Duke Energy announced Tuesday that it will close Progress Energy’s idled Crystal River nuclear reactor in Florida.

The company is reviewing alternatives to replace the power produced by the plant, including possibly constructing a natural gas-fueled plant to meet the needs of its Florida customers. Duke is evaluating several potential sites for the project.

The Crystal River plant has been shut down since 2009 after a botched component-replacement project cracked concrete in its reactor containment structure. Duke had been mulling over whether to repair the plant, at an estimated cost of $1.5 billion to $3.4 billion, or retire it.

“We believe this decision to retire the nuclear plant is in the best overall interests of our customers, investors, the state of Florida and our company,” Duke CEO Jim Rogers 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 the right choice.”

Duke also announced Tuesday that it has reached a solution with the insurer, Nuclear Electric Insurance Limited, known as NEIL, about claims to be paid as a result of the damages that occurred at Crystal River. Under the terms of a mediator’s proposal, NEIL will pay $530 million in addition to the $305 million it has already paid. Duke said the $835 million payout is the largest in NEIL’s history.

The troubles at Progress’ Crystal River reactor were cited by Rogers and other Duke board members as one of the reasons that Duke moved to fire Progress CEO Bill Johnson just hours after Duke and Progress completed their merger last summer. Johnson had been slated to lead the combined Duke after the merger, but Duke’s board said Progress’ poor nuclear performance in recent years reflected badly on his leadership.

Duke’s board became particularly concerned about missed deadlines and rising costs at Crystal River after the merger between Duke and Progress was proposed, Duke’s lead director Ann Maynard Gray said during testimony before the N.C. Utilities Commission.

Duke reported in November that subsidiary Progress Energy Florida would record a $100 million charge against third-quarter income from its Crystal River nuclear plant.

An agreement the Florida Public Service Commission approved in February triggered the expected $100 million charge. Progress agreed to refund to customers $40 million in 2015 and $60 million in 2016 if repairs don’t begin by the end of this year – the money paid for replacement power while Crystal River was not operating.