NSUF 26-5643: Radiation Examination of Novel Ni-based alloy (Ni-Cr-Mo-W-(Ti/Al)) for Molten Chloride Fast Reactor Structural Applications
Molten chloride salts are promising high-temperature (400–950 °C) heat transfer fluids and thermal energy storage media for next-generation nuclear systems, including molten chloride fast reactors (MCFRs), electrochemical separation of spent nuclear fuel, and concentrated solar power applications. However, corrosion, irradiation damage, helium embrittlement, and insufficient high-temperature creep strength of structural alloys remain critical challenges, particularly at service temperatures of 750–950 °C.
Ni-based alloys containing Mo, Cr, and W (e.g., Hastelloy C-276, Hastelloy N, Haynes 244) exhibit superior molten-salt corrosion resistance compared to stainless steels, but none provide the necessary combination of high-temperature mechanical strength, irradiation tolerance, and resistance to He- and Te-induced grain boundary embrittlement required for MCFR operation. Our recent NEUP project efforts incorporating Al, Ti, and W additions have demonstrated improved performance, highlighting the potential of Ni-Mo-W-Cr-Al-X alloys with tailored microstructures. The complex interplay between multiple alloying elements promotes the formation of diverse strengthening precipitates (e.g., L12, DO22) in hierarchical structures, which will likely enhance radiation resistance substantially. These alloys achieved exceptional yield strengths of ~1.45 GPa at room temperature and ~1.2 GPa at 750 °C with >15% ductility, exceeding Haynes 244 by 300–600 MPa owing to the presence of various coherent/semicoherent precipitates as well as remarkable microstructural stability.
The objective of this RTE proposal is to systematically evaluate irradiation-induced microstructural evolution and mechanical property changes in the subject Ni-Mo-Cr-W-Al-Ti alloys relative to their unirradiated baseline behavior. The scientific outcome is achieving a mechanistic understanding of how short-range order, hierarchical precipitate architectures and coherent/semi-coherent interfaces influence radiation tolerance, defect evolution, and strength retention at elevated temperatures.
Additional Info
| Field | Value |
|---|---|
| Awarded Institution | University of North Texas |
| DOI | 10.46936/NSUF/60017666 |
| Embargo End Date | 2028-04-22 |
| Facility Tech Lead | Fei Teng, Lin Shao |
| Irradiation Facilities | Accelerator Laboratory |
| NSUF Call | FY 2026 RTE 1st Call |
| PI | Priyanka Agrawal |
| PIE Facilities | Microscopy and Characterization Suite |
| Prep Facilities | Microscopy and Characterization Suite |
| Project Member | Professor Lin Shao, Professor - Texas A&M University (https://orcid.org/0000-0002-5703-1153) |
| Project Member | Professor Vijay Vasudevan, Professor - University of North Texas (https://orcid.org/0000-0002-4509-0973) |
| Project Member | Dr. Mukesh Bachhav, Staff Scientist - Idaho National Laboratory (https://orcid.org/0000-0001-8104-6032) |
| Project Member | Dr Kaustubh Bawane, Staff Scientist - Idaho National Laboratory (https://orcid.org/0000-0002-2291-4466) |
| Project Member | Dr. Priyanka Agrawal, Research Assistant Professor - University of North Texas (https://orcid.org/0000-0001-9894-9625) |
| Project Type | RTE |