3-27-2017 | On January 25, 2017, at 1800 CST, while operating at 100% power, during planned surveillance testing, Drywell Vent Inboard Isolation Valve, CV4302 (System Code JM), was found to exceed its Leakage Integrity Test limits and was declared inoperable. The initial observed conditions indicated that CV4302 was the likely source of leakage and was the focus of repair efforts. After completion of repairs to CV4302, post maintenance testing showed that the Drywell Vent Line Outboard Isolation valve, CV4303, was exceeding its valve leakage limits, and therefore, was declared inoperable at 0300 CST on January 26, 2017. This resulted in a containment penetration flow path not within purge valve leakage limits and was reported in accordance with 10 CFR 50.72(b)(3)(v)(C) (reference EN#52511). Repairs were completed on CV4303 and both primary containment valves were declared operable at 1007 CST on January 26, 2017.
The cause of this event was determined to be inadequate work instructions and maintenance procedures.
This event was of low safety significance and had no impact on public health or safety. This event is reportable pursuant to 10CFR50.73(a)(2)(i)(B) as a condition prohibited by Technical Specifications. |
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Category:Letter
MONTHYEARL-2024-010, Point Units 3 and 4, Seabrook, Duane Arnold, and Point Beach Units 1 and 2, Nuclear Property Insurance - 10 CFR 50.54(w)(3)2024-01-25025 January 2024 Point Units 3 and 4, Seabrook, Duane Arnold, and Point Beach Units 1 and 2, Nuclear Property Insurance - 10 CFR 50.54(w)(3) NG-23-0010, Supplement to Duane Arnold Exemption Request Regarding Enhanced Weapons, Firearms Background Checks, and Security Event Notifications Final Rule2023-12-0606 December 2023 Supplement to Duane Arnold Exemption Request Regarding Enhanced Weapons, Firearms Background Checks, and Security Event Notifications Final Rule NG-23-0009, Part 73 Exemption Request Regarding Enhanced Weapons, Firearms Background Checks, and Security Event Notifications Final Rule2023-11-16016 November 2023 Part 73 Exemption Request Regarding Enhanced Weapons, Firearms Background Checks, and Security Event Notifications Final Rule ML23201A0872023-08-0303 August 2023 Audit Plan in Support of Review of License Amendment NG-23-0006, Independent Spent Fuel Storage Installation (ISFSI) Financial Assurance Update2023-05-23023 May 2023 Independent Spent Fuel Storage Installation (ISFSI) Financial Assurance Update ML23137A1672023-05-11011 May 2023 Submittal of 2022 Annual Radiological Environmental Operating Report NG-23-0004, 2022 Annual Radioactive Material Release Report2023-04-25025 April 2023 2022 Annual Radioactive Material Release Report NG-23-0003, 2022 Annual Exposure Report - Form 5s2023-04-21021 April 2023 2022 Annual Exposure Report - Form 5s NG-23-0002, 10 CFR 50.59 Report, Commitment Changes, 10 CFR 72.48 Report, Quality Assurance Program Changes, Technical Specification Basis Changes, and Revision of the DAEC Defueled Safety Analysis Report2023-03-27027 March 2023 10 CFR 50.59 Report, Commitment Changes, 10 CFR 72.48 Report, Quality Assurance Program Changes, Technical Specification Basis Changes, and Revision of the DAEC Defueled Safety Analysis Report NG-23-0001, 2023 Annual Decommissioning and Spent Fuel Management Funding Status Report2023-03-27027 March 2023 2023 Annual Decommissioning and Spent Fuel Management Funding Status Report L-2023-029, and Point Beach Units 1 and 2 Nuclear Property Insurance - 10 CFR 50.54(w)(3)2023-03-10010 March 2023 and Point Beach Units 1 and 2 Nuclear Property Insurance - 10 CFR 50.54(w)(3) ML22361A1022023-02-24024 February 2023 Reactor Decommissioning Branch Project Management Changes for Some Decommissioning Facilities and Establishment of Backup Project Manager for All Decommissioning Facilities ML22339A0012022-12-22022 December 2022 Acceptance of Requested Licensing Action Amendment Request for Common Emergency Plan IR 05000331/20220032022-12-13013 December 2022 NRC Inspection Report No. 05000331/2022003 (Drss) ML22285A0072022-10-13013 October 2022 NRC Analysis of NextEra Energy Duane Arnold'S Decommissioning Funding Status Report, Docket No. 50-331 IR 