ML15313A025
| ML15313A025 | |
| Person / Time | |
|---|---|
| Site: | Nine Mile Point  |
| Issue date: | 10/05/2015 |
| From: | Trafton W J Exelon Generation Co |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| NMP2L 2599 LER 14-007-01 | |
| Download: ML15313A025 (8) | |
Text
~Exelton Generation10 CFR 50.73NMP2L 2599October 5, 2015U. S. Nuclear Regulatory CommissionATTN: Document Control DeskWashington, DC 20555-0001Nine Mile Point Nuclear Station, Unit 2Renewed Facility Operating License No. NPF-69Docket No. 50-410
Subject:
NMP2 Licensee Event Report 2014-007, Revision 1, Secondary ContainmentInoperable Due to Simultaneous Opening of Airlock DoorsIn accordance with the reporting requirements contained in 10 CFR 50.73(a)(2)(v)(C), pleasefind enclosed NMP2 Licensee Event Report (LER) 2014-007, Revision 1, SecondaryContainment Inoperable Due to Simultaneous Opening of Airlock Doors. The LER is beingrevised to add a second occurrence of the airlock doors being opened on the same day. Thiswas identified during an internal review of records. The causes and actions taken were notchanged.There are no regulatory commitments contained in this letter.Should you have any questions regarding the information in this submittal, please contactDennis Moore, Site Regulatory Assurance Manager, at (315) 349-5219.Respectfully,Plant Manager, Nine Mile Point Nuclear StationExelon Generation Company, LLCWJT/KJ K
Enclosure:
NMP2 Licensee Event Report 2014-007, Revision 1, Secondary ContainmentInoperable Due to Simultaneous Opening of Airlock Doorscc: NRC Regional Administrator, Region INRC Resident InspectorNRC Project Manager EnclosureNMP2 Licensee Event Report 2014-007, Revision 1Secondary Containment Inoperable Due to Simultaneous Opening of Airlock DoorsNine Mile Point Nuclear Station, Unit 2Renewed Facility Operating License No. NPF-69 NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY 0MB: NO. 3150-0104 EXPIRES: 01/3112017(02-2014)burden per response to comply with this mandatory collection request: 80 hours9.259259e-4 days <br />0.0222 hours <br />1.322751e-4 weeks <br />3.044e-5 months <br />.lessons learned sre incorporated into the licensing process and fed back to industry.comments regarding burden estimate to the FOIA, Privacy and Information CollectionsLIEN EEE EN/R P RT(L R Branch (T-5 F53), U.S. Nudlear Regulatory Commission, Washington, DC 20555-0001, or byLICE SEEEVE T n~,.ji (ER) internet e-mail to Infocollects.Resource@nrc.gov, and to the Desk Officer, Office of Information and(See Page 2 for required number of Regulatory Affairs, NEOB-10202, (3150-0104), Office of Management and Budget, Washington, DC20503. It a means used to impose an information collection does not display a currentiy valid 0MBdigits/characters fouechbock) 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 NUMBER 3. PAGENine Mile Point Unit 2 05000410 1 OF 64. TITLESecondary Containment Inoperable Due to Simultaneous Opening of Airlock Doors5. EVENT DATE 6. LER NUMBER [ 7. REPORT DATE 8. OTHER FACILITIES INVOLVEDMONH AY YEAR YEAR SEQUENTIAL REV MONITHTDY EAR /7/NUMBER NO.FACLIYANMEDOETN__ E4 2 014 2014- 007 -01 10 151 2015N/NA9. OPERATING MODE 11. THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR §: (Check all that apply)[] 20.2201(b) [] 20.2203(a)(3)(i) [] 50.73(a)(2)(i)(C) El 50.73(a)(2)(vii)El 20.2201(d) El 20.2203(a)(3)(ii) El 50.73(a)(2)(ii)(A) El 50.73(a)(2)(viii)(A)5 ____________El 20.2203(a)(1) El 20.2203(a)(4) El 50.73(a)(2)(ii)(B) El 50.73(a)(2)(viii)(B)___________ E 20.2203(a)(2)(i) LIJ 50.36(0)(1)(i)(A) El 50.73(a)(2)(iii) El 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) El 50.73(a)(2)(x)El 20.2203(a)(2)(iii) El 50.36(o)(2) El 50.73(a)(2)(v)(A) El 73.71(a)(4)El 20.2203(a)(2)(iv) El 50.46(a)(3)(ii) El 50.73(a)(2)(v)(g) LI 73.71(Ca)(5)0%El 20.2203(a)(2)(v) El 50.73(a)(2)(i)(A) 0] 50.73(a)(2)(v)(C) El OTHEREl 20.2203(a)(2)(vi) El 50.73(a)(2)(i)(B) III 50.73(a)(2)(v)(g) Specify in Abstract below or