Optical fiber temperature/radiation measuring device

The present invention provides a temperature/radiation measuring device suitable to be disposed to a pipeline system in a reactor container. Namely, scintillation light by radiation rays is discriminated by way of both ends of a radiation optical fiber. A calculation means determines the difference between reaching time of each of discriminated scintillation light and determines the incident position of the radiation and the radiation intensity in the radiation optical fiber based on the calculated time difference. On the other hand, temperature is determined based on the ratio of the intensity of each of discriminated Stokes light and anti-Stokes light, and position of temperature in the optical fiber is determined based on the pulse generation time and the difference between the Stokes light and anti-Stokes light. With such a constitution, both of radiation and temperature can be measured simultaneously reliably. As a result, it is no more necessary to prepare measuring devices for radiation and temperature separately. (I.S.)