PROPER UNDERSTANDING OF RELEVANT ARTICLES IN RCC-MAND PANE G-7-002

摘要

The French code, "Design and construction rules for mechanical components of PWR nuclear island" RCC-Mand the Russian code "Regulations for strength analysis of equipment and pipelines of atomic power plants" PANEG-7-002, both for nuke plant design, are sometimes used in China, and discrepancies in understanding somearticles of such foreign design codes will some times give different conclusions as "acceptable" or "unacceptable"the concerned material or product. Section IV of RCC-M concerns with qualification and performance of weldingoperations. Article S 3150 in this section covers the retesting procedures and article S 3152 in it relates todestructive tests. One sentence in Article S 3152 reads like this, "Where an unsatisfactory result is due to the poorexecution of the test or the presence of a defect in the specimen, the relevant result must be discarded and the testshall be repeated." The "presence of a defect" arose discrepancies in understanding the sentence because there isno definition in RCC-M to clarify their scopes such as how big a defect should be considered as a "defect" that caninvalidate the test results. Section 5.5 of PANE G-7-002 concerns the determination of critical brittle temperature.It stipulates that critical brittle temperature TK is a temperature at which the impact strength values must be higherthan the specified ones. The specified criterion values of impact strength are related to the yield strength but it isnot quite definite that the yield strength values in the table should be the documented minimum values fordifferent materials or that they should be the tested results of the concerned lots of materials the specimenrepresents. The two different understandings of the yield strength values will sometimes give contraryconclusions. This paper introduces the different opinions in understanding the code texts, makes clear what itsupports, and states in detail the reasons it so believes.