Case Studies

Onsite Technical Services Team Installs Critical Cooling Fans in Nuclear Power Plant

The Primary Challenge

With the combination of plant and equipment aging in nuclear facilities and the unprecedented 60 and 80-year licensing extensions, it is increasingly critical for technicians that serve these installations to provide multi-faceted and robust oversight for equipment repair, installation, and testing to help reduce cost and be more responsive to the needs of their customers. This is especially crucial for First-in-a-While (FIAW) site evolutions to maximize first-time success.

When a nuclear power plant in South Carolina needed technical support to install and balance two 6-foot diameter, 300 HP axial fans to complete their installation process, they reached out to Schulz Electric. The plant’s technicians contacted the Schulz Electric Nuclear Group because of their success with a previous fan unit repair at the Schulz Electric facility. The fans in need of balancing were the rotating elements in the reactor building cooling unit (RBCU), which provides the temperature control required to keep plant personnel and equipment safe while in the reactor building. These Vaneaxial fans have a history of failure from excessive vibration due to imbalance, and the client decided to turn to experienced professionals to ensure a successful installation.

Contaminated Motor Repair Including RCP Motor Overhaul and Rewind

The Onsite Technical Services Team

As a part of Timken Power Systems, the Schulz Nuclear team contacted Smith Services, one of their sister facilities located close to the plant, for assistance with balancing the fans under a short deadline. Both Smith Services and Schulz Electric have onsite technical service experts that have decades of mechanical service expertise. They were well suited for the project as they were experts in both in-shop balancing and onsite trim balancing, which each require a unique set of skills and test equipment knowledge.

When the Smith Services technicians were deployed, they were initially intended only to work the night shift with the OEM team handling the process during the day. After a day, plant technicians elected to replace the OEM crew with another Smith Services expert due to their superior understanding of the facility’s testing equipment and general expertise.

Meeting Exacting Standards

Nuclear plants are held to higher operational and quality standards than typical industrial facilities, and 100% compliance is essential. The Schulz Electric and Smith Services teams were utilized by the customer because of their understanding of the complete electro-mechanical drive system and their nuclear power plant expertise. In projects of this scope, highly trained personnel are required and it is essential that they are familiar with all of the specifications, standards, and industry guidelines necessary to carry out the testing and balancing process correctly, efficiently, and safely. Using advanced vibration analysis tools and accelerometers, they cycled the fan repeatedly to evaluate, detect, and correct any imbalance to meet the strict acceptance criteria. The blade pitch of the fans were also adjusted and accurately set to ensure optimum performance.

Key Results

The successful onsite fan balancing took only three days, with a 24/7 work schedule. “This project demonstrates Schulz Electric’s versatility and ability to work within our network to provide more than just motor repair services,” said Whit Ward, a field support engineer for Schulz Electric. “Critical systems often require immediate service and knowledge that goes beyond just one part of a drive train system. Our ability to leverage experience from multiple experts that are a part of our broader network allows us to respond quickly and offer a higher level of technical know-how to develop the best solutions for our customer's problems,” finished Whit.

Since successfully performing the work with the nuclear power plant, the Schulz and Smith Services teams have received multiple new orders for in-shop balancing and blade pitch adjustments on critical fans to support final equipment installations. “It’s a testament to the expertise and quality of work of our service centers that the customer came back to us and chose us over the OEM,” said Whit. “Since the time of the first project, our Smith Services team fabricated a specialized fixture to make the balancing process easier and much quicker. It’s this kind of ingenuity that helps us stand apart from the original equipment manufacturer and other repair facilities, and makes us the preferred choice for end-users,” finished Whit.

Schulz Electric’s nuclear group specializes in nuclear motor repair and offers the full range of nuclear equipment and repair capabilities. Through the expanded range of skills and resources provided through Timken Power Systems, Schulz is prepared to address any repair or maintenance challenge, including 24/7 state-of-the-art emergency repair services. We offer a variety of nuclear services including environmentally qualified form and random wound insulation, contaminated electric motor repair with RCP electric motor overhaul and rewind, safety-related repairs, electric motor testing capabilities, high quality, cost effective solutions for MOV dilemmas, all from our nuclear motor repair facility and in-house decontamination facility.