03-22-2017 | On January 24, 2017, at 10:00 hours, Operations was notified that both doors in the secondary containment interlock on the 595 foot elevation between the Reactor Building ( RB) and the Unit 2 Reactor Feed Pump room (located inside the Turbine Building ( TB)) were opened simultaneously for approximately 3 seconds. The failure of this interlock caused a loss of secondary containment per Technical Specification (TS) 3.6.4.1, Condition A. The doors were immediately reclosed, and the secondary containment boundary was immediately reestablished. Operators verified the RB ( secondary containment) differential pressure was maintained operable at greater than 0.10 inches of water vacuum.
Secondary containment remained available and functional during the event since the secondary containment interlock was immediately restored by closing the doors and since the RB differential pressure was maintained during the event. The RB is a common volume to both Units 1 and 2, and an interlock failure can impact the secondary containment for both units.
The cause of the interlock failure was due to a dirty contact that caused the interlock relay to stick. This allowed the second door to open before the first door was secured. Corrective actions included inspecting and cleaning of the interlock relay contacts. Steps will be added to the Preventative Maintenance Work Orders to perform a visual inspection and cleaning of interlock relays.
The safety significance of this event was minimal. Given the impact on the secondary containment, this report is submitted (for Units 1 and 2) in accordance with the requirements of 10 CFR 50.73 (a)(2)(v)(C), which requires the reporting of any event or condition that could have prevented the fulfillment of the safety function of structures or systems that are needed to control the release of radioactive material. |
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Category:Letter
MONTHYEARIR 05000254/20230042024-02-0505 February 2024 Integrated Inspection Report 05000254/2023004 and 05000265/2023004 ML24004A0052024-01-17017 January 2024 Exemption from Select Requirements of 10 CFR Part 73 (EPID L-2023-LLE-0042 (Security Notifications, Reports, and Recordkeeping and Suspicious Activity Reporting)) RS-24-001, Response to Request for Additional Information Regarding Relief Request I5R-26, Inservice Inspection Program Relief Request Regarding Examination Coverage for the Fifth Inservice Inspection Interval2024-01-0303 January 2024 Response to Request for Additional Information Regarding Relief Request I5R-26, Inservice Inspection Program Relief Request Regarding Examination Coverage for the Fifth Inservice Inspection Interval IR 05000254/20234032023-12-22022 December 2023 Public- Quad Cities Nuclear Power Station Security Baseline Inspection Report 05000254/2023403 and 05000265/2023403 IR 05000254/20230102023-12-20020 December 2023 Comprehensive Engineering Team Inspection Report 05000254/2023010 and 05000265/2023010 ML23349A1622023-12-17017 December 2023 Issuance of Amendment Nos. 298 and 294 Increase Completion Time in Technical Specification 3.8.1.B.4 (Emergency Circumstances) RS-23-128, Response to Request for Additional Information for the Emergency License Amendment Request Increase Technical Specifications Completion Time in TS 3.8.1.B.4 from 7 Days to 30 Days2023-12-15015 December 2023 Response to Request for Additional Information for the Emergency License Amendment Request Increase Technical Specifications Completion Time in TS 3.8.1.B.4 from 7 Days to 30 Days ML23305A1402023-12-13013 December 2023 Units 1 & 2; Nine Mile Point, Unit 2; Peach Bottom, Units 2 & 3; and Quad Cities, Units 1 and 2 - Issuance of Amendments to Adopt Traveler TSTF-580 RS-23-123, Emergency License Amendment Request - Increase Technical Specifications Completion Time in TS 3.8.1.B.4 from 7 Days to 30 Days2023-12-13013 December 2023 Emergency License Amendment Request - Increase Technical Specifications Completion Time in TS 3.8.1.B.4 from 7 Days to 30 Days ML23339A1762023-12-0505 December 2023 Notification of NRC Baseline