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.

1. Introduction
    1.1 Uranium Chlorination and Liquid Fuel Fabricationfor Molten Salt Reactors
    1.2 Evaluation of Corrosion Characteristics ofMSR Materials Using a Natural ConvectionMolten Salt Loop
2. Experimental
    2.1 Uranium Chlorination and Liquid FuelFabrication for Molten Salt Reactors
    2.2 Evaluation of Corrosion Characteristics ofMSR Materials Using a Natural ConvectionMolten Salt Loop
3. Results and Discussion
    3.1 Uranium Chlorination and Liquid FuelFabrication for Molten Salt Reactors
    3.2 Evaluation of Corrosion Characteristics ofMSR Materials Using a Natural ConvectionMolten Salt Loop
4. Conclusions
Conflict of Interest
Acknowledgements
REFERENCES

• Chang Hwa Lee(Korea Atomic Energy Research Institute, 111, Daedeok-daero 989beon-gil, Yuseong-gu, Daejeon 34057, Republic of Korea) Corresponding author
• Dalsung Yoon(Korea Atomic Energy Research Institute, 111, Daedeok-daero 989beon-gil, Yuseong-gu, Daejeon 34057, Republic of Korea)
• Taeho Kim(Korea Atomic Energy Research Institute, 111, Daedeok-daero 989beon-gil, Yuseong-gu, Daejeon 34057, Republic of Korea, University of Science and Technology, 217, Gajeong-ro, Yuseong-gu, Daejeon 34113, Republic of Korea)