NONDESTRUCTIVE INSPECTION METHOD IN BOTTOM MIRROR PART OF REACTOR PRESSURE VESSEL

摘要

PROBLEM TO BE SOLVED: To improve an accuracy of inspecting a narrow and complex-shaped welded portion of a bottom mirror part of a reactor pressure vessel to solve the problem wherein it will be difficult to obtain sufficient information for soundness evaluation since a shape of the welded portion to be inspected in the bottom mirror part of the RPV is complicated and the vicinity is narrow to cause inspection conditions to be limited in terms of accessibility and contactability to restrict an inspectable range and accuracy.SOLUTION: In inspecting the reactor pressure vessel (hereinafter referred to as RPV) or an internal structure attached to the RPV, nondestructive inspection is made from two directions including from the inside of the RPV (inside the reactor) and the outside of the RPV (outside the reactor) to determine whether a fault is present, or to measure a size or a range of the fault.