Guest column: Navajo Generating Station overhaul comes at right time of year

Robert Talbot

Robert Talbot

It may be the slow and sleepier time of year for most of Page, Arizona, but it's anything but that at the Navajo Generating Station right now. That's because in a little more than a week we will launch a major 52-day, $47 million overhaul of Generating Unit 3.

From shutdown to start-up, there will be more than eight full and busy weeks with at least 1,000 highly skilled craftsmen and professionals, from welders to engineers, both men and women, performing and supervising 10,000 to 12,000 individual tasks.

For more than 40 years, all of the equipment and parts that make each of NGS's three units work in synchrony to produce its 750 megawatts 24 hours a day have been diligently inspected and repaired through these annual scheduled outages.

 NGS recently received high national rankings for 2013 for both our annual power production and reliability. The December 2014 issue of Power Engineering magazine listed NGS sixth in the nation for total power production when compared to all coal-fired power plants in the United States. And we were ranked 20th in reliability with a capacity factor of 86.9 percent.

The commitment to and investment in this kind of quality maintenance by NGS's owners and managers are what has given the plant its long, productive and efficient life. It is the primary reason NGS runs better, cleaner, more efficiently and more dependably today than ever.

Last year, NGS completed a three-year cycle of minor overhauls and we are now beginning a three-year cycle of major overhauls beginning with Unit 3.

In a major overhaul, the entire turbine and generator are completely disassembled, inspected, repaired where needed and reassembled to specification. The boiler, boiler feed pumps, auxiliary turbines, precipitator and many dozens of other pieces of equipment are torn down to their essential components and rebuilt like new again.  All of the unit's instrumentation is recalibrated to ensure accuracy and precision. All ducts, fans, pumps, steam lines and valves are inspected and repaired to last until the next overhaul. 

Our planners, schedulers and coordinators have a three-year process to prepare for these overhauls. They have worked out a finely choreographed sequence of work to be done from beginning to end. Much of it has been developed through the years based on previous experience. They can estimate to the hour six weeks out when a particular job should begin, how long it should take and when it should be completed - and for the most part it is.

This year, most of the overhaul crews of regular and temporary workers will put in 10-hour shifts six days a week. The busiest times tend to be at the beginning, when things are taken apart, and the end when they are reassembled.

Each day begins with a meeting of managers, engineers, inspectors, schedulers, supervisors and contractors to discuss the previous day's work and the issues that arise. The first priority and first topic of discussion is always safety. Salt River Project and its overhaul primary contractor Zachry are proud of their commitment to safety for everyone who steps onto the plant site.

While the work being done at NGS won't be apparent to most northern Arizona residents, the positive impact on our local economy will. The workers who come to Page will eat in our restaurants, stay in our motels, fuel up at our convenience stories, spend in our businesses and have their vehicles serviced in our auto shops. This, in turn, will require those businesses to keep their own workers employed at a time of year they might otherwise have to lay off people.

The overhaul also brings home hundreds of highly skilled Navajo craftsmen and craftswomen who travel the country from power plant to power plant. Through the years, many have said they look forward to this time to spend two months with their families while earning high wages. In recent overhauls, as much as 98 percent of temporary workers are Navajo.

Once the overhaul is completed, we'll spend about four days to bring each system online and get Unit 3 operating at full load. That's when we know we've done our job right and our staff can breathe a little easier - until we start it all again next year. 

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