2-1-2016 | At 2036 on December 1, 2015, James A. FitzPatrick Nuclear Power Plant (JAF) was operating at 100 percent power when differential pressure of the Secondary Containment exceeded a Technical Specification requirement. The requirement is for the Secondary Containment to have a >1= 0.25 inches of vacuum water gauge compared to the external environment.
This event was caused by hardened grease in the operating mechanism of the motor starter contactor 71MCC-141-062.
This led to a slow start of the above refuel floor Reactor Building exhaust fan 66FN-13B while the intake air supply fans were running. The exhaust fan started, without Plant Operator action, after approximately 60 seconds; however, Reactor Building differential pressure exceeded 0.25 inches of vacuum water gauge for approximately 80 seconds.
When Secondary Containment did not meet the Technical Specification Surveillance Requirement 3.6.4.1.1 for differential pressure, the Limiting Condition of Operation (LCO) was not met. Therefore, Secondary Containment was Inoperable.
Restoration of the LCO was completed within the allowed action completion time. This report is being submitted per 10 CFR 50.73(a)(2)(v)(C) as a condition that could have prevented the fulfillment of safety function to control the release of radioactive material. |
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Category:Letter
MONTHYEARIR 05000333/20240052024-08-29029 August 2024 Updated Inspection Plan for James A. Fitzpatrick Nuclear Power Plant (Report 05000333/2024005) ML24222A6772024-08-0909 August 2024 Response to Request for Additional Information for Application to Revise Technical Specifications to Adopt TSTF-591-A, “Revise Risk Informed Completion Time (RICT) Program” Revision 0 and Revise 10 CFR 50.69 License Condition IR 05000333/20240022024-08-0707 August 2024 Integrated Inspection Report 05000333/2024002 JAFP-24-0034, 10 CFR 50.46 Annual Report2024-07-31031 July 2024 10 CFR 50.46 Annual Report ML24208A0492024-07-30030 July 2024 Notice of Consideration of Issuance of Amendments to Facility Operating Licenses and Proposed No Significant Hazards Consideration Determination (Letter) JAFP-24-0036, Supplement to License Amendment Request to Update the Technical Specification Bases to Change the Fuel Handling Accident Analysis2024-07-29029 July 2024 Supplement to License Amendment Request to Update the Technical Specification Bases to Change the Fuel Handling Accident Analysis JAFP-24-0033, Response to Request for Information Pertaining to a Licensed Operator Positive Fitness-For-Duty Test2024-07-23023 July 2024 Response to Request for Information Pertaining to a Licensed Operator Positive Fitness-For-Duty Test IR 05000333/20244032024-07-18018 July 2024 Biennial Problem Identification and Resolution Inspection Report 05000333/2024403 (Cover Letter Only) IR 05000333/20244012024-07-15015 July 2024 Security Baseline Inspection 05000333/2024401 RS-24-070, Independent Spent Fuel Storage Installation, Nine Mile Point, Units 1 and 2, Quad Cities, Units 1 and 2, R. E. Ginna - Nuclear Radiological Emergency Plan Document Revisions2024-07-12012 July 2024 Independent Spent Fuel Storage Installation, Nine Mile Point, Units 1 and 2, Quad Cities, Units 1 and 2, R. E. Ginna - Nuclear Radiological Emergency Plan Document Revisions ML24190A1932024-07-0909 July 2024 Correction Letter of Amendment No. 355 Revise Technical Specifications Section 3.4.3.1, Safety Relief Valves Setpoint Lower Tolerance IR 05000333/20240102024-07-0808 July 2024 Commercial Grade Dedication Inspection Report 05000333/2024010 ML24184A1662024-07-0303 July 2024 Senior Reactor and Reactor Operator Initial License Examinations ML24136A1162024-06-26026 June 2024 Issuance of Amendment No. 355 Revise Technical Specifications Section 3.4.3.1, Safety Relief Valves Setpoint Lower Tolerance ML24176A2412024-06-24024 June 2024 Licensed Operator Positive Fitness-for-Duty Test RS-24-061, Constellation Energy Generation, LLC, Response to NRC Regulatory Issue Summary 2024-01, Preparation and Scheduling of Operator Licensing Examinations2024-06-14014 June 2024 Constellation Energy Generation, LLC, Response to NRC Regulatory Issue Summary 2024-01, Preparation and Scheduling of Operator Licensing Examinations JAFP-24-0026, Supplement to License