years.