Detecting ‘Hidden Damage’ in Spacecraft and Reactor Components

[Financial News] Researchers in South Korea have developed a new assessment technique that can accurately diagnose “invisible radiation damage” in high-performance polymer materials used in spacecraft or nuclear reactors. The technology can detect in advance defects in components caused by changes to their internal molecular structure, even when no cracks appear on the surface. It is expected to help ensure the safety of space and nuclear components and predict their service life. A research team led by Professor Youngho Eom of the Department of Organic and Nano Engineering at Hanyang University, together with teams led by Professor Hyeongmin Jin of Chungnam National University and Dr. Jaegi Lee of KAERI, established a “multiscale property assessment framework” to comprehensively analyze changes in the internal structure and mechanical properties of polymer materials in extreme radiation environments, the researchers said on the 19th.
High-performance thermosetting polymer materials, including cyanate ester (CE) resins used in aerospace and nuclear applications, must withstand high temperatures and intense radiation. However, prolonged radiation exposure can cause complex damage, such as the breaking or recombination of internal chemical bonds, even when no clear cracks appear on the surface. Previously, assessments relied on surface observation or measurements of a single property, limiting the ability to precisely identify how materials weaken or deform from within.
The research team used KAERI’s research reactor HANARO to irradiate CE resin with high-dose mixed neutron and gamma radiation at doses of up to 6.2 megagrays (MGy). They conducted a detailed assessment from the molecular scale to surface morphology using a range of analytical methods, including electron microscopy, positron annihilation lifetime spectroscopy, X-ray scattering analysis and nanoindentation testing.
The analysis showed that the decline in the material’s properties under radiation exposure did not progress in one direction, and that the pattern of degradation changed at around 2.1 MGy. At lower doses, chemical bonds were partially broken, reducing stiffness. At higher doses, particles formed by the radiation bonded again, making the structure denser and partially restoring its mechanical strength. The researchers identified at the molecular and nanoscale the point at which microscopic damage shifted—something difficult to detect with conventional surface observation methods such as electron microscopy.
“This study is significant because it establishes an analytical framework that allows us to understand radiation-induced degradation in polymer materials not simply as a decline in their properties, but as a process of molecular structural change and reconstruction,” said Hanyang University Professor Youngho Eom. “Going forward, we hope to expand the assessment framework to a variety of polymer materials and extreme radiation environments and contribute to ensuring material reliability in aerospace and nuclear applications.”
Supported by the Ministry of Science and ICT and the National Research Foundation of Korea (NRF), the study was published in No. 164 of Polymer Testing, an international journal in the field of polymer materials testing and evaluation.

[email protected] Man-gi Kim Reporter