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Category:Letter
MONTHYEARLIC-25-0002, Independent Spent Fuel Storage Installation - Transmittal of Annual Radioactive Effluent Release Report2025-01-30030 January 2025 Independent Spent Fuel Storage Installation - Transmittal of Annual Radioactive Effluent Release Report LIC-25-0001, Independent Spent Fuel Storage Installation - Response to Acceptance of Requested Licensing Action License Amendment Request to Revise the License Termination Plan (L-2024-LLA-0095)2025-01-16016 January 2025 Independent Spent Fuel Storage Installation - Response to Acceptance of Requested Licensing Action License Amendment Request to Revise the License Termination Plan (L-2024-LLA-0095) LIC-24-0017, ISFSI - Phase 1 Final Status Survey Report to Support Approved License Termination Plan, Revision 1; and Technical Support Document for the Ludlum 44-20 Detector Sensitivity2024-11-21021 November 2024 ISFSI - Phase 1 Final Status Survey Report to Support Approved License Termination Plan, Revision 1; and Technical Support Document for the Ludlum 44-20 Detector Sensitivity LIC-24-0015, Response to Proposed Revision to the Omaha Public Power District (OPPD) Fort Calhoun Station (FCS) Decommissioning Quality Assurance Plan (DQAP) – Clarification of Request for Additional Information Response2024-11-20020 November 2024 Response to Proposed Revision to the Omaha Public Power District (OPPD) Fort Calhoun Station (FCS) Decommissioning Quality Assurance Plan (DQAP) – Clarification of Request for Additional Information Response LIC-24-0016, Independent Spent Fuel Storage Installation - 2024 Decommissioning Funding Plan Required 72.30(c) Updated Financial Information2024-11-19019 November 2024 Independent Spent Fuel Storage Installation - 2024 Decommissioning Funding Plan Required 72.30(c) Updated Financial Information ML24318C2532024-11-18018 November 2024 Acceptance of Requested Licensing Action License Amendment Request to Revise the License Termination Plan (L-2024-LLA-0095) IR 05000285/20240032024-10-29029 October 2024 NRC Inspection Report 05000285/2024003 LIC-24-0013, Independent Spent Fuel Storage Installation - Intent to Submit a Supplement to 2021, and 2024 Nuclear Decommissioning Funding Plan Required 72.30(c) Update2024-10-10010 October 2024 Independent Spent Fuel Storage Installation - Intent to Submit a Supplement to 2021, and 2024 Nuclear Decommissioning Funding Plan Required 72.30(c) Update LIC-24-0014, Independent Spent Fuel Storage Installation - Supplement to 2021, and 2024 Nuclear Decommissioning Funding Plan Required 72.30(c) Update2024-10-10010 October 2024 Independent Spent Fuel Storage Installation - Supplement to 2021, and 2024 Nuclear Decommissioning Funding Plan Required 72.30(c) Update LIC-24-0012, Independent Spent Fuel Storage Installation - Response to Proposed Revision to Decommissioning Quality Assurance Plan (DQAP) - Request for Additional Information2024-10-0707 October 2024 Independent Spent Fuel Storage Installation - Response to Proposed Revision to Decommissioning Quality Assurance Plan (DQAP) - Request for Additional Information LIC-24-0011, Independent Spent Fuel Storage Installation - Response to Application for License Amendment Request to Revise the License Termination Plan - Supplemental Information Needed, EPID L-2024-LLA-00952024-10-0202 October 2024 Independent Spent Fuel Storage Installation - Response to Application for License Amendment Request to Revise the License Termination Plan - Supplemental Information Needed, EPID L-2024-LLA-0095 ML24240A1692024-09-18018 September 2024 Cy 2023 Summary of Decommissioning Trust Fund Status ML24243A1042024-09-12012 September 2024 Proposed Revision to the OPPD FCS