Risk-based inspection in ASME Section XI
By 1970 the first edition of the ASME Code Section XI, Inservice Inspection of Nuclear Reactor Coolant Systems was published. From its inception, the Section XI inservice inspection scope was based on a fundamental risk-based selection process. In other words the inservice inspection scope included components where the consequences of a pressure boundary failure were high. Once the consequence significant system boundaries were established, inspections would then be performed at locations believed to be most susceptible service induced failure. Current Section XI requirements require that inspection locations be selected on the basis of peak stress and fatigue usage values contained in the Design Reports. These original stress calculations were designed to qualify a design and assure that the plant would provide reliable service throughout its design life. For the most part, the fatigue usage values in these reports do not provide an accurate measure of service life. As service history has demonstrated, the use of Design Report stresses and fatigue usage values can be misleading. The Section XI ISI inspection requirements have always been intended to focus inspections at those locations in the plant that pose the greater risk to reactor safety. This fundamental principle behind the Section XI inspection requirements has guided Section XI since its inception. However, today Utility resources are limited. The move in many states to deregulate utilities and growing competition from independent power producers is challenging Owners to reduce operating and maintenance cost without sacrificing safety. These programs should allow plants to focus limited resources on those locations where damage mechanisms are active and consequences are high. This will provide for efficient use of plants resources and improve safety.
- OSTI ID:
- 404251
- Report Number(s):
- CONF-960706-; ISBN 0-7918-1786-5; TRN: 97:000412
- Resource Relation:
- Conference: American Society of Mechanical Engineers (ASME) pressure vessels and piping conference, Montreal (Canada), 21-26 Jul 1996; Other Information: PBD: 1996; Related Information: Is Part Of Pressure vessels and piping codes and standards: Volume 2. PVP-Volume 339; Esselman, T.C. [ed.] [Altran Corp., Boston, MA (United States)]; Balkey, K. [ed.] [Westinghouse Electric Corp., Pittsburgh, PA (United States)]; Chao, K.K.N. [ed.] [Consumers Power Co., Jackson, MI (United States)]; Gosselin, S. [ed.] [Electric Power Research Institute, Charlotte, NC (United States)]; Hollinger, G. [ed.] [Babcock and Wilcox, Barberton, OH (United States)]; Lubin, B.T. [ed.] [ABB Combustion Engineering, Windsor, CT (United States)]; Mohktarain, K. [ed.] [CB and I Technical Services, Plainfield, IL (United States)]; O`Donnell, W. [ed.] [O`Donnell Consulting Engineers, Inc., Pittsburgh, PA (United States)]; Rao, K.R. [ed.] [Entergy Operations, Inc, Jackson, MI (United States)]; PB: 225 p.
- Country of Publication:
- United States
- Language:
- English
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