05000331/20220022022-07-13013 July 2022 NRC Inspection Report Nos. 05000331/2022002(DNMS) and 07200032/2022002(DNMS) ML22090A1922022-05-26026 May 2022 Letter to B. Coffey, FPL from M. Doell - Duane Arnold Post Shutdown Activities Report Review Letter ML22132A2872022-05-24024 May 2022 ISFSI DQAP Approval Letter ML22111A0332022-05-20020 May 2022 Operating License Page Correction Letter to B. Coffey, Florida Power and Light, from M. Doell NG-22-0055, Revision to Duane Arnold Energy Center (DAEC) ISFSI-Only Emergency Plan2022-05-20020 May 2022 Revision to Duane Arnold Energy Center (DAEC) ISFSI-Only Emergency Plan ML22089A0492022-05-12012 May 2022 Sfmp Review Letter NG-22-0053, 2021 Annual Radiological Environmental Operating Report2022-05-0606 May 2022 2021 Annual Radiological Environmental Operating Report NG-22-0052, Regulatory Issue Summary 2000-11. NRC Emergency Telecommunications System, Statement of Intent to Implement the Proposed Voluntary Initiative2022-05-0404 May 2022 Regulatory Issue Summary 2000-11. NRC Emergency Telecommunications System, Statement of Intent to Implement the Proposed Voluntary Initiative IR 05000331/20224012022-04-27027 April 2022 Decommissioning Security Inspection Report 05000331/2022401 NG-22-0050, Revised Response to Request for Additional Information Relating to Decommissioning Quality Assurance Program, Revision 02022-04-26026 April 2022 Revised Response to Request for Additional Information Relating to Decommissioning Quality Assurance Program, Revision 0 NG-22-0049, 2021 Annual Radioactive Material Release Report2022-04-26026 April 2022 2021 Annual Radioactive Material Release Report L-2022-068, NextEra Energy Duane Arnold Quality Assurance Topical Report (FPL-3) Revision 22022-04-25025 April 2022 NextEra Energy Duane Arnold Quality Assurance Topical Report (FPL-3) Revision 2 ML22066A7632022-04-25025 April 2022 ISFSI-Only Emergency Plan License Amendment Approval NG-22-0035, Response to Request for Additional Information Relating to Decommissioning Quality Assurance Program. Revision 02022-04-13013 April 2022 Response to Request for Additional Information Relating to Decommissioning Quality Assurance Program. Revision 0 NG-22-0047, Registration of Independent Spent Fuel Installation Storage Cask and Notification of Permanent Removal of All Spent Fuel Assemblies from the Spent Fuel Pool2022-04-11011 April 2022 Registration of Independent Spent Fuel Installation Storage Cask and Notification of Permanent Removal of All Spent Fuel Assemblies from the Spent Fuel Pool NG-22-0042, Registration of Independent Spent Fuel Installation Storage Casks2022-04-0808 April 2022 Registration of Independent Spent Fuel Installation Storage Casks NG-22-0041, and Independent Spent Fuel Storage Installation, 2022 Annual Decommissioning and Spent Fuel Management Funding Status Report2022-03-31031 March 2022 and Independent Spent Fuel Storage Installation, 2022 Annual Decommissioning and Spent Fuel Management Funding Status Report NG-22-0031, 2021 Annual Exposure Report - Form 5s2022-03-23023 March 2022 2021 Annual Exposure Report - Form 5s NG-22-0030, Registration of Independent Spent Fuel Installation Storage Casks2022-03-23023 March 2022 Registration of Independent Spent Fuel Installation Storage Casks ML22080A1822022-03-22022 March 2022 Letter to B. Coffey from M. Doell - Duane Arnold ISFSI QAPD RAI Letter L-2022-012, Florida Power & Light Company Nuclear Property Insurance - 10 CFR 50.54(w)(3)2022-03-16016 March 2022 Florida Power & Light Company Nuclear Property Insurance - 10 CFR 50.54(w)(3) ML22059A7462022-03-10010 March 2022 ISFSI-Only Physical Security Plan License Amendment Approval NG-22-0025, Registration of Independent Spent Fuel Installation Storage Casks2022-03-0808 March 2022 Registration of Independent Spent Fuel Installation Storage Casks IR 05000331/20220012022-03-0404 March 2022 Subject: NRC Inspection Report Nos. 05000331/2022001(DNMS) and 07200032/2022001(DNMS) NG-22-0021, Registration of Independent Spent Fuel Installation Storage Casks2022-02-24024 February 2022 Registration of Independent Spent Fuel Installation Storage Casks ML22007A2722022-02-11011 February 2022 Cover Letter - NRC Duane Arnold Exemption Issuance NG-22-0014, Registration