DQAP - Request for Additional Information (License No. DPR-40, Docket Nos. 50-285, 72-054, and 71-0256) ML24255A0962024-09-12012 September 2024 License Amendment Request to Revise the License Termination Plan - Request Supplemental Information (License No. DPR-40, Docket No. 50-285) IR 05000285/20240022024-08-21021 August 2024 NRC Inspection Report 05000285/2024002 ML24235A0822024-08-10010 August 2024 Response to Fort Calhoun Station, Unit No. 1 - Phase 1 Final Status Survey Report to Support Approved License Termination Plan - Request for Additional Information - Request for Additional Information (EPID L-2024-DFR-0002) July 8, 2024 ML24183A3222024-07-0808 July 2024 Proposed Revision to the Omaha Public Power District Fort Calhoun Station Decommissioning Quality Assurance Plan - Acceptance Review ML24180A2082024-07-0808 July 2024 Phase 1 Final Status Survey Reports Request for Additional Information Letter LIC-24-0007, License Amendment Request (LAR) to Revise License Termination Plan (LTP)2024-06-18018 June 2024 License Amendment Request (LAR) to Revise License Termination Plan (LTP) IR 05000285/20240012024-06-0505 June 2024 NRC Inspection Report 05000285/2024001 ML24151A6482024-06-0303 June 2024 Changes in Reactor Decommissioning Branch Project Management Assignments for Some Decommissioning Facilities LIC-24-0008, Proposed Revision to the Omaha Public Power District (OPPD) Fort Calhoun Station (FCS) Decommissioning Quality Assurance Plan (Dqap), Unit No. 1 and ISFSI2024-05-16016 May 2024 Proposed Revision to the Omaha Public Power District (OPPD) Fort Calhoun Station (FCS) Decommissioning Quality Assurance Plan (Dqap), Unit No. 1 and ISFSI LIC-24-0003, Independent Spent Fuel Storage Installation - Radiological Effluent Release Report and Radiological Environmental Operating Report2024-04-25025 April 2024 Independent Spent Fuel Storage Installation - Radiological Effluent Release Report and Radiological Environmental Operating Report LIC-24-0006, (Fcs), Unit 1, Independent Spent Fuel Storage Installation, Phase 1 Final Status Survey Report to Support Approved License Termination Plan2024-04-17017 April 2024 (Fcs), Unit 1, Independent Spent Fuel Storage Installation, Phase 1 Final Status Survey Report to Support Approved License Termination Plan ML24079A1702024-03-10010 March 2024 ISFSI, Unit 1 - 10 CFR 50.59 Report, Quality Assurance (QA) Program Changes, Technical Specification Basis Changes, 10 CFR 71.106 Quality Assurance Program Approval, Aging Management Review, Commitment Revisions and Revision of Updated Safe LIC-24-0005, Annual Decommissioning Funding / Irradiated Fuel Management Status Report2024-03-0101 March 2024 Annual Decommissioning Funding / Irradiated Fuel Management Status Report LIC-24-0002, Independent Spent Fuel Storage Installation - Submittal of Annual Radioactive Effluent Release Report2024-02-27027 February 2024 Independent Spent Fuel Storage Installation - Submittal of Annual Radioactive Effluent Release Report ML24019A1672024-01-31031 January 2024 Issuance of Amendment to Renewed Facility License to Add License Condition to Include License Termination Plan Requirements IR 05000285/20230062023-12-21021 December 2023 NRC Inspection Report 05000285/2023006 LIC-23-0007, Response to Fort Calhoun, Unit 1 & Independent Spent Fuel Storage Installation Review of License Amendment Request to Add License Condition to Include License Termination Plan Requirements – Request for Additional Information2023-12-0606 December 2023 Response to Fort Calhoun, Unit 1 & Independent Spent Fuel Storage Installation Review of License Amendment Request to Add License Condition to Include License Termination Plan Requirements – Request for Additional Information IR 