Application of a Raman distributed temperature sensor to the experimental fast reactor JOYO with correction techniques

In order to apply a Raman distributed temperature sensor (RDTS) to the moni toring of nuclear facilities, some correction techniques for radiation-indu ced errors were developed and investigated. One is a simple correction tech nique with two thermocouples, when uniform radiation-induced loss distribut ion can be assumed. The other is a special technique with a loop-type arran gement. In this technique, even when the loss distribution is not uniform, radiation-induced errors can be cancelled. To demonstrate these techniques, RDTS has been installed at the experimenta l fast reactor JOYO. During continuous measurements with a total dose of mo re than 7.7 x 10(3) C kg(-1) (3.0 x 10(7) R), the radiation-induced error s howed a tendency to saturate and the feasibility of the correction techniqu es was demonstrated. These results show that RDTS could be useful as a temp erature distribution monitor in nuclear plants.