Inspection and Request for Information (05000265/2024001) ML23319A3342023-11-20020 November 2023 Regulatory Audit in Support of License Amendment Requests to Adopt TSTF 505, Revision 2 and 10 CFR 50.69 RS-23-104, Request for Exemption from Enhanced Weapons, Firearms Background Checks, and Security Event Notifications Implementation2023-11-17017 November 2023 Request for Exemption from Enhanced Weapons, Firearms Background Checks, and Security Event Notifications Implementation ML23317A1192023-11-10010 November 2023 Constellation Energy Generation, LLC - 2023 Annual Report - Guarantees of Payment of Deferred Premiums IR 05000254/20230032023-11-0909 November 2023 Integrated Inspection Report 05000254/2023003 and 05000265/2023003 RS-23-113, Submittal of Updated Final Safety Analysis Report (Ufsar), Revision 17 and Fire Protection Report (Fpr), Revision 262023-10-20020 October 2023 Submittal of Updated Final Safety Analysis Report (Ufsar), Revision 17 and Fire Protection Report (Fpr), Revision 26 RS-23-097, Constellation Energy Generation, LLC, Advisement of Leadership Changes and Submittal of Updated Standard Practice Procedures Plans2023-10-12012 October 2023 Constellation Energy Generation, LLC, Advisement of Leadership Changes and Submittal of Updated Standard Practice Procedures Plans ML23206A0382023-09-21021 September 2023 Proposed Alternative to the Requirements of the ASME Code IR 05000254/20230112023-09-20020 September 2023 Safety-Conscious Work Environment Issue of Concern Team Inspection Report 05000254/2023011 and 05000265/2023011 RS-23-089, Sixth Ten-Year Interval Inservice Testing Program2023-09-0505 September 2023 Sixth Ten-Year Interval Inservice Testing Program RS-23-080, Constellation Energy Generation, LLC, Application to Revise Technical Specifications to Adopt TSTF-264-A, Revision 0, 3.3.9 and 3.3.10 - Delete Flux Monitors Specific Overlap Requirement SRs2023-08-30030 August 2023 Constellation Energy Generation, LLC, Application to Revise Technical Specifications to Adopt TSTF-264-A, Revision 0, 3.3.9 and 3.3.10 - Delete Flux Monitors Specific Overlap Requirement SRs RS-23-086, Relief Request I5R-26, Inservice Inspection Program Relief Request Regarding Examination Coverage for the Fifth Inservice Inspection Interval2023-08-28028 August 2023 Relief Request I5R-26, Inservice Inspection Program Relief Request Regarding Examination Coverage for the Fifth Inservice Inspection Interval SVP-23-038, Owner'S Activity Report Submittal Fifth 10-Year Interval 2023 Refueling Outage Activities2023-08-14014 August 2023 Owner'S Activity Report Submittal Fifth 10-Year Interval 2023 Refueling Outage Activities IR 05000254/20230022023-08-0808 August 2023 Integrated Inspection Report 05000254/2023002 and 05000265/2023002 ML23178A0742023-08-0707 August 2023 Issuance of Amendment Nos. 296 and 292 Adoption of TSTF-416 Low Pressure Coolant Injection (LPCI) Valve Alignment Verification Note Location ML23216A0362023-08-0707 August 2023 Notification of an NRC Biennial Licensed Operator Requalification Program Inspection and RFI ML23216A0562023-08-0404 August 2023 Information Meeting (Open House) with a Question and Answer Session to Discuss NRC 2022 End-Of-Cycle Plant Performance Assessment of Quad Cities Nuclear Power Station, Units 1 and 2 SVP-23-031, Regulatory Commitment Change Summary Report2023-07-14014 July 2023 Regulatory Commitment Change Summary Report ML23181A1062023-06-30030 June 2023 Postponement- Information Meeting (Open House) with a Question-And-Answer Session to Discuss NRC 2022 End-Of-Cycle Plant Performance Assessment of Quad Cities Nuclear Power Station ML23178A2422023-06-28028 June 2023 Reassignment of the U.S. Nuclear Regulatory Commission Branch Chief in the Division of Operating Reactor Licensing for Plant Licensing Branch III ML23179A1932023-06-28028 June 2023 07122023 Letter-Significant Public Meeting to Discuss NRC End-of-Cycle Performance Assessment of Quad Cities Nuclear Plant for Performance for 2022 Calendar Year IR 05000254/20234012023-06-26026 June 2023 Cyber Security Inspection Report 05000254/2023401 