05000348/FIN-2012003-01
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Finding | |
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Title | Failure to Perform ISI General Visual Examinations of Containment Moisture Barrier Associated with Containment Liner Leak Chase Test Connection Threaded Pipe Plugs |
Description | The inspectors identified a Green non-cited violation of 10 CFR Part 50.55a, Codes and Standards, involving the licensees failure to properly apply Subsection IWE of ASME Section XI for conducting general visual examinations of the metal-to-metal pipe plugs installed in the containment liner channel weld leak chase test connections that provide a moisture barrier to the containment liner seam welds. Following the inspectors identification of this issue, the licensee conducted the visual examinations and found missing covers on two of the leak chase test connection upper cavities. Upon further inspection of both of these leak chase test connections, the licensee found blockages in the test connection piping and significant corrosion of the metal plate making up the upper cavities. The licensee found one leak chase test connection lower cavity to be full of water, which was tested and determined to be borated water. The licensee adequately evaluated the deficiencies prior to entering Mode 4 (Hot Shutdown) to ensure the integrity of containment was maintained. The license conducted the required in-service inspection general visual examinations of the 45 leak chase test connections and found two covers were degraded and two other covers were missing. The licensee conducted further inspections on the two connections that did not have a cover and found, and removed, blockages from both test connections and water from one test connection. The licensee further evaluated these four connections to verify that containment integrity had been maintained and would continue to be maintained through the next operating cycle. The licensee entered this issue into their corrective action program as condition report (CR) 437663. The licensee was evaluating planned corrective actions at the conclusion of this inspection period. The failure to conduct a general visual examination of 100 percent of the moisture barriers intended to prevent intrusion of moisture against inaccessible areas of the containment liner at metal-to-metal interfaces which are not seal welded, was a performance deficiency that was within the licensees ability to foresee and correct. This finding was of more than minor significance because the failure to conduct required visual examinations and identify the degraded moisture barriers which allowed the intrusion of water into the liner leak chase channel, if left uncorrected, would have resulted in more significant corrosion degradation of the containment liner or associated liner welds. The finding was associated with the design control attribute of the Barrier Integrity Cornerstone and affected the cornerstone objective of providing reasonable assurance that physical design barriers protect the public from radionuclide releases caused by accidents or events. Specifically, visual examinations of the containment metal liner provide assurance that the liner remains capable of performing its intended safety function. The inspectors used IMC 0609, Significance Determination Process, Attachment 0609.04, Phase 1 Initial Screening and Characterization of Findings, and determined that the finding was of low safety significance (Green) because it did not represent an actual open pathway in the physical integrity of the reactor containment. The inspectors identified a cross-cutting aspect in the Operating Experience component of the Corrective Action Program (CAP) cross-cutting area (P.2(b)). In their evaluation of the issue, the licensee identified relevant Operating Experience (OE) from four other plants. The inspectors concluded that the licensee did not use this information to make changes in station processes that would implement the ASME Code requirement and would have prevented the intrusion of water into inaccessible containment liner seam welds. |
Site: | Farley ![]() |
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Report | IR 05000348/2012003 Section 1R08 |
Date counted | Jun 30, 2012 (2012Q2) |
Type: | NCV: Green |
cornerstone | Barrier Integrity |
Identified by: | NRC identified |
Inspection Procedure: | IP 71111.08 |
Inspectors (proximate) | E Crowe A Nielsen F Ehrhardt G Kuzo S Sandal B Collins J Sowa C Dykes |
INPO aspect | |
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Finding - Farley - IR 05000348/2012003 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Finding List (Farley) @ 2012Q2
Self-Identified List (Farley)
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