| 摘要 |
PURPOSE:To effect extensive detection of leaking radiant rays from a reactor by simple construction, by irradiating rays of light of 2 kinds and up of wave lengths onto a optical fiber surrounding a radiant ray generator and receiving the incident rays for detecting exposed amount by change of spectroscopic characteristics of transmission loss. CONSTITUTION:An optical fiber coil 2 surrounds the periphery of a reactor vessel 1, etc. and a ray of light from a radiant element 3 with 2 wave lengths and up irradiates onto one end of the optical fiber 2 through an optical connector 4. On the other hand, a ray of light irradiating from the other end of this fiber 2 through the optical connector 5 is divided into 2 sections by a beam splitter 6 and after becoming a ray of different wave length with filters 7, 8, it is received by receiving light elements 9, 10 detecting intensity of light of its wave length. Further, corresponding to change of spectroscopic characteristics of transmission loss of the fiber 2 due to radiant ray exposure, a ratio P1/P2 of the output powers P1, P2 of the elements 9, 10 changes and an exposure amount is detected by a decision circuit 13. With these arrangements, detection of leakage radiant ray of a reactor, etc. can be detected in an extensive range with a simple construction. |