and 05000265/2023401 IR 05000265/20230402023-06-22022 June 2023 Reissue Quad Cities Nuclear Power Station 95001 Supplemental Inspection Supplemental Report 05000265/2023040 and Follow Up Assessment Letter RS-23-077, Response to NRC Regulatory Issue Summary 2023-01, Preparation and Scheduling of Operator Licensing Examinations2023-06-16016 June 2023 Response to NRC Regulatory Issue Summary 2023-01, Preparation and Scheduling of Operator Licensing Examinations ML23167B1722023-06-16016 June 2023 95001 Supplemental Inspection Report 05000265/2023040 and Follow-Up Assessment Letter RS-23-060, Application to Adopt 10 CFR 50.69, Risk-Informed Categorization and Treatment of Structures, Systems, and Components for Nuclear Power Reactors2023-06-0808 June 2023 Application to Adopt 10 CFR 50.69, Risk-Informed Categorization and Treatment of Structures, Systems, and Components for Nuclear Power Reactors RS-23-059, License Amendment Request to Revise Technical Specifications to Adopt Risk Informed Completion Times TSTF-505, Revision 2, Provide Risk-Informed Extended Completion Times - RITSTF Initiative 4b2023-06-0808 June 2023 License Amendment Request to Revise Technical Specifications to Adopt Risk Informed Completion Times TSTF-505, Revision 2, Provide Risk-Informed Extended Completion Times - RITSTF Initiative 4b ML23144A3632023-05-26026 May 2023 Information Meeting (Open House) with a Question and Answer Session to Discuss NRC 2022 End-of-Cycle Plant Performance Assessment of Quad Cities Nuclear Power Station, Units 1 and 2 RS-23-042, Application to Revise Technical Specifications to Adopt TSTF-580, Provide Exception from Entering Mode 4 with No Operable RHR Shutdown Cooling2023-05-25025 May 2023 Application to Revise Technical Specifications to Adopt TSTF-580, Provide Exception from Entering Mode 4 with No Operable RHR Shutdown Cooling ML23033A4042023-05-15015 May 2023 Exemption from the Requirements of 10 CFR Part 2, Section 2.109(B) Related to Submission of Subsequent License Renewal Application Letter IR 05000254/20234022023-05-15015 May 2023 Security Baseline and ISFSI Inspection Reports 05000254/2023402, 05000265/2023402, 07200053/2023401 ML23132A2022023-05-12012 May 2023 Annual Radiological Environmental Operating Report ML23125A0612023-05-0808 May 2023 Proposed Alternative to the Requirements of the ASME Code IR 05000254/20230012023-05-0808 May 2023 Integrated Report 05000254/2023001 and 05000265/2023001 RS-22-067, 10 CFR 50.46 Annual Report2023-05-0404 May 2023 10 CFR 50.46 Annual Report ML23118A3472023-05-0101 May 2023 County, 1 & 2; Nine Mile Point, 2; and Quad Cities, 1 & 2 - Correction of Amendment No. 193 Adoption of TSTF-306, Revision 2, Add Action to LCO 3.3.6.1 to Give Option to Isolate the Penetration EPID L-2022-LLA-0143 RS-23-068, Response to Request for Additional Information for Quad Cities Relief Request I6R-11, Proposed Alternatives for a Temper Bead Weld Repair of the Mating Surfaces of the Reactor Pressure Vessel Head and Shell2023-04-28028 April 2023 Response to Request for Additional Information for Quad Cities Relief Request I6R-11, Proposed Alternatives for a Temper Bead Weld Repair of the Mating Surfaces of the Reactor Pressure Vessel Head and Shell SVP-23-018, Radioactive Effluent Release Report for 20222023-04-28028 April 2023 Radioactive Effluent Release Report for 2022 ML23114A2522023-04-28028 April 2023 Request to Use a Provision of a Later Edition of the ASME Boiler & Pressure Vessel Code, Section XI ML23110A0622023-04-25025 April 2023 Transmittal of Final Quad Cities Nuclear Power Plant, Unit 1 Accident Sequence Precursor Report (Licensee Event Report 254-2022-001) ML23081A0382023-04-25025 April 2023 County, 1 & 2; Nine Mile Point, 2; and Quad Cities, 1 & 2 - Issuance of Amendments to Adopt TSTF-306, Rev. 2, Add Action to LCO 3.3.6.1 to Give Option to Isolate the Penetration 2024-02-05
[Table view] Category:Licensee Event Report (LER)
