Progress of the 2000 Addenda of the RSE-M Code in Analytical Evaluation and Acceptance Criteria of Flaws

摘要

The RSE-M Code provides rules and requirements for in-service inspection of Pressurized Water Reactor power plant components. This paper presents the main features of the Code in the field of flaw assessment procedures, comprising fracture mechanics analyses based on engineering methods, flaw acceptance criteria and codification of material characteristics. The Code gives non mandatory guidance for analytical evaluation of flaws. Influence coefficients used to calculate the stress intensity factors in pipes and shells containing semi-elliptical surface defects are given for a wide range of geometrical parameters. Simplified methods to calculate the J integral in a pipe containing a circumferentially oriented surface crack are available for mechanical loads (in-plane bending and torsional moments, pressure, tension), thermal loads as well as for the combination of these loads. The rules that are used to verify the acceptability of flaws in components generally rely on deterministic criteria supposed to ensure the safe operation of plants. Based on a probabilistic calibration methodology, partial safety factors on the main random variables involved in flaw assessments (loading, crack size, yield strength and material toughness) are given for each category of operating conditions (A, C or D) and for the possible failure modes (plastic collapse, ductile tearing or brittle fracture). The Code gives data on the mechanical properties of main base and weld materials used in primary and secondary Systems of the NSSS.