CR-3 went offline in September 2009 for RFO-16. While the reactor was down, the old steam generators were to be replaced. There are 426 steel tendons within the concrete walls of the reactor containment dome which reinforce the dome. Plan developer Sargent & Lundy specified that 97 tendons be loosened. Progress rejected that number as excessive. The next proposal was to loosen 74 tendons, which was typical of other nuclear plants doing the procedure. According to a Progress employee, "de-tensioning the tendons is a very expensive and time-consuming effort", so the number was further reduced to 65. Progress engaged Bechtel to provide a 3rd party review, which agreed that 65 was appropriate. However, when the work was performed, only 27 tendons were loosened, and a foreman and supervisor sent emails questioning the way the tendons were loosened.