MONTHYEARSVP-22-072, Manual Scram Due to Feedwater Regulator Valve Failure Increasing Reactor Water Level2022-12-30030 December 2022 Manual Scram Due to Feedwater Regulator Valve Failure Increasing Reactor Water Level 05000254/LER-2017-0042018-01-0505 January 2018 Unit 1 HPCI Did Not Trip Due to Wear Debris in the Turbine Stop Valve Oil Resetting Solenoid, LER 17-004-00 For Quad Cities Nuclear Power Station, Unit 1 re: Unit 1 HPCI Did Not Trip Due to Wear Debris in the Turbine Stop Valve Oil Resetting Solenoid 05000254/LER-2017-0032017-11-17017 November 2017 Control Room Emergency Ventilation Air Conditioning Piping Refrigerant Leak Due to High Cycle Fatigue, LER 17-003-00 for Quad Cities, Unit 1, Regarding Control Room Emergency Ventilation Air Conditioning Piping Refrigerant Leak Due to High Cycle Fatigue 05000265/LER-2017-0012017-07-13013 July 2017 High Pressure Coolant Injection Minimum Flow Valve Failed to Open, LER 17-001-00 for Quad Cities, Unit 2, Regarding High Pressure Coolant Injection Minimum Flow Valve Failed to Open 05000254/LER-2017-0022017-05-26026 May 2017 Four Main Steam Isolation Valves (MSIVs) Closure Times Exceeded, LER 17-002-00 for Quad Cities, Unit 1, Regarding Four Main Steam Isolation Valves (MSIVs) Closure Times Exceeded 05000254/LER-2017-0012017-03-22022 March 2017 Secondary Containment Interlock Doors Opened Simultaneously, LER 17-001-00 for Quad Cities, Unit 1, Regarding Secondary Containment Interlock Doors Opened Simultaneously 05000265/LER-2016-0022016-06-24024 June 2016 High Pressure Coolant Injection System Declared Inoperable Due to Valve Packing Leak, LER 16-002-00 for Quad Cities Nuclear Power Station Unit 2 - RE: High Pressure Coolant Injection System Declared Inoperable Due to Valve Packing Leak 05000265/LER-2016-0012016-05-19019 May 2016 Main Steam Isolation Valve Local Leak Rate Tests Exceed Technical Specification Limits, LER 2016-001-00 for Quad Cities Nuclear Power Station, Unit 2 Regarding Main Steam Isolation Valve Local Leak Rate Tests Exceed Technical Specification Limits 05000254/LER-2016-0022016-03-14014 March 2016 Secondary Containment Differential Pressure Momentarily Lost Due to Air Line Failure (RWCU Pump Rm), LER 16-002-00 for Quad Cities Units 1 and 2, Regarding Secondary Containment Different Pressure Momentarily Lost due to Air Failure (RWCU pump Rm) 05000254/LER-2016-0012016-03-10010 March 2016 Secondary Containment Differential Pressure Momentarily Lost Due to Air Line Failure (RWCU Hx Rm), LER 16-001-00 for Quad Cities, Unit 1, Regarding Secondary Containment Differential Pressure Momentarily Lost Due to Air Line Failure (RWCU Hx Rm) 05000254/LER-2015-0102016-02-0505 February 2016 Loss of Control Room Emergency Ventilation System Due to Differential Pressure Switch Failure, LER 15-010-00 for Quad Cities, Unit 1, Regarding Loss of Control Room Emergency Ventilation System Due to Differential Pressure Switch Failure SVP-03-036, LER 03-S01-00, Security Event Report for Quad Cities, Unescorted Protected Area Access Granted Based on Falsified Information and Inadequate Screening Caused by a Failure of Administrative Controls.2003-03-0303 March 2003 LER 03-S01-00, Security Event Report for Quad Cities, Unescorted Protected Area Access Granted Based on Falsified Information and Inadequate Screening Caused by a Failure of Administrative Controls. ML17252B4771976-09-15015 September 1976 LER 76-059-00 for Dresden, Units 2 and 3 Re Review of Quad-Cities Unusual Event Letter Led to Discovery That Dresden'S Standby Gas Treatment System Deviated from Single Failure Criteria That Disabled the SBGT System ML18348A2401976-08-0606 August 1976 LER 1976-027-00, Reportable Occurrence of Control Rods for Quad-Cities, Unit 1 ML18348A2391976-08-0404 August 1976 LER 1976-026-00, Reportable Occurrence of Control Rods for Quad-Cities, Unit 1 2022-12-30
[Table view] |
comments regarding burden estimate to the FOIA, Privacy and Information Collections Branch (T-5 F53), U.S. Nuclear Regulatory Commission, Washington, DC 20555-0001, or by e-mail to used to impose an information collection does not display a currently valid OMB control number, the NRC may not conduct or sponsor, and a person is not required to respond to, the information collection.
