Section XI of the ASME code: A new approach to qualifying procedures and personnel

Following the results of numerous programs and trials which measured the effectiveness of the nondestructive examinations required by Section XI of the ASME Code on Nuclear Inservice Inspection of Nuclear Power Plant Components, revisions have been made to the Code to improve the over-all reliability. The results of the round-robin programs designed to measure the reliability of detection and the reliability of correctly sizing the flaws indicated that the rather specific requirements in Section XI did not always achieve the desired results in both heavy section pressure vessel steels, nor in austenitic stainless steel piping welds. One of the two major contributors to the less-than-desired reliability was identified as being the training, understanding and qualification of the personnel; the other was principally due to the fact that the exact methods specified in the Code were not always applicable on every steel or every weld joint configuration. Revisions to the Code were proposed and approved to address these deficiencies, and which revisions have been issued for immediate implementation. The new approach is to permit any procedure or method to be used provided the procedure can be qualified on actual specimens containing the type of flaws to be detected, and following the qualification of the procedure, the personnel must be trained and qualified to obtain a certain level of proficiency using the qualified procedure on actual samples. The qualification of each procedure and each individual is required before examining an actual nuclear plant