NOZZLE REPAIR METHOD AND NUCLEAR REACTOR VESSEL

摘要

A nozzle repair method and a nuclear reactor vessel include: removing a trepanning portion (208) as a connection portion with respect to an in-core instrumentation cylinder (204) in a groove-welding portion (206); removing the in-core instrumentation cylinder (204) from a lower end plate (66); forming a plug attachment opening (211) by removing the groove-welding portion (206); applying a pressing load to the lower end plate (66) by attaching a plug (212) to the plug attachment opening (211); and welding and fixing the plug (212) attached to the plug attachment opening (211). Accordingly, since a repair is easily performed, it is possible to improve the workability and to decrease a repair cost.

主权项

1. A nozzle repair method for an instrumentation nozzle in which an in-core instrumentation cylinder is inserted into an attachment hole formed in a semi-spherical portion of a nuclear reactor vessel and the inner surface side of the semi-spherical portion is groove-welded so as to fix the in-core instrumentation cylinder, the nozzle repair method comprising:
removing a connection portion with respect to the in-core instrumentation cylinder in a groove-welding portion; removing the in-core instrumentation cylinder from the semi-spherical portion; forming a plug attachment portion by removing the groove-welding portion; applying a pressing load to the semi-spherical portion by attaching a plug to the plug attachment portion; and welding and fixing the plug attached to the plug attachment portion.