of Independent Spent Fuel Installation Storage Casks2022-02-10010 February 2022 Registration of Independent Spent Fuel Installation Storage Casks ML22028A2822022-02-0303 February 2022 Defueled Physical Security Plan License Amendment Approval ML22033A0802022-02-0202 February 2022 Supplement to License Amendment Request (TSCR-188): Proposed Change to the Physical Security Plan for the Post-Shutdown and Permanently Defueled Condition IR 05000331/20210012022-01-25025 January 2022 NRC Inspection Report Nos. 05000331/2021001(DNMS); 07200032/2021001(DNMS); and 07200032/2021002(DNMS) - Duane Arnold Energy Center ML21172A2172022-01-21021 January 2022 Issuance of License Amendment to Adopt ISFSI-Only Technical Specifications NG-22-0009, Registration of Independent Spent Fuel Installation Storage Casks2022-01-20020 January 2022 Registration of Independent Spent Fuel Installation Storage Casks NG-22-0001, Supplement to Exemption Request for Failed Fuel Can Weight in a Certificate of Compliance 1004 Renewed Amendment 17 61BTH Type 2 Dry Shielded Canister2022-01-0606 January 2022 Supplement to Exemption Request for Failed Fuel Can Weight in a Certificate of Compliance 1004 Renewed Amendment 17 61BTH Type 2 Dry Shielded Canister NG-21-0038, Registration of Independent Spent Fuel Installation Storage Casks2021-12-22022 December 2021 Registration of Independent Spent Fuel Installation Storage Casks NG-21-0035, Supplement to Exemption Request for Failed Fuel Can Weight in a Certificate of Compliance 1004 Renewed Amendment 17 61 Bth Type 2 Dry Shielded Canister2021-12-10010 December 2021 Supplement to Exemption Request for Failed Fuel Can Weight in a Certificate of Compliance 1004 Renewed Amendment 17 61 Bth Type 2 Dry Shielded Canister 2024-01-25
[Table view] Category:Licensee Event Report (LER)
MONTHYEARNG-18-0040, LER 2018-001-00 for Duane Arnold Energy Center Regarding Loss of RPS Function During MSIV and TSV Channel Functional Testing Due to Use of a Test Box2018-04-0404 April 2018 LER 2018-001-00 for Duane Arnold Energy Center Regarding Loss of RPS Function During MSIV and TSV Channel Functional Testing Due to Use of a Test Box 05000331/LER-2017-0012017-03-27027 March 2017 Condition Prohibited by Technical Specification - Containment Vent and Purge Valve Leakage, LER 17-001-00 for Duane Arnold Energy Center Regarding Condition Prohibited by Technical Specification - Containment Vent and Purge Valve Leakage NG-17-0072, LER 17-001-00 for Duane Arnold Energy Center Regarding Condition Prohibited by Technical Specification - Containment Vent and Purge Valve Leakage2017-03-27027 March 2017 LER 17-001-00 for Duane Arnold Energy Center Regarding Condition Prohibited by Technical Specification - Containment Vent and Purge Valve Leakage 05000331/LER-2016-0032016-12-0606 December 2016 Main Steam Isolation Valve Leakage Exceeded Technical Specification Limit, LER 16-003-00 for Duane Arnold Energy Center Regarding Main Steam Isolation Valve Leakage Exceeded Technical Specification Limit 05000331/LER-2016-0022016-12-0606 December 2016 Unplanned RCIC Inoperability Results in Safety System Functional Failure, LER 16-002-00 for Duane Arnold Energy Center Regarding Unplanned RCIC Inoperability Results in Safety Functional Failure NG-16-0225, LER 16-003-00 for Duane Arnold Energy Center Regarding Main Steam Isolation Valve Leakage Exceeded Technical Specification Limit2016-12-0606 December 2016 LER 16-003-00 for Duane Arnold Energy Center Regarding Main Steam Isolation Valve Leakage Exceeded Technical Specification Limit NG-16-0226, LER 16-002-00 for Duane Arnold Energy Center Regarding Unplanned RCIC Inoperability Results in Safety Functional Failure2016-12-0606 December 2016 LER 16-002-00 for Duane Arnold Energy Center Regarding Unplanned RCIC Inoperability Results in Safety Functional Failure 05000331/LER-2016-0012016-08-18018 August 2016 Two Instances of Both Doors in Secondary Containment Airlock Opened Concurrently, LER 16-001-00 for Duane Arnold Energy Center Regarding Two Instances of Both Doors in Secondary Containment Airlock Opened Concurrently 05000331/LER-2015-0062016-02-18018 February 2016 HPCI and RCIC Condensate Storage Tank Suction Transfer Inoperable, LER 