Nashville District Continues Hydropower Modernization Repairs

Project managers managing Nashville District 212 projects include Sam Jaser, Chris Stoltz, Omar Acevedo, Austin P’Pool, Mason Carter, and Mike Lee. Dana Sexton is the 212 Program Manager. All Hydropower managers can work on 212 projects within the Nashville District.

Section 212 authorized the Corps to accept and expend a portion of hydroelectricity revenues to perform rehabilitation work on hydropower equipment throughout the Nashville District in Tennessee and Kentucky. The rehabilitation of nine hydropower plants, 28 units and aging equipment ensure the production of more hydropower into the future to energize local cities and towns.

Sexton said these rehabilitation projects bring the hydropower plants up to date and they also ensure the Nashville District can reliably produce power that can quickly come online during periods of peak usage and critical energy shortages, like the Christmas Eve blackouts that swept across Nashville last winter.

“Hydropower is very helpful during power shortage situations, because we can quickly come online and produce the power needed during emergencies and fill that gap, so people aren’t as greatly impacted,” said Sexton.

Most hydropower units in the Nashville District began operating between 1950 and 1977, making these units outdated and challenging to find replacement parts for repairs.

“Most hydropower equipment has met the service life at Nashville District plants in the Cumberland River system. The objective for the Section 212 Program is to replace old equipment with more modern equipment so these plants can continue to produce power and increase the amount of power they produce,” said Sexton.

The hydropower plants in the Nashville District have been operating for over 50 years, exceeding their typical design life of 35-40 years. As a result, the risk of component failure increases every day.

Memorandum of Agreements between the Army Corps of Engineers, Nashville District, Department of Energy Southeastern Power Administration, and power preference customers provides Section 212 rehabilitation funding for these rehabilitation projects.

“Wolf Creek and Old Hickory have substantial turbine generator rehabilitation work upcoming. Taking care of these upgrades now will ensure a more cost-effective hydropower impact on the region in for the future,” said Sexton.

The projects are complete turbine generator rehabilitations, consisting of replacing and upgrading the main generating equipment. The direct current exciter replacement projects help power the plant while engineers get a generator online. These projects are done in preparation for the larger turbine generator rehabilitation projects.

Wolf Creek turbine generator rehabilitation is currently in the design phase and is expected to be rewarded to a hydropower construction contractor in 2024,” said Jaser.

The design process for Wolf Creek turbine generator rehabilitation is currently ongoing at 90% complete, meeting the September deadline for this step of the process.

Jaser, who also leads the Generator Step-up Unit transformer replacement project, said the Nashville District will meet with contractors who are considered industry expects to review the design plans.

“By reviewing the specs beforehand, the solicitation process happens a lot easier. We want to ensure there’s nothing that needs to be modified before the acquisition and solicitation portion of the process is completed,” said Jaser.

With a technical background in electrical engineering, Jaser is a huge asset to the hydropower team. His experience with the electrical equipment used at hydropower projects helps with planning the work and understanding the challenges, so teams can prioritize the necessary work.

Sexton said Jaser’s unique engineering knowledge helps him manage the projects he’s working on and serve as another layer of review on the project.

“Jaser’s background strengthens the Nashville District on several levels, one being the ability to review certain steps ahead of time and make any necessary changes before we move to the next phase,” said Sexton.

The Wolf Creek Hydropower Plant Rehabilitation Project design phase started in 2022. Jaser works closely with the quality control team and technical teams during this phase.

“As a project manager with an electrical engineering background, I’m glad to put these skills to work. I help create functional and critical ways to improve the processes we use to get these projects done quickly and efficiently,” said Jaser.

The project is expected to take approximately 10 years and will enter the acquisition phase in 2024, then contractors will bid for the contract and eventually begin construction.

The Old Hickory turbine generator rehabilitation project will replace three out of four turbine generator units. The Corps rehabilitated the fourth generator under a separate Section 212 funded contract.

Stoltz, project manager for Old Hickory Dam Turbine Generator Rehabilitation Project, said the new generators will be rated at 40,500 MW and contractors will replace three turbines with new Kaplan turbines, rewind existing generators, and refurbish associated equipment and components for three units.

Before starting the turbine generator rehabilitation work, the Corps completed a Hydropower Rehabilitation Analysis Report in 2022, where engineers studied different alternatives to complete the necessary repairs.

“This report helps the design team leading the engineering and design phase to know which alternative will yield the most benefit once completed,” said Stoltz.

The Corps awarded the construction contract in January 2023 and the project is currently in the engineering during construction and supervisory and administration phase. Repairs are scheduled to begin in March 2025 after the contractor submits and gets approval for their construction plans.

“The contractor will be off-site for two years planning, designing, and manufacturing before mobilizing and removing the first unit in 2025. This off-site time is critical and lays the foundation for the successful replacement of the first unit. It gives the team an opportunity to look over the contractor’s plan and ensure it meets the requirements of the plans and specifications,” said Stoltz.

Sexton said Stoltz has done a great job leading the Old Hickory rehabilitation project, he’s been actively involved with the contract from the beginning.

“Stoltz and his team had a technical site visit with the contractor and our technical staff early in the contract ensuring everyone was on the same page to meet deadlines successfully. He’s committed to being as cost effective as possible through this entire process,” said Sexton.

The Corps awarded the Old Hickory Dam Turbine Generator Rehabilitation Project to Andritz Hydro, a global supplier of plants, equipment, and services for hydropower stations, in February 2023 and is expected to complete the work by August 2029.

The Nashville District power plants produce over 3.2 billion kilowatt-hours per year on average.  Based on an average annual household consumption of 10,715 kWh, as provided by the U.S. Energy Information Administration, that is enough energy to support 304,000 homes annually.

(The public can obtain news, updates and information from the U.S. Army Corps of Engineers Nashville District on the district’s website at www.lrn.usace.army.mil, on Facebook at http://www.facebook.com/nashvillecorps and on Twitter at http://www.twitter.com/nashvillecorps.)

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