Advancing Nuclear Energy Research

Though it may not be the first clean energy source to come to mind, nuclear energy— responsible for 8 percent of all U.S. energy consumption—is a zero-emission clean energy source that can produce more electricity on less land than other sources and produces minimal waste. The U.S. is the largest producer of nuclear power, contributing nearly 20 percent of the electricity generated in the U.S.

Researchers from the University of Pittsburgh Swanson School of Engineering are among the 43 university-led nuclear energy research and development projects supported by the U.S. Department of Energy (DOE), which provided $41.2 million in funding in 2023. The DOE aims to maintain the nation’s leadership in nuclear energy research by supporting innovative technologies and solutions through its Nuclear Energy University Programs (NEUP).  

Jung-Kun Lee, professor of mechanical engineering and materials science, is leading a project that received $999,886 from the DOE to develop new materials for nuclear reactor cores. SiC/SiC ceramic matrix composites (CMCs) can tolerate multiple levels of damage well and have predictable failure behavior, which make them a good material for claddings of nuclear fuels. However, they are expensive, since a manufacturing process is time-consuming and energy-intensive. 

Lee’s research aims to apply aerodynamic fiber deposition (AFD) and metal assisted polymer impregnation and pyrolysis (MAPIP) to the manufacturing process.

“Existing manufacturing methods involve laying fibers in the preforms in several steps and conversion of preforms to dense ceramics requires another complicated post-process procedure,” explained Lee. “AFD places fibers over complex geometry with controlled alignment in a single high-throughput step and MAPIP enables the facile transformation of preforms into dense CMCs. If we can apply these methods to CMCs, they would not only simplify the process but also enhance their performance.”

Lee partners with Assistant Professor Quihan Liu and Associate Professor Ian Nettleship, both in the Department of Mechanical Engineering and Material Science at Pitt, and Edward Lohoda, consulting engineer at Westinghouse, on the project. 

Kevin P. Chen, the Paul E. Lego Professor of electrical and computer engineering at Pitt, received $1 million from the DOE to develop optical sensors to monitor molten salt reactors (MSR). MSRs are reactors that use fluoride salts as coolants when producing nuclear energy.

“Molten salts are highly corrosive at high temperatures, so we need sensors that can monitor both physical and chemical properties in hot, radioactive environments,” explained Chen. “We are developing stand-off optical sensors that don’t require physical contact with liquid coolants to perform both physical and chemical measurements. Through advanced sensors to perform real-time and comprehensive measurements, the goal of this project is to achieve condition-based maintenance of nuclear energy systems, which could have the potential to reduce operation cost of nuclear reactors by as much as 50 percent.” 

Chen will work with Oak Ridge National Laboratory and industry partner Kairos Power Inc. to develop highly affordable sensors that can function well in extreme environments and to explore potential sensor deployment in large-scale engineering test units.

"Through their research, Professors Lee and Chen provide stunning examples of the ways that engineering finds solutions that positively impact our world,” said Heng Ban, Richard K. Mellon professor, associate dean for strategic initiatives, and director of the nuclear engineering program at Pitt. “These new projects will illuminate the path to a greener, more efficient world and leave a lasting impact on nuclear energy. I’m happy that their research has been recognized with funding from the Department of Energy and look forward to their continued work in this area.”

Ban also joins a NEUP-funded project led by Brigham Young University Professor Troy Munro, along with Oak Ridge National Laboratory and industry partner X-energy. The $1 million award, with $275,000 allocated to Pitt, will fund research into new models that can better predict the thermal conductivity of the fuel used in nuclear reactors.

This project Ban’s lab will measure the microscopic and bulk thermal conductivity of TRISO and graphite composites that are frequently used in advanced reactor systems such as micro-reactors and integrate the data into thermal models. At the end of the three-year project, the team hopes to provide a more accurate understanding of graphite structure and properties that can lead to optimized performance in reactors. 

Two graduate students in Ban’s research group, Billy Spirnock and Paul Cox, received three-year, $169,000 DOE University Nuclear Leadership Graduate Fellowships this year as part of the NEUP. The award supports graduate research and a summer internship at a DOE national laboratory or approved facility.