The efficient fabrication of uranium-based liquid fuels and the structural integrity of reactor materials are critical challenges for the deployment of chloride-based molten salt reactors (MSRs). As part of KAERI’s ongoing MSR development, this study investigates an optimized uranium chlorination process and a corrosion assessment of candidate structural materials under conditions more closely resembling actual reactor cores. To enhance process efficiency and scalability, metallic uranium was converted into uranium trihydride (UH3) via hydriding, achieving 34.1% efficiency. UH3 was chlorinated with ammonium chloride (NH4Cl), yielding uranium trichloride (UCl3) with a conversion rate over 98% and purity above 99%, as confirmed by ICP-OES. The UCl3 was used to fabricate various uranium-based liquid fuels for MSR applications. Simultaneously, the corrosion behavior of SS304, SS316, and Hastelloy-N was evaluated using a natural convection loop filled with a NaCl– MgCl2 eutectic salt mixture. The system operated for 500 hours at 500–580°C to replicate MSR conditions. Corrosion analysis revealed that SS304 suffered severe degradation, SS316 showed moderate resistance, and Hastelloy-N demonstrated superior stability, although some cold leg samples experienced mass gain due to corrosion product deposition. These findings provide key insights into optimizing liquid fuel synthesis and selecting corrosion-resistant materials for safe, long-term MSR operation.

The corrosion and degradation factors of a current collector in a molten carbonate fuel cell (MCFC) were investigated to determine the optimized coating thickness of nickel on STS316L. The results show that the surface morphology and electrical properties depended on the nickel coating thickness. The surface morphology gradually changed from a flat to a porous structure along as the nickel coating thickness decreased, and the electrical resistance of the nickel-coated STS316L increased as the nickel coating thickness decreased. This can be attributed to the diffusion of elements of Fe and Cr from the substrate through the nickel grain boundaries. Additionally, carburization in the metal grains or grain boundaries in an anodic environment was found to influence the electrical properties due to matrix distortion. The resistance of Cr-oxide layers formed in an anodic environment causes a drop in the potential, resulting in a decrease in the system efficiency.

The durability of a steel floodgate can have disadvantage to corrosion damage, because it is often come in contact with high humidity condition. In this study, to evaluate the corrosion rate depending on installation environment of a steel floodgate, atmospheric exposure test was performed using corrosion environment measurement sensors and monitoring specimens. From the correlation between the mean corrosion depth and corrosion current, the corrosion rate was estimated depending on the installed environment for the member of a steel floodgate.

Durability and structural safety of steel structure are severely affected by corrosion caused by deicer material as well as by airborne chlorides in the marine environment. In this study, based on analysis of current status it is suggested that deterioration and durability reduction by the environmental factor such as chlorides should be more reasonably taken into consideration for the accurate inspection and condition evaluation of steel structures.