Sensors for Next-Generation Nuclear Plants: Fiber-Optic and Wireless

Abstract

Because fourth-generation (Generation IV) reactors will operate at coolant temperatures three or four times higher than light water reactors, up to ~1000°C, they will require instrumentation and control sensors that have been qualified for these new and extreme environmental conditions. In the next 10 to 15 years, advances in sensors and transmitters for nuclear power plants (NPPs) are expected to include fiber-optic and wireless sensors. Three fiber-optic sensing technologies - single-point interferometry, distributed fiber Bragg grating, and optical counter and encoder techniques - most closely replace the functionality of the largest market fraction of conventional non-fiber-optic instrumentation currently installed in NPPs. The qualification of fiber-optic sensors for next-generation NPPs must address concerns over radiation darkening. Wireless sensor networks, typically built on the American National Standards Institute (ANSI)/Institute of Electrical and Electronics Engineers (IEEE) ANSI/IEEE 802.11 or ANSI/IEEE 802.15.4 standards, provide NPPs with the capability to employ distributed processing, thereby increasing overall system redundancy and the potential to reduce hands-on maintenance and to improve reliability. Qualification of wireless sensors for NPPs must address concerns over security, reliability, and electromagnetic interference and radio-frequency interference. An appropriate industry standard should resolve all these concerns.