Amendment Request to Modify Technical Specification Surveillance Requirement (SR) 3.4.3.1 Safety Relief Valves (Srvs) Setpoint Lower Tolerance2024-06-12012 June 2024 Supplement to License Amendment Request to Modify Technical Specification Surveillance Requirement (SR) 3.4.3.1 Safety Relief Valves (Srvs) Setpoint Lower Tolerance ML24079A0762024-05-23023 May 2024 Issuance of Amendments to Adopt TSTF 264 IR 05000333/20240012024-05-0909 May 2024 Integrated Inspection Report 05000333/2024001 JAFP-24-0023, 2023 Annual Radiological Environmental Operating Report2024-05-0909 May 2024 2023 Annual Radiological Environmental Operating Report RS-24-041, Alternative Request to Utilize Code Case OMN-32, Alternative Requirements for Range and Accuracy of Pressure, Flow, and Differential Pressure Instruments Used in Pump Tests2024-04-30030 April 2024 Alternative Request to Utilize Code Case OMN-32, Alternative Requirements for Range and Accuracy of Pressure, Flow, and Differential Pressure Instruments Used in Pump Tests JAFP-24-0020, 2023 Annual Radioactive Effluent Release Report2024-04-25025 April 2024 2023 Annual Radioactive Effluent Release Report JAFP-24-0019, 2023 REIRS Transmittal of NRC Form 52024-04-18018 April 2024 2023 REIRS Transmittal of NRC Form 5 ML24106A0152024-04-15015 April 2024 Request for Withholding Information from Public Disclosure Response to Request for Additional Information for License Amendment Request to Update the Technical Specification Bases to Change the Fuel Handling ML24103A2042024-04-12012 April 2024 Constellation Energy Generation, LLC, Application to Revise Technical Specifications to Adopt TSTF-591-A, Revise Risk Informed Completion Time (RICT) Program Revision 0 and Revise 10 CFR 50.69 License Condition ML24107A6972024-04-12012 April 2024 Engine Systems, Inc Part 21 Report Re EMD Cylinder Liner Water Leak RS-24-002, Constellation Energy Generation, LLC - Annual Property Insurance Status Report2024-04-0101 April 2024 Constellation Energy Generation, LLC - Annual Property Insurance Status Report ML24068A0532024-03-28028 March 2024 Issuance of Amendment No. 354 Revise Technical Specifications Section 3.3.1.2, Source Range Monitors Instrumentation JAFP-24-0014, Response to Request for Additional Information for License Amendment Request to Update the Technical Specification Bases to Change the Fuel Handling Accident Analysis2024-03-25025 March 2024 Response to Request for Additional Information for License Amendment Request to Update the Technical Specification Bases to Change the Fuel Handling Accident Analysis JAFP-24-0010, Response to Request for Additional Information for License Amendment Request to Modify Technical Specification Surveillance Requirement (SR) 3.4.3.1 Safety Relief Valves (S/Rvs) Setpoint Lower Tolerance2024-02-29029 February 2024 Response to Request for Additional Information for License Amendment Request to Modify Technical Specification Surveillance Requirement (SR) 3.4.3.1 Safety Relief Valves (S/Rvs) Setpoint Lower Tolerance IR 05000333/20230062024-02-28028 February 2024 Annual Assessment Letter for James A. FitzPatrick Nuclear Power Plant (Report 05000333/2023006) JAFP-24-0009, Response to Request for Additional Information for License Amendment Request to Update the Technical Specification Bases to Change the Fuel Handling Accident Analysis2024-02-28028 February 2024 Response to Request for Additional Information for License Amendment Request to Update the Technical Specification Bases to Change the Fuel Handling Accident Analysis IR 05000333/20230042024-02-0707 February 2024 Integrated Inspection Report 05000333/2023004 and Independent Spent Fuel Storage Installation Inspection Report 07200012/2023001 ML24037A0102024-02-0606 February 2024 Requalification Program Inspection ML24018A0012024-01-18018 January 2024 Notification of Commercial Grade Dedication Inspection (05000333/2024010) and Request for Information ML24004A2302024-01-0808 January 2024 Project Manager Reassignment ML23356A0832024-01-0404 January 2024 Exemption from Select Requirements of 10 CFR Part 73 (EPID L-2023-LLE-0058 (Security Notifications, Reports, and Recordkeeping and Suspicious Activity Reporting)) JAFP-23-0065, License Amendment Request to Revise Technical Specifications to Adopt TSTF-529, Clarify