Materials intended for next-generation nuclear reactors can now be evaluated in roughly six hours instead of multiple days, following the launch of a consolidated X-ray testing station. The system and its performance figures were detailed in the Journal of Synchrotron Radiation.
Engineers deployed the setup at the X-ray Powder Diffraction beamline, part of the National Synchrotron Light Source II at Brookhaven National Laboratory. The apparatus unifies four separate computed tomography modes onto a single test stage.
Consequently, researchers can observe an object’s physical form, elemental composition, and atomic order simultaneously, without cutting into or degrading the target material.
Nuclear components must remain intact for decades under severe operational stress. High radiation fields, mechanical strain, elevated temperatures, and chemical corrosion slowly degrade fuel elements and containment vessels. Understanding these microstructural changes is necessary before engineers can certify new reactor designs.
Computed tomography constructs three-dimensional views of internal structural patterns without physical sectioning. Historically, capturing a full analytical picture required operators to transfer a specimen across several distinct instruments to run individual tests. This logistical friction extended experiments across days and made it difficult to inspect the exact same region across different testing conditions.
High-resolution beamline mechanics
The new station resolves this issue by focusing high-energy, or “hard,” X-rays into an exceptionally narrow stream measuring 15 microns across. This width corresponds to roughly one-fourth the thickness of a human hair.
Hard X-rays have the penetration power needed to pass through dense, heavy substances, including structural reactor steels and radioactive actinide fuels like uranium. The narrow beam provides the spatial resolution needed to measure both highly organized sections and irregular zones within a single sample.
During a test cycle, the instrument’s four imaging modes register different physical characteristics at the same time.
X-ray absorption tomography records density shifts across the sample, exposing internal cavities, fissures, and void formations. Concurrently, X-ray fluorescence tomography tracks elemental signatures and maps where specific chemical elements reside inside the specimen volume.
Validation for future applications
X-ray diffraction tomography targets ordered crystalline areas, measuring the geometric patterns formed by internal atomic lattices. Pair distribution function tomography analyzes disordered, non-crystalline regions, detailing atomic-scale structures where regular lattice patterns are absent.
“By conducting these four techniques simultaneously, we can pinpoint exactly where those chemical changes occurred and connect them to how the material’s strength and brittleness have changed,” concluded Simerjeet Gill, deputy chair of Brookhaven’s Nuclear Science and Security Department and co-author of the new paper. “That structure-composition-property relationship is what we want to understand when studying nuclear materials.”
To confirm the station’s capabilities, investigators created an evaluation sample combining powders with metal wires of varying diameters and chemical compositions. The trial proved that the station could simultaneously log atomic positions, elemental distributions, and physical boundaries within a six-hour window.
Development work is already underway to equip the station with updated detectors, with the goal of reducing overall scan durations to under 30 minutes. Beyond reactor materials, scientists have used the system to study porous filtration media for environmental water remediation and to evaluate internal battery changes during charge cycles.