08-22-2017 | On June 26, 2017, Operations commenced a downpower from 100 percent to 93 percent reactor power to support performance of the Main Turbine Stop and Control Valve Test. With reactor power at 94 percent, the 22 Main Boiler Feed Pump Turbine (MBFPT) speed control trouble alarm annunciated coincident with pump speed swings of 800 revolutions per minute (rpm). The operators ceased the downpower and placed the 22 Main Boiler Feedwater Pump ( MBFP) in Manual speed control to control the rpm swings. This was unsuccessful, and the rpm swings continued. The 22 MBFPT low pressure ( LP) governor valves were observed to be cycling from full-closed to full-open. The decision was made to take local pneumatic control of the 22 MBFP to stabilize pump speed. Two minutes after establishing local pneumatic control, the LP governor valves went to full closed. With the rapid reduction in 22 MBFP speed, the pump was no longer delivering feedwater flow to the SGs. An automatic main turbine runback signal should have been generated on a low speed signal; however, there was no turbine runback actuation. In response, the operators commenced a manual runback to reduce main turbine load, but the decreasing SG levels reached 15 percent, and at 1531 hours0.0177 days <br />0.425 hours <br />0.00253 weeks <br />5.825455e-4 months <br /> a manual reactor trip was initiated.
All control rods fully inserted and all required safety systems functioned properly. The plant was stabilized in hot standby with decay heat being removed by the main condenser. The direct cause of the reactor trip was that the shoulder screws used on the 22 MBFPT LP governor valve servomotor linkage had backed out and detached. This caused the LP governor valves to fail closed, shutting off the turbine steam supply. This event had no effect on the public health and safety. The event was reported to the Nuclear Regulatory Commission (NRC) on June 26, 2017 under 10 CFR 50.72(b)(2)(iv)(B), 50.72(b)(2)(xi), and 50.72(b)(3)(iv)(A). |
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Category:Letter
MONTHYEARML24011A1982024-01-12012 January 2024 ISFSI, Notice of Organization Change for Site Vice President ML23342A1082024-01-0909 January 2024 Independent Spent Fuel Storage Installation Security Inspection Plan ML23353A1742023-12-19019 December 2023 ISFSI, Emergency Plan, Revision 23-04 L-23-019, Proof of Financial Protection 10 CFR 140.152023-12-18018 December 2023 Proof of Financial Protection 10 CFR 140.15 ML23339A0442023-12-0505 December 2023 Issuance of Amendment No. 68, 301 and 277 Regarding Changes to Implement the Independent Spent Fuel Storage Installation Physical Security Plan ML23326A1322023-12-0505 December 2023 Issuance of Amendment No. 67, 300 & 276 to Implement the Independent Spent Fuel Storage Installation Only Emergency Plan ML23338A2262023-12-0404 December 2023 Signed Amendment No. 27 to Indemnity Agreement No. B-19 ML23356A0212023-12-0101 December 2023 American Nuclear Insurers, Secondary Financial Protection (SFP) Program ML23242A2772023-11-30030 November 2023 NRC Letter Issuance - IP LAR for Units 2 and 3 Renewed Facility Licenses and PDTS to Reflect Permanent Removal of Spent Fuel from SFPs ML23338A0482023-11-30030 November 2023 ISFSI, Report of Changes to Physical Security, Training and Qualification, Safeguards Contingency Plan, and ISFSI Security Program, Revision 28 ML22339A1572023-11-27027 November 2023 Letter - Indian Point - Ea/Fonsi Request for Exemptions from Certain Emergency Planning Requirements for 10 CFR 50.47 and 10 CFR Part 50, Appendix E IR 05000003/20230032023-11-21021 