15-006-00 for Duane Arnold Regarding HPCI and RCIC Condensate Storage Tank Suction Transfer Inoperable 05000331/LER-2015-0022016-01-28028 January 2016 Unanalyzed Condition Due to Degraded Primary Containment Suppression Pool Coating, LER 15-002-01 for Duane Arnold Regarding Unanalyzed Condition Due to Degraded Primary Containment Suppression Pool Coating NG-15-0236, LERs 15-001-01 and 15-003-01 for Duane Arnold Regarding Both Doors in Secondary Containment Airlock Opened Concurrently2015-06-25025 June 2015 LERs 15-001-01 and 15-003-01 for Duane Arnold Regarding Both Doors in Secondary Containment Airlock Opened Concurrently NG-07-0355, LER 07-S01-00 for Duane Arnold Regarding Unauthorized Person Allowed Entry to Duane Arnold Energy Center Protected Area2007-05-0303 May 2007 LER 07-S01-00 for Duane Arnold Regarding Unauthorized Person Allowed Entry to Duane Arnold Energy Center Protected Area NG-03-0373, LER 03-S01-00, Duane Arnold Unattended Safeguards Information Outside of the Protected Area Caused by Personnel Error2003-05-15015 May 2003 LER 03-S01-00, Duane Arnold Unattended Safeguards Information Outside of the Protected Area Caused by Personnel Error 2018-04-04
[Table view] |
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I. Description of Event:
CV4302/CV4303 Background The Fisher series 9200 butterfly valve used for the Primary Containment Purge and Vent System, including valves CV4302, Drywell Vent Line Inboard Isolation valve, and CV4303, Drywell Vent Line Outboard Isolation valve, employs a heavy-duty butterfly valve body designed for stringent shutoff requirements. In the particular model valve used for Containment Purge and Vent, a rubber T-ring seat is contained in the valve body, and an external sealing pressure forces the T-ring against the disc periphery only when the disc is closed. There is no contact between the disc and T-ring when the disc is opening or closing.
T-ring (or T-seal) pressurization is accomplished automatically through the use of a plunger-actuated Numatics valve which allows air pressure to the T-seal chamber when activated by an external lever. This lever is attached to the valve shaft opposite the actuator end, and is secured with a key and setscrew such that the lever is in line with the disc. Fine adjustment of the Numatics valve plunger depression is afforded by a capscrew threaded into the lever and held in place with a locking nut.
Event
During Refueling Outage (RFO) 25, planned maintenance was performed on CV4302 and CV4303. The following narrative discusses the work performed on CV4302, which is also indicative of work performed on CV4303.
RFO 25 began on October 3, 2016. On October 6, 2016, as-found Local Leak Rate Tests (LLRTs) were performed on CV4302 and CV4303 with satisfactorily results. On October 9, Preventative Maintenance (PM) 40389727, CV4302: Replace T-seal, 0-Rings, and Numatics Valve, commenced. From October 10 to October 17, the valve rebuild activities were completed. On October 19, a new Numatics valve was installed. As part of this task, the Numatics valve is set up in accordance with maintenance procedure VALVE-F130-01, Repair of 9200 Series T-ring Butterfly Valves, Appendix 3. Post Maintenance Testing (PMT) was completed satisfactorily on October 20, 2016. As-left Leakage Integrity Testing was completed with satisfactory results on October 25. During startup from RFO 25, CV4302 and CV4303 were cycled as part of primary containment inerting. The cycling of the valves started a 92 day Technical Specification (TS) Action Statement, to perform Surveillance Requirements (SRs) for Leakage Integrity Testing (TS SR 3.6.1.3.4).
Duane Arnold Energy Center 05000-331 On January 25, 2017, Surveillance Test Procedure (STP) 3.6.1.3-02 was commenced in accordance with TS SR 3.6.1.3.3, to verify the isolation time of each power operated automatic PCIV, except for MSIVs, is within limits. Both CV4203 and CV4303 were found within their stroke time limits. Following performance of STP 3.6.1.3-02, STP 3.6.1.3-01, Containment Purge and Vent Valve Leakage Integrity Test, was conducted in accordance with TS SR 3.6.1.3.4, to perform leakage rate testing for each primary containment purge valve with resilient seals.
