Non-invasive micromechanical testing for tensile and fracture properties of metallic alloys

The U.S. Nuclear Regulatory Commission (NRC) has licensed commercial nuclear reactors for 40 years [U.S. Energy Information Administration (EIA)]. As the average age of U.S. nuclear reactors is approximately 40 years, 88 of the 93 U.S. reactors have already received approval from the NRC for a 20-year extension, the majority of which will expire in the 2030s. As facilities age and are exposed to radiation, monitoring construction material properties over time becomes critically important to assess strength and durability. Facilities utilize sacrificial material coupons stored within the reactor since the time of installation, which are subject to the same levels of radiation and other stresses as the in-service components. As materials are being rapidly consumed for regular assessment, coupled with additional testing requirements of the NRC license renewal process, it is becoming necessary for facilities to develop alternative testing plans to preserve sacrificial coupons and to explore nondestructive testing (NDT) technologies that allow in-situ testing of materials. Massachusetts Materials Technologies (MMT) has already developed an NDT technology for measuring material toughness properties, in-situ, as alternatives to conventional destructive laboratory testing methods. MMT aims to use the DOE SBIR Phase I funding opportunity to show the feasibility of this technology for testing commonly used materials in the nuclear industry and initiate basic adjustments required on hardware and analytics of our tools to better fit the purpose of testing these new materials that are of higher strength than most material tested to date. Overall, the goal for this project is to introduce a tool that can support material verification and safety regulations, reducing the risk for the crew working and nuclear facilities and the general public.