Above: Nishant Garg (left) and John Popovics

By Kristina Shidlauski

Researchers from the Department of Civil and Environmental Engineering (CEE) at the University of Illinois at Urbana-Champaign were awarded $800,000 from the United States Department of Energy (DOE) to improve methods by which the effect of radiation on concrete used in nuclear power plants is assessed.  Assistant professor Nishant Garg and professor John Popovics will lead the three-year project.

Throughout the service life of a typical nuclear power plant, neutron radiation may affect and deteriorate concrete used in certain structural elements, such as the biological shield exiting the reactor pressure vessel, Garg said. When the concrete is exposed to neutron radiation, residual stresses and cracking occur due to radiation-induced volumetric expansion of the component mineral aggregates.

Understanding how concrete degrades when exposed to radiation is important when planning for the long-term operation of a power plant. In order to better estimate concrete’s tolerance of radiation, the researchers will develop a multiscale and multimodal approach to characterize the concrete and its aggregates using a combination of spectroscopy, diffraction, and electron microscopy-based techniques. These improved material characterization data will then be used to empower existing mechanical models that predict radiation-induced concrete degradation, Garg said.

“Data obtained from state-of-the-art techniques here at Illinois will significantly contribute to modelling efforts currently pursued by our colleagues in Oak Ridge National Lab, improving our ability to predict the damage induced in concrete upon long-term radiation,” Garg said. “This information is key for the long-term operation of nuclear power plants across the world.”

The grant to support this project is administered under the DOE program Nuclear Energy University Program, which funds nuclear energy research and equipment upgrades at U.S. colleges and universities. Collaborators include Chris Wetteland and Kurt Sickafus of the University of Tennessee, Knoxville and Yann Le Pape of Oak Ridge National Lab.