| 摘要 |
PURPOSE:To cover the detection of leakage radiation over a wide area by detecting the presence of leakage radiation and the kind thereof from the decrease in the intensity of the light transmitted through a quartz optical fiber formed by doping germanium to the core and a quartz optical fiber for which boron is used. CONSTITUTION:The 1st optical fiber F1 doped with germanium and the 2nd optical fiber F2 doped with boron are wound around a nuclear reactor 1. Supposing a nuclear reactor vessel 1 have a hole and radiations leak therethrough, the fibers F1, F2 receive radiation irradiation in some part. The intensity of the transmitted light of the fiber F1 decreases if the radiation is gamma rays. Namely, L1 decreases. The intensity L2 of the light transmitted through the fiber F2 decreases if the radiation is neutron rays. A discriminating circuit 12 displays the values L1, L2, records the same and emits an alarm on detecting of the decrease in the intensities L1, L2 of the transmitted light. |
