Crystal River, Fla. — Progress Energy Florida, a subsidiary of Duke Energy, announced Tuesday that it will retire the Crystal River Nuclear Plant, a facility that has been shut down since late 2009.

The plant was closed in the fall of 2009 after a crack was found in the outer layer of the containment building's concrete wall. 

While trying to repair the problem in 2011, crews cracked other portions of the wall. In its release Tuesday, Progress Energy said the nature and scope of repairs needed at the plant could raise costs dramatically.

"We believe the decision to retire the nuclear plant is in the best overall interests of our customers, investors, the state of Florida and our company," Jim Rogers, chairman, president and CEO of Duke Energy, said in a statement.

"This has been an arduous process of modeling, engineering, analysis and evaluation over many months. The decision was very difficult, but it is the right choice."

About 600 full-time employees work at the Crystal River plant, and many will remain onsite to work through the closing and decommissioning of the unit, Duke Energy said.

Progress Energy Florida provides electricity and related services to more than 1.6 million people in the central part of the state.