Use and Application Rules, Revision 4, and Administrative Changes to the Technical Specifications2023-12-14014 December 2023 License Amendment Request to Revise Technical Specifications to Adopt TSTF-529, Clarify Use and Application Rules, Revision 4, and Administrative Changes to the Technical Specifications ML23278A1292023-12-14014 December 2023 Units 1 & 2; Limerick, Units 1 & 2; Nine Mile Point, Units 1 & 2; and Peach Bottom, Units 2 & 3 -Revision to Approved Alternatives to Use Boiling Water Reactor Vessel and Internals Project Guidelines IR 05000333/20234012023-12-0808 December 2023 Cybersecurity Inspection Report 05000333/2023401 (Cover Letter Only) RS-23-126, Request for Exemption from 10 CFR 2.109(b)2023-12-0707 December 2023 Request for Exemption from 10 CFR 2.109(b) JAFP-23-0069, Supplemental Response to Part 73 Exemption Request Withdrawal of Request for Exemption from 10 CFR 73, Subpart B, Preemption Authority Requirements2023-12-0707 December 2023 Supplemental Response to Part 73 Exemption Request Withdrawal of Request for Exemption from 10 CFR 73, Subpart B, Preemption Authority Requirements JAFP-23-0057, and Independent Spent Fuel Storage Installation - Request for Exemption from Enhanced Weapons, Firearms Background Checks, and Security Event Notifications Implementation2023-11-22022 November 2023 and Independent Spent Fuel Storage Installation - Request for Exemption from Enhanced Weapons, Firearms Background Checks, and Security Event Notifications Implementation JAFP-23-0064, Emergency Plan Document Revision2023-11-15015 November 2023 Emergency Plan Document Revision JAFP-23-0063, Registration of Spent Fuel Cask Use2023-11-13013 November 2023 Registration of Spent Fuel Cask Use IR 05000333/20230032023-11-13013 November 2023 Integrated Inspection Report 05000333/2023003 ML23317A1192023-11-10010 November 2023 Constellation Energy Generation, LLC - 2023 Annual Report - Guarantees of Payment of Deferred Premiums IR 05000333/20230102023-10-26026 October 2023 Biennial Problem Identification and Resolution Inspection Report 05000333/2023010 JAFP-23-0059, Registration of Spent Fuel Cask Use2023-10-24024 October 2023 Registration of Spent Fuel Cask Use IR 05000333/20233012023-10-19019 October 2023 Initial Operator Licensing Examination Report 05000333/2023301 2024-08-09
[Table view] Category:Licensee Event Report (LER)
MONTHYEARJAFP-17-0051, LER 17-03-00 for FitzPatrick Regarding Inadvertent Isolation of the High Pressure Coolant Injection System2017-06-0505 June 2017 LER 17-03-00 for FitzPatrick Regarding Inadvertent Isolation of the High Pressure Coolant Injection System 05000333/LER-2017-0012017-03-13013 March 2017 Vent Line Socket Weld Failure, LER 17-001-00 for James A. Fitzpatrick Nuclear Power Plant RE: Vent Line Socket Weld Failure 05000333/LER-2016-0042016-08-23023 August 2016 Transformer Fault Results in Manual Scram and Secondary Containment Vacuum Below Technical Specification Limit, LER 16-004-00 for James A. Fitzpatrick Regarding Transformer Fault Results in Manual Scram and Secondary Containment Vacuum Below Technical Specification Limit 05000333/LER-2016-0032016-08-0303 August 2016 Concurrent Opening of Reactor Building Airlock Doors, LER 16-003-00 for James A. FitzPatrick Regarding Concurrent Opening of Reactor Building Airlock Doors 05000333/LER-2016-0022016-04-25025 April 2016 Sticking DC Pilot in Solenoid Valve Cluster Assembly Results in Slow MSIV Closures, LER 16-002-00 for James A. Fitzpatrick Nuclear Power Plant, Regarding Sticking DC Pilot in Solenoid Valve Cluster Assembly Results in Slowly MSIV Closure 05000333/LER-2016-0012016-03-23023 March 2016 System Actuations during Manual Scram in Response to Frazil Ice Blockage and Residual Transfer, LER 16-001-00 for James A. FitzPatrick Regarding System Actuations during Manual Scram in Response to Frazil Ice Blockage and Residual Transfer 05000333/LER-2015-0082016-02-16016 February 2016 Containment Atmosphere Dilution System Reliability Degraded due to Manufacturer Defect in Temperature Transmitters, LER 15-008-00 for James A. Fitzpatrick Regarding Containment Atmosphere Dilution System Reliability Degraded Due to Manufacturer Defect in Temperature Transmitters 05000333/LER-2015-0062016-02-0404 February 2016 Transitory Secondary Containment