A troubled nuclear power plant near Omaha is being heated up to test its pressurized steam pipes for leaks after an outage that dates to April 2011.

Nuclear Regulatory Commission spokeswoman Lara Uselding tells The Associated Press the utility began heating up the water in the Fort Calhoun plant's power-generating system to 515 degrees yesterday.

The plant about 20 miles north of Omaha will remain heated for the next several days, so the commission and the utility can test systems that are used only when the plant is running.