PIPE BASE REPAIR METHOD AND NUCLEAR REACTOR VESSEL

摘要

A pipe base repair method and a nuclear reactor vessel that aim to improve the efficiency of repair work by suppressing the welding area of a pipe base to within a prescribed range, by providing: a step in which a trepanning work section (208) acting as a section for connecting to a furnace internal instrumentation pipe (204) in a groove-welding section (206) is removed; a step in which the furnace internal instrumentation pipe (204) is removed from a hemisphere section (66) acting as a lower plate; a step in which build-up welding is performed on the surface of the groove-welding section (206) and a surface-welded built up section (210) is formed; a step in which the surface-welded built-up section (210) is grooved, and a welding groove section (212) is formed; and a step in which a new furnace internal instrumentation pipe (204A), having a groove section (204f) following the perimeter direction thereof provided on the outside of an instrumentation device guide path (204d), is inserted into an attachment hole (203); and a step in which the welding groove section (212) is groove-welded and the new furnace internal instrumentation pipe (204A) is fixed.