Selection of statistical distributions for prediction of steam generator tube degradation

Conference · Thu Dec 31 04:00:00 EST 1992

OSTI ID:48107

Stavropoulos, K D; Gorman, J A ^[1]; Staehle, R W ^[2]; Welty, Jr, C S ^[3]

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1. Dominion Engr., Inc., McLean, VA (United States)
2. Univ. of Minnesota, Minneapolis, MN (United States)
3. Electric Power Research Institute, Palo Alto, CA (United States)

This paper presents the first part of a project directed at developing methods for characterizing and predicting the progression of degradation of PWR steam generator tubes. This first part covers the evaluation of statistical distributions for use in such analyses. The data used in the evaluation of statistical distributions included data for primary water stress corrosion cracking (PWSCC) at roll transitions and U-bends, and intergranular attack/stress corrosion cracking (IGA/SCC) at tube sheet and tube support plate crevices. Laboratory data for PWSCC of reverse U-bends were also used. The review of statistical distributions indicated that the Weibull distribution provides an easy to use and effective method. Another statistical function, the log-normal, was found to provide essentially equivalent results. Two parameter fits, without an initiation time, were found to provide the most reliable predictions.

• OSTI ID: 48107
• Report Number(s): CONF-910808--
• Country of Publication: United States
• Language: English

Related Subjects

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS
36 MATERIALS SCIENCE
FAILURES
INTERGRANULAR CORROSION
PWR TYPE REACTORS
STATISTICAL MODELS
STEAM GENERATORS
STRESS CORROSION
TUBES