November 2023 NRC Inspection Report Nos. 05000003/2023003, 05000247/2023003, 05000286/2023003, and 07200051/2023003 ML23100A1172023-11-17017 November 2023 NRC Response - Indian Point Energy Center Generating Units 1, 2, and 3 Letter with Enclosures Regarding Changes to Remove the Cyber Security Plan License Condition ML23050A0032023-11-17017 November 2023 Letter - Issuance Indian Point Unit 2 License Amendment Request to Modify Tech Specs for Staffing Requirements Following Spent Fuel Transfer to Dry Storage ML23100A1252023-11-17017 November 2023 Letter and Enclosure 1 - Issuance Indian Point Energy Center Units 1, 2, and 3 Exemption for Offsite Primary and Secondary Liability Insurance Indemnity Agreement ML23100A1432023-11-16016 November 2023 Letter - Issuance Indian Point Energy Center Generating Units 1, 2, and 3 Exemption Concerning Onsite Property Damage Insurance (Docket Nos. 50-003, 50-247, 50-286) ML23064A0002023-11-13013 November 2023 NRC Issuance for Approval-Indian Point EC Units 1, 2 and 3 Emergency Plan and Emergency Action Level Scheme Amendments L-23-012, Master Decommissioning Trust Agreement Changes for Indian Point Nuclear Generating Units 1, 2 and 3, Pilgrim Nuclear Power Station, Palisades Nuclear Plant and the Non-Qualified Trust for Big Rock Point2023-11-13013 November 2023 Master Decommissioning Trust Agreement Changes for Indian Point Nuclear Generating Units 1, 2 and 3, Pilgrim Nuclear Power Station, Palisades Nuclear Plant and the Non-Qualified Trust for Big Rock Point ML23306A0992023-11-0202 November 2023 and Indian Point Energy Center, Notification of Changes in Schedule in Accordance with 10 CFR 50.82(a)(7) ML23063A1432023-11-0101 November 2023 Letter - Issuance Holtec Request for Indian Point Energy Center Generating Units 1, 2, and 3 Exemptions from Certain Emergency Planning Requirements of 10 CFR 50.47 and Part 50 ML23292A0262023-10-19019 October 2023 LTR-23-0211-RI Thomas Congdon, Executive Deputy, Department of Public Service, Chair, Indian Point Decommissioning Oversight Board, Letter Independent Spent Fuel Storage Installation Inspection and Office of the Inspector General Report-RI ML23289A1582023-10-16016 October 2023 Decommissioning International - Registration of Spent Fuel Casks and Notification of Permanent Removal of All Indian Point Unit 3 Spent Fuel Assemblies from the Spent Fuel Pit ML23270A0082023-09-27027 September 2023 Registration of Spent Fuel Casks ML23237A5712023-09-22022 September 2023 09-22-2023 Letter to Dwaine Perry, Chief, Ramapo Munsee Nation, from Chair Hanson, Responds to Letter Regarding Opposition of the Release and Dumping of Radioactive Waste from Indian Point Nuclear Power Plant Into the Hudson River ML23242A2182023-09-12012 September 2023 IPEC NRC Response to the Town of New Windsor, Ny Board Certified Motion Letter Regarding Treated Water Release from IP Site (Dockets 50-003, 50-247, 50-286) ML23250A0812023-09-0707 September 2023 Registration of Spent Fuel Casks ML23255A0142023-08-31031 August 2023 LTR-23-0211 Thomas Congdon, Executive Deputy, Department of Public Service, Chair, Indian Point Decommissioning Oversight Board, Letter Independent Spent Fuel Storage Installation Inspection and Office of the Inspector General Report IR 05000003/20230022023-08-22022 August 2023 NRC Inspection Report 05000003/2023002, 05000247/2023002, 05000286/2023002, and 07200051/2023002 ML23227A1852023-08-15015 August 2023 Request for a Revised Approval Date Regarding the Indian Point Energy Center Permanently Defueled Emergency Plan and Emergency Action Level Scheme ML23222A1442023-08-10010 