05000498/FIN-2012004-01
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Finding | |
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| Title | Inadequate Procedure Results in Stator Cooling Water Coil Damage and Main Generator Trip |
| Description | The inspectors reviewed a self-revealing finding for the failure to follow Procedure 0POP02-GG-0001, Generator Hydrogen and Carbon Dioxide Gas System, Revision 43, for a verified alarm on the Unit 2 main generator. On November 26, 2011, the Unit 2 control room received a stator cooling water differential temperature high alarm. The crew responded by reviewing the annunciator response and determined that none of the parameters for contacting system engineering were reached. On November 27, 2011, the control room received multiple generator condition monitor alarms and determined that the generator condition monitor system was malfunctioning, and generated a condition report. The generator condition monitor began to alarm again, on November 29, 2011, but since the control room thought the system was not functioning properly, they did not perform any of the required actions of Procedure 0POP02-GG-0001. Shortly after the alarms were received, the Unit 2 reactor tripped due to a main generator lockout, documented in Condition Report 11-28753. Corrective actions included: replacing all 72 stator cooling coils, refurbishing the stator and rotor, replacing the hydrogen cooler, revising the procedure, and operations training. This finding was more than minor because it affected the Initiating Events Cornerstone attribute of Procedure Quality and affected the cornerstone objective to limit the likelihood of events that upset plant stability and challenge critical safety functions in that it resulted in a turbine/reactor trip. The inspectors performed the significance determination using NRC Inspection Manual Chapter 0609. Because the finding affected the Initiating Events Cornerstone while the plant was at power, Attachment 0609.04, Initial Characterization of Findings, dated June 19, 2012, evaluates the finding using Appendix A. Using Appendix A, Exhibit 1, Transient Initiators question, the finding was determined to be of very low safety significance because it did not cause a reactor trip and the loss of mitigation equipment. This finding did not have cross-cutting aspects because the generator condition monitor alarm portion of the procedure was last changed in 2005 and this was the last time that could be reasonably viewed to have identified the deficiency and therefore was not indicative of current licensee performance |
| Site: | South Texas  |
|---|---|
| Report | IR 05000498/2012004 Section 4OA2 |
| Date counted | Sep 30, 2012 (2012Q3) |
| Type: | Finding: Green |
| cornerstone | Initiating Events |
| Identified by: | NRC identified |
| Inspection Procedure: | IP 71152 |
| Inspectors (proximate) | J Dixon B Tharakan W Walker J Laughlin N Hernandez J Wingebach |
| INPO aspect | |
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Finding - South Texas - IR 05000498/2012004 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Finding List (South Texas) @ 2012Q3
Self-Identified List (South Texas)
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