DETECTING DEVICE FOR LEAKAGE OF FLUID IN NUCLEAR POWER PLANT

摘要

PURPOSE:To enable simple and sure detection of the place of leakage of fluid in a quantity from little to much throughout a plant by using an optical-fiber cable as a detecting element. CONSTITUTION:The optical-fiber cable 10 whose phototransmitting property is deteriorated by radioactive rays is arranged in the piping 1 and the like of the nuclear power plant and one end thereof is provided with a luminous part 20 impressing a light from a fixed light source, while the other end thereof is provided with a light-receiving part 30 receiving a photosignal impressed by the luminous part 20. And the photosignal received is sent to a discriminating device 40 and there the discrimination of the level value of the received photosignal when the deterioration of the transmitting property of the optical-fiber cable 10 continues abruptly and the discrimination of the level value of the received photosignal when the deterioration of the transmitting property continues for a long time, though it is gentle, and thereby the property goes down below a prescribed value are performed respectively, whereby the leakage of cooling material and the like inside the piping 1 is detected.