August 2023 Registration of Spent Fuel Casks ML23208A1642023-07-26026 July 2023 Village of Croton-on-Hudson New York Letter Dated 7-26-23 Re Holtec Wastewater ML23200A0422023-07-19019 July 2023 Registration of Spent Fuel Casks ML23235A0602023-07-17017 July 2023 LTR-23-0194 Dwaine Perry, Chief, Ramapo Munsee Nation, Ltr Opposition of the Release and Dumping of Radioactive Waste from Indian Point Nuclear Power Plant Into the Hudson River ML23194A0442023-07-11011 July 2023 Clarification for Indian Point Energy Center License Amendment Request, Independent Spent Fuel Storage Installation Physical Security Plan ML23192A1002023-07-11011 July 2023 Response to Request for Additional Information Regarding License Amendment Request to Revise the Emergency Plan and Emergency Action Level Scheme ML23171B0432023-06-23023 June 2023 Letter - Indian Point Energy Center - Request for Additional Information for Independent Spent Fuel Storage Installation Facility-Only Emergency Plan License Amendment ML23118A0972023-06-0606 June 2023 06-06-23 Letter to the Honorable Michael V. Lawler, Et Al., from Chair Hanson Regarding Holtec'S Announcement to Expedite Plans to Release Over 500,000 Gallons of Radioactive Wastewater from Indian Point Energy Center Into the Hudson River ML23144A3512023-05-25025 May 2023 Clementina Bartolotta of Pearl River, New York Email Against Treated Water Release from Indian Point Site ML23144A3522023-05-25025 May 2023 Loredana Bidmead of New York E-Mail Against Treated Water Release from Indian Point Site ML23144A3412023-05-25025 May 2023 Dianne Schirripa of Rockland County, New York Email Against Treated Water Release from Indian Point Site ML23144A3472023-05-25025 May 2023 David Mart of Blauvelt, New York Email Against Treated Water Release from Indian Point Site ML23144A3402023-05-25025 May 2023 Melvin Israel of New York Email Against Treated Water Release from Indian Point Site ML23144A3542023-05-25025 May 2023 Terri Thal of New City, New York Email Against Treated Water Release from Indian Point Site ML23144A3532023-05-25025 May 2023 John Shaw of New York Email Against Treated Water Release from Indian Point Site 2024-01-09
[Table view] Category:Licensee Event Report (LER)
MONTHYEARNL-18-039, LER 2018-001-00 for Indian Point, Unit 2 Re Penetration Indications Discovered During Reactor Pressure Vessel Head Inspection2018-05-21021 May 2018 LER 2018-001-00 for Indian Point, Unit 2 Re Penetration Indications Discovered During Reactor Pressure Vessel Head Inspection 05000286/LER-2017-0042017-12-20020 December 2017 Reactor Trip Due to Main Generator Loss of Field, LER 17-004-00 for Indian Point Unit 3, Regarding Reactor Trip Due to Main Generator Loss of Field ML17252A8662017-09-0909 September 2017 Letter Regarding a 04/26/1977 Occurrence Concerning Failure of Number 22 Main Steam Line Isolation Valve to Close to a Manual Signal Initiated by the Control Room Operator - Indian Point Unit No. 2 05000247/LER-2015-0012017-08-29029 August 2017 Technical Specification (TS) Prohibited Condition Due to an Inoperable Containment Caused by a Service Water Pipe Leak with a Flaw Size that Results in Exceeding the Allowed Leakage Rate for Containment, LER 15-001-02 for Indian Point, Unit 2, Regarding Technical Specification (TS) Prohibited Condition Due to an Inoperable Containment Caused by a Service Water Pipe Leak with a Flaw Size that Results in Exceeding the Allowed Leakage Rate for Containment 05000286/LER-2017-0032017-08-29029 August 2017 Condensate Storage Tank Declared Inoperable Per Technical Specification, LER 17-003-00 for Indian Point, Unit 