36q: Scaled Reduced Mode Sapphire Fiber Production Towards High Temperature Radiation Resilient Sensors

Statement of the problem or situation that is being addressed:
Continued use of nuclear power is critical to meeting carbon emission goals and ensuring national security. Nuclear power production will rely on both current generation (LWR and PWR) as well as next generation designs including the very-high-temperature reactor, lead-cooled fast reactor, molten-salt reactor, supercritical-water-cooled reactor, and sodium-cooled fast reactor. The development and deployment of these high temperature and harsh environment reactors will require advanced sensors capable of operating in these environments.
General statement of how this problem is being addressed:
Among Luna’s core Fiber Optic Sensing (FOS) technologies is Optical Frequency Domain Reflectometry (OFDR) utilizing the Rayleigh backscatter and Fiber Bragg Gratings within optical fiber to make temperature measurements. Recently Dr. Thomas Blue’s research group at The Ohio State University developed a method for producing reduced mode sapphire fiber (RMSF) an enabling technology for ultra high-temperature FOS using OFDR, in excess of 1700°C. The combination of these technologies with Type-II Fiber Bragg Gratings has already proven high density fiber optic sensors that can operate at temperatures in excess of 1500°C and in high radiation environments. The proposed program looks to advance manufacturing methods to reduce production costs by an order of magnitude. The sensors developed in this program will ultimately be packaged into a deployable unit that can be installed into test, research, and commercial reactor facilities. This technology will provide for methods of measuring temperature, strain, and pressure in high radiation environments with temperatures in excess of 1700°C.
Phase I activity:
During the Phase I effort, Luna will build on the success of earlier work. The key Phase I efforts will prove advance manufacturing through put while reducing costs. Throughout the Phase I effort, Luna will stay in contact with its industry partners towards defining and developing a final deployment package that best meets the needs of our future customers.
Commercial applications and other benefits
High temperature (1700°C+) RMSF utilizing Distributed High Definition Fiber Optic Sensing (HD-FOS) will enable safe operation of high temperature Gen-IV reactor designs, and provide many measurement points along a single fiber, reducing the number of required reactor vessel penetrations. Since the radiation tolerant developed sensors will also be high-temperature capable, they will also find application in rocket engine monitoring, rocket engine development, gas and coal power plants, solar salt power plants, and in gas turbine health monitoring.