Differential Pressure Excursions, LER 15-006-01 for James A. FizPatrick Regarding Transitory Secondary Containment Differential Pressure Excursions 05000333/LER-2015-0072016-02-0101 February 2016 Slow Exhaust Fan Start Leads to Secondary Containment Vacuum Below Technical Specification Limit, LER 15-007-00 for James A. Fitzpatrick Regarding Slow Exhaust Fan Start Leads to Secondary Containment Vacuum Below Technical Specification Limit ML1015505722009-12-28028 December 2009 Event Notification for Fitzpatrick on Offsite Notification for Elevated Tritium Levels ML0509505652004-12-17017 December 2004 Final Precursor Analysis - Fitzpatrick Grip Loop 2017-06-05
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Background
The Secondary Containment [El IS identifier: NG] is a structure comprised of the Reactor Building that surrounds the primary containment and refuel equipment. Its safety function is designed to provide containment for postulated accident scenarios: loss-of-coolant accident and refueling accident. This structure forms a control volume that serves to hold up and dilute the fission products. Since pressure may increase in Secondary Containment relative to the environmental pressure, it was designed to include a differential pressure vacuum such that external atmosphere would leak into containment rather than fission products leak out.
The systems which maintain a differential pressure vacuum inside Secondary Containment include the normal Reactor Building Ventilation (RBV) system [VA] and the safety-related Standby Gas Treatment (SBGT) system [BH]. During a postulated accident scenario, the normal RBV isolates by closing two intake isolation valves and two exhaust isolation valves. At the same time, SBGT initiates in order to filter the Secondary Containment atmosphere prior to releasing to the environment. SBGT has the capacity to maintain the required differential pressure vacuum.
Secondary Containment differential pressure vacuum is maintained either in Normal Mode with RBV or in Isolation Mode with SBGT. During Normal Mode, the RBV system operates with two of three supply fans and two of four exhaust fans inservice. Non-inservice fans are kept on standby. Periodically, as a result of surveillance tests or planned maintenance, Secondary Containment may need to transition between these two modes.
The event described in this Licensee Event Report (LER) involves a deficiency with one exhaust fan, 66FN- 13B, while transitioning to Normal Mode from Isolate Mode.
Event Description
Immediately prior to this event, a test was performed to verify proper operation of "B" above refuel floor exhaust fan damper position switch. The test involved initiating a RBV isolation in order to verify that the damper will close and damper position switch will initiate a signal for 66FN-13B to stop. The test was successful. This planned maintenance was a result of investigations into extent of condition initiated after the events of September 18, 2015 (Reference LER-15-005).
At 20:36 on December 1, 2015, while JAF was at 100 percent power, Secondary Containment was transitioning back to unisolate mode when exhaust fan 66FN-13B did not start as expected. The RBV maintains a fresh air supply in the building using intake and exhaust fans. If the exhaust air capacity becomes degraded, as it did during this event, then the intake air supply begins to overfill the building. The extra air increases building pressure relative to the outside environment. This condition was corrected when 66FN-13B started, without intervention, in approximately 60 seconds.
The change in differential pressure exceeded the Technical Specification (TS) Surveillance Requirement (SR) 3.6.4.1.1 of >1= 0.25 inches of vacuum water gauge for approximately 80 seconds. During the period in which Secondary Containment did not meet the SR the TS Limiting Condition of Operation (LCO) was not met.
Therefore, Secondary Containment was Inoperable. Restoration of the LCO was completed within the allowed action completion time of the TS. A notification was made to the NRC by ENS 51579. This Licensee Event Report (LER) is being submitted per 10 CFR 50.73(a)(2)(v)(C) as an event that could have prevented the fulfillment of safety function to control the release of radioactive material.