3, Regarding Condensate Storage Tank Declared Inoperable Per Technical Specification NL-17-107, LER 15-001-02 for Indian Point, Unit 2, Regarding Technical Specification (TS) Prohibited Condition Due to an Inoperable Containment Caused by a Service Water Pipe Leak with a Flaw Size That Results in Exceeding the Allowed Leakage Rate fo2017-08-29029 August 2017 LER 15-001-02 for Indian Point, Unit 2, Regarding Technical Specification (TS) Prohibited Condition Due to an Inoperable Containment Caused by a Service Water Pipe Leak with a Flaw Size That Results in Exceeding the Allowed Leakage Rate for 05000247/LER-2017-0032017-08-23023 August 2017 Technical Specification Violation of Section 3.3.1 RPS Instrumentation, LER 17-003-00 for Indian Point Unit 2, Regarding Technical Specification Violation of Section 3.3.1 RPS Instrumentation 05000247/LER-2017-0012017-08-22022 August 2017 Manual Reactor Trip Due to Decreasing Steam Generator Levels Caused By Main Boiler Feedwater Pump Turbine Low Pressure Governor Valves Failed Closed, LER 17-001-00 for Indian Point, Unit 2 Regarding Manual Reactor Trip Due to Decreasing Steam Generator Levels Caused By Main Boiler Feedwater Pump Turbine Low Pressure Governor Valves Failed Closed 05000247/LER-2017-0022017-08-22022 August 2017 Auxiliary Feedwater Flow Indication Inoperable for Longer Than the Allowed Technical Specification Completion Time Due to Failure of Complete Restoration Following Calibration, LER 17-002-00 for Indian Point, Unit 2 Regarding Auxiliary Feedwater Flow Indication Inoperable for Longer Than the Allowed Technical Specification Completion Time Due to Failure of Complete Restoration Following Calibration 05000286/LER-2017-0022017-08-0909 August 2017 Manual Isolation of Chemical and Volume Control System Normal Letdown to Stop a Valve Leak Resulted in an Exceedance of Technical Specification 3.4.9 Condition A Limit for Pressurizer Level, LER 17-002-00 for Indian Point, Unit 3 re Manual Isolation of Chemical and Volume Control System Normal letdown to Stop a Valve Leak Resulted in an Exceedance of Technical Specification 3.4.9 Condition A Limit for Pressurizer Level 05000286/LER-2017-0012017-07-13013 July 2017 Single Flow Barrier Access Point Found Unbolted, LER 17-001-00 for Indian Point, Unit 3 Regarding Single Flow Barrier Access Point Found Unbolted 05000247/LER-2016-0102017-02-28028 February 2017 Safety System Functional Failure Due to an Inoperable Containment Caused by a Through Wall Defect in a Service Water Supply Pipe Elbow to the 24, Fan Cooler Unit, LER 16-010-01 for Indian Point 2 Regarding Safety System Functional Failure Due to an Inoperable Containment Caused by a Through Wall Defect in a Service Water Supply Pipe Elbow to the 24 Fan Cooler Unit 05000247/LER-2016-0022017-02-28028 February 2017 Automatic Actuation of Emergency Diesel Generators (EDGs) Due to 480 VAC Bus Undervoltage Condition and Loss of Residual Heat Removal (RHR) While in Cold Shutdown, LER 16-002-01 for Indian Point, Unit 2 Regarding Automatic Actuation of Emergency Diesel Generators (EDGs) Due to 480 VAC Bus Undervoltage Condition and Loss of Residual Heat Removal (RHR) While in Cold Shutdown NL-16-108, LER 15-001-01 for Indian Point 2 Regarding Technical Specification (TS) Prohibited Condition Due to an Inoperable Containment Caused by a Service Water Pipe Leak with a Flaw Size That Results in Exceeding the Allowed Leakage Rate for Conta2016-09-29029 September 2016 LER 15-001-01 for Indian Point 2 Regarding Technical Specification (TS) Prohibited Condition Due to an Inoperable Containment Caused by a Service