ML14220A364

LER 14-002-00 for Calvert Cliffs, Unit 2 Diesel Generator Technical Specification Surveillance Requirement Missed Due to Human Performance Error

ML14220A364
Person / Time
Site:	Calvert Cliffs
Issue date:	08/07/2014
From:	Flaherty M D Exelon Generation Co
To:	Document Control Desk, NRC Region 1
References
LER 14-002-00
Download: ML14220A364 (7)

Text

7Mark FlahertyExelon Generation Plant ManagerCalvert Cliffs Nuclear Power Plant1650 Calvert Cliffs ParkwayLusby, MD 20657410 495 5205 Office443-534-5475 Mobilewww.exeloncorp.commark.flaherty@exeloncorp.com10 CFR 50.73August 7, 2014U.S. Nuclear Regulatory CommissionATTN: Document Control DeskWashington, DC 20555Calvert Cliffs Nuclear Power Plant, Unit No. 2Renewed Facility Operating License No. DPR-69NRC Docket No. 50-318

Subject:

Licensee Event Report 2014-002, Revision 00Diesel Generator Technical Specification Surveillance Requirement Missed Dueto Human Performance ErrorThe attached report is being sent to you as required by 10 CFR 50.73.There are no regulatory commitments contained in this correspondence.Should you have questions regarding this report, please contact Mr. Douglas E. Lauver at(410) 495-5219.Respectfully,Mark D. FlahertyPlant ManagerMDF/SMR/bjd

Attachment:

As statedcc: NRC Project Manager, Calvert Cliffs NRC Resident Inspector, Calvert CliffsNRC Regional Administrator, Region I S. Gray, MD-DNR RC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY 0MB: NO. 3150-0104 EXPIRES: 01/31/2017(02-2014)Estimated burden per response to comply with this mandatory collectionrequest: 80 hours9.259259e-4 days <br />0.0222 hours <br />1.322751e-4 weeks <br />3.044e-5 months <br />. Reported lessons learned are incorporated into thelicensing process and fed back to industry. Send comments regarding burdenestimate to the FOIA, Privacy and Information Collections Branch (T-5 F53),LICENSEE EVENT REPORT (LER) U.S. Nuclear Regulatory Commission, Washington, DC 20555-0001, or byintemet e-mail to Intocollects.Resource@nrc.gov, and to the Desk Officer,Office of Information and Regulatory Affairs, NEOB-10202, (3150-0104), Office2for required number of of Management and Budget, Washington, DC 20503. If a means used to(See Page 2 fimpose an information collection does not display a currently valid OMBdigits/characters for each block) control number, the NRC may not conduct or sponsor, and a person is notrequired to respond to, the information collection.1. FACILITY NAME 2. DOCKET NUMBER 3. PAGECalvert Cliffs Nuclear Power Plant, Unit 2 05000 318 1 OF 64. TITLEDiesel Generator Technical Specification Surveillance Requirement Missed Due to Human PerformanceError5. EVENT DATE 6. LER NUMBER 7. REPORT DATE 8. OTHER FACILITIES INVOLVEDMONTH DAY YEAR YEAR SEQUENTIAL REV MONTH FACILITY NAME DOCKET NUMBERNUMBER NO.I 05000FACILITY NAME DOCKET NUMBER06 09 2014 2014 -002 -00 08 07 2014 050009. OPERATING MODE 11. THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR§: (Check all that apply)El 20.2201(b) El 20.2203(a)(3)(i) [I 50.73(a)(2)(i)(C) El 50.73(a)(2)(vii)El 20.2201(d) El 20.2203(a)(3)(ii) [I 50.73(a)(2)(ii)(A) [I 50.73(a)(2)(viii)(A)El 20.2203(a)(1) El 20.2203(a)(4) El 50.73(a)(2)(ii)(B) El 50.73(a)(2)(viii)(B)El 20.2203(a)(2)(i) El 50.36(c)(1)(i)(A) El 50.73(a)(2)(iii) [I 50.73(a)(2)(ix)(A)10. POWER LEVEL El 20.2203(a)(2)(ii) El 50.36(c)(1)(ii)(A) El 50.73(a)(2)(iv)(A) [I 50.73(a)(2)(x)[I 20.2203(a)(2)(iii) El 50.36(c)(2) El 50.73(a)(2)(v)(A) E3 73.71(a)(4)100 El 20.2203(a)(2)(iv) [I 50.46(a)(3)(ii) El 50.73(a)(2)(v)(B) El 73.71(a)(5)El 20.2203(a)(2)(v) [I 50.73(a)(2)(i)(A) El 50.73(a)(2)(v)(C) El 50.73(a)(2)(vii)El 20.2203(a)(2)(vi) 0 50.73(a)(2)(i)(B) El 50.73(a)(2)(v)(D) Specify in Abstract belowor in NRC Form 366A12. LICENSEE CONTACT FOR THIS LERFACILITY NAME TELEPHONE NUMBER (include Area Code)S.M. Reichard, Engineering Analyst 410-495-364813. COMPLETE ONE LINE FOR EACH COMPONENT FAILURE DESCRIBED IN THIS REPORTSYSTEM MANU- REPORTABLE II CAUSE SYSTEM COMPONENT MANU- REPORTABLEFACTURER TO EPIX FACTURER TO EPIXA EK DG F010 Y 114. SUPPLEMENTAL REPORT EXPECTED 15. EXPECTED MONTH DAY YEARSUBMISSIONEl YES (If yes, complete 15. EXPECTED SUBMISSION DATE) Z NO DATEABSTRACT (Limit to 1400 spaces, i.e., approximately 15 single-spaced typewritten lines)On June 9, 2014 at 1735, a 2A diesel generator field flash monitoring relay alarm was receivedin the Control Room. Investigation revealed no local alarms and no conditions consistent withan alarm condition existed. The Control Room alarm manual was referenced but criticalinformation was missed. Following investigation by the Operations crew, a determination wasmade that the issue did not impact diesel generator operability based on proper indications andsatisfactory status of standby systems for the diesel generator. Troubleshooting on June 11,2014 determined that a field flash fuse clip was loose, rendering the diesel generatorinoperable. Initial Technical Specification Condition 3.8.1..B which requires one hour Actions,and subsequent Technical Specification Condition 3.8.1 .J to be in Mode 3 in six hours wasmissed due to the late identification of the diesel generator inoperability. The apparent cause ofthis event is human performance error. Corrective actions include operator training focused onunderstanding the causes of the degraded condition and validation of indications for potentialinoperability and updating specific guidance for diesel generator alarms.

NFIRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSI APPROVED BY 0MB: NO. 3150-0104 EXPIRES: 01/31/20(01-2014)Estimated burden per response to comply with this mandatory collectionrequest: 80 hours9.259259e-4 days <br />0.0222 hours <br />1.322751e-4 weeks <br />3.044e-5 months <br />. Reported lessons learned are incorporated into thelicensing process and fed back to industry. Send comments regardingburden estimate to the FOIA, Privacy and Information Collections BranchLICENSEE EVENT REPORT (LER) (T-5 F53), U.S. Nuclear Regulatory Commission, Washington, DC 20555-0001, or by internet e-mail to Infocollects.Resource@nrc.gov, and to theCONTINUATION SHEET Desk Officer, Office of Information and Regulatory Affairs, NEOB-10202,(3150-0104), Office of Management and Budget, Washington, DC 20503. Ifa means used to impose an information collection does not display acurrently valid 0MB control number, the NRC may not conduct or sponsor,and a person is not required to respond to, the information collection.1. FACILITY NAME 2. DOCKET 6. LER NUMBER 3. PAGESEQUENTIAL I REVYEAR NUMBER NO.Calvert Cliffs Nuclear Power Plant, Unit 2 05000 318 2014 -- 002 -- 00 2 of 6NARRATIVEI. DESCRIPTION OF EVENT:A. INITIAL CONDITIONS:Unit 2 was operating in Mode 1 on June 11, 2014 prior to the event.B. EVENT:On June 9, 2014 at 1735, the 2A Diesel Generator (DG) field flash monitoring relay alarmed inthe Control Room. The Control Room licensed operator dispatched the outside operator todetermine the cause of the alarm. Local investigation revealed no alarms and no conditions orparameters consistent with an alarm condition. The outside operator checked the AlarmResponse Manual and notified the Control Room Supervisor (CRS) and Shift Manager of anaction in the alarm manual which required Operations staff to contact electrical maintenance.During shift turnover to the nightshift Operations crew, the Alarm Response Manual action tocontact electrical maintenance was delayed pending an investigation by Operations personnel.The Operations crew conducted a detailed investigation and concluded that the issue was mostlikely an alarm card that did not impact the DG's operability. Based on this conclusion, it wasdetermined by the Operations crew that Electrical Maintenance did not need to be immediatelycontacted to begin troubleshooting. The oncoming dayshift Operations crew contacted theElectrical Maintenance department and troubleshooting of the circuit began on June 10, 2014.On June 11, 2014 at 1035, it was determined by the Electrical Maintenance technicians that thealarm was caused by a loose fuse clip, which made the 2A DG inoperable due to the inability toflash the generator field. The fuse clip was adjusted and the 2A DG was tested to re-establishoperability on June 11, 2014 at 1632.C. INOPERABLE STRUCTURES, COMPONENTS, OR SYSTEMS THAT CONTRIBUTEDTO THE EVENT:There were no structures, components, or systems inoperable at the start of the event thatcontributed to the event.D. DATES AND APPROXIMATE TIMES OF MAJOR OCCURRENCES:June 9, 2014, 1735: An unexpected alarm (1C20A AA01) for the 2A DG was received in thecontrol room.June 9, 2014, 1830: Operations crew conducted the shift turnover meeting. It was determinedto delay contacting Electrical Maintenance pending Operations investigation of the alarm.