Event Analysis
This event began when Secondary Containment was transitioning from Isolation Mode to Normal Mode. First, the fan damper fully opened. Next, the damper position switch gave an initiation signal for the exhaust fan 66FN-13B to start; however, it did not initiate for approximately 60 seconds.
Electricians investigated and discovered that the 66FN-13B motor starter contactor in motor control center 71MCC-141-0B2 was operating sluggishly because of hardened grease in the operating mechanisms. The contactor was cleaned and lubricated with Dow Corning 44 and then verified to operate properly.
The chemical process of oxidation degrades grease by breaking down the molecules and changing its lubrication properties. This oxidation is due to either a stress being placed on the grease or the grease being exposed to air for a long period of time. This degradation manifests itself by increasing grease viscosity until it becomes hardened or caked. In effect, the grease will inhibit mechanical movement rather than assisting it.
Cause
The likely cause of this event is identified as hardened grease on motor starter contactor in 71MCC-141-0B2 which prevented a prompt start of Reactor Building above refuel floor exhaust fan 66FN-13B.
Similar Events Internal On October 5, 2013, hardened grease in the motor starter contactor in 71MCC-431-AR1 led to a blown fuse which tripped stator water pump 94P-15A. 71MCC-431-AR1 had its Preventative Maintenance (PM) Frequency changed from 10 years to 16 years. As a corrective action, the PM Frequency was returned to 10 years.
During the events of October 28, 2014 (LER-14-002-01) and September 18, 2015 (LER-15-005) Reactor Building Ventilation exhaust flow was obstructed and Secondary Containment pressure increased. In both events, the exhaust fan 66FN-13A air flow was obstructed because its damper 66A0D-106A was not full open due to damper operator diaphragm failures and the position switch 66PNS-106A1 did not function to initiate a swap from 66FN-13A and to 66FN-13B. Even though these events resulted in a similar effect (increased pressure), they do not share the same failure mechanism with the event reported by this LER.
External River Bend, November 7, 2007, Reactor Scram as a Result of Loss of Normal Power 13.8 kV Bus. The 13.8 kV breaker supplying the step-down transformer should have tripped to isolate the fault; however, the breaker was slow to operate. The likely cause of the slow operation was likely due to hardened, dirty grease in the breaker mechanism. (ML080080031)
FAILED COMPONENT IDENTIFICATION:
Position Switch Manufacturer: General Electric Manufacturer Model Number: CR106F000BAA NPRDS Manufacturer Code: G080 NPRDS Component Code: CNTR FitzPatrick Component ID: 71MCC-141-0B2
Corrective Actions
Completed Actions
Future Actions Preventative Maintenance (PM) is periodically performed on 71MCC-141-0B2 to ensure its proper operation.
The last performance was conducted on January 22, 2010. This included cleaning and reapplying lubrication to motor starter contactor in 71MCC-141-0B2. The prior PM was performed on January 4, 2005. During this five year interval, the equipment in 71MCC-141-0B2 was found to be in good condition.
In May 2013, (similar to the internal event for 71MCC-431-AR1) the PM frequency for 71MCC-241-0B2 was changed to 15 years. This change was based on the Preventative Maintenance Optimization System (PMOS) Template recommend frequency of 12 years plus a fleet procedure (EN-DC-324) allowance of 1.5 times longer for Non-Critical components.
- As a result of this event, PM frequency for 71MCC-141-0B2 will be adjusted from 15 years to 5 years.
Safety Significance
There was no radiological consequence during this event.
The potential for a radiological consequence was only applicable during the time period that Secondary Containment did not meet >1= 0.25 inches of vacuum water gauge differential pressure. A higher Reactor Building pressure could allow for the exfiltration of radioactive material during an accident. However, the release would be detected by radiation monitors and this would initiate a Secondary Containment isolation.
A differential pressure vacuum is maintained within Secondary Containment by two of four RBV exhaust fans or one of two SBGT trains. During a postulated accident scenario, RBV is placed in isolation and the SBGT is used to maintain differential pressure. This event only affected one of four RBV exhaust fans.
The condition does not adversely impact that ability of RBV to isolate or SBGT to initiate and maintain a sufficient differential pressure. Therefore, the capability of Secondary Containment to mitigate the consequence of an accident is unaffected by this deficiency.
References
- Event Report: LER-15-005, "A" Position Switch and Damper Failure