Water Pipe Leak with a Flaw Size That Results in Exceeding the Allowed Leakage Rate for Contai 05000286/LER-2015-0052016-09-14014 September 2016 Automatic Reactor Trip Due to a Turbine-Generator Trip Caused by the Trip of 345kV Main Generator Output Breaker 3 due to a Failure of South Ring Bus 345kV Breaker 5, LER 15-005-01 for Indian Point 3 RE: Automatic Reactor Trip Due to a Turbine-Generator Trip Caused by the Trip of 345kV Main Generator output Breaker 3 due to a Failure of South Ring Bus 345kV Breaker 5 05000286/LER-2015-0042016-09-14014 September 2016 Automatic Reactor Trip Due to a Turbine-Generator Trip Caused by a Failure of the 31 Main Transformer, LER 15-004-01 for Indian Point Unit No. 3 Regarding Automatic Reactor Trip Due to a Turbine-Generator Trip Caused by a Failure of the 31 Main Transformer 05000286/LER-2015-0072016-09-0606 September 2016 Manual Reactor Trip Due to Decreasing Steam Generator Water Levels Caused by a Miss- Wired Circuit Board in the Main Feedwater Pump Speed Control System, LER 2015-007-01 for Indian Point, Unit 3 Regarding Manual Reactor Trip Due to Decreasing Steam Generator Water Level Caused by a Miss-Wired Circuit Board in the Main Feedwater Pump Speed Control System 05000286/LER-2015-0062016-08-0808 August 2016 Technical SpecificatiOn Prohibited Condition Due to Two Pressurizer Code Safety Valves Discovered Outside their As-Found Lift Setpoint Test Acceptance Criteria, LER 15-006-01 for Indian Point Unit No. 3 Regarding Technical Specification Prohibited Condition Due to Two Pressurizer Code Safety Valves Discovered Outside Their As-Found Lift Setpoint Test Acceptance Criteria 05000286/LER-2014-0042016-08-0101 August 2016 Automatic Reactor Trip as a Result of Meeting the Trip Logic for Over Temperature Delta Temperature during Reactor Protection System Pressurizer Pressure Calibration, LER 14-004-01 for Indian Point Unit 3, Regarding Automatic Reactor Trip as a Result of Meeting the Trip Logic for Over Temperature Delta Temperature During Reactor Protection System Pressurizer Pressure Calibration 05000247/LER-2016-0042016-05-31031 May 2016 Unanalyzed Condition due to Degraded Reactor Baffle-Former Bolts, LER 16-004-00 for Indian Point 2 re Unanalyzed Condition Due to Degraded Reactor Baffle-Former Bolts 05000247/LER-2016-0052016-05-25025 May 2016 Technical Specification (TS) Prohibited Condition Due to a Surveillance Requirement Never Performed for Testing the Trip of the Main Boiler Feedwater Pumps, LER 16-005-00 for Indian Point, Unit 2, Regarding Technical Specification (TS) Prohibited Condition Due to a Surveillance Requirement Never Performed for Testing the Trip of the Main Boiler Feedwater Pumps 05000247/LER-2016-0012016-05-0202 May 2016 Technical Specification Prohibited Condition Caused by One Main Steam Safety Valve Outside Its As-Found Lift Set Point Test Acceptance Criteria, LER 16-001-00 for Indian Point 2 RE: Technical Specification Prohibited Condition Caused by One Main Steam Safety Valve Outside Its As-Found Lift Set Point Test Acceptance Criteria 05000247/LER-2015-0042016-02-18018 February 2016 Safety System Functional Failure Due to an Inoperable Containment Caused by a Flawed Elbow on the 21 Fan Cooler Unit Service Water Motor Cooling Return Pipe, LER 15-004-00 for Indian Point 2 Regarding Safety System Functional Failure Due to an Inoperable Containment Caused by a Flawed Elbow on the 21 Fan Cooler Unit Service Water Motor Cooling Return Pipe 05000286/LER-2015-0082016-02-11011 February 2016 Automatic Reactor Trip Due to a Turbine-Generator Trip as a Result of a Fault on 345 kV Feeder