US-based QuesTek Innovations announced on 17 May that it had been awarded $1.1 million in Small Business Innovation Research (SBIR) Phase II funding from the US Department of Energy (DOE). The funding will be used to design, develop and qualify a novel materials solution and process for next generation molten salt reactors. This new Phase II project will focus on efficient and cost-effective cold spray processing of bimetallic structures, with refractory-based alloys (e.g., molybdenum) as a surface layer to provide corrosion resistance and high temperature stability on the surface of ASME-certified structural materials.
During the Phase I project, QuesTek used its Integrated Computational Materials Engineering (ICME) technologies to design novel molybdenum alloy compositions that combine improved cold spray processability with high molten salt corrosion resistance and strong interfacial bonding to the substrate material. Initial cold spray trials successfully deposited these compositions on 316 stainless steel. QuesTek will further explore additional refractory alloy designs beyond molybdenum (e.g. niobium, tungsten, tantalum) and more extensive functionally graded, cold spray structure evaluations. Evaluations will focus on both the material and the process, and address scale-up considerations.
Dr Pin Lu, QuesTek Materials Design Engineer and project Principal Investigator said cold spray is one of the most effective and economical coating technologies to greatly extend the lifetime of next-generation nuclear reactors. “We are excited for this opportunity to apply our proven computational materials design approach to design novel high performance cold sprayable refractory materials, improving the economic feasibility and performance of future clean energy.”
QuesTek is partnering with Solvus Global, a specialist in advanced cold spray technology process optimisation, AM powder development and commercialisation, and machine learning process control, as well as with Professor Vilupanur Ravi at Cal Poly Pomona, an expert in materials behaviour in molten salt, to achieve concurrent design of both material and process.
Solvus Global co-founder and CEO, Dr Aaron Birt commented: “Further development of functionally graded coatings applied via cold spray will augment the commercialisation of critical technologies. This project team combines all the key facets needed to successfully transfer a materials solution out of the lab and into industry, from modeling to production scale up. We look forward to continued project involvement and we are ready to deliver this materials solution at scale to the nuclear industry.”
Cal Poly Pomona Professor Ravi noted that the project covers the full range – materials design, novel coatings development, and environmental stability. He welcomed the opportunity “to evaluate the stability of these novel coatings in molten salt environments through innovative and careful testing protocols accompanied by detailed characterisation”.
This research supports DOE’s clean energy initiative of enabling more efficient electricity generation. Current ASME code-approved materials for metallic nuclear molten salt reactors have adequate temperature and oxidation resistance but lack the required corrosion resistance. As reactors are designed to push efficiency limits, novel materials and processes are necessary to also function in the highly corrosive environment.