05000285/20230052023-11-0202 November 2023 NRC Inspection Room 05000285/2023005 ML23276A0042023-09-28028 September 2023 U.S. EPA Response Letter to NRC Letter on Consultation and Finality on Decommissioning and Decontamination of Contaminated Sites MOU - Fort Calhoun Station, Unit 1 – (License No. DPR-40, Docket No. 50-285) IR 05000285/20230042023-09-13013 September 2023 NRC Inspection Report 05000285/2023-004 LIC-23-0005, Response to Fort Calhoun Station, Unit No. 1 - Review of License Amendment Request to Add License Condition to Include License Termination Plan Requirements - 2nd Request for Additional Information (EPID L-2021-LIT-0000) June 2, 20232023-08-24024 August 2023 Response to Fort Calhoun Station, Unit No. 1 - Review of License Amendment Request to Add License Condition to Include License Termination Plan Requirements - 2nd Request for Additional Information (EPID L-2021-LIT-0000) June 2, 2023 ML23234A2392023-08-18018 August 2023 Letter to B Harisis Re Ft Calhoun Unit 1 LTP EA State of Nebraska Comment Request.Pdf ML23234A2412023-08-18018 August 2023 Email - Letter to M Porath Re Ft Calhoun Unit 1 LTP EA Section 7 Informal Consultation Request IR 05000285/20230032023-07-10010 July 2023 – NRC Inspection Report 05000285/2023003 ML23082A2202023-06-26026 June 2023 Consultation on the Decommissioning of the Fort Calhoun Station Unit 1 Pressurized Water Reactor in Fort Calhoun, Nebraska IR 05000285/20230022023-06-0505 June 2023 NRC Inspection Report 05000285/2023002 ML23151A0032023-06-0505 June 2023 – Review of License Amendment Request to Add License Condition to Include License Termination Plan Requirements – 2nd Request for Additional Information (EPID L-2021-LIT-0000) June 2, 2023 LIC-23-0004, (FCS) Radiological Effluent Release Report and Radiological Environmental Operating Report2023-04-20020 April 2023 (FCS) Radiological Effluent Release Report and Radiological Environmental Operating Report LIC-23-0003, Annual Decommissioning Funding / Irradiated Fuel Management Status Report2023-03-15015 March 2023 Annual Decommissioning Funding / Irradiated Fuel Management Status Report LIC-23-0001, Response to Fort Calhoun Station, Unit No. 1 - Review of License Amendment Request to Add License Condition to Include License Termination Plan Requirements - Request for Additional Information2023-02-27027 February 2023 Response to Fort Calhoun Station, Unit No. 1 - Review of License Amendment Request to Add License Condition to Include License Termination Plan Requirements - Request for Additional Information IR 05000285/20230012023-02-24024 February 2023 NRC Inspection Report 05000285/2023001 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 LIC-23-0002, Independent Spent Fuel Storage Installation, Annual Radioactive Effluent Release Report2023-02-20020 February 2023 Independent Spent Fuel Storage Installation, Annual Radioactive Effluent Release Report ML23020A0462023-01-19019 January 2023 Threatened and Endangered Species List: Nebraska Ecological Services Field Office IR 05000285/20220062023-01-0505 January 2023 NRC Inspection Report 05000285/2022-006 ML22357A0662022-12-30030 December 2022 Technical RAI Submittal Letter on License Amendment Request for Approval of License Termination Plan IR 05000285/20220052022-10-26026 October 2022 NRC Inspection Report 05000285/2022-005 2025-01-30
[Table view] Category:Licensee Event Report (LER)