W96 Tower Lines Caused by Pre-Existing Degraded Insulator, LER 15-008-00 for Indian Point, Unit 3, Regarding Automatic Reactor Trip Due to a Turbine-Generator Trip as a Result of a Fault on 345 kV Feeder W96 Tower Lines Caused by Bird Streaming 05000247/LER-2015-0032016-02-0303 February 2016 Manual Reactor Trip Due to Indications of Multiple Dropped Control Rods Caused by Loss of Control Rod Power Due to a Power Supply Failure, LER 15-003-00 for Indian Point, Unit 2, Regarding Manual Reactor Trip Due to Indications of Multiple Dropped Control Rods Caused by Loss of Control Rod Power Due to a Power Supply Failure NL-15-124, LER 15-001-00 for Indian Point 2, Regarding Technical Specification (TS) Prohibited Condition Due to an Inoperable Containment Caused by a Service Water Pipe Leak with a Flaw Size That Results in Exceeding the Allowed Leakage Rate for Cont2015-10-0909 October 2015 LER 15-001-00 for Indian Point 2, Regarding Technical Specification (TS) Prohibited Condition Due to an Inoperable Containment Caused by a Service Water Pipe Leak with a Flaw Size That Results in Exceeding the Allowed Leakage Rate for Conta NL-13-166, Report on Inoperable Gross Failed Fuel Detector2013-12-20020 December 2013 Report on Inoperable Gross Failed Fuel Detector NL-13-038, Event Report for Discovery of a Condition That Prevented Immediate Protective Actions to Avoid Exposures to Radiation from Byproduct Material2013-02-19019 February 2013 Event Report for Discovery of a Condition That Prevented Immediate Protective Actions to Avoid Exposures to Radiation from Byproduct Material NL-12-060, Submittal of Report on Inoperable Gross Failed Fuel Detector2012-04-26026 April 2012 Submittal of Report on Inoperable Gross Failed Fuel Detector ML1101906402010-11-0909 November 2010 Event Notification Report; Subject: Power Reactor Indian Point Unit 2 NL-09-108, Submittal of Report on Inoperable Core Exit Thermocouples2009-08-10010 August 2009 Submittal of Report on Inoperable Core Exit Thermocouples ML0509600412004-12-17017 December 2004 Final Precursor Analysis - IP-2 Grid Loop ML0509600512004-12-17017 December 2004 Final Precursor Analysis - IP-3 Grid Loop NL-03-136, LER 03-03-00 for Indian Point Unit 3 Regarding Automatic Turbine Trip/Reactor Trip Due to Fault in 345kV Generator Output Breaker 32003-08-21021 August 2003 LER 03-03-00 for Indian Point Unit 3 Regarding Automatic Turbine Trip/Reactor Trip Due to Fault in 345kV Generator Output Breaker 3 ML0209104352002-03-19019 March 2002 LER 98-001-01 for Indian Point Unit 3 Re Potential Failure or Inadvertent Operation of Fire Protection Systems, Caused by Personnel Error in Design ML17252A8951979-05-25025 May 1979 Letter Reporting a 05/18/1973 Occurrence of a Pressure Transient within the Reactor Coolant System Due to the Closure of Certain Air Operated Valves in the Reactor Coolant Letdown System - Indian Point Unit 2 ML17252A8461974-02-19019 February 1974 Letter Regarding Performance of a Surveillance Test PT-M2 Reactor Coolant Temperature Analog Channel Functional Test - Delta T Overtemperature and T Overpower - Indian Point Unit No. 2 ML17252A8481974-02-19019 February 1974 Letter Regarding a February 1, 1974 Occurrence Where Both Door of the 80 Foot Elevation Personnel Air Lock to the Containment Building Were Inadvertently Open at the Same Time for a Period of About Thirty Seconds - Indian Point Unit. 2 ML17252A8471974-02-0808 February 1974 Letter Regarding an Occurrence on 1/25/1974 at the Indian Point Unit No. 2 Reactor Was Brought Critical in Preparation for Placing the Plant Back in Service Following Completion