In-Situ Mechanical Characterization of Refractory Materials up to 1600??C for Gen-IV Reactors using Sapphire Fiber Optic Sensors

Nuclear energy is widely held as being the only viable source of abundant, CO2 emissions-free electrical energy meeting projected needs in the near term. The primary challenges associated with emerging Very High Temperature Reactors (VHTR) stem from their extremely high operating temperatures, especially during accident conditions. This environment has necessitated new material systems to be developed for most of the core construction. There currently exists no method to directly measure structural changes, in situ, in the refractory materials used. This capability is needed for safety to ensure the integrity of core structural components. In order to meet these challenges, extremely high-temperature sensors must be developed. Lambda Instruments, Inc. proposes to develop extremely high-temperature, radiation-hardened fiber optic strain sensors based on their unique sapphire waveguide technology. Sapphire is an inherently high-temperature material and has been shown to retain acceptable transmission properties in moderate radiation environments. Lambda Instruments has developed sapphire fiber-based optical sensors and has demonstrated strain sensors operating up to 1200