3. LER NUMBER
2017 - 00 001
PLANT AND SYSTEM IDENTIFICATION
General Electric - Boiling Water Reactor, 2957 Megawatts Thermal Rated Core Power Energy Industry Identification System (El IS) codes are identified in the text as [X0(].
EVENT IDENTIFICATION
Both doors in the secondary containment interlock between the Reactor Building and the Unit 2 Reactor Feed Pump room were opened simultaneously and caused a momentary loss of secondary containment.
A. CONDITION PRIOR TO EVENT
Unit: 1 / 2 Reactor Mode: 1 / 1 Event Date: January 24, 2017 Event Time: 10:00 hours Mode Name: Power Operation / Power Operation Power Level: 98% / 100%
B. DESCRIPTION OF EVENT
On January 24, 2017 at 10:00 hours, the Operations Department was notified that both doors [DR] in the secondary Reactor Feed Pump (RFP) [SK] room (located inside the Turbine Building (TB)) [NM] were opened simultaneously for approximately 3 seconds. The failure of this interlock caused a loss of secondary containment per Technical Specification (TS) 3.6.4.1, Condition A. The doors were immediately reclosed, and the secondary containment boundary was immediately reestablished. Operators verified the RB (secondary containment) differential pressure was maintained operable at greater than 0.10 inches of water vacuum.
The Operations Field Supervisor was then dispatched to the interlock to investigate the condition. It was determined that the condition that led to both doors being open simultaneously could be recreated. At no time during the initial investigation were the doors opened at the same time. The doors were then taken out of service to allow repairs.
Secondary containment remained available and functional during the event since the secondary containment interlock was immediately restored by closing the doors and since the RB differential pressure was maintained during the event. A review of the Station Event Recorder (SER) verified that RB low differential pressure alarms were not received during this event. The RB is a common volume to both Units 1 and 2, and an interlock failure can impact the secondary containment for both units.
On January 24, 2017, at 14:00 hours, ENS #52508 was made to the NRC under 10 CFR 50.72(b)(3)(v)(C), to report this event as an event or condition that could have prevented the fulfillment of a safety function.
At the time of the event, another individual had traversed through the RB door when a contractor started transitioning through the TB door. As they opened the TB-side door the RB-side door was noticed open and in the process of closing. At no time during the event were the open door indicating lights illuminated. The door was fully closed in three seconds. It was found that the sticking relay made up the logic falsely signaling to the system that the opposite door was closed.
comments regarding burden estimate to the FOIA, Privacy and Information Collections Branch (T-5 F53), U.S. Nuclear Regulatory Commission, Washington, DC 20555-0001, or by e-mail to used to impose an information collection does not display a currently valid OMB control number, the NRC may not conduct or sponsor, and a person is not required to respond to, the information collection.
3. LER NUMBER
2017 - 00 001 Given the impact on the secondary containment, this report is submitted (for Units 1 and 2) in accordance with the requirements of 10 CFR 50.73(a)(2)(v)(C), which requires the reporting of any event or condition that could have prevented the fulfillment of the safety function of structures or systems that are needed to control the release of radioactive material.
C. CAUSE OF EVENT
The cause was determined to be a dirty contact on an interlock relay that caused the relay to stick. The contact was inspected, cleaned, and tested satisfactory. The door was operated approximately 35 times and the sticking relay could not be repeated.