MONTHYEAR05000285/LER-1917-001, Regarding Unprotected Vital Area Barrier Due to Maintenance2017-05-11011 May 2017 Regarding Unprotected Vital Area Barrier Due to Maintenance 05000285/LER-2016-003, Regarding Unplanned Turbine Trip During DCS Modification Due to Failure to Identify and Disable the Transmitter Deviation Based Trip2016-08-22022 August 2016 Regarding Unplanned Turbine Trip During DCS Modification Due to Failure to Identify and Disable the Transmitter Deviation Based Trip 05000285/LER-2016-002, Regarding Unanalyzed Condition Shutdown Heat Exchanger Isolations2016-07-0707 July 2016 Regarding Unanalyzed Condition Shutdown Heat Exchanger Isolations 05000285/LER-2016-001, Regarding Technical Specification Violation Due to Installation of an Unqualified Part in a Radiation Monitor2016-04-0808 April 2016 Regarding Technical Specification Violation Due to Installation of an Unqualified Part in a Radiation Monitor 05000285/LER-2015-006, Regarding Unanalyzed Fire Vulnerability Due to Inadequate Design2015-12-11011 December 2015 Regarding Unanalyzed Fire Vulnerability Due to Inadequate Design 05000285/LER-2015-005, Regarding Reactor Coolant Leak at Reactor Coolant Pump Seal Due to Cyclic Fatigue2015-09-17017 September 2015 Regarding Reactor Coolant Leak at Reactor Coolant Pump Seal Due to Cyclic Fatigue 05000285/LER-2015-004, Regarding Inoperability of Auxiliary Feedwater Trains Due to Failure of Steam Generator Isolation Valve2015-08-0303 August 2015 Regarding Inoperability of Auxiliary Feedwater Trains Due to Failure of Steam Generator Isolation Valve 05000285/LER-2015-003, Regarding Containment Spray Inoperable Due to Original Design Error2015-06-15015 June 2015 Regarding Containment Spray Inoperable Due to Original Design Error 05000285/LER-2015-002, Regarding Inoperable Auxiliary Feedwater System Due to Inadequate Procedure Change2015-05-28028 May 2015 Regarding Inoperable Auxiliary Feedwater System Due to Inadequate Procedure Change 05000285/LER-2015-001, Regarding Inadequate Design of High Energy Line Break Barriers2015-03-27027 March 2015 Regarding Inadequate Design of High Energy Line Break Barriers 05000285/LER-2014-007, Regarding Plant Trip Due to Moisture Intrusion Into a Transformer Control Cabinet2015-02-13013 February 2015 Regarding Plant Trip Due to Moisture Intrusion Into a Transformer Control Cabinet 05000285/LER-2013-014-02, Regarding Unqualified Components Used in Safety System Control Circuit2015-01-29029 January 2015 Regarding Unqualified Components Used in Safety System Control Circuit 05000285/LER-2014-006, Regarding Inoperability of Radiation Monitors Due to an Error in Technical Specifications2014-11-12012 November 2014 Regarding Inoperability of Radiation Monitors Due to an Error in Technical Specifications 05000285/LER-2014-005, Regarding Technical Specification Violation of Containment Integrity2014-08-25025 August 2014 Regarding Technical Specification Violation of Containment Integrity 05000285/LER-2014-004, Regarding Unqualified Limit Switches Render Safety Equipment Inoperable2014-06-20020 June 2014 Regarding Unqualified Limit Switches Render Safety Equipment Inoperable 05000285/LER-2014-003, Regarding Reactor Trip Due to Stator Water Cooling Leak During Maintenance2014-05-14014 May 2014 Regarding Reactor Trip Due to Stator Water Cooling Leak During Maintenance 05000285/LER-2013-014-01, 1 for Fort Calhoun Station Regarding Unqualified Components Used in Safety System Control Circuit2014-05-0202 May 2014 1 for Fort Calhoun Station Regarding Unqualified Components Used in Safety System Control Circuit 05000285/LER-2013-019-01, 1 for Fort Calhoun Regarding Non-Seismic Circulating Water Pipe Could Disable Raw Water Pumps2014-04-14014 April 2014 1 for Fort Calhoun Regarding Non-Seismic Circulating Water Pipe Could Disable Raw Water Pumps 05000285/LER-2014-002, Regarding Reactor Manual Trip Due to Control Rod Misalignment2014-03-12012 March 2014 Regarding Reactor Manual Trip Due to Control Rod Misalignment 05000285/LER-2014-001, Regarding Reactor Shutdown Due to Sluice Gate