Allowable Subsurface Flaws Located Near Vessel Surface in JSME Code

Abstract

JSME Code on Fitness-for Service for Nuclear Power Generation Facilities defines allowable subsurface flaws for Class 1 ferritic vessels in the Acceptance Standard. When detected subsurface flaws are located near vessel surface, the subsurface flaws are transformed to be surface flaws for assessment of acceptability in JSME Code. This paper describes inconsistency of the subsurface flaws transforming to surface flaws and introduces an improvement method for the subsurface flaws.