in_____________________________________________________________________________NR_____oNRCmorm36612. LICENSEE CONTACT FOR THIS LERLICENSEE CONTACT TLPOENME IcueAe oeCAUniE MooSYSiteM ReCOPONEtor MANsu-ac REORana Ler CAUSE39-2113. COMPLETE ONE LINE FOR EACH COMPONENT FAILURE DESCRIBED IN THIS REPORTIIFACTURER TO EPIXCA EA NG DR N/A N N/A14. SUPPLEMENTAL REPORT EXPECTEDEl]YES (If yes, complete 15. EXPECTED SUBMISSION DATE) []NOABSTRACT (Limit to 1400 spaces, i.e., approximately 15 single-spaced typewritten lines)On April 2, 2014, at approximately 0123 hours0.00142 days <br />0.0342 hours <br />2.03373e-4 weeks <br />4.68015e-5 months <br />, the secondary containment of the Nine Mile Point Unit 2(NMP2) Reactor Building was breached when workers opened both inner and outer airlock doors, R261-1and R261-2, simultaneously while passing through. The integrity of the airlock was re-established within 4to 5 seconds when one of the doors was closed and latched. A second opening of both airlock doorsoccurred at 1140 that same day. Secondary containment differential pressure never exceeded theminimum Technical Specification limit of 0.25 inch of vacuum water gauge. These events are significantin that the secondary containment was momentarily breached during replacement of the ReactorRecirculation Pump "B" seal, an activity which had the potential for draining the reactor vessel (OPDRV).The causal analysis identified that workers did not use their human performance verification tools toensure the .opposing outer door of the airlock was closed prior to opening the inner door. Correctiveactions taken include coaching and counseling for workers involved in the event on the importance ofapplying their human performance tools of self-checking and peer-checking when passing throughsecondary containment doors. A previous LER submitted on a similar event could not be identified.NRC FORM 388 (02-20141 NIRC FORM 366A U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY 0MB: NO. 3150-01 04 EXPIRES: 01/311201702-214) burden per response to comply with this mandatory collection request: 80 hours9.259259e-4 days <br />0.0222 hours <br />1.322751e-4 weeks <br />3.044e-5 months <br />.lessons learned are incorporated into the licensing process and fed back to industry.comments regarding burden estimate to the FOIA, Privacy and Information Collechions(~ ) Branch (T-5 F53), U.S. Nuclear Regulatory Commission. Washington, DC 20555-0001, or by" " LICENSEE EVENT REPORT (LER) intemet e-mail to lnfocollects.Resource@nrc.gov, and to the Desk Officer, Office of Informationand Regulatory Affairs, NEOB-10202, (3150-0104), Office of Management and Budget,CONTINUATION SHEET Washington, DC 20503. It a means used to rmpose an information ccllection does not display acurrently valid OMB 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 6. LER NUMBER 3. PAGETYER SEQUENTIAL REVYEA N UMBER NO.Nine Mile Point Unit 2 105000410 12 OF 62014 -007 -01NARRATIVEI.DESCRIPTION OF EVENTA. PRE-EVENT PLANT CONDITIONS:Prior to the event, Nine Mile Point Unit 2 (NMP2) was in Mode 5 on the 1 0th day of its refuelingoutage and operating at 0% reactor power. The plant was in a condition of operation with thepotential for draining the reactor vessel (OPDRV). The reactor coolant temperature wasapproximately 95°F and pressure was 0 psig. The reactor cavity was flooded twenty-two feetand three inches above the reactor flange and the refueling gates were removed.B. EVENT:On April 2, 2014 at 0123, the simultaneous opening of Reactor Building airlock doorsresulted in a momentary loss of secondary containment safety function. NMP2 was in Mode5 and in the other specified condition of OPDRV as noted above. The incident occurredduring the refueling outage in the main airlock for entry and egress for the Reactor Building.The badging transaction report indicated that three outage workers carded into R261-2(outer door) and entered the airlock toward the Reactor Building. Before the outer doorcould close, one of the workers within the airlock