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Title: Inspection of Nuclear Power Plant Containment Structures

Safety-related nuclear power plant (NPP) structures are designed to withstand loadings from a number of low-probability external and interval events, such as earthquakes, tornadoes, and loss-of-coolant accidents. Loadings incurred during normal plant operation therefore generally are not significant enough to cause appreciable degradation. However, these structures are susceptible to aging by various processes depending on the operating environment and service conditions. The effects of these processes may accumulate within these structures over time to cause failure under design conditions, or lead to costly repair. In the late 1980s and early 1990s several occurrences of degradation of NPP structures were discovered at various facilities (e.g., corrosion of pressure boundary components, freeze- thaw damage of concrete, and larger than anticipated loss of prestressing force). Despite these degradation occurrences and a trend for an increasing rate of occurrence, in-service inspection of the safety-related structures continued to be performed in a somewhat cursory manner. Starting in 1991, the U.S. Nuclear Regulatory Commission (USNRC) published the first of several new requirements to help ensure that adequate in-service inspection of these structures is performed. Current regulatory in-service inspection requirements are reviewed and a summary of degradation experience presented. Nondestructive examination techniques commonly used to inspect themore » NPP steel and concrete structures to identify and quantify the amount of damage present are reviewed. Finally, areas where nondestructive evaluation techniques require development (i.e., inaccessible portions of the containment pressure boundary, and thick heavily reinforced concrete sections are discussed.« less
Authors:
; ;
Publication Date:
OSTI Identifier:
1762
Report Number(s):
ORNL/CP-100051
41 10 01 06 0; ON: DE00001762
DOE Contract Number:
AC05-96OR22464
Resource Type:
Conference
Resource Relation:
Conference: 7th International Symposium on Current Issues Related to Nuclear Power Plant Structures, Equipment and Piping, Raleigh, NC (USA), December 1-4, 1998
Research Org:
Oak Ridge National Laboratory; Oak Ridge, TN
Sponsoring Org:
USDOE Office of Nuclear Energy, Science and Technology (NE)
Country of Publication:
United States
Language:
English
Subject:
22 NUCLEAR REACTOR TECHNOLOGY; 21 NUCLEAR POWER REACTORS AND ASSOCIATED PLANTS; Nuclear Power Plants; Nuclear Power Plants; Reactor Safety; Reactor Safety; Containment; Containment