Monitoring Sodium Circuits Using Fiber Optic Sensors

Leak detection in the coolant loops of Fast Breeder Reactor (FBR) is critical for the safety of the reactors. This paper discusses the feasibility of using Raman Distributed Temperature Sensor (RDTS) for leak detection in double walled pipelines of primary sodium circuits in FBR. The leak detection is based on the resultant change in temperature due to leak. Since handling sodium is difficult, as a “proof of concept”, leak detection is demonstrated on a test loop with water as the leaking medium. Path delay multiplexing is adopted to improve the spatial resolution from 1.02 m to 0.51 m.