opened R261 -1 (inner door) to the ReactorBuilding resulting in both doors being open concurrently for several seconds. Stationpersonnel in the area of the Reactor Building airlock doors witnessed a rush of air and thesound associated with the simultaneous opening of airlock doors. An event investigationconfirmed the outer door was opened first, the inner door was opened second; both doorswere open at the same time for 4 to 5 seconds. In response to this condition, operatorsentered Technical Specification (TS) action statement 3.6.4.1, Condition C then promptlyexited this action statement when the inner airlock door was closed. At 1140, a similarcondition occurred with both airlock doors being opened simultaneously and closed within afew seconds.Following these incidents, personnel associated with both events were coached on theimportance of using their human performance tools to ensure the airlock doors wereproperly closed.The 0123 event has been documented in the plant's corrective action program as CR 2014-002881. The 1140 event is documented in CR-2014-002909.C. INOPERABLE STRUCTURES, COMPONENTS, OR SYSTEMS THAT CONTRIBUTEDTO THE EVENT:No other systems, structures, or components contributed to this event.NRC FORM 366A (02-2014) 7/NRC FORM 366A U.S. NUCLEAR REGULATORY COMMISSION(02-2014) LICENSEE EVENT REPORT (LER)CONTINUATION SHEET1. FACILITY NAME f2. DOCKET 6. LER NUMBER J 3. PAGEIISEQUENTIAL REVYEAR NUMBER NO.Nine Mile Point Unit 2 05000410 j3 OF 6I _2014 -007 -01NARRATIVED. DATES AND APPROXIMATE TIMES OF MAJOR OCCURRENCES:The dates, times and major occurrences for this event are as follows:A__ril 20123 Workers carded inl R261-2 (outer door)0123 Secondary containment was breachedR261-1 (inner door) is shutEntered TS action statement 3.6.4.1, Condition C and exited.1140 Workers opened R261-1 (inner door) nearly at the same time as workers insidethe airlock opened R261-2 (outer door) to exit the airlock.1140 Secondary containment was breached.The inner door was shut immediately until workers exited through the outer door.Entered TS action statement 3.6.4.1, Condition C and exited.E. OTHER SYSTEMS OR SECONDARY FUNCTIONS AFFECTED:No other systems or secondary functions were affected beyond the systems discussed inSection I.B.F. METHOD OF DISCOVERY:This event was discovered by station personnel in the area of the Reactor Building airlockdoors. Personnel heard a rush of air through the airlock and felt the air pressure from theconcurrent opening of the airlock doors.G. MAJOR OPERATOR ACTION:NMP2 entered TS action statement 3.6.4.1, Condition C, then, exited it when the innerdoor was shut.H. SAFETY SYSTEM RESPONSES:The duration of each event was 4 to 5 seconds, or less. There was no impact on buildingdifferential pressure. Operators entered the applicable TS action statement then exited itsoon afterwards. At the time of the events, the Reactor Building was isolated for otheroutage related activities and the Division I Standby Gas Treatment System (GTS) wasoperable and in operation. Both events concluded when the inner airlock door was shut.I1. CAUSE OF EVENT:This event was caused by the simultaneous opening of Airlock Doors R261 -1 and R261 -2 byworkers as they passed through the doors.NRC FORM 366A (02-2014)
/NRC FORM 366A U.S. NUCLEAR REGULATORY COMMISSION(02-2014) LICENSEE EVENT REPORT (LER)CONTINUATION SHEET1. FACILITY NAME j2. DOCKET 6. LER NUMBER 3. PAGEIISEQUENTIAL REVYERj NUMBER NO.Nine Mile Point Unit 2 05000410 J4 OF 6_____________________I[2014 -007 -01NARRATIVEIll. ANALYSIS OF THE EVENT:The reportable condition associated with airlock doors R261-1 and R261-2 being opensimultaneously represents a loss of secondary containment safety function. This conditionis reportable under 10 CFR 50.72(b)(3)(v)(C) and 10 CFR 50.73(a)(2)(v)(C).It is defined under paragraph 10 CFR 50.73(a)(2)(v)(C) as any event or condition that couldhave prevented the fulfillment of the safety function of structures or systems that areneeded to control