Bulk Electrical Cable Non-Destructive Examination Methods for Nuclear Power Plant Cable Aging Management Programs

Technical Report · Thu Sep 01 00:00:00 EDT 2016

DOI:https://doi.org/10.2172/1328060· OSTI ID:1328060

Glass, Samuel W. ^[1]; Jones, Anthony M. ^[1]; Fifield, Leonard S. ^[1]; Hartman, Trenton S. ^[1]

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1. Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

This Pacific Northwest National Laboratory milestone report describes progress to date on the investigation of nondestructive test methods focusing particularly on bulk electrical test methods that provide key indicators of cable aging and damage. The work includes a review of relevant literature as well as hands-on experimental verification of inspection capabilities. As nuclear power plants consider applying for second, or subsequent, license renewal to extend their operating period from 60 years to 80 years, it is important to understand how the materials installed in plant systems and components will age during that time and develop aging management programs to assure continued safe operation under normal and design basis events (DBE). Normal component and system tests typically confirm the cables can perform their normal operational function. The focus of the cable test program, however, is directed toward the more demanding challenge of assuring the cable function under accident or DBE. The industry has adopted 50% elongation at break (EAB) relative to the un-aged cable condition as the acceptability standard. All tests are benchmarked against the cable EAB test. EAB, however, is a destructive test so the test programs must apply an array of other nondestructive examination (NDE) tests to assure or infer the overall set of cable’s system integrity. Assessment of cable integrity is further complicated in many cases by vendor’s use of dissimilar material for jacket and insulation. Frequently the jacket will degrade more rapidly than the underlying insulation. Although this can serve as an early alert to cable damage, direct test of the cable insulation without violating the protective jacket becomes problematic. This report addresses the range of bulk electrical NDE cable tests that are or could be practically implemented in a field-test situation with a particular focus on frequency domain reflectometry (FDR). The FDR test method offers numerous advantages over many other bulk electrical tests. Two commercial FDR systems plus a laboratory vector network analyzer are used to test an array of aged and un-aged cables under identical conditions. Several conclusions are set forth, and a number of knowledge gaps are identified.

• Research Organization: Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC05-76RL01830
• OSTI ID: 1328060
• Report Number(s): PNNL-25634; 830403000; TRN: US1700044
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS
NUCLEAR POWER PLANTS
ELECTRIC CABLES
DECOMPOSITION
SERVICE LIFE
NONDESTRUCTIVE TESTING
JACKETS
MANAGEMENT
FIELD TESTS
DAMAGE
ACCIDENTS
EVALUATION
LIFETIME EXTENSION
INSPECTION
OPERATION
STANDARDS
VERIFICATION
INFORMATION NEEDS
cable NDE
frequency domain reflectometry
cable bulk electrical tests