of Repairs Associated with No. 22 Steam Generator Feedwater Li ML17252A8491974-02-0606 February 1974 Letter Regarding an Occurrence Where Both Doors of the 80 Foot Elevation Personnel Air Lock to the Containment Building Were Inadvertently Opened at the Same Time for About Thirty Seconds - Indian Point Unit 2 ML17252A8501974-02-0505 February 1974 Letter Regarding an Occurrence Where a Slight Reactor Coolant System Pressure Transient Was Experienced in the Course of Placing a Reactor Coolant Pump in Service - Indian Point Unit No. 2 ML17252A8511974-02-0101 February 1974 Letter Regarding an Inspection of All Bergen-Paterson Hydraulic Shock and Sway Arrestors (Snubbers) Located in the Vapor Containment Was Performed and Two Did Not Meet the Established Criterion for Operability - Indian Point Unit No. 2 ML17252A8521974-01-31031 January 1974 Letter Regarding an Occurrence Where the Reactor Was Brought Critical Preparatory to Placing the Plant Back in Service Following Completion of Repairs Associated with the 11/13/1973 Feedwater Line Break Incident - Indian Point Unit No. 2 ML17252A8591974-01-28028 January 1974 Letter Regarding an Occurrence 01/23/1974 Where a Slight Reactor Coolant System Pressure Transient Above the Technical Specifications Limit Was Experienced in the Course of Placing a Reactor Coolant Pump in Service - Indian Point Unit No. 2 ML17252A8721974-01-18018 January 1974 Letter Regarding Analysis of Results of Monthly Periodic Surveillance Test PT-M11 (Steam Line Pressure Analog Channel Function Test) Indicated That One of the Low Steam Line Pressure Bistables Associated with High Steam - Indian Point Unit ML17252A8761973-12-28028 December 1973 Letter Regarding 12/17/1973 Analysis of the Results of Periodic Tests and Calibration Checks Relating to Pressurizer Level Indicated a Setpoint Drift - Indian Point Unit 2 ML17252A8771973-12-18018 December 1973 Letter Regarding a 12/17/1973 Analysis of Results of Periodic Tests and Calibration Checks Relating to Pressurizer Level Indicated a Setting for One of the Bistables Was Above the Technical Spec. Limit - Indian Point Unit 2 ML17252A8791973-12-0303 December 1973 Letter Regarding a 11/18/1973 Occurrence Relating to the Discovery of the Erroneous Setting for 1 of the Bistables Associated with Low Pressurizer Safety Injection Required by the Technical Specifications - Indian Point Unit No. 2 ML17252A8781973-11-30030 November 1973 Letter Providing Supplemental Information Concerning the 11/13/1973 Incident at Indian Point Unit No. 2 ML17252A8821973-11-19019 November 1973 Letter Concerning a 11/16/1973 Occurrence Regarding Periodic Tests and Calibration Checks Indicating the Setting for 1 of the Bistable Device Was Below the Technical Specification Requirements - Indian Point Unit 2 2018-05-21
[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.
Note: The Energy Industry Identification System Codes are identified within the brackets { }.
DESCRIPTION OF EVENT
On June 26, 2017, at 1000 hours0.0116 days <br />0.278 hours <br />0.00165 weeks <br />3.805e-4 months <br />, Operations commenced a planned downpower from 100 percent to approximately 93 percent reactor power to support performance of the Indian Point Unit 2 (IP2) Main Turbine Stop and Control Valve {SB, ISV, FCV} Test, which is required to be performed every 6 months. In preparation for this planned special evolution, just-in-time training had been conducted for the operating crew, an infrequently performed test and evolution brief had been performed, and continuous manager oversight was established in the Central Control Room (CCR).
