Session: CS-08-01 ASME Code Section XI Activities-1

Paper Number: 121858

121858 - Review of Original Calculations and Pc-Praise Source Code Used to Develop Asme Code Section Xi Appendix L Equivalent Single Crack Tables 

ASME Section XI Appendix L permits the use of flaw tolerance procedures to determine the allowable operating period for operating plant components and piping subjected to cyclic loadings, providing NDE confirms that the location of interest has no flaw larger than allowed by the Acceptance Standards. The flaw tolerance analysis postulates a pre-existing flaw at the location of interest and calculates fatigue crack growth to determine inspection intervals necessary to assure that the fatigue-growing flaw can be detected before it exceeds the allowable size. To account for the possibility of multiple flaws coalescing and forming longer flaws during the fatigue crack growth, the postulated single flaw is assigned with an aspect ratio, known as the ESC (equivalent single crack) aspect ratio, based on the applied loading and material type.

As part of the activities undertaken by the Section XI Task Group on Appendix L, an effort was made to conduct a detailed review of the original calculations performed to develop the Appendix L ESC tables and the pc-PRAISE source code that was used for those calculations. This effort was necessary because the available Appendix L and pc-PRAISE technical basis documents do not contain all the necessary details to reproduce the ESC tables, and there were knowledge gaps that prevented a complete understanding of the original technical basis. This paper documents the review findings and their impacts on calculating ESC so that future improvements to Appendix L can be considered appropriately.

Presenting Author: Steven Xu Kinectrics

Presenting Author Biography: later

Authors:

Steven Xu Kinectrics
Nate Glunt EPRI
Do Jun Shim EPRI
Gary Stevens Consultant
Doug Scarth Kinectrics