05-26-2017 | On March 27, 2017, during refueling outage Q1R24 at 0840 hours0.00972 days <br />0.233 hours <br />0.00139 weeks <br />3.1962e-4 months <br />, the Unit 1 Main Steam Isolation Valve ( MSIV) as-found closure time test results indicated that four MSIVs failed to close within the required Technical Specification (TS) time of less than or equal to five seconds. The safety significance of this event was minimal.
The cause of three of the slow closure timing events was due to a less than optimal replacement frequency for the MSIV actuators, and the cause of the fourth slow closure timing event was due to a less than optimal replacement frequency for the MSIV springs.
Corrective actions included replacing the 1-0203-1B and 1-0203-1D MSIV actuators, replacing the springs on the 1-0203-2C MSIV, readjusting the as-left closure times on all four MSIVs and satisfactory retesting prior to startup. Follow-up corrective actions include replacing the 1-0203-2D MSIV actuator and changing the preventive maintenance frequency and description.
Since the MSIV slow closure times were due to degradation from less than optimal replacement frequencies, it is likely the degradation occurred over time since the last successful refueling outage testing and during power operations when the required TS 3.6.1.3, Primary Containment Isolation Valves was applicable. Therefore, this condition is being reported in accordance with 10 CFR 50.73(a)(2)(i)(B), which requires reporting of any operation or condition that was prohibited by the plant's TS. |
---|
|
---|
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 Information Services Branch (T-2 F43), 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 - 00 002
PLANT AND SYSTEM IDENTIFICATION
General Electric - Boiling Water Reactor, 2957 Megawatts Thermal Rated Core Power Energy Industry Identification System (EIIS) codes are identified in the text as [XX].
EVENT IDENTIFICATION
Four Main Steam Isolation Valves (MSIVs) Closure Times Exceed Technical Specifications Limit
A. CONDITION PRIOR TO EVENT
Unit: 1 Reactor Mode: 4 Event Date: March 27, 2017 Event Time: 0840 hours0.00972 days <br />0.233 hours <br />0.00139 weeks <br />3.1962e-4 months <br /> Mode Name: Cold Shutdown Power Level: 0%
B. DESCRIPTION OF EVENT
On March 27, 2017, while Unit 1 was in Mode 4 for refueling outage Q1R24, Operations was performing surveillance, "MSIV Closure Timing," when four of the eight Unit 1 Main Steam [SB] Isolation Valves [ISV] (MSIVs), 1-0203-1B, 1- 0203-1D, 1-0203-2C, and 1-0203-2D failed to close within the required cold shutdown Technical Specification (TS) limit of greater than or equal to three seconds and less than or equal to five seconds. The closure times for those four MSIVs were 5.7, 5.2, 5.1, and 5.6 seconds, respectively. The other four MSIVs all closed within the required TS time.
As part of the event investigation, the actuator vendor provided that an increase in closure timing of the valves is linked to degradation of the actuator [HCU] because it has surpassed its recommended eight year lifespan. The current preventive maintenance (PM) frequency for valve actuator replacement was established based off of the theoretical lifespan of the elastomers. The PM frequencies are currently at 12 years (six refueling outages) for MSIVs 1-0203-1B and 1-0203-1D and 14 years (seven refueling outages) for MSIVs 1-0203-2C and 1-0203-2D. The actuators for MSIVs 1-0203-1B, 1-0203-1D and 1-0203-2D were last replaced in November 2002, while the 1-0203- 2C MSIV actuator was last replaced in March 2015. However, when the 1-0203-2C MSIV actuator was replaced in March 2015, the springs were not replaced. The springs had been in-service for nearly 15 years.
Since the MSIV slow closure times were due to age related degradation from less than optimal PM frequencies, it is likely the degradation occurred over time since the last successful refueling outage testing and during power operations when the required TS 3.6.1.3, Primary Containment Isolation Valves, was applicable. Therefore, this condition is being reported in accordance with 10 CFR 50.73(a)(2)(i)(B), which requires reporting of any operation or condition that was prohibited by the plant's Technical Specifications.
comments regarding burden estimate to the Information Services Branch (T-2 F43), 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 00 002
C. CAUSE OF EVENT
The cause of the slow closure timing for MSIVs 1-0203-1B, 1-0203-1D and 1-0203-2D is due to a less than optimal replacement frequency of the MSIV actuator. The basis of this decision was because ten Unit 1 MSIVs have had slow closure times since the valve actuator replacement PM frequency was extended in 2002. The vendor recommended replacement frequency is eight years (every fourth outage) and the Exelon PM Template replacement frequency is eight years as well. The current PM frequency is either every sixth (twelve years) or every seventh (fourteen years) refueling outage.
The cause of the slow closure for the 1-0203-2C MSIV was due to a less than optimal replacement frequency of the MSIV springs. The springs were replaced for the 1-0203-2C MSIV after being in-service for nearly 15 years. The MSIVs are normally open valves, which have their springs in compression for the entire cycle. If a spring is in compression for nearly 15 years continuously, the overall free length and spring rate decrease with age.
D. SAFETY ANALYSIS
System Design The design of the MSIVs is to prevent reactor coolant [AD] inventory loss and protect plant personnel in the event of steam line breakage outside the isolation valves, and to complete the primary containment [NH] boundary after a Loss of Coolant Accident (LOCA). The MSIVs are 20-inch air/spring operated, balanced "Y"-type globe valves. There are four main steam lines and each steam line has two isolation valves, one inside (inboard MSIV) and one outside (outboard MSIV) of primary containment.