the release of radioactive material. While the doors were openedsimultaneously for approximately 4 to 5 seconds, the mechanical pump seal for ReactorRecirculation Pump "B" was in the process of being replaced. This activity represents anOPDRV. Not having secondary containment integrity established while in an OPDRVcondition temporarily placed the plant outside the condition established per TS 3.6.4.1,Condition C.During the outage, the primary access to the NMP2 Reactor Building is through the airlockdoors R261-1 and R261 -2. In the sequence of actions leading to the two breaches ofsecondary containment, three workers entered the Reactor Building. In each event, thegroup did not perform an adequate peer-check of each other and the individual whoopened the inner door did not perform a self-check and verify the outer door was closedbefore opening the inner door. The failure to adequately use human performanceverification tools prior to opening the inner door was identified in the causal analysis as theapparent cause of this event.In response to the event, the station entered the action statement for TS 3.6.4.1 thenpromptly exited it when the airlock doors were shut. Computer data identified thatsecondary containment differential pressure was unaffected by this event. Secondarycontainment structural integrity, the ability to automatically isolate the non-safety relatedReactor Building ventilation system, and the GTS availability were not impacted.Based on the above discussion, it is concluded that the safety significance of this event islow and the event did not pose a threat to the health and safety of the public or plantpersonnel.This event does not affect the NRC Regulatory Oversight Process Indicators.NRC FORM 366A (02-2014)
NRC FORM 366A U.S. NUCLEAR REGULATORY COMMISSION(02-2014) LICENSEE EVENT REPORT (LER)CONTINUATION SHEET1. FACILITY NAME [2. DOCKET 6. LER NUMBER 3. PAGEIISEQUENTIAL REVIIYEAR NUMBER NO. 5 O 6Nine Mile Point Unit 2 05000410 51F__ __ __ __ __ __ __ __ __ __ __ __I ______ j 2014 -007 -01NARRATIVEIV. CORRECTIVE ACTIONS:A. ACTION TAKEN TO RETURN AFFECTED SYSTEMS TO PRE-EVENT NORMALSTATUS:Compensatory measures taken to restore secondary containment to pre-event statusinclude:A door coach was posted at the outer door during high traffic periods for a period of4 shifts (2 days) to provide coaching on door use.Clarifying signage was placed at airlock doors (Units 1 and 2). Signage reads asfollows: "NOTICE: Check for green light then pause for five (5) seconds to allow forpersonnel who may be traversing to exit. Then re-check that the light is still greenbefore proceeding to open the door. Immediately notify the Control Room if bothdoors are opened at the same time."Communication provided to all Maintenance, Projects, and Contractor personnel onthe event, appropriate practices for use of airlocks (i.e. observation of lights prior toentry), and the importance of maintaining secondary integrity by keeping one doorclosed at all times.B. ACTION TAKEN OR PLANNED TO PREVENT RECURRENCE:Workers involved in the events were coached and counseled on the importance ofapplying their human performance tools of self-checking and peer-checking especiallywhen passing through secondary containment doors.V. ADDITIONAL INFORMATION:A. FAILED COMPONENTS:There were no other failed components that contributed to this event.B. PREVIOUS LERs ON SIMILAR EVENTS:There were no previously submitted similar LERs identified.NRC FORM 366A (02-2014)
/SNRC FORM 366A U.S. NUCLEAR REGULATORY COMMISSION(02-2014) LICENSEE EVENT REPORT (LER)CONTINUATION SHEET1. FACILITY NAME [2. DOCKET 6. LER NUMBER J 3. PAGEISEQUENTIAL REVYEAR NUMBER NO.Nine Mile Point Unit 2 05000410 j6 OF 6__ __ _ __ __ _ __ __ _ __ __ _ __ Ij 2014 -007 -01NARRATIVEC. THE ENERGY INDUSTRY IDENTIFICATION SYSTEM (EllS) COMPONENT FUNCTIONIDENTIFIER AND SYSTEM NAME OF EACH COMPONENT OR SYSTEM REFERREDTO IN THIS LER:IEEE 803 FUNCTIONIDENTIFIERIEEE 805 SYSTEMIDENTIFICATIONCOMPONENTReactor Building (BWR)Reactor Building Ventilation SystemStandby Gas Treatment SystemAirlock DoorD. SPECIAL COMMENTS:NoneN/APDICN/ADRNGVABHNGNRC FORM 366A (02-2014)
