This fall, McGuire Nuclear Station will power down one of its units as it undergoes a refueling outage. Although outages occur every 18 months and are critical to the operation of the plant, this outage is perhaps even more significant because McGuire will perform a first-time evolution for the station - the replacement of a generator stator. The stator is part of the electric generator and is among the largest and heaviest components in the plant, weighing approximately 1.2 million pounds. This equipment replacement, along with other changes will ensure the station continues to deliver safe and reliable service to millions of customers.
To prepare for the arrival of the stator, work began early this year. Due to its weight and size, this massive piece of equipment had to be shipped by rail. Teammates at McGuire first began reconstructing a 50 year-old railroad embankment near the site to ensure it could safely accommodate the transportation of this new equipment. Then, load testing was conducted on haul paths at various locations throughout McGuire, as well as the railroad system to ensure all segments of the Duke Energy railroad, including areas which were reconstructed, could accommodate the weight of the new generator stator.
In July, the first key evolution took place with the delivery of a new high pressure turbine. Replacing the high pressure turbine components of the 1970s with a new, modern rotor and cylinders will increase the plant's efficiency as well as the overall output by approximately 30 megawatts. But perhaps the most important evolution thus far has been the arrival of the generator stator earlier this month. The stator took a 40-mile journey from the Siemens Facility in Charlotte, NC to McGuire Nuclear Station; loading and preparing the stator for shipment from Siemens took nearly five days.
McGuire’s original generator was built in 1973. In 2010, Siemens was awarded the contract to manufacture, design and build a new generator stator. As part of the manufacturing process, a newly-fabricated stator frame was received at the Charlotte facility in December 2011. The frame was assembled over a two-year period at Siemens’ sister service facility, Turbocare, in Poland. Before the delivery, McGuire teammates spent months working side-by-side with Siemens personnel assisting in the building of the current stator and exciter. Now that the stator has arrived at McGuire, nearly 300 Siemens teammates will be providing assistance on site to help with this massive project throughout the fall outage.
The generator stator replacement is a significant project for McGuire Nuclear Station and is one of the largest projects in Duke's nuclear history.