Application of Fiber Bragg Grating Sensor in Nuclear Industry

The nuclear industry is a place with high radiation, and nuclear leakage is a great threat to human beings. The impact of the leakage of the Belgley nuclear power plant has not been eliminated so far, so the safety detection of nuclear power plants is very important. As nuclear installations age, more maintenance and repairs are required, and eventually they must be dismantled, all of which cannot be foreseen at design time, thus requiring more sensors to remotely control the equipment and deal with uncertain situations. At the same time, the management of nuclear waste is becoming more and more important, and a monitoring network is needed to monitor the status of the nuclear waste station, and the requirement for the long-term stability of the monitoring network is unprecedented.

The application prospects of optical fiber sensing technology in nuclear power plants include vibration monitoring of pipelines, strain and temperature monitoring of concrete by using the fbg strain senor and other types of fbg sensors. Optical fiber sensing technology has great advantages and broad application prospects in the field of nuclear power plant safety monitoring.

1. Reliability and safety of fiber grating sensors

The reactor building or shell structure of a nuclear power plant is a very thick steel or reinforced concrete floor and wall designed to be the last protective barrier against nuclear leakage. Telemetry using static distributed fiber grating sensor systems will greatly enhance reliability, safety, and reduce maintenance costs. In 1995, France started a joint program to develop Bragg grating deformation measuring instruments for concrete measurement in nuclear power plants. They installed the fiber grating sensor on the surface of the nuclear shell or buried it in the nuclear shell to monitor the large wall of the high-performance prestressed concrete core shell.

2. The advantages of fiber grating sensors in the nuclear industry

In pressurized water reactor nuclear power plants, water is used to absorb heat but not boil, and because the water is kept at high pressure, pipes and joints will age during the thermo-mechanical cycle, so early leak detection is an important issue. The leakage and rupture of nuclear reactor water pipes are very dangerous, and in extreme cases, the nuclear reactor will melt and cause nuclear leakage. In early 1996, a consortium led by the United Kingdom launched a three-year program to develop a distributed static monitoring system with perfect temperature compensation, which could multiplex multiple fbg temperature sensor for high temperature components (~550 °C) for real-time life prediction. Highly radioactive nuclear waste must be stored underground for long periods of time. Germany will study the use of Bragg grating sensors to monitor strain and temperature in underground nuclear waste dumps.

The safe operation of nuclear power plants is related to the safety of human life and property, and timely grasping the operation status of nuclear power plants is an important prerequisite to ensure the safe operation of nuclear power plants. Fiber Bragg grating sensors have a series of advantages such as anti-electromagnetic interference, intrinsic safety, easy networking, and easy remote and online measurement. They can solve many problems in current nuclear power plant operation monitoring and provide more accurate and reliable data. The application prospects of optical fiber sensing technology in nuclear power plants include vibration monitoring of pipelines, strain and temperature monitoring of concrete by using the fbg strain sensor and other types of fbg sensors. Optical fiber sensing technology has great advantages and broad application prospects in the field of nuclear power plant safety monitoring.