~Exelton Generation10 CFR 50.73NMP2L 2599October 5, 2015U. S. Nuclear Regulatory CommissionATTN: Document Control DeskWashington, DC 20555-0001Nine Mile Point Nuclear Station, Unit 2Renewed Facility Operating License No. NPF-69Docket No. 50-410
Subject:
NMP2 Licensee Event Report 2014-007, Revision 1, Secondary ContainmentInoperable Due to Simultaneous Opening of Airlock DoorsIn accordance with the reporting requirements contained in 10 CFR 50.73(a)(2)(v)(C), pleasefind enclosed NMP2 Licensee Event Report (LER) 2014-007, Revision 1, SecondaryContainment Inoperable Due to Simultaneous Opening of Airlock Doors. The LER is beingrevised to add a second occurrence of the airlock doors being opened on the same day. Thiswas identified during an internal review of records. The causes and actions taken were notchanged.There are no regulatory commitments contained in this letter.Should you have any questions regarding the information in this submittal, please contactDennis Moore, Site Regulatory Assurance Manager, at (315) 349-5219.Respectfully,Plant Manager, Nine Mile Point Nuclear StationExelon Generation Company, LLCWJT/KJ K
Enclosure:
NMP2 Licensee Event Report 2014-007, Revision 1, Secondary ContainmentInoperable Due to Simultaneous Opening of Airlock Doorscc: NRC Regional Administrator, Region INRC Resident InspectorNRC Project Manager EnclosureNMP2 Licensee Event Report 2014-007, Revision 1Secondary Containment Inoperable Due to Simultaneous Opening of Airlock DoorsNine Mile Point Nuclear Station, Unit 2Renewed Facility Operating License No. NPF-69 NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY 0MB: NO. 3150-0104 EXPIRES: 01/3112017(02-2014)burden per response to comply with this mandatory collection request: 80 hours9.259259e-4 days <br />0.0222 hours <br />1.322751e-4 weeks <br />3.044e-5 months <br />.lessons learned sre incorporated into the licensing process and fed back to industry.comments regarding burden estimate to the FOIA, Privacy and Information CollectionsLIEN EEE EN/R P RT(L R Branch (T-5 F53), U.S. Nudlear Regulatory Commission, Washington, DC 20555-0001, or byLICE SEEEVE T n~,.ji (ER) internet e-mail to Infocollects.Resource@nrc.gov, and to the Desk Officer, Office of Information and(See Page 2 for required number of Regulatory Affairs, NEOB-10202, (3150-0104), Office of Management and Budget, Washington, DC20503. It a means used to impose an information collection does not display a currentiy valid 0MBdigits/characters fouechbock) 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 NUMBER 3. PAGENine Mile Point Unit 2 05000410 1 OF 64. TITLESecondary Containment Inoperable Due to Simultaneous Opening of Airlock Doors5. EVENT DATE 6. LER NUMBER [ 7. REPORT DATE 8. OTHER FACILITIES INVOLVEDMONH AY YEAR YEAR SEQUENTIAL REV MONITHTDY EAR /7/NUMBER NO.FACLIYANMEDOETN__ E4 2 014 2014- 007 -01 10 151 2015N/NA9. OPERATING MODE 11. THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR §: (Check all that apply)[] 20.2201(b) [] 20.2203(a)(3)(i) [] 50.73(a)(2)(i)(C) El 50.73(a)(2)(vii)El 20.2201(d) El 20.2203(a)(3)(ii) El 50.73(a)(2)(ii)(A) El 50.73(a)(2)(viii)(A)5 ____________El 20.2203(a)(1) El 20.2203(a)(4) El 50.73(a)(2)(ii)(B) El 50.73(a)(2)(viii)(B)___________ E 20.2203(a)(2)(i) LIJ 50.36(0)(1)(i)(A) El 50.73(a)(2)(iii) El 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) El 50.73(a)(2)(x)El 20.2203(a)(2)(iii) El 50.36(o)(2) El 50.73(a)(2)(v)(A) El 73.71(a)(4)El 20.2203(a)(2)(iv) El 50.46(a)(3)(ii) El 50.73(a)(2)(v)(g) LI 73.71(Ca)(5)0%El 20.2203(a)(2)(v) El 50.73(a)(2)(i)(A) 0] 50.73(a)(2)(v)(C) El OTHEREl 20.2203(a)(2)(vi) El 50.73(a)(2)(i)(B) III 50.73(a)(2)(v)(g) Specify in Abstract below or in_____________________________________________________________________________NR_____oNRCmorm36612. LICENSEE CONTACT FOR THIS LERLICENSEE CONTACT TLPOENME IcueAe oeCAUniE