A scheduled triennial outage at Laramie River Station (LRS) Unit 1 has been extended after inspections revealed unexpected damage to the unit’s low pressure (LP) turbine. LRS was brought off-line March 14 for a scheduled outage to repair the LP turbine and complete periodic maintenance tasks. During inspection, additional damage was discovered on a small number of LP turbine buckets. Due to the unexpected repairs, the outage schedule has been lengthened by 14 days and the unit is expected to return to service June 26.
“The additional repairs to the LP turbine will extend an already lengthy outage, but should not impact Heartland operations significantly,” said Heartland Director of Power Supply Adam Graff.
LRS is a three-unit, 1,710 megawatt coal-fired generating station located near Wheatland, Wyoming. It has been part of Heartland’s resource portfolio since it was constructed in 1980 as part of the Missouri Basin Power Project (MBPP). Heartland owns a three percent undivided share of MBPP, equal to 51 megawatts, which we receive from Unit 1.
MBPP owners have continuously upgraded all three units of LRS to provide up-to-date emissions controls and to ensure optimal output. Officials also perform a major scheduled outage triennially on each unit. The current Unit 1 outage is longer than usual due to the need to completely disassemble the turbine and ship components off-site for repairs. Damaged turbine components must be shipped by train to a facility in New York where they are repaired then returned to the site.
In addition to the LP turbine repairs, significant repairs are being made to a large number of the Unit 1 burners. These low-NOx burners were installed on Unit 1 in 2012 as an emissions-reduction and efficiency measure, and have experienced damage due to overheating of the burner tips. The overheating is due to design flaws that effect air flow across the burner tips.
According to Graff, the burners installed in Unit 1 are the same design and vintage as the burners installed at Heartland resource Whelan Energy Center Unit 2 (WEC2). Similarly, the damage discovered and the proposed design changes and repairs from the manufacturer are nearly identical to the latest repairs done at WEC2.
“These changes at WEC2 seemed to have alleviated the overheating issues and subsequent damage,” said Graff. “We expect to see similar results from the repairs at LRS.”
Members of Heartland’s board and staff visited LRS during the outage. For more pictures from their visit, click HERE.