Updated Final Safety Analysis Report (UFSAR) Section 6.2.4.1 provides the valve closure time for the main steam line is based on the main steam line break accident discussed in Section 15.6. Ensuring the MSIV closure time less than or equal to five seconds, sufficient coolant will remain in the reactor vessel to provide adequate core cooling. The valves are designed to close and to be leak-tight during the worst conditions of pressure, temperature, and steam flow following a break in the main steam line outside the containment. The MSIVs are leak tested in accordance with the 10 CFR 50 Appendix J program. UFSAR Section 15.6 provides that a maximum MSIV closure time of 10.5 seconds would limit the total amount of liquid and steam lost from the primary system to prevent the core from being uncovered, and this closure time will ensure the radiological doses are well below the guidelines set forth in 10 CFR 100.
Proper adjustment of the MSIV closure times prevents operation outside of the operational and design limits.
Safety Impact Technical Specifications and the In-Service Testing program require the MSIVs to close in a three to five second time range. Five seconds is fast enough to prevent a gross release of fission products, and three seconds is slow enough to minimize the severity of the pressure transient resulting from isolating the main steam lines during full power operation. Slow MSIV stroke times would challenge the steam release limits of a steam line break outside of containment should the corresponding inboard valve simultaneously fail to close.
The Unit 1 MSIVs 1-0203-1B, 1-0203-1D, 1-0203-2C, and 1-0203-2D failed to close within the required Technical Specification limit of less than or equal to five seconds. The closure times for those four MSIVs were 5.7, 5.2, 5.1, and 5.6 seconds, respectively, however, the four MSIVs all closed inside the UFSAR limit of less than or equal to 10.5 seconds. Although the required five second Technical Specification limit was not met for these four MSIVs, the MSIVs were capable of performing the required UFSAR safety function during the operating cycle prior to Q1 R24.
comments regarding burden estimate to the Information Services Branch (T-2 F43), 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 - 00 002 Furthermore, since the MSIVs were not required to be operable or available at the time of discovery, this condition did not create any actual plant or safety consequences since the unit was not in an accident or transient condition requiring the use of main steam line isolation valves during this period of time.
Risk Insights The closure times for the four MSIVs were 5.7, 5.2, 5.1, and 5.6 seconds and recorded as slow, but the MSIVs did fully close. The MSIV success criterion in the Plant Probabilistic Risk Assessment (PRA) model, however, does not depend on closure time. Therefore, a difference of a fraction of a second between actual MSIV closure time and the acceptance criterion for the Technical Specification closure time has no effect on the PRA model. As a result, there is no effect on Core Damage Frequency (CDF) or Large Early Release Frequency (LERF).
In conclusion, the failure of the four MSIVs to close within the required time would not have caused the station to exceed the inventory and dose release limits. Furthermore, the impact on risk of this event is negligible. Therefore, the overall safety significance of this event was minimal.
E. CORRECTIVE ACTIONS
Immediate:
1. The 1-0203-1B and 1-0203-1D MSIV actuators were replaced during the outage, Q1R24 in 2017.
2. The 1-0203-2C MSIV springs were replaced during the outage, Q1R24 in 2017.
3. All four MSIVs were adjusted for proper as-left closure times, and retested satisfactorily.
Follow-up:
1. The 1-0203-2D MSIV actuator will be replaced during the next refuel outage, Q1R25, in 2019.
2. The PM frequency will be changed to eight years for replacing the Unit 1 and Unit 2 MSIV actuators with additional instructions to replace the MSIV springs during the actuator replacement.
F. PREVIOUS OCCURRENCES
The station events database, LERs, and INPO ICES were reviewed for similar events at Quad Cities. Specifically, this event was primarily attributed to a less than optimal replacement frequency of the MSIV actuators and springs. Based on the causes of this event and associated corrective actions, the events listed below, assisted with the resolution of this event.
- Station Issue Report (IR) 1213432, Unit 1 Outboard MSIV 1-0203-2C Failed QCOS 0250-04 (05/09/2011) - The 1-0203-2C outboard MSIV closure time exceeded the acceptance criteria for cold timing, which is less than or equal to five seconds. The stroke time recorded was 5.2 seconds. The cause was dirty contacts within the control circuitry creating an electrical time delay. This is one of the ten slow closure time events on Unit 1 since 2002, which led to the current action to reduce the valve actuator PM frequency. Therefore, IR 1213432 provided useful insights associated with this event.
- Station Issue Report (IR) 333083, Unit 2 Inboard MSIV 2-0203-1C Slow Closure (05/09/2005) - While performing QCOS 0250-04, "MSIV Closure Timing," the 2-0203-1C MSIV closure time was 5.05 seconds, which is outside of the surveillance acceptance criteria of 3-5 seconds. The cause of the slow valve stroke time was determined to be within the human response time for actuating the stopwatch. This previous event is similar in that stopwatches continue to be used to perform the closure time surveillance. However, this past event is not directly applicable comments regarding burden estimate to the Information Services Branch (T-2 F43), 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 - 00 002 and is not considered a significant station experience that would have directly contributed to preventing the event of this current LER.
- LER 2013-002-00 Outboard Main Steam Isolation Valves (MSIVs) Stroke Times Exceeded (03/11/2013) — All four Unit 1 outboard MSIVs closed slowly due to actuator seals had degraded due to age and wear. The vendor recommended a replacement frequency of eight years for the actuators. This event was four of the ten slow closure events on Unit 1 since 2002, which led to the current action to reduce the valve actuator PM frequency.
Therefore, LER 2013-002-00 provided useful insights associated with this event.
G. COMPONENT FAILURE DATA
The failed component was the air/hydraulic actuator on three of the four MSIVs and springs on the fourth MSIV.
These actuators are Model Numbers SA-A104 and SA-A119 manufactured by Rotork Hiller. The MSIVs are manufactured by Crane.
This event has been reported to ICES under record #407880.
|
---|
|
|
| | Reporting criterion |
---|
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 | |
|