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| Quarter | Site | Title | Description | |
|---|---|---|---|---|
| 05000368/FIN-2018001-02 | 2018Q1 | Arkansas Nuclear | Failure to Preplan and Perform Service Water Pre-Screen Maintenance | The inspectors reviewed a self-revealed,non-cited violation and associated finding of Arkansas Nuclear One, Unit 2, Technical Specification 6.4.1.a, for the licensees failure to properly preplan maintenance that can affect the performance of safety-related equipment. Specifically, the licensee failed to properly preplan pre-screen cleaning maintenance, causing the trainB service water system to become inoperable |
| 05000382/FIN-2017001-01 | 2017Q1 | Waterford | Failure to Perform Field Changes in Accordance with Design Control Measures | Green . The inspectors reviewed a self -revealed, non-cited violation of 10 CFR Part 50, Appendix B, Criterion III, Design Control, because the licensee failed to perform field changes in accordance with design control measures. Specifically, following maintenance on reactor coolant pump 1B , the licensee performed unauthorized field changes by not reinstalling two design supports for the differential pressure instrument line. As a result, the instrument line developed a vibration- induced fl aw, which caused an increase in reactor coolant system unidentified leakage, and consequently , an unplanned reactor shutdown. The licensee entered this condition into their corrective action program as Condition Report CR- WF3 -2016 -06698. The licensees corrective actions included replacing the damaged instrument line and installing the missing supports. The performance deficiency was more than minor , and therefore a finding, because it affected the equipment performance attribute of the Initiating Events Cornerstone and its objective to limit the likelihood of events that upset plant stability and challenge critical safety functions during shutdown as well as power operations. Specifically, the licensees failure to reinstall the required supports on the reactor coolant pump 1B instrumentation line resulted in plant operation with increased reactor coolant system unidentified leakage, requiring an unplanned reactor shutdown to perform repairs. The inspectors screened the finding in accordance wit h NRC Inspection Manual Chapter 0609, Significance Determination Process . Using Inspection Manual Chapter 0609, Appendix A, The Significance Determination Process (SDP) for Findings At -Power, the inspectors determined that the finding was of very low safety significance (Green) because the instrument line flaw, after a reasonable assessment of degradation, could not result in exceeding the reactor coolant system leak rate for a small loss -of-coolant accident , and could not likely affect other systems used to mitigate a loss-of-coolant accident , resulting in a total loss of their function. Because the licensees review indicated that no work had been performed in this instrument line within the last three years, and a specific date for the performance deficiency was not identified, the inspectors concluded that the finding does not reflect current licensee performance, and therefore, did not assign a cross -cutting aspect . |