05000317/FIN-2013005-01
Finding | |
|---|---|
| Title | Inadequate Emergency and Abnormal Operating Procedures for the Loss of the 21 DC Bus |
| Description | The inspectors identified an NCV of Technical Specification (TS) 5.4.1
Procedures, because Constellation Energy Nuclear Group (CENG) failed to maintai adequate guidance in Emergency Operating Procedure (EOP) 8, Functional Recover Procedure, and/or Abnormal Operating Procedure (AOP) 7J, Loss of 120 Volt Vital Alternating Current (AC) or 125 Volt Vital Direct Current (DC) Power. Specifically, EOP-8 and/or AOP-7J did not contain adequate instructions to cross-tie the 480 volt AC vital buses to restore the 120 volt AC vital buses during a loss of offsite power (LOOP) event concurrent with a single failure of the 21 125 volt DC bus. As a result, the engineered safety features actuation system (ESFAS) and auxiliary feedwater actuation system (AFAS) would inadvertently actuate on both units if the 120 volt AC vital buses were not restored within a specified period of time. CENG staffs immediate corrective actions included entering this issue into their corrective action program (CAP). Corrective actions planned include revising AOP-7J to add in steps to cross-tie the 480 volt AC vital buses. The finding is more than minor because it is associated with the procedure quality attribute of the Initiating Events cornerstone and affected the cornerstone objective to limit the likelihood of events that upset plant stability and challenge critical safety functions during shutdown as well as power operations. Specifically, following a LOOP concurrent with a failure of the 21 DC bus, inadvertent ESFAS and AFAS actuations would occur on both units if power is not restored to the vital 120 volt AC buses. The inspectors evaluated the finding using IMC 0609, Appendix A, The Significance Determination Process for Findings at Power, Exhibit 1, Initiating Events Screening Questions. The inspectors determined that this finding was of very low safety significance (Green) because the finding did not cause a reactor trip and the loss of mitigation equipment relied upon to transition the plant from the onset of the trip to stable shutdown condition. The inspectors determined that this finding did not have cross-cutting aspect because the most significant contributor to the performance deficiency was not reflective of current licensee performance. Specifically, the inspectors determined that this was a legacy procedure issue and did not note any recent reasonable opportunities for CENG personnel to identify this issue. |
| Site: | Calvert Cliffs  |
|---|---|
| Report | IR 05000317/2013005 Section 1R15 |
| Date counted | Dec 31, 2013 (2013Q4) |
| Type: | NCV: Green |
| cornerstone | Initiating Events |
| Identified by: | NRC identified |
| Inspection Procedure: | IP 71111.15 |
| Inspectors (proximate) | D Schroeder E Torres J D'Antonio M Orr P Presby R Rolph S Kennedy |
| Violation of: | Technical Specification - Procedures Technical Specification |
| INPO aspect | |
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Finding - Calvert Cliffs - IR 05000317/2013005 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Finding List (Calvert Cliffs) @ 2013Q4
Self-Identified List (Calvert Cliffs)
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