Failure2014-03-0707 March 2014 Regarding Reactor Shutdown Due to Sluice Gate Failure 05000285/LER-2013-015-01, Regarding Unqualified Coating Used as a Water Tight Barrier in Rooms 81 and 822014-02-14014 February 2014 Regarding Unqualified Coating Used as a Water Tight Barrier in Rooms 81 and 82 05000285/LER-2013-019, Regarding Non-Seismic Circulating Water Pipe Could Disable Raw Water Pumps2014-01-31031 January 2014 Regarding Non-Seismic Circulating Water Pipe Could Disable Raw Water Pumps 05000285/LER-2013-016, Regarding Reporting of Additional High Energy Line Break Concerns2014-01-0606 January 2014 Regarding Reporting of Additional High Energy Line Break Concerns 05000285/LER-2013-017, Regarding Containment Spray Pump Design Documents Do Not Support Operation in Runout2013-12-27027 December 2013 Regarding Containment Spray Pump Design Documents Do Not Support Operation in Runout 05000285/LER-2013-018, Regarding Postulated Fire Event Could Result in Shorts Impacting Safe Shutdown2013-12-26026 December 2013 Regarding Postulated Fire Event Could Result in Shorts Impacting Safe Shutdown 05000285/LER-2013-008-01, Regarding Previously Installed GE Iva Relays Failed Seismic Testing2013-12-18018 December 2013 Regarding Previously Installed GE Iva Relays Failed Seismic Testing 05000285/LER-2013-014, Regarding Unqualified Components Used in Safety System Control Circuit2013-12-18018 December 2013 Regarding Unqualified Components Used in Safety System Control Circuit 05000285/LER-2012-017-02, Regarding Containment Valve Actuators Design Temperature Ratings Below Those Required for Design Basis Accidents2013-12-0606 December 2013 Regarding Containment Valve Actuators Design Temperature Ratings Below Those Required for Design Basis Accidents 05000285/LER-2013-013, Unqualified Components Used in Safety System Control Circuit2013-12-0202 December 2013 Unqualified Components Used in Safety System Control Circuit 05000285/LER-2013-015, Regarding Unqualified Coating Used as a Water Tight Barrier in Rooms 81 and 822013-11-12012 November 2013 Regarding Unqualified Coating Used as a Water Tight Barrier in Rooms 81 and 82 05000285/LER-2012-009-01, Inoperable Equipment Due to Lack of Environmental Qualifications2013-10-31031 October 2013 Inoperable Equipment Due to Lack of Environmental Qualifications 05000285/LER-2013-010-01, Regarding HPSI Pump Flow Imbalance2013-10-23023 October 2013 Regarding HPSI Pump Flow Imbalance 05000285/LER-2012-015-01, Fort Calhouns Station Re Electrical Equipment Impacted by High Energy Line Break Outside Containment2013-09-30030 September 2013 Fort Calhouns Station Re Electrical Equipment Impacted by High Energy Line Break Outside Containment 05000285/LER-2013-012, Regarding Intake Structure Crane Seismic Qualification2013-09-30030 September 2013 Regarding Intake Structure Crane Seismic Qualification 05000285/LER-2013-006-01, Regarding Use of Teflon in LPSI and CS Pump Mechanical Seal2013-08-26026 August 2013 Regarding Use of Teflon in LPSI and CS Pump Mechanical Seal 05000285/LER-2013-007-01, Regarding Containment Air Cooling Unit (VA-16A/B) Seismic Criteria2013-08-16016 August 2013 Regarding Containment Air Cooling Unit (VA-16A/B) Seismic Criteria 05000285/LER-2013-011, The Fort Calhoun Station, Inadequate Design for High Energy Line Break in Rooms 13 and 19 of the Auxiliary Building2013-08-12012 August 2013 The Fort Calhoun Station, Inadequate Design for High Energy Line Break in Rooms 13 and 19 of the Auxiliary Building 05000285/LER-2013-005-01, Regarding Control Room HVAC Modification Not Properly Evaluated2013-07-31031 July 2013 Regarding Control Room HVAC Modification Not Properly Evaluated 05000285/LER-2013-010, Regarding HPSI Pump Flow Imbalance2013-07-0202 