Improving heat exchanger reliability for advanced nuclear reactors
U.S. Department of Energy’s (DOE) Argonne National Laboratory researchers Mark Messner and Sagar Bhatt are contributing to a multi-institutional effort to strengthen diffusion bonds in compact heat exchangers, critical components in advanced nuclear reactors.
Advanced reactors are designed to be smaller, more efficient and more cost-effective than today’s systems. Compact heat exchangers play an essential role in safely transferring heat within these reactors, but their performance depends on the strength and durability of diffusion-bonded metal plates exposed to high temperatures and mechanical stress over extended periods.
Launched in 2022 with support from the DOE’s Office of Nuclear Energy, the project brings together materials scientists, computational modelers and mechanical testing experts to better understand how these bonds form, perform and degrade over time.
Rather than studying bonding from a single perspective, the team integrates:
- Advanced microscopy to observe how bonds develop at the microscopic level
- Computational models to predict long-term behavior
- Mechanical testing to evaluate real-world performance
By linking these approaches, researchers can compare predicted outcomes with experimental results and refine their understanding.
“Modeling develops a mechanistic description of the physics driving bonding and deformation. Microstructural analysis verifies those hypotheses. Mechanical testing links substructural features to component-scale performance. In isolation, these methods give us only a part of the picture,” said Bhatt.
Bhatt and his collaborators found that carefully preparing metal surfaces before bonding helps prevent the formation of unwanted compounds that can weaken joints. By reducing these weaknesses at the bonding surface, the team demonstrated a pathway to stronger and more durable heat exchanger components.
Stronger bonds can improve the reliability of critical reactor systems and help reduce maintenance demands and unplanned outages. By better understanding how these metal bonds behave over time, the research supports the development of safer, longer-lasting advanced nuclear technologies.
This integrated approach provides data that could help establish validated performance metrics for diffusion-bonded components. In turn, the findings may support future industry standards and inform certification pathways for advanced nuclear systems.
This material is based on work supported by the U.S. Department of Energy, Office of Nuclear Energy, under Award No. IRP-22-27979. Collaborating institutions include the University of Michigan, University of Wisconsin–Madison, University of Illinois Urbana-Champaign, Fort Lewis College, Idaho National Laboratory, Argonne National Laboratory, Electric Power Research Institute and MPR Associates Inc.