05000397/FIN-2015003-01
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Finding | |
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Title | Failure to Maintain Seismic Instrumentation Functional to Alert Plant Operators of Ground Motions Exceeding the Operating Basis Earthquake |
Description | The inspectors identified a finding associated with the licensees failure to maintain seismic instrumentation functional as required by Licensee Controlled Specification 1.3.7.2, Seismic Monitoring Instrumentation. Specifically, because of inadequate calibration procedures, several as-left setpoints for the seismic response spectrum recorders indicating lights were non-conservative relative to their function to alert operators of ground motion exceeding the operating basis earthquake (OBE). Following discovery of this issue, the licensee recalibrated the seismic response spectrum recorders using OBE ground motions as the upper tolerance. The licensee entered this issue into their corrective action program as Action Request 333996. The performance deficiency was more than minor because it affected the configuration control attribute of the Mitigating Systems Cornerstone objective and adversely affected the cornerstone objective to ensure the availability, reliability, and capability of systems that respond to initiating events to prevent undesirable consequences. Specifically, the performance deficiency resulted in seismic instruments calibrations that were nonconservative relative to their function to alert plant operators that a shutdown is required. NRC regulations require a plant shutdown since systems necessary for continued operation without undue risk to the health and safety of the public are not designed to remain functional, in all cases, following an OBE. The inspector performed the initial significance determination using NRC Inspection Manual Chapter 0609, Appendix A, Exhibit 2, Mitigating Systems Screening Questions. The inspectors determined that the finding was of very low safety significance because (1) the finding was not a deficiency affecting the design or qualification of a mitigating system; (2) the finding did not represent a loss of system and/or function; (3) the finding did not represent an actual loss of function of a single train for greater than its technical specification allowed outage time; and (4) the finding does not represent an actual loss of function of one or more non-technical specification trains of equipment designated as high safety-significant in accordance with the licensees maintenance rule program for greater than 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. Additionally, the finding did not involve the loss or degradation of equipment or function specifically designed to mitigate a seismic, flooding, or severe weather initiating event. The finding does not have a cross-cutting aspect since the configuration control error is associated with an instrument setpoint change request from 1990 and therefore not reflective of current licensee performance. |
Site: | Columbia |
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Report | IR 05000397/2015003 Section 1R04 |
Date counted | Sep 30, 2015 (2015Q3) |
Type: | Finding: Green |
cornerstone | Mitigating Systems |
Identified by: | NRC identified |
Inspection Procedure: | IP 71111.04 |
Inspectors (proximate) | C Stott D Bradley J Groom J O'Donnell L Carson M Phalen N Greene R Smith |
INPO aspect | |
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Finding - Columbia - IR 05000397/2015003 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Finding List (Columbia) @ 2015Q3
Self-Identified List (Columbia)
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