When workers began to cut the access hole for the steam generators, a crack formed. That crack was repaired, but more cracks appeared. Engineers noticed that parts of the concrete had delaminated. This was repaired, and the concrete re-tensioned, but the same problem was found in other areas. The plant had originally been due to restart in April 2011 following the uprate, but in June 2011 Progress Energy said that it did not expect it to restart until 2014. Preliminary cost estimates for the repairs was put at between $900 million and $1.3 billion, but this estimate was later called into question by Duke Energy. In October 2012 an independent review estimated the repair cost at $1.5 billion, with a worst-case scenario of $3.4 billion. In February 2013 Duke Energy announced that Crystal River would be permanently shut down and that they will recover $850 million in insurance claims.