July 2013 Regarding HPSI Pump Flow Imbalance 05000285/LER-2012-016-01, Regarding Unanalyzed Charging System Socket Welds to the Reactor Coolant System2013-06-25025 June 2013 Regarding Unanalyzed Charging System Socket Welds to the Reactor Coolant System 05000285/LER-2013-009, Regarding Tornado Missile Vulnerabilities2013-06-14014 June 2013 Regarding Tornado Missile Vulnerabilities 05000285/LER-2013-008, The Fort Calhoun Station, Previously Installed GE Iav Relays Failed Seismic Testing2013-06-0707 June 2013 The Fort Calhoun Station, Previously Installed GE Iav Relays Failed Seismic Testing 05000285/LER-2013-007, Regarding Containment Air Cooling Units (VA-16A/B) Seismic Criteria2013-06-0404 June 2013 Regarding Containment Air Cooling Units (VA-16A/B) Seismic Criteria 05000285/LER-2012-019-01, Regarding Traveling Screen Sluice Gates Found with Dual Indication2013-05-14014 May 2013 Regarding Traveling Screen Sluice Gates Found with Dual Indication 05000285/LER-2012-018-01, Regarding Containment Air Cooling Units Not Properly Tested During Cycle 262013-05-0808 May 2013 Regarding Containment Air Cooling Units Not Properly Tested During Cycle 26 05000285/LER-2013-006, Use of Teflon in LPSI and CS Pump Mechanical Seals2013-05-0303 May 2013 Use of Teflon in LPSI and CS Pump Mechanical Seals 05000285/LER-2013-005, Regarding Control Room HVAC Modification Not Properly Evaluated2013-04-29029 April 2013 Regarding Control Room HVAC Modification Not Properly Evaluated 05000285/LER-2013-004, Regarding Inverters Inoperable During Emergency Diesel Generator Operation2013-04-23023 April 2013 Regarding Inverters Inoperable During Emergency Diesel Generator Operation 05000285/LER-2013-003, Regarding Calculations Indicate the HPSI Pumps Will Operate in Run-out During a DBA2013-04-0101 April 2013 Regarding Calculations Indicate the HPSI Pumps Will Operate in Run-out During a DBA 05000285/LER-2013-002, Regarding CVCS Class 1 & 2 Charging Supports Are Unanalyzed2013-03-26026 March 2013 Regarding CVCS Class 1 & 2 Charging Supports Are Unanalyzed 2017-05-11
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jjjjjjjj Omaha Public Power District 444 South 16" Street Mall Omaha, NE 68102-2247 LIC-15-0106 September 17, 2015 U.S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555-0001 Fort Calhoun Station, Unit No. 1 Renewed Facility Operating License No. DPR-40 NRC Docket No. 50-285 10 CFR 50.73
Subject:
Licensee Event Report 2015-005, Revision 0, for the Fort Calhoun Station Please find attached Licensee Event Report 2015-005, Revision 0. This report is being submitted pursuant to 1 O CFR 50. 73(a)(2)(i)(B) and 50. 73(a)(2)(ii)(A). There are no new commitments being made in this letter.
If you should have any questions, please contact Brad Blome, Manager, Site Regulatory Assurance, at (402) 533-7270.
ouis P. Cortopassi Site Vice President and CNO LPC/epm Attachment c:
M. L. Dapas, NRC Regional Administrator, Region IV C. F. Lyon, NRC Senior Project Manager S.M. Schneider, NRC Senior Resident Inspector
NRC FORM366 U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB: NO. 3150-0104 EXPIRES: 01/31/2017 (02-2014)
, the NRC may not conduct or sponsor, and a person Is not required to respond to, the information collection.
YEAR 2015
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Fort Calhoun Station (FCS) is a two-loop reactor coolant system (RCS) of Combustion Engineering design.
EVENT DESCRIPTION
The station started up from a refueling outage on June 10, 2015. On June 19, unidentified reactor coolant system (RCS) leakage was determined to be greater than 0.163 gpm and reactor coolant pump (RCP) seal pressure plots of the middle and upper seals of RCP RC-3A showed a steady decrease.