NRC FORM 366A U.S. NUCLEAR REGULATORY COMMISSION(01.2014) LICENSEE EVENT REPORT (LER)CONTINUATION SHEET1. FACILITY NAME 2. DOCKET 6. LER NUMBER 3. PAGESEQUENTIAL REVYEAR NUMBER NO.Calvert Cliffs Nuclear Power Plant, Unit 2 05000 318 2014 -- 002 -- 00 3 of 6NARRATIVEJune 9, 2014, 1915: The Operations Work Coordinator (OWC) investigated the alarm,performs intrusive panel inspections, references prints, verifies relays to be in their proper state,diesel and auxiliaries are walked down and found to be satisfactory. Findings were reported tothe CRS.June 9, 2014, 2126: The CRS determined the 2A D.G to be operable. The Shift Manageragreed with the determination. Electrical Maintenance is not contacted until morning since thebelief was that the issue is related to alarm circuit based on investigation.June 10, 2014, 0830: Troubleshooting by Electrical Maintenance technicians began andconcluded that there were no issues present in the annunciation circuitry in the Control Room.June 10, 2014, 1100: The control fuse relays were inspected. It was found that the 2A DGalarm would clear by opening the affected cabinet door containing the control power fuses andalarm relays in the 2A DG room.June 10, 2014, 1130-1500: A troubleshooting plan was developed to determine the cause ofthe alarm issue and the troubleshooting plan was implemented.June 11, 2014, 0930: The system engineer reviewed the schematic prints and notified the OWCand the Shift Manager that the source of the alarm could be caused by a condition whichrenders the 2A DG inoperable.June 11, 2014,1022: Operations declares the 2A DG inoperable and enters TechnicalSpecification (TS) Condition 3.8.1..B while further troubleshooting is performed. Thetroubleshooting was focused on CF-5 (field flash and alarm circuit) and CF-6 (control power).The inoperability of the 2A DG was confirmed due to the likely inability of the 2A DG to flash itsfield during a start demand.June 11, 2014, 1035: Electrical Maintenance personnel notified the Control Room Operatorsthat the F5 fuse clip was loose, thus the diesel would not flash its field, verifying that the 2A DGwas inoperable and that the condition would cause an alarm in the Control Room with no localalarms present.June 11, 2014, 1408: Troubleshooting and repair of the F-5 fuse clip was completedsatisfactorily.June 11, 2014, 1632: A one hour loaded run of the 2A DG was completed. Operationsdeclared the 2A DG operable and exited TS Required Action 3.8.1 .B.E. FAILURE MODES:The significance of the event was that the 2A DG was inoperable as a result of the loose F-5fuse clip and was unable to perform its design function of automatic starting and loading on to21 4 kV Bus (the loose F-5 fuse clip would prevent flashing of the generator field). The involved NRC FORM 366A U.S. NUCLEAR REGULATORY COMMISSION(01-2014) LICENSEE EVENT REPORT (LER)CONTINUATION SHEET1. FACILITY NAME 2. DOCKET 6. LER NUMBER 3. PAGESEQUENTIAL REVYEAR NUMBER NO.Calvert Cliffs Nuclear Power Plant, Unit 2 05000 318 2014 -- 002 -- 00 4 of 6NARRATIVEOperations crews did not aggressively pursue the anomalous alarm to identify the cause,missing an opportunity to determine the true status of 2A DG operability earlier than June 11,2014.The 2A DG alarm for loss of control power came in on June 9, 2014 at 1735. The field flashfuse clip for fuse F5 was found to be loose during troubleshooting on June 11, 2014. The causeof the loose fuse clip was determined to be inadequate installation of the fuse. The loose fuseclip would have prevented flashing of the generator field and automatically starting.No additional systems or secondary functions were affected.The Control Room alarm identifying the probable time of DG failure occurred on June 9, 2014 at1735. The 2A DG was restored to service on June 11, 2014 at 1632. This results in aninoperability time of 46 hours5.324074e-4 days <br />0.0128 hours <br />7.60582e-5 weeks <br />1.7503e-5 months <br /> and 57 minutes.F. METHOD OF DISCOVERY:During troubleshooting, the control fuse relays were inspected and it was found that the 2A DGalarm cleared by opening the affected cabinet door containing the control power fuses andalarm relays in the 2A DG room. Further troubleshooting determined that the F5 fuse clip wasloose and the DG would not flash its field, verifying that the 2A DG was inoperable and that thecondition would cause an alarm with no local alarms present.I1. CAUSE OF EVENT:When faced with an unknown condition of the 2A DG (alarm present in the Control Room withno local alarms), the Operations staff reasoned that the most likely cause was an annunciationproblem. The Operations