3D Printed Runners for Hydropower Dams to be Developed by ORNL

According to the Department of Energy (DOE), hydropower accounts for nearly 27% of utility-scale renewable electricity generation in the United States. A runner, the rotating part of a turbine that turns the energy of falling water into electricity, is key to this technology. However, runners are almost entirely produced overseas; when they fail, it can take years to create and receive replacements. To address this problem, the DOE allocated $15 million to their Oak Ridge National Laboratory so they could develop a system to produce runners themselves. Their project, the Rapid Research on Universal Near Net Shape Fabrication Strategies for Expedited Runner Systems (Rapid RUNNERS), will develop a program combining additive manufacturing and conventional tools to produce runners domestically.

Throughout the three-year project, the Rapid RUNNERS team at ORNL will create the software, hardware, robotics, and manufacturing strategies necessary to produce these large components. The program relies on software that allows six or more robots to work simultaneously, completing tasks like wire arc welding, grinding, metrology, and other functions traditionally done by workers.

ORNL’s Jay Tiley inspects a hydroelectric runner from TVA’s Cherokee Dam (photo credits: Jim Tobin/ORNL, U.S. Dept. of Energy)

At ORNL, Rapid RUNNERS will produce three runners for hydropower dams, demonstrating their system’s capability. They’ll fabricate the runners using a robotic welder that will deposit metal layer by layer. While the solution used isn’t explicitly noted, the technology clearly falls under Directed Energy Deposition, DED. This AM strategy will quickly create metal parts that are close to the desired final dimensions, known as near-net-shape. Traditional machining techniques will then be used for post-processing in a way that is more time and materially-efficient than existing procedures.