The inspectors identified a Green NCV of Title 10 of the10 CFR Part 50.55a, Codes and Standards, involving the licensees failure to properly apply Subsection IWE of American Society of Mechanical Engineers, Section XI, for conducting general visual examinations of the metal-to-metal pipe plugs of the leak-chase channel test connections, installed inside the access box, that provide a moisture barrier to the basemat containment liner seam welds. Following the inspectors identification of this issue, the licensee initiated actions to conduct the required inservice inspection (ISI) general visual examinations. Inspection of the access boxes and leak-chase channels revealed the presence of standing water as well as general corrosion in both locations. The licensee took actions to remove the water and evaluate the condition of the applicable structure, system, and components to verify that containment integrity had been maintained, and would continue to be maintained through the expected life of the plant. The licensee updated the ISI plan such that the required inspections will be performed in the future. The inspectors determined that the licensee had taken adequate immediate corrective actions to address the deficiencies identified, and to ensure the leak-tight integrity of the containment. The issue was entered into the licensees corrective action program (CAP) as Condition Report 1092415. This performance deficiency 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 Inspection Manual Chapter 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.
Failure to Perform ISI General Visual Examination of Containment Moisture Barrier Associated with Containment Liner Leak-chase Test Connection Threaded Pipe Plugs
05000390/FIN-2015004-01
IR 05000390/2015004
≤31 December 2015 ≥31 December 2015
≤31 March 2015 ≥31 March 2015
~IR 05000390/2015000
~IR 05000390/2015001
~IR 05000390/2015002
~IR 05000390/2015003
~IR 05000390/2015004
~IR 05000390/2015005
~IR 05000390/2015007
~IR 05000390/2015009
~IR 05000390/2015010
~IR 05000390/2015301
~IR 05000390/2015403
~IR 05000390/2015404
~IR 05000390/2015405
~IR 05000390/2015406
~IR 05000390/2015407
~IR 05000390/2015408
~IR 05000390/2015410
~IR 05000390/2015502
~IR 05000390/2015602
~IR 05000390/2015603
~IR 05000390/2015604
~IR 05000390/2015605
~IR 05000390/2015608
~IR 05000390/2015609
~IR 05000390/2015610
~IR 05000390/2015611
~IR 05000390/2015613
~IR 05000390/2015614
~IR 05000390/2015615
~IR 05000390/2015616
~IR 05000391/2015601
~IR 05000391/2015602
~IR 05000391/2015603
~IR 05000391/2015604
~IR 05000391/2015605
~IR 05000391/2015606
~IR 05000391/2015607
~IR 05000391/2015609
~IR 05000391/2015610
~IR 05000391/2015611
~IR 05000391/2015613
Watts Bar 2015
!Licensee-identified ≥1 January 2015 Watts Bar ≤31 December 2015 23:59:59
Licensee-identified ≥1 January 2015 Watts Bar ≤31 December 2015 23:59:59
Watts Bar