A containment entry made on July 8 identified a leak at RC-3A but station personnel only viewed the leak from the front. Station personnel did not access the back of the pump to identify the exact source of the leak. Based on the trended data and the walkdown it was believed that the leak was from the mechanical seal connections such as the shaft or 0-ring. On 7/15/15 an additional walkdown was performed and included visual inspection of the backside of RC-3A. Based on the walkdown video evidence and existing available data it was concluded that the failure location was from one of two mechanical seal 0-rings. An additional containment entry at power was performed on July 19, 2015.
This walkdown confirmed that RC-3A had no additional leakage sources and was confined to the one location on the back side of the pump.
On July 20, 2015, an increase in RCS leak rate required station personnel to perform a controlled shutdown of the reactor (Condition Report (CR) 2015-09023). The walkdown on July 21 (CR 2015-09130) determined that the location was not at the mechanical seals but rather at the middle seal cartridge inlet pressure tap as the result of a through-wall crack. The location of the crack was at the toe of the weld where the piping connects to the mechanical seal. The piping is a class 1 pressure boundary. Due to some initial confusion, station personnel did not immediately recognize this piping as part of the RCS pressure boundary.
At 1701 CDT on July 22, 2015, the station notified the NRG Headquarters Operations Office (HOO) of RCP seal leak as a crack per 10 CFR 50.72(b)(3)(ii)(A). The report was late due to the failure of station personnel to recognize this part of the seal as reactor coolant system boundary. This report is being submitted pursuant to 10 CFR 50.73(a)(2)(i)(B) and 50.73(a)(2)(ii)(A).
CAUSE OF THE EVENT
Altran was contracted by Fort Calhoun Station to perform a failure analysis of the middle seal inlet pressure tap through-wall crack. Report 15-0456-TR-001 was completed to document all findings. The report was performed to determine the cause of the crack and identify any initiating contributors.
The conclusion of the report establishes the direct cause of the failure was low stress high cycle fatigue. The failure was noted to have started at the toe of the weld where the crack progressed inward from the outside diameter (OD) to the Inside diameter (ID). The report establishes that the NRC FORM 366 (02-2014)
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geometry of the fillet weld resulted in a stress riser which when stressed in a cyclic fashion initiated the fatigue cracking.
The station assembled a team to review the issue and determine the root cause of the problem. The station has determined that the probable root cause was:
A design weakness resulted in the vibrations from RC-3A combined with the cantilevered pipe load caused cyclical stresses on the toe of a weld on the seal inlet pressure pipe tap. These stresses initiated a fatigue crack at the toe of the weld on the piping which subsequently propagated inward and progressed through the pipe wall causing the failure.
CORRECTIVE ACTIONS
Short Term Corrective Actions The station was shutdown using normal operating procedures and the seal package for RC-3A was replaced with a spare unit.
Long Term Corrective Actions The station will review design options to determine the appropriate resolution to the design issue with the seal package piping.
SAFETY SIGNIFICANCE
The leak occurred in a 3/4 inch schedule 80 pipe connected to a pressure sensor. The leak was well within the capacity of the charging system. This leak is bounded by station design analyses.
SAFETY SYSTEM FUNCTIONAL FAILURE This does not represent a safety system functional failure in accordance with NEI 99-02, Revision 7.
PREVIOUS EVENTS There have not been any previous incidents of cracking on N7500 reactor coolant pump seal piping at the station.
