Session: MF-05-02 Fitness-For-Service and Failure Assessment-2

Paper Number: 125166

125166 - Statistical Analysis of Multiple Encoded Ultrasonic Testing Data Sets 

Localized corrosion, commonly referred to as “pitting,” in carbon steel piping systems has a significant financial and regulatory impact on commercial nuclear power plants.  Quantifying the level of degradation and identifying locations which may violate the minimum wall thickness requirements or leak is an ongoing task at most, if not all, sites.  Utilizing historic inspection data to predict the current and future state of a piping system is challenging without a robust definition of a pit.  Work has recently been conducted by Parker, Roukema, and Patten to define “pitting” in geometric terms as it relates to localized wall loss due to corrosion in carbon steel piping [Parker et. all, Statistical Analysis of Localized Corrosion in Service Water Piping, PVP2021-61831]. The authors presented a novel approach to identifying the non-uniform pipe wall as a “pit” at discrete locations. As the authors note, the limited data set restricted the applicability of the paper’s conclusions to only the Service Water system for which the data was obtained.

This paper will expand upon the previous work by increasing the number of data sets evaluated and will include additional systems and plants, as well as plants outside of nuclear power generation.  The paper will utilize the same statistical analysis of localized corrosion to identify the number of pits within an encoded ultrasonic thickness data set.  The objective of this paper is to determine if the set of geometric characteristics proposed in the previous work can be reasonably applied to a diverse set of piping systems and/or industries.

Presenting Author: Eric Houston Industrial Inspection & Analysis

Presenting Author Biography: Eric Houston is the Engineering Programs Manager at Industrial Inspection & Analysis (IIA). He works with sections of the ASME Boiler and Pressure Vessel Code in structural analyses of reactor internals, system piping, and tanks. He has experience in operability assessments of pressure boundaries with through-wall or near through-wall flaws as well as design by rule and design by analysis of piping and components.

He previously worked for Applied Technical Services and Structural Integrity Associates and has been supporting the nuclear field for over 15 years.

Authors:

Eric Houston Industrial Inspection & Analysis
Stephen Parker Dominion Engineering, Inc.
Doug Keene Industrial Inspection & Analysis