MooSYSiteM ReCOPONEtor MANsu-ac REORana Ler CAUSE39-2113. COMPLETE ONE LINE FOR EACH COMPONENT FAILURE DESCRIBED IN THIS REPORTIIFACTURER TO EPIXCA EA NG DR N/A N N/A14. SUPPLEMENTAL REPORT EXPECTEDEl]YES (If yes, complete 15. EXPECTED SUBMISSION DATE) []NOABSTRACT (Limit to 1400 spaces, i.e., approximately 15 single-spaced typewritten lines)On April 2, 2014, at approximately 0123 hours0.00142 days <br />0.0342 hours <br />2.03373e-4 weeks <br />4.68015e-5 months <br />, the secondary containment of the Nine Mile Point Unit 2(NMP2) Reactor Building was breached when workers opened both inner and outer airlock doors, R261-1and R261-2, simultaneously while passing through. The integrity of the airlock was re-established within 4to 5 seconds when one of the doors was closed and latched. A second opening of both airlock doorsoccurred at 1140 that same day. Secondary containment differential pressure never exceeded theminimum Technical Specification limit of 0.25 inch of vacuum water gauge. These events are significantin that the secondary containment was momentarily breached during replacement of the ReactorRecirculation Pump "B" seal, an activity which had the potential for draining the reactor vessel (OPDRV).The causal analysis identified that workers did not use their human performance verification tools toensure the .opposing outer door of the airlock was closed prior to opening the inner door. Correctiveactions taken include coaching and counseling for workers involved in the event on the importance ofapplying their human performance tools of self-checking and peer-checking when passing throughsecondary containment doors. A previous LER submitted on a similar event could not be identified.NRC FORM 388 (02-20141 NIRC FORM 366A U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY 0MB: NO. 3150-01 04 EXPIRES: 01/311201702-214) burden per response to comply with this mandatory collection request: 80 hours9.259259e-4 days <br />0.0222 hours <br />1.322751e-4 weeks <br />3.044e-5 months <br />.lessons learned are incorporated into the licensing process and fed back to industry.comments regarding burden estimate to the FOIA, Privacy and Information Collechions(~ ) Branch (T-5 F53), U.S. Nuclear Regulatory Commission. Washington, DC 20555-0001, or by" " LICENSEE EVENT REPORT (LER) intemet e-mail to lnfocollects.Resource@nrc.gov, and to the Desk Officer, Office of Informationand Regulatory Affairs, NEOB-10202, (3150-0104), Office of Management and Budget,CONTINUATION SHEET Washington, DC 20503. It a means used to rmpose an information ccllection does not display acurrently valid OMB 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 6. LER NUMBER 3. PAGETYER SEQUENTIAL REVYEA N UMBER NO.Nine Mile Point Unit 2 105000410 12 OF 62014 -007 -01NARRATIVEI.DESCRIPTION OF EVENTA. PRE-EVENT PLANT CONDITIONS:Prior to the event, Nine Mile Point Unit 2 (NMP2) was in Mode 5 on the 1 0th day of its refuelingoutage and operating at 0% reactor power. The plant was in a condition of operation with thepotential for draining the reactor vessel (OPDRV). The reactor coolant temperature wasapproximately 95°F and pressure was 0 psig. The reactor cavity was flooded twenty-two feetand three inches above the reactor flange and the refueling gates were removed.B. EVENT:On April 2, 2014 at 0123, the simultaneous opening of Reactor Building airlock doorsresulted in a momentary loss of secondary containment safety function. NMP2 was in Mode5 and in the other specified condition of OPDRV as noted above. The incident occurredduring the refueling outage in the main airlock for entry and egress for the Reactor Building.The badging transaction report indicated that three outage workers carded into R261-2(outer door) and entered the airlock toward the Reactor Building. Before the outer doorcould close, one of the workers within the airlock opened R261 -1 (inner door) to the ReactorBuilding resulting in both doors being open concurrently for several seconds. Stationpersonnel in