staff incorrectly determined that the 2A DG was operable based onthe indications available and the results of the Operations crew investigation without recognizingthe consequences of the unknown cause of the alarm. This is the apparent cause of the event.Contributing to the event, the Alarm Response Manual guidance was not strict enough toensure a clear understanding of the impact to DG operability.A. SAFETY CONSEQUENCES:There were no automatic or manually initiated safety system responses.The DGs provide onsite electrical power to safety-related plant systems in the event that offsiteelectrical power is interrupted. Calvert Cliffs Unit 2 has two safety-related DGs, 2A and 2B.Calvert Cliffs also has a non-safety-related DG that can be manually aligned to either of theUnit 2 safety-related 4 kV busses that are served by the 2A and 2B DGs.This event did not result in any actual nuclear safety consequences. The potentialconsequence was to have a DG inoperable without recognizing it during a design basis eventwith a loss of offsite power. This event was reviewed for potential probabilistic risk assessment NRC FORM 366A U.S. NUCLEAR REGULATORY COMMISSION(01-2014) LICENSEE EVENT REPORT (LER)CONTINUATION SHEET1. FACILITY NAME 2. DOCKET 6. LER NUMBER 3. PAGEI SEQUENTIAL I REVYEAR NUMBER NO.Calvert Cliffs Nuclear Power Plant, Unit 2 05000 318 2014 -- 002 -- 00 5 of 6NARRATIVEimpact. The Nuclear Regulatory Commission (NRC) Inspection Manual 0609 identifies that aGREEN (very low safety significance) is quantitatively less than 1 E-6 change in core damagefrequency or 1 E-7 change in large early release frequency. This issue would be GREEN usingthe NRC's Significance Determination Process.If an event had occurred for which the DGs would have been required, the safety function of theDGs would have been performed. In addition to the 2A DG, there is an equivalent safety-related DG (2B) which could have fully performed the safety function.As noted above, the inoperability time for the 2A DG is 46 hours5.324074e-4 days <br />0.0128 hours <br />7.60582e-5 weeks <br />1.7503e-5 months <br />, 57 minutes. TechnicalSpecification Condition 3.8.1 .B applies if a required DG is inoperable. Technical Specification3.8.1 .B has two Required Actions that must be performed within an hour, one Required Actionthat must be performed in 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> and one Required Action that must be performed within24 hours. These Required Actions were not performed within their Completion Times. Sincethese Required Actions were not performed within their Completion Times, TS Condition 3.8.1 .Jshould have been entered. It requires that the Unit be placed in Mode 3 in 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and Mode 5in 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br /> from entry into the Condition. Unit 2 was not placed in Mode 3 in 7 hours8.101852e-5 days <br />0.00194 hours <br />1.157407e-5 weeks <br />2.6635e-6 months <br />, norMode 5 within 37 hours4.282407e-4 days <br />0.0103 hours <br />6.117725e-5 weeks <br />1.40785e-5 months <br /> from the time the 2A DG became inoperable. Therefore, the conditionexisted for a time longer than allowed by TSs.B. CORRECTIVE ACTIONS:1. Conduct training on operability/reportability calls during Licensed Operator Initialand Requalification training, specific to understanding the causes of thedegraded condition and validation of indications for potential inoperability. Alsoinclude an assessment to evaluate licensed operators on the performance ofoperability/reportability calls.2. Implement change to 01-49 (Operability Verification) to include guidance forControl Room personnel to determine status of Fairbanks Morse DGs alarms.This guidance is in the outside operator portion of the checklist, but only checkslocal alarms.3. Implement change to 2A DG Alarm annunciator window (AA01 @ 1C20A) orother Fairbanks Morse DG annunciator windows that do not specifically identifythat a loss of control power could affect DG operability. Clarify when to declarethe affected DG out-of-service until validated or repaired, as well as priority 1maintenance.C. PREVIOUS SIMILAR EVENTS:There are no previous similar events.

NRC FORM 366A U.S. NUCLEAR REGULATORY COMMISSION(01-2014) LICENSEE EVENT REPORT (LER)CONTINUATION SHEET1. FACILITY NAME 2. DOCKET 6. LER NUMBER 3. PAGESEQUENTIAL REVYEAR NUMBER INO.Calvert Cliffs Nuclear Power Plant, Unit 2 05000 318 2014 --002 -- 00 16 of 6NARRATIVE1. COMPONENT INFORMATION:COMPONENTIEEE 803FUNCTION IDIEEE 805SYSTEM IDGenerator, Diesel (2A)FuseThe 2A DG is manufactured by Fairbanks Morse.DGFUEKEK