NRC FORM 366 (02-2014)
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05000285/LER-2015-001, Inadequate Design of High Energy Line Break Barriers | Inadequate Design of High Energy Line Break Barriers | 10 CFR 50.73(a)(2)(ii)(B), Unanalyzed Condition | 05000285/LER-2015-001, Regarding Inadequate Design of High Energy Line Break Barriers | Regarding Inadequate Design of High Energy Line Break Barriers | 10 CFR 50.73(a)(2)(ii)(B), Unanalyzed Condition 10 CFR 50.73(a)(2)(v)(B), Loss of Safety Function - Remove Residual Heat 10 CFR 50.73(a)(2)(v), Loss of Safety Function 10 CFR 50.73(a)(2)(i) 10 CFR 50.73(a)(2)(ix)(A), Prevented Safety Function in Multiple System | 05000285/LER-2015-002, Regarding Inoperable Auxiliary Feedwater System Due to Inadequate Procedure Change | Regarding Inoperable Auxiliary Feedwater System Due to Inadequate Procedure Change | 10 CFR 50.73(a)(2)(v)(B), Loss of Safety Function - Remove Residual Heat 10 CFR 50.73(a)(2) | 05000285/LER-2015-003, Regarding Containment Spray Inoperable Due to Original Design Error | Regarding Containment Spray Inoperable Due to Original Design Error | 10 CFR 50.73(a)(2)(iv)(A), System Actuation 10 CFR 50.73(a)(2)(ii)(B), Unanalyzed Condition 10 CFR 50.73(a)(2)(v)(A), Loss of Safety Function - Shutdown the Reactor 10 CFR 50.73(a)(2)(v)(B), Loss of Safety Function - Remove Residual Heat 10 CFR 50.73(a)(2)(v), Loss of Safety Function 10 CFR 50.73(a)(2)(vii), Common Cause Inoperability 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications 10 CFR 50.73(a)(2)(i) 10 CFR 50.73(a)(2)(x) 10 CFR 50.73(a)(2)(ii)(A), Seriously Degraded 10 CFR 50.73(a)(2)(iii) 10 CFR 50.73(a)(2)(i)(A), Completion of TS Shutdown 10 CFR 50.73(a)(2)(ix)(A), Prevented Safety Function in Multiple System 10 CFR 50.73(a)(2)(viii)(A) 10 CFR 50.73(a)(2)(viii)(B) | 05000285/LER-2015-004, Regarding Inoperability of Auxiliary Feedwater Trains Due to Failure of Steam Generator Isolation Valve | Regarding Inoperability of Auxiliary Feedwater Trains Due to Failure of Steam Generator Isolation Valve | 10 CFR 50.73(a)(2)(iv)(A), System Actuation 10 CFR 50.73(a)(2)(ii)(B), Unanalyzed Condition 10 CFR 50.73(a)(2)(v)(A), Loss of Safety Function - Shutdown the Reactor 10 CFR 50.73(a)(2)(v)(B), Loss of Safety Function - Remove Residual Heat 10 CFR 50.73(a)(2)(v), Loss of Safety Function 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications 10 CFR 50.73(a)(2)(i) 10 CFR 50.73(a)(2)(ii)(A), Seriously Degraded 10 CFR 50.73(a)(2)(i)(A), Completion of TS Shutdown 10 CFR 50.73(a)(2)(ix)(A), Prevented Safety Function in Multiple System 10 CFR 50.73(a)(2) 10 CFR 50.73(a)(2)(viii)(A) 10 CFR 50.73(a)(2)(viii)(B) | 05000285/LER-2015-005, Regarding Reactor Coolant Leak at Reactor Coolant Pump Seal Due to Cyclic Fatigue | Regarding Reactor Coolant Leak at Reactor Coolant Pump Seal Due to Cyclic Fatigue | 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications 10 CFR 50.73(a)(2)(ii)(A), Seriously Degraded | 05000285/LER-2015-006, Regarding Unanalyzed Fire Vulnerability Due to Inadequate Design | Regarding Unanalyzed Fire Vulnerability Due to Inadequate Design | 10 CFR 50.73(a)(2)(iv)(A), System Actuation 10 CFR 50.73(a)(2)(ii)(B), Unanalyzed Condition 10 CFR 50.73(a)(2)(v)(A), Loss of Safety Function - Shutdown the Reactor 10 CFR 50.73(a)(2)(v)(B), Loss of Safety Function - Remove Residual Heat 10 CFR 50.73(a)(2)(v), Loss of Safety Function 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications 10 CFR 50.73(a)(2)(i) 10 CFR 50.73(a)(2)(x) 10 CFR 50.73(a)(2)(ii)(A), Seriously Degraded 10 CFR 50.73(a)(2)(i)(A), Completion of TS Shutdown |
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