Abstract
A lot of thermometers are used for monitoring the fluid and reactive conditions in thermal and nuclear power plants. From the experience of failure of the thermometer well due to flow-induced vibration in fast breeder reactor "MONJU" JSME proposed the guideline for the flow-induced vibration of a cylindrical structure. Its applicable scope is limited in structures subjected to homogeneous and cross flow. In some case of monitoring of reaction in pressure vessel, thermometer wells are installed downstream bend pipe and subjected to complicated flow. In the present study, the structural integrity of the thermometer well installed in pressure vessel was evaluated through scale tests with respect to flow-induced vibration. Lock in synchronization would not occur for the thermometer well. The predictable maximum fluctuating stresses induced by the turbulence and the Karman vortex shedding were bellow 1MPa and was satisfied the allowable level of fatigue limit.