the area of the Reactor Building airlock doors witnessed a rush of air and thesound associated with the simultaneous opening of airlock doors. An event investigationconfirmed the outer door was opened first, the inner door was opened second; both doorswere open at the same time for 4 to 5 seconds. In response to this condition, operatorsentered Technical Specification (TS) action statement 3.6.4.1, Condition C then promptlyexited this action statement when the inner airlock door was closed. At 1140, a similarcondition occurred with both airlock doors being opened simultaneously and closed within afew seconds.Following these incidents, personnel associated with both events were coached on theimportance of using their human performance tools to ensure the airlock doors wereproperly closed.The 0123 event has been documented in the plant's corrective action program as CR 2014-002881. The 1140 event is documented in CR-2014-002909.C. INOPERABLE STRUCTURES, COMPONENTS, OR SYSTEMS THAT CONTRIBUTEDTO THE EVENT:No other systems, structures, or components contributed to this event.NRC FORM 366A (02-2014) 7/NRC FORM 366A U.S. NUCLEAR REGULATORY COMMISSION(02-2014) LICENSEE EVENT REPORT (LER)CONTINUATION SHEET1. FACILITY NAME f2. DOCKET 6. LER NUMBER J 3. PAGEIISEQUENTIAL REVYEAR NUMBER NO.Nine Mile Point Unit 2 05000410 j3 OF 6I _2014 -007 -01NARRATIVED. DATES AND APPROXIMATE TIMES OF MAJOR OCCURRENCES:The dates, times and major occurrences for this event are as follows:A__ril 20123 Workers carded inl R261-2 (outer door)0123 Secondary containment was breachedR261-1 (inner door) is shutEntered TS action statement 3.6.4.1, Condition C and exited.1140 Workers opened R261-1 (inner door) nearly at the same time as workers insidethe airlock opened R261-2 (outer door) to exit the airlock.1140 Secondary containment was breached.The inner door was shut immediately until workers exited through the outer door.Entered TS action statement 3.6.4.1, Condition C and exited.E. OTHER SYSTEMS OR SECONDARY FUNCTIONS AFFECTED:No other systems or secondary functions were affected beyond the systems discussed inSection I.B.F. METHOD OF DISCOVERY:This event was discovered by station personnel in the area of the Reactor Building airlockdoors. Personnel heard a rush of air through the airlock and felt the air pressure from theconcurrent opening of the airlock doors.G. MAJOR OPERATOR ACTION:NMP2 entered TS action statement 3.6.4.1, Condition C, then, exited it when the innerdoor was shut.H. SAFETY SYSTEM RESPONSES:The duration of each event was 4 to 5 seconds, or less. There was no impact on buildingdifferential pressure. Operators entered the applicable TS action statement then exited itsoon afterwards. At the time of the events, the Reactor Building was isolated for otheroutage related activities and the Division I Standby Gas Treatment System (GTS) wasoperable and in operation. Both events concluded when the inner airlock door was shut.I1. CAUSE OF EVENT:This event was caused by the simultaneous opening of Airlock Doors R261 -1 and R261 -2 byworkers as they passed through the doors.NRC FORM 366A (02-2014)
/NRC FORM 366A U.S. NUCLEAR REGULATORY COMMISSION(02-2014) LICENSEE EVENT REPORT (LER)CONTINUATION SHEET1. FACILITY NAME j2. DOCKET 6. LER NUMBER 3. PAGEIISEQUENTIAL REVYERj NUMBER NO.Nine Mile Point Unit 2 05000410 J4 OF 6_____________________I[2014 -007 -01NARRATIVEIll. ANALYSIS OF THE EVENT:The reportable condition associated with airlock doors R261-1 and R261-2 being opensimultaneously represents a loss of secondary containment safety function. This conditionis reportable under 10 CFR 50.72(b)(3)(v)(C) and 10 CFR 50.73(a)(2)(v)(C).It is defined under paragraph 10 CFR 50.73(a)(2)(v)(C) as any event or condition that couldhave prevented the fulfillment of the safety function of structures or systems that areneeded to control the release of radioactive material. While the doors were openedsimultaneously for approximately 4 to 5 seconds, the mechanical pump seal for