Structure for suppressing flow vibration of instrumentation guide tube

Abstract

A structure for suppressing flow vibration of an instrumentation guide tube, the structure being constructed such that an upper hole (37A) and a lower hole (37B) are formed at two upper and lower positions in a side face of the guide tube (27) and that a thimble tube (22) is pressed against the inner peripheral surface of the guide tube (27) by a difference between pressures of a cooling materialin the inside and outside of the upper and lower hole (37A, 37B). Further, the structure desirably has an upper pressure regulation hole and lower pressure regulation hole formed at two upper and lower positions in a side face of an upper reactor core support column (21). The upper and lower pressure regulation holes allow a cooling material, having flown from the upper end of the guide tube intothe guide tube, to flow from the inside to the outside of the guide tube through a gap between the thimble tube and the upper hole, flow from the inside to the outside of the upper reactor core support column through the upper pressure regulating hole, flow from the lower end of the guide tube into the guide tube, flow from the inside to the outside of the guide tube through a gap between the thimble tube and the lower hole, and then flow from the inside to the outside of the upper core reactor support column through the lower pressure regulating hole.

Description

technical field [0001] The present invention relates to a flow vibration suppressing structure of a gauge conduit inserted into a core. Background technique [0002] When a neutron detector is installed in the core of a pressurized water reactor (PWR), the detector is guided into the core through a gauge guide inserted into the core. In addition, as a method of inserting the gauge conduit into the core, the bottom insertion method of inserting the gauge conduit from the bottom to the top of the reactor vessel has been used previously, but in the current technology, the method of inserting the gauge conduit from the top of the reactor vessel to the top is being considered. An upper insertion method that inserts the gauge catheter from below. [0003] Figure 51 It is a schematic diagram showing the insertion state of the gauge catheter when the top insertion method is adopted. Such as Figure 51 As shown, after the gauge conduit 1 is inserted into the reactor vessel from th...

AI Technical Summary

Problems solved by technology

Therefore, the gauge pipe 1 may be repeatedly contacted with the upper core support column 4 and the structure of the core 5, resulting in abrasion.

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