The Technical Basis Supporting ASME Code, Section XI, Appendix VIII: Performance Demonstration for Ultrasonic Examination Systems (NUREG/CR-7165)

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Publication Information

Manuscript Completed: November 2012
Date Published: May 2013

Prepared by:
S. R. Doctor, S. E. Cumblidge1, T. T. Taylor, M. T. Anderson

Pacific Northwest National Laboratory
P.O. Box 999
Richland, WA 99352

1U.S. Nuclear Regulatory Commission

Prepared for:
Office of Nuclear Regulatory Research
U.S. Nuclear Regulatory Commission
Washington, DC 20555-0001

W. E. Norris, NRC Project Manager

NRC Job Codes N6398 and V6323

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Ultrasonic inspection requirements specified in the American Society of Mechanical Engineers (ASME) Code, Section XI (ASME 2004) were written in a very prescriptive fashion until an accumulation of field experience in examinations that failed to detect defects in piping and pressure vessels, coupled with evidence from round-robin tests conducted by the Pressure Vessel Research Council, the Programme for the Inspection of Steel Components, and Pacific Northwest National Laboratory, demonstrated that improvements in ultrasonic inspection reliability were needed.

At an October 1984 meeting held between the U.S. Nuclear Regulatory Commission (NRC) and industry in Rockville, Maryland, a draft qualification document was proposed and discussed as the basis for an NRC Regulatory Guide. This meeting resulted in the formation of an ASME Code Ad Hoc Task Group of industry experts charged with developing new Code rules that would improve the reliability of ultrasonic inspection. This Ad Hoc Task Group developed the initial rules that were later documented in Appendix VIII. The rules of Appendix VIII marked a revolutionary change in the conduct of inservice ultrasonic examination requirements for piping and reactor pressure vessels; rather than prescriptive requirements, the Ad Hoc Task Group developed the concept of ultrasonic system qualification through performance demonstration.

This report addresses the technical bases that support the requirements of the performance demonstration specified in the 2007 Edition, 2008 and 2009 Addenda of ASME Boiler and Pressure Vessel Code, Section XI, Appendix VIII. The intent of this report is to provide the reader with an understanding of the technical rationale for the requirements stated in Section XI, Appendix VIII.

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