Outage pit crews
Question: When are TVA employees and contractors like NASCAR pit crews?
Answer: During planned outages!
“Quick in, quick out,” says Joan Dodd, general manager for Fossil Power Group’s Power Service Shops Field Services. “To do that, everything must be totally orchestrated. We spend numerous hours on the front end with the goal of working safe and working smart.”
At a recent Raccoon Mountain Pumped Storage Plant scheduled outage, Robin Morrison (left) and Ronnie Sexton of Voith Siemens Hydro Power Generation use a level to prepare for the installation of a new scroll-case door.
The master schedules for outages – such as last fall’s outage at Sequoyah Nuclear Plant Unit 1 and the current ones at Raccoon Mountain Pumped Storage Plant Unit 4 and Allen Fossil Plant Unit 2 – are overseen by the outage managers.
Raccoon Mountain Unit 4 began its 64-day outage on Sept. 22, during which the unit has been disassembled. “Everything was removed except for the turbine,” says Tim Gaddis, Raccoon Mountain regional hydro production manager. “Everyone has done an incredible amount of work with the focus on safety.”
The Allen Unit 2 outage is scheduled for six weeks – Oct. 3 to Nov. 21 – breaker open to breaker close. Onsite at outages, John Nutbrown, field supervisor of fossil site services, coordinates the efforts of 50 to 75 TVA employees and machinist contractors, who carry out a sequence of tasks on a demanding timetable.
“We work two 12-hour shifts, around the clock, seven days a week,” says Nutbrown. “You go all out in the fall and spring, when we do the outages, and you recover when you have some off time. It’s sort of like the work crews become your families, when you spend that much time away from home.”
The crew at work
The tasks at Allen Unit 2 include disassembling, inspecting and reassembling the high-pressure, intermediate and low-pressure turbines. The HP rotor is replaced, and the other rotors are inspected and serviced.
The rotors, sometimes weighing up to 30 tons, are shipped to the Power Service Shops in Muscle Shoals. “We perform a complete inspection of these components to determine the repairs required to restore them to acceptable standards and set the new inspection interval for the unit,” says PSS General Manager Raul Alfonso. “Our objective is to perform the work required safely and within the shortest time possible so we return the unit to service.
“Each site outage manager spends over a year preparing for the outage. Meticulous? Yes! But the results are the shortest, most cost-effective outages achievable, while ensuring we perform the appropriate activities to guarantee the highest possible reliability.”
The Power Service Shops are typically responsible for the turbine-generator activities while contractor partners GUBMK and NPS perform a major role assisting maintenance in the repair of the boiler and plant equipment.
Morrison (left) and Sexton inspect the turbine stay vanes and wicket gates.
For each outage to be successful, a large team of people must be assembled, coordinated and orchestrated to resemble a finely tuned NASCAR pit crew. This concept goes a long way in reducing TVA’s cost and increasing the reliability of the generating stations.
Like pit crews getting race cars back on the race track, outage crews are working to get units back online as soon as possible with no return-to-service issues.
“If we meet the schedule, it puts the unit back in service and reduces off-system purchases,” says Dodd. “But just as it is on the track, the top priority is always working safely and performing quality work.
“We tell our crews, ‘Focus on safety. Focus on quality. Cost and schedule will fall in line.’”
