Optimized internal structures in 3D printing: KSU research targets safer nuclear components

Many industries rely on additively manufactured components but are reaching limits in terms of strength and reliability. A research team at Kennesaw State University (KSU) is now systematically investigating how print parameters and internal geometries affect mechanical properties. The goal is to develop 3D-printed structures that achieve nearly three times the load-bearing capacity of conventionally printed parts and are suitable for safety-critical applications.

Under the direction of Aaron Adams, associate professor and assistant chair of the Department of Engineering Technology, mechatronics student Eric Miller is analyzing various lattice structures and internal channels in 3D-printed components in KSU’s START Lab. The focus is on component concepts for use in fuel systems of nuclear power plants.

“Right now, the fuel is in the form of a pellet about the size of a penny, and the pellets are stacked together like a roll of coins,” said Aaron Adams, an associate professor of mechanical engineering technology.

“These fuel pellets are then placed inside a fuel rod. When the nuclear reaction begins, they heat up, expand, and come into contact with the rod wall. Because they have no room to expand, they must be removed before the fuel is completely depleted, limiting how much of the fuel can be used. Ultimately, we hope to achieve a 15 percent increase in fuel utilization using complex geometries.”

To this end, Miller creates parametric models and uses finite element analyses to test combinations of lattice density and orientation. He describes the project as an entry into the “strength-of-materials world” that goes far beyond the usual mechatronics curriculum.

“I wanted to get more into the mechanical engineering world because we focus less on that in mechatronics,” Miller said. “Getting into strength of materials and FEA has been a great learning experience.

When I was younger, I was kind of clumsy and would break things all the time,” he said. “Using a $200 printer and free software, I’ve been able to make replacement parts for things I’ve broken. It really lets me imagine something and then build it at home, even if it’s not as complex as nuclear fuels.”

“If you sum up our biggest challenge in one word, it’s resources, specifically our ability to run highly computational simulation models,” Adams said. “But I give Eric the task, and he runs with it. He always exceeds expectations.”

The work is funded by internal university research programs and embedded in a more practice-oriented alignment of the department. Lawrence Whitman, dean of the Southern Polytechnic College, emphasizes that such projects are intended to directly contribute to energy security and the advancement of additive manufacturing processes.

“This is the kind of real-world research we champion,” SPCEET Dean Lawrence Whitman said. “Eric and Dr. Adams are developing solutions that contribute to national energy security and strengthen the future of manufacturing.”

“Even when something appears to be a failure, it’s still a success because it tells us what direction not to take,” Miller said. “I’ve really appreciated this experience, and it’s been incredibly helpful for my growth.”