My first special inspection
got four green findings and a white finding…
My second got three green
findings plus another white findings.
Why do I feel like these findings were selectively chosen.
February 16, 2016
EA-15-140
Dear Mr. Olson:On March 24, 2015, the U.S. Nuclear Regulatory Commission (NRC) completed its initial assessment of the circumstances surrounding a loss of control building ventilation, which occurred on March 9, 2015, at the River Bend Station. Based upon the risk and deterministic criteria specified in NRC Management Directive 8.3, “NRC Incident Investigation Program,” the NRC initiated a special inspection in accordance with Inspection Procedure 93812, “Special
Inspection.” The basis for initiating the special inspection and the focus areas for review are detailed in the Special Inspection Charter (Attachment 2 of the enclosed inspection report). Based on this initial assessment, the NRC sent an inspection team to your site on March 30, 2015.
On January 20, 2016, the NRC completed its special inspection. The enclosed report documents the inspection findings that were discussed on January 20, 2016, with Mr. Dean Burnett, Acting Director, Regulatory and Performance Improvement, and other members of your staff. The team documented the results of this inspection in the enclosed inspection report. The enclosed inspection report documents a finding that has preliminarily been determined to be White, a finding with low to moderate safety significance that may require additional NRC inspections, regulatory actions, and oversight. As described in Section 2.6.a of the enclosed report, the team identified an apparent violation for a failure to adequately assess the increase in risk of operating the control building chilled water system chillers in various single-failure vulnerable configurations. As a result of this deficiency, the station reduced the reliability and availability of systems contained in the main control room and failed to account for the significant, uncompensated impairment of the safety functions of the associated systems.
***TBD. The NRC identified an apparent violation of 10 CFR 50.65, “Requirements for Monitoring the Effectiveness of Maintenance at Nuclear Power Plants,” paragraph (a)(4) with preliminary white significance.
Prior to March 30, 2015, before performing maintenance activities, the licensee failed to adequately assess the increase in risk that may result from proposed maintenance activities. Specifically, the risk assessment performed by the licensee for plant maintenance failed to account for certain safety significant structures, systems, and components that were concurrently out of service. On multiple occasions, the licensee failed to adequately assess the risk of operating the control building chilled water system (HVK) chillers in various single failure vulnerable configurations. As a result of this deficiency, the station reduced the reliability and availability of systems contained in the main control room and failed to account for the significant, uncompensated impairment of the safety functions of the associated systems. In response to the NRC’s conclusions, the licensee initiated Condition Report CR-RBS-2016-00095. The licensee also completed engineering analyses to evaluate alternate cooling methods, including cross-connecting service water and the HVK chiller systems, in order to provide cooling to spaces housing electrical components.
***Green. The team reviewed a self-revealing non-cited violation of 10 CFR Part 50, Appendix B, Criterion XVI, “Corrective Action,” for the licensee’s failure to promptly identify and correct a condition adverse to quality related to Masterpact circuit breakers. Specifically, the licensee did not promptly identify and correct a Masterpact breaker failure mechanism, even though related industry operating experience was available. The licensee determined the failure mechanism caused nine breaker failures since 2007, and may have contributed to an additional six failures where the cause was not conclusively determined. In response to the NRC’s conclusions, the licensee initiated Condition Report CR-RBS- 2015-03951. Further, the licensee modified all vulnerable Masterpact circuit breakers to remove this failure mechanism.
***Green. The team identified a non-cited violation of 10 CFR Part 50, Appendix B, Criterion V, “Instructions, Procedures, and Drawings,” for the licensee’s failure to accomplish an operability determination in accordance with procedure EN-OP-104, “Operability Determination Process,” Revision 8. Specifically, the licensee referenced non-conservative data, contrary to steps 5.5 and 5.11 of procedure EN-OP-104, when assessing the reduced reliability of Masterpact circuit breakers as a degraded or nonconforming condition. The licensee restored compliance by completing a design modification to eliminate the failure mode and initiated Condition Report CR-RBS-2015-03952.