When Leakage Integrity Testing commenced, it was evident that the test volume between CV4302 and CV4303 would not maintain pressure from the Leak Rate Monitor equipment.
Once this was identified, troubleshooting commenced and found the indicated T-seal chamber pressures lower than expected for both CV4302 (10 psig) and CV4303 (40 psig).
With these as-found indicated pressures it was assumed that CV4302 was the cause of the high leakage and was it was subsequently declared inoperable. Additional troubleshooting utilizing calibrated pressure instrumentation found the T-seal chamber pressures at 35 psig for CV4302 and 18 psig for CV4303. Work was completed under Work Order 40405348 on CV4302, which restored the T-seal pressure by adjusting the hex head screw that engages the Numatics T-seal pressure switch plunger. Subsequent Leakage Integrity Testing on CV4302 found the penetration was still unable to be pressurized to test pressure, thus CV4303 was declared inoperable as well.
This resulted in a primary containment penetration flow path not within purge valve leakage limits and was reported to the NRC in accordance with 10 CFR 50.72(b)(3)(v)(C) (reference EN#52511).
II. Assessment of Safety Consequences:
As a result of this event, a Root Cause Evaluation (RCE) was completed. As part of the RCE, data gathering testing was conducted on February 17, 2017 to determine if the actual CV4302 T-seal pressure of 35 psig would have adequately sealed the penetration. The test configuration held the CV4303 T-seal fully pressurized and CV4302's T-seal pressurized to the initial troubleshooting as-found pressure of 35 psig. The test was performed with the CV4302 T-seal initially depressurized to 0 psig and then inflated to 35 psig as would have occurred when the valve was cycled during the surveillance testing performed on January 25, 2017. The leakage rate in the test boundary between CV4302 and CV4303 was less than 300 sccm, which was well below the allowable limit of 22,000 sccm. The test results with the CV4302 T-seal chamber pressurized to 35 psig provided evidence that CV4302 remained operable during the period of concern. Therefore, the penetration flow path would have met the TS requirements to isolate and not impact the primary containment operational leakage limit of 1.0 La.
Based on the penetration flow path being operable from reactor, startup in October 2016 until discovery of the condition on January 25, 2017, this event was not a condition that could have prevented the fulfillment of a safety function and is not reportable pursuant to 10CFR50.73(a)(2)(v). However, CV4303 would have been considered inoperable during that time period. Since TS Condition 3.6.1.3, Condition E, one or more penetration flow paths with one or more containment purge valves not within purge valve leakage limits, Required Action E.1, isolate the affected penetration flow path by use of at least one closed and de-activated automatic valve, closed manual valve, blind flange, or check valve with flow through the valve secured, with a Completion Time of 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />, was not completed, this event is reportable as a Condition Prohibited by TS.
III. Cause of Event:
The RCE determined that the cause of this event was inadequate work instructions and maintenance procedures. Specifically, the work packages associated with rebuilding containment vent and purge valves did not contain the appropriate level of detail to ensure adequate T-seal pressurization is maintained after return to service, and maintenance procedure VALVE-F130-01, Section 'A', did not contain the appropriate level of detail to ensure the Numatics switch operates properly to maintain Primary Containment Isolation Valve (PCIV) operability.
IV. Corrective Actions:
Immediate Corrective Actions
Repairs were completed on CV4303 and CV4302 under Work Order 40405348 and both containment valves were declared operable at 1007 CST on January 26, 2017.
An Extent of Condition review was completed for the other primary containment isolation valves that utilize a pressurized T-seal. No other valves were identified with operability concerns or low T-seal pressures.
Corrective Actions for Cause of Event Model Work Orders for the series 9200 T-seal valves will be revised to improve content and quality to ensure repeatability of T-seal pressurization.
Maintenance procedure VALVE-F130-01 Sections A and C, will be revised to improve the content and level of detail to ensure the Numatics switch operates properly to maintain PCIV operability.
V. Additional Information:
Previous Similar Occurrences:
A review of NextEra Energy Duane Arnold LERs from the previous 10 years found no other instance of events related to Primary Containment Vent and Purge Valve "as found" Leakage Integrity testing.
EIIS System and Component Codes:
JM - Containment Isolation Control System Reporting Requirements:
This activity is being reported pursuant to the requirements of 1 OCFR50.73(a)(2)(i)(B).