Over the last thirty years, much research has been done on the development and application of failure event databases, NDE databases, and material property databases for pressure vessels and piping, as reported in two recent symposia: (1) ASME 2007 PVP Symposium (in honor of the late Dr. Spencer Bush), San Antonio, Texas, on “Engineering Safety, Applied Mechanics, and Nondestructive Evaluation (NDE).” (2) ASME 2008 PVP Symposium, Chicago, Illinois, on “Failure Prevention via Robust Design and Continuous NDE Monitoring.” The two symposia concluded that those three types of databases, if properly documented and maintained on a worldwide basis, could hold the key to the continued safe and reliable operation of numerous aging nuclear power or petrochemical processing plants. During the 2008 symposium, four uncertainty categories associated with causing uncertainty in fatigue life estimates were identified, namely, (1) Uncertainty-1 in failure event databases, (2) Uncertainty-2 in NDE databases, (3) Uncertainty-3 in material property databases, and (4) Uncertainty-M in crack-growth and damage modeling. In this paper, which is one of a series of four to address all those four uncertainty categories, we address Uncertainty-2 in NDE databases by developing a Web-based Uncertainty Plug-In (WUPI), which automates the uncertainty estimation algorithms of flaw sizing, fracture toughness, and crack growth vs. ΔK data such that NDE data from the field can be acted on by office engineers with a reduced feedback time for maintenance decision making.

Recent advances in computer technology, internet communication networks, and finite element modeling and analysis capability have made it feasible for engineers to accelerate the feedback loop between the field inspectors of a structure or component for critical flaws by nondestructive evaluation (NDE) and the office engineers who do the damage assessment and recommendations for field action to prevent failure. For example, field inspection data of critical flaws can be transmitted to the office instantly via the internet, and the office engineer with a computer database of equipment geometry, material properties, past loading/deformation histories, and potential future loadings, can process the NDE data as input to a damage assessment model to simulate the equipment performance under a variety of loading conditions until its failure. Results of such simulations can be combined with engineering judgment to produce a specific recommendation for field action, which can also be transmitted to the field by the internet. In this paper, we describe a web-based NDE data analysis methodology to estimate the reliability of weld flaw detection, location, and sizing by using a public-domain statistical data analysis software named DATAPLOT and a ten-step sensitivity analysis of NDE data from a two-level fractional factorial orthogonal experimental design. A numerical example using the 1968 ultrasonic examination data of weld seam in PVRC test block 251J, and the 1984 sectioning data of 251J containing 15 implanted flaws, is presented and discussed.

This article will describe the development of Section XI from a pamphlet-sized document to the lengthy and complex set of requirements, interpretations, and Code Cases that it has become by the year 2000. Section XI began as a set of rules for inservice inspection of the primary pressure boundary system of nuclear power plants. It has evolved to include other aspects of maintaining the structural integrity of safety class pressure boundaries. These include procedures for component repair/replacement activities, analysis of revised and new plant operating conditions, and specialized provisions for nondestructive examination of components and piping. It has also increased in scope to cover other Section III construction: Class 2, Class 3 and containment structures. First, to provide a context for the discussions to follow, the differences in administration and enforcement between Section XI and the other Code Sections will be explained, including its dependence on the US Nuclear Regulatory Commission. The importance of interpretations and Code Cases then will be discussed. The development of general requirements and requirements for each class of structure will be traced. The movement of Section XI toward a new philosophy, risk-informed inspection, will also be discussed. Finally, an annotated bibliography of papers describing the philosophy and technical basis behind Section XI will be provided. [S0094-9930(00)01703-0]

Nondestructive examination (NDE) in Section XI of the ASME Boiler and Pressure Vessel Code has been an evolving process. The Code’s use of NDE for in-service inspection (ISI) to establish fitness for duty has brought about major changes in applied NDE philosophy and practice. The publication in Section XI, 1989 Addenda, of mandatory Appendix VIII, “Performance Demonstration for Ultrasonic Examination System,” sets a precedent for both NDE performance and recognition of the total NDE system (personnel, equipment and procedures). This paper highlights appropriate portions of Appendix VIII. Performance values such as probability of detection (POD) and flaw sizing accuracy are addressed. The use of flawed specimens for performance demonstration qualifies personnel, equipment and procedures, hence the “Ultrasonic System” qualification. Appendix VIII provides the opportunity for technique performance demonstration for assessment of material aging and qualification of components and systems for continued service. This article provides the background and justification for Code action to publish Appendix VIII.

Code Case 2235 provides a technical basis for substitution of the ultrasonic method for radiography for examination for acceptance of welds in pressure vessels and piping. This paper first describes the background for the development of UT technique qualification by performance demonstration and the associated fitness-for-service flaw acceptance criteria of Code Case 2235. It then proceeds with review of the ASME and other standards based on the same or similar criteria, and continues with comments on typical examples of subsequent technical papers addressing field applications of Code Case 2235.