GUIDE FOR UPPER INTERNAL EQUIPMENT WRITING PRESSURIZED WATER TYPE NUCLEAR REACTOR AND METHOD AND APPARATUS FOR INSPECTING DIMENSIONS AND SHAPE OF POSITIONING MEMBER

摘要

PURPOSE: To check the dimensions and the profile of a guide and a positioning member for the upper facility in a reactor by measuring the capacitance between the surface of these member and a measuring means and then measuring the measurements. CONSTITUTION: A guide tube 10 for the upper facility in a reactor has an upper part 10a secured to the top plate 8 of the inner facility and guide cards 14, 15 are contained therein. Each guide card has a central opening 19 and a radial opening 20, 21 wherein the opening 21 is provided with a guide channel 23 for passing a suction rod. A measuring unit 48 comprising a metal plate 50 arranged in a rod 49 of insulating material is set in the channel 23 and the capacitance is measured for a capacitor formed by the plate 50, the inner surface of the channel 23 and water or an air layer filling the channel. Abrasion of the channel can be determined by measuring the variation of capacitance caused by shitting the rod 49 in the axial direction of the channel.