D. SAFETY ANALYSIS
System Design The function of the secondary containment is to contain, dilute, and hold up fission products that may leak from primary containment following a Design Basis Accident (DBA). In conjunction with operation of the Standby Gas Treatment System (SBGTS) [BH] and closure of certain valves [V] whose lines penetrate the secondary containment, the secondary containment is designed to reduce the activity level of the fission products prior to release to the environment, and to isolate and contain fission products that are released during certain operations that take place inside primary containment, when primary containment is not required to be operable, or that take place outside primary containment.
Updated Final Safety Analysis Report (UFSAR) Section 6.2.3.1 provides that the safety objective of the secondary containment system, in conjunction with other engineered safeguards and nuclear safety systems, is to limit the release of radioactive materials so that offsite doses resulting from a postulated DBA will remain below 10 CFR 100 guideline values.
The secondary containment interlocks are designed to provide personnel access to the RB from the TB while maintaining a negative differential pressure in the RB. The Unit 2 RFP interlock doors are normally secured closed by energized electromagnets. The doors are operated by a pushbutton near each door that de-energize the electromagnets and start an actuator to open the door. The doors are designed with relay logic so that only one door can be opened at a time. A red light near each door illuminates when one of the doors is open.
Safety Impact Both Units 1 and 2 share a common RB (secondary containment). When both RFP interlock doors were opened simultaneously, this caused a momentary loss of secondary containment.
TS 3.6.4.1, Action A.1, requires restoration of secondary containment to operable status within four hours. This four hour Completion Time provides a period of time to correct the problem that is commensurate with the importance of maintaining secondary containment during Modes 1, 2, and 3, since the probability of an accident occurring during this short period where secondary containment is inoperable is minimal.
The primary purpose of the secondary containment is to minimize the ground level release of airborne radioactive materials and to provide a controlled, elevated release of the building atmosphere under accident conditions. An engineering analysis was performed to demonstrate that during the short (momentary) time that both doors of the corresponding interlock were simultaneously opened, the doors were not open sufficiently long enough to cause a RB comments regarding burden estimate to the FOIA, Privacy and Information Collections Branch (T-5 F53), U.S. Nuclear Regulatory Commission, Washington, DC 20555-0001, or by e-mail to used to impose an information collection does not display a currently valid OMB control number, the NRC may not conduct or sponsor, and a person is not required to respond to, the information collection.
3. LER NUMBER
2017 - 00 001 low differential pressure alarm, hence no loss of secondary containment differential pressure occurred. Secondary containment would have sufficiently contained radioactive materials during a Loss of Coolant Accident (LOCA) such that all current dose limits would remain to be met. As a result, the system safety function of secondary containment would have been maintained throughout the event. Therefore, the dose consequence from postulated releases from the RB during this short duration would remain to be bounded by the existing design basis LOCA dose analysis. The safety significance of this event was minimal.
The engineering analysis that was performed demonstrated this event did not constitute a Safety System Functional Failure (SSFF). (Reference NEI 99-02, Revision 7, Regulatory Assessment Performance Indicator Guideline, Section 2.2, Mitigating Systems Cornerstone, Safety System Functional Failures, Clarifying Notes, Engineering analyses.) As such, this event will not be reported in the NRC Performance Indicator (PI) for safety system functional failures since an engineering analysis was performed which determined that the system was capable of performing its safety function during this event when both doors of the secondary containment interlock were momentarily simultaneously opened.
Risk Insights The plant Probabilistic Risk Assessment (PRA) model gives no credit to the secondary containment and does not include it in the model, hence the as-found conditions did not contribute to an increase in risk. In addition, the physical integrity of the secondary containment structure was never compromised and the primary containment function was never lost.
Although secondary containment was momentarily inoperable per TS 3.6.4.1, Condition A, when the Unit 2 RFP interlock doors were opened simultaneously due to an intermittently binding interlock relay contact, there was no DBA condition in progress, and secondary containment function was restored immediately when one of the doors was closed. RB differential pressure was maintained during the event.
In conclusion, the overall safety significance and impact on risk of this event were minimal.
E. CORRECTIVE ACTIONS
Immediate:
1. The dirty contact was inspected, cleaned and tested satisfactorily. The door was operated approximately 35 times and the issue did not reoccur.
Follow-up:
1. Add steps to all interlock Preventive Maintenance and current Work Orders for visual inspection, voltage checks, and cleaning of all interlock relays.
