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Structural integrity programs of the United States Air Force (USAF) include periodic inspection to detect damage before it grows to a critical size that can impact the safety of USAF systems. Current inspection methods have been used successfully to ensure the required risk metrics for these systems are being met as mandated by the relevant USAF Standards. However, there is a continual desire to improve the capability of inspection methods while increasing the efficiency and reliability of these methods. As new approaches are being explored for the enhancement of damage sensing, a number of foundational issues that represent hurdles for the application of these enhancements have been identified. This paper provides background of how damage sensing is used by the USAF and expands on identified foundational challenges that represent technical barriers to the implementation of new damage sensing methods. As the desired capability of the damage sensing methods expand from detection of damage to the characterization of damage, the degree of complexity grows and additional challenges emerge. Representative case studies are used to illustrate challenges for detection, localization and characterization of damage. [ABSTRACT FROM AUTHOR]

The Nuclear Regulatory Commission established the Program to Assess the Reliability of Emerging Nondestructive Techniques (PARENT) to follow on from the successful Program for the Inspection of Nickel alloy Components. The goals of PARENT are to conduct a confirmatory assessment of the reliability of nondestructive evaluation (NDE) techniques for detecting and sizing primary water stress corrosion cracks and apply the lessons learned from PINC to a series of round-robin tests. These open and blind round-robin tests will comprise a new set of typical pressure boundary components including dissimilar metal welds and bottom-mounted instrumentation penetrations. Open round-robin tests will engage research and industry teams worldwide to investigate and demonstrate the reliability of emerging NDE techniques to detect and size flaws with a wide range of lengths, depths, orientations, and locations. Blind round-robin tests will utilize various testing organizations, whose inspectors and procedures are certified by the standards for the nuclear industry in their respective countries, to investigate the ability of established NDE techniques to detect and size flaws whose characteristics range from relatively easy to very difficult for detection and sizing. Blind and open round-robin testing started in late 2011 and early 2012, respectively. This paper will present the work scope with reports on progress, NDE methods evaluated, and project timeline for PARENT. [ABSTRACT FROM AUTHOR]

Early demonstrations of the use of models in the U.S. and U.K. to assist in the determination of NDE reliability and probability of detection (POD), as dictated by the advent of damage tolerant design, will be reviewed. A major motivation in the U.S. was the adoption of POD as the primary metric for effectiveness of an inspection and the empirical observation that field and depot inspections were not adequate so support the desired structural integrity. In parallel, a series of round robin trials in Europe raised issues with the effectiveness of nuclear power plant inspections, and the resulting concerns became an important part of the 'Public Inquiry' in the UK regarding the construction of the Sizewell B power plant. In each country, physics-based models of the inspection process became an important part of the response. This paper describes these early developments in the use of models to assess inspection reliability, contrasts the philosophies and approaches taken, and notes how these provide the origins of NDE simulation activities today. [ABSTRACT FROM AUTHOR]