ReactorRecirculation Pump "B" was in the process of being replaced. This activity represents anOPDRV. Not having secondary containment integrity established while in an OPDRVcondition temporarily placed the plant outside the condition established per TS 3.6.4.1,Condition C.During the outage, the primary access to the NMP2 Reactor Building is through the airlockdoors R261-1 and R261 -2. In the sequence of actions leading to the two breaches ofsecondary containment, three workers entered the Reactor Building. In each event, thegroup did not perform an adequate peer-check of each other and the individual whoopened the inner door did not perform a self-check and verify the outer door was closedbefore opening the inner door. The failure to adequately use human performanceverification tools prior to opening the inner door was identified in the causal analysis as theapparent cause of this event.In response to the event, the station entered the action statement for TS 3.6.4.1 thenpromptly exited it when the airlock doors were shut. Computer data identified thatsecondary containment differential pressure was unaffected by this event. Secondarycontainment structural integrity, the ability to automatically isolate the non-safety relatedReactor Building ventilation system, and the GTS availability were not impacted.Based on the above discussion, it is concluded that the safety significance of this event islow and the event did not pose a threat to the health and safety of the public or plantpersonnel.This event does not affect the NRC Regulatory Oversight Process Indicators.NRC FORM 366A (02-2014)
NRC FORM 366A U.S. NUCLEAR REGULATORY COMMISSION(02-2014) LICENSEE EVENT REPORT (LER)CONTINUATION SHEET1. FACILITY NAME [2. DOCKET 6. LER NUMBER 3. PAGEIISEQUENTIAL REVIIYEAR NUMBER NO. 5 O 6Nine Mile Point Unit 2 05000410 51F__ __ __ __ __ __ __ __ __ __ __ __I ______ j 2014 -007 -01NARRATIVEIV. CORRECTIVE ACTIONS:A. ACTION TAKEN TO RETURN AFFECTED SYSTEMS TO PRE-EVENT NORMALSTATUS:Compensatory measures taken to restore secondary containment to pre-event statusinclude:A door coach was posted at the outer door during high traffic periods for a period of4 shifts (2 days) to provide coaching on door use.Clarifying signage was placed at airlock doors (Units 1 and 2). Signage reads asfollows: "NOTICE: Check for green light then pause for five (5) seconds to allow forpersonnel who may be traversing to exit. Then re-check that the light is still greenbefore proceeding to open the door. Immediately notify the Control Room if bothdoors are opened at the same time."Communication provided to all Maintenance, Projects, and Contractor personnel onthe event, appropriate practices for use of airlocks (i.e. observation of lights prior toentry), and the importance of maintaining secondary integrity by keeping one doorclosed at all times.B. ACTION TAKEN OR PLANNED TO PREVENT RECURRENCE:Workers involved in the events were coached and counseled on the importance ofapplying their human performance tools of self-checking and peer-checking especiallywhen passing through secondary containment doors.V. ADDITIONAL INFORMATION:A. FAILED COMPONENTS:There were no other failed components that contributed to this event.B. PREVIOUS LERs ON SIMILAR EVENTS:There were no previously submitted similar LERs identified.NRC FORM 366A (02-2014)
/SNRC FORM 366A U.S. NUCLEAR REGULATORY COMMISSION(02-2014) LICENSEE EVENT REPORT (LER)CONTINUATION SHEET1. FACILITY NAME [2. DOCKET 6. LER NUMBER J 3. PAGEISEQUENTIAL REVYEAR NUMBER NO.Nine Mile Point Unit 2 05000410 j6 OF 6__ __ _ __ __ _ __ __ _ __ __ _ __ Ij 2014 -007 -01NARRATIVEC. THE ENERGY INDUSTRY IDENTIFICATION SYSTEM (EllS) COMPONENT FUNCTIONIDENTIFIER AND SYSTEM NAME OF EACH COMPONENT OR SYSTEM REFERREDTO IN THIS LER:IEEE 803 FUNCTIONIDENTIFIERIEEE 805 SYSTEMIDENTIFICATIONCOMPONENTReactor Building (BWR)Reactor Building Ventilation SystemStandby Gas Treatment SystemAirlock DoorD. SPECIAL COMMENTS:NoneN/APDICN/ADRNGVABHNGNRC FORM 366A (02-2014)