F. PREVIOUS OCCURRENCES
The station events database, LERs, and INPO Consolidated Event System (ICES) were reviewed for similar events at Quad Cities Nuclear Power Station. This event was a failure of a secondary containment interlock door caused by a dirty contact on an interlock relay, which allowed two interlock doors to be opened simultaneously. Based on the conditions of this event, causes, and associated corrective actions, the events listed below, although similar in topic, are not considered significant station experiences that would have directly contributed to preventing this event.
comments regarding burden estimate to the FOIA, Privacy and Information Collections Branch (T-5 F53), U.S. Nuclear Regulatory Commission, Washington, DC 20555-0001, or by e-mail to used to impose an information collection does not display a currently valid OMB control number, the NRC may not conduct or sponsor, and a person is not required to respond to, the information collection.
3. LER NUMBER
2017 - 00 001
- LER 254/2014-002-00, 06/02/14, Reactor Building Interlock Doors Opened Simultaneously Cause Loss of Secondary Containment (04/1/14) - Both doors in the secondary containment interlock on the 595 foot elevation from the Unit 2 Reactor Feed Pump room to the Reactor Building were opened simultaneously. The cause of the interlock failure was due to a malfunctioning interlock door hydraulic actuator and time delay relays had allowed the second door to open before the first door was secured. Corrective actions included replacing the failed actuator, adjusting the limit switch, and a set point change to resolve relay time delay issues. Since this event cause is different from the current event cause (sticking relay), the previous interlock failure event is not directly applicable to the event of this current LER.
- LER 254/2015-006-00, 6/24/15, Interlock Doors Opened Simultaneously Cause Loss of Secondary Containment (04/28/15) - the control room was notified that the Unit 1/2 emergency diesel generator (EDG) room manual side door and the Unit 1 reactor building (RB) side door, as a part of the personnel interlock to the 1/2 EDG room, were opened simultaneously. The failure of this interlock caused a temporary loss of secondary containment (inoperable) per Technical Specification (TS) 3.6.4.1, Condition A. The 1/2 EDG manual interlock door was closed immediately, and the secondary containment boundary was immediately reestablished. Operators verified the RB (secondary containment) differential pressure remained negative during this event. It was determined that the latch did not engage into the strike plate, hence this failure mechanism is not directly applicable to the event of this current LER.
G. COMPONENT FAILURE DATA
Failed Equipment: Relay Component Manufacturer: General Electric Component Model Number: CR122 Component Part Number: N/A This event has been reported to ICES as Report No. 326170
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05000265/LER-2017-001 | High Pressure Coolant Injection Minimum Flow Valve Failed to Open LER 17-001-00 for Quad Cities, Unit 2, Regarding High Pressure Coolant Injection Minimum Flow Valve Failed to Open | 10 CFR 50.73(a)(2)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident | 05000254/LER-2017-001 | Secondary Containment Interlock Doors Opened Simultaneously LER 17-001-00 for Quad Cities, Unit 1, Regarding Secondary Containment Interlock Doors Opened Simultaneously | 10 CFR 50.73(a)(2)(v)(C), Loss of Safety Function - Release of Radioactive Material | 05000254/LER-2017-002 | Four Main Steam Isolation Valves (MSIVs) Closure Times Exceeded LER 17-002-00 for Quad Cities, Unit 1, Regarding Four Main Steam Isolation Valves (MSIVs) Closure Times Exceeded | 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications | 05000254/LER-2017-003 | Control Room Emergency Ventilation Air Conditioning Piping Refrigerant Leak Due to High Cycle Fatigue LER 17-003-00 for Quad Cities, Unit 1, Regarding Control Room Emergency Ventilation Air Conditioning Piping Refrigerant Leak Due to High Cycle Fatigue | 10 CFR 50.73(a)(2)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident | 05000254/LER-2017-004 | Unit 1 HPCI Did Not Trip Due to Wear Debris in the Turbine Stop Valve Oil Resetting Solenoid LER 17-004-00 For Quad Cities Nuclear Power Station, Unit 1 re: Unit 1 HPCI Did Not Trip Due to Wear Debris in the Turbine Stop Valve Oil Resetting Solenoid | |
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