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http://dx.doi.org/10.5516/NET.2008.40.3.239

SURGE LINE STRESS DUE TO THERMAL STRATIFICATION  

Jhung, Myung-Jo (Korea Institute of Nuclear Safety)
Choi, Young-Hwan (Korea Institute of Nuclear Safety)
Publication Information
Nuclear Engineering and Technology / v.40, no.3, 2008 , pp. 239-250 More about this Journal
Abstract
If there is a water flow with a range of temperature inside a pipe, the wanner water tends to float on top of the cooler water because it is lighter, resulting in the upper portion of the pipe being hotter than the lower portion. Under these conditions, such thermal stratification can play an important role in the aging of nuclear power plant piping because of the stress caused by the temperature difference and the cyclic temperature changes. This stress can limit the lifetime of the piping, even leading to penetrating cracks. Investigated in this study is the effect of thermal stratification on the structural integrity of the pressurizer surge line, which is reported to be one of the pipes most severely affected. Finite element models of the surge line are developed using several element types available in a general purpose structural analysis program and stress analyses are performed to determine the response characteristics for the various types of top-to-bottom temperature differentials due to thermal stratification. Fatigue analyses are also performed and an allowable environmental correction factor is suggested.
Keywords
Surge Line; Thermal Stratification; Equivalent Stress; Environmental Fatigue;
Citations & Related Records

Times Cited By Web Of Science : 3  (Related Records In Web of Science)
Times Cited By SCOPUS : 5
연도 인용수 순위
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