At 1037 hours0.012 days <br />0.288 hours <br />0.00171 weeks <br />3.945785e-4 months <br />, with reactor power at approximately 94 percent, the 22 Main Boiler Feed Pump Turbine (MBFPT) {SB, TRB} speed control trouble alarm {ALM} annunciated coincident with 22 Main Boiler Feed Pump (MBFP) {SJ, P} speed swings of approximately 800 revolutions per minute (rpm). The operators ceased the downpower and placed 22 MBFP in Manual CCR speed control per the main feedwater system {SJ} operating procedure (SOP) in an attempt to control the rpm swings. This was unsuccessful, and the rpm swings continued. Field operators were dispatched to the MBFP local control panel in accordance with the MBFPT speed control trouble alarm response procedure (ARP), and Operations entered the loss of main feedwater abnormal operating procedure (AOP) at 1041 hours0.012 days <br />0.289 hours <br />0.00172 weeks <br />3.961005e-4 months <br />. The field operators reported that the trouble alarm was due to high delta pressure {PDA} on both (A and B) control oil orifice {SL, OR} flow paths, with both alarms lit at the local panel. The field operators were briefed and then dispatched with an off-watch shift manager to clean the standby B control oil orifice filter (fine mesh screen canister) {FLT} and place it in service per the MBFP lube oil SOP.
The B orifice flowpath filter was cleaned and placed in service at 1144 hours0.0132 days <br />0.318 hours <br />0.00189 weeks <br />4.35292e-4 months <br />. Debris was visible on the filter.
Attempts to isolate and clean the now standby A orifice {SL, OR} flowpath filter {FLT} were unsuccessful, as the solenoid valve {FSV} that switches between the A and B flow paths would not fully isolate from the B flow path.
This led to the belief that particulate in the oil system was causing the 22 MBFP rpm swings, and a concern that the 21 MBFP {SJ, P} would be similarly affected because the oil system is common to both MBFPs.
The operators and engineers involved recognized that the 22 MBFP needed to be removed from service. Senior management was notified, and they concurred with the recommendation to downpower the unit to approximately 65 percent reactor power and remove the pump from service. The 22 MBFPT low pressure (LP) governor valves {SB, FCV} were cycling from full-closed to full-open as control oil pressure was cycling from 20 to 29 pounds per square inch gauge (psig). The LP steam supply to the turbine is controlled by eight governor valves that open and close sequentially. The LP governor valves should go full open at 40 psig control oil pressure. Attempts to lower the speed of the 22 MBFP led to larger rpm swings, which were upwards of 1000 rpm. In addition, the 22 MBFP rpm swings were causing the 21 MBFP suction flow to cycle from about 7500 gallons per minute (gpm) to 8000 gpm with the speed control in Auto, and this resulted in a 21 MBFP bearing monitor alarm {TA} on thrust bearing rear facing metal temperature, which was an added concern. Speed control for the 21 MBFP was left in Auto to dampen swings in the pump discharge pressure, as there was a concern that the excessive rpm swings would cause elevated pump discharge pressures without this modulation.
During the ongoing attempts to stabilize the 22 MBFP rpm swings, steam generator (SG) {AB, SG} water levels remained relatively stable. The operating crew was briefed on the potential loss of an MBFP and the potential for a unit trip. At approximately 1330 hours0.0154 days <br />0.369 hours <br />0.0022 weeks <br />5.06065e-4 months <br />, the outage control center (OCC) was staffed to organize efforts to assist in the downpower and remove the 22 MBFP from service. The unit was stabilized at 93 percent reactor power at this time. In an attempt to stabilize the cyclic speed oscillations, Operations transferred the 22 MBFP to - 001 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.
startup/governor control in accordance with the loss of main feedwater AOP and MBFPT speed control trouble ARP. This action placed the startup control signal in service and removed the feedwater signal, and was only partially effective. The 22 MBFP LP governor valves continued to cycle and any further attempts to reduce reactor power made the rpm swings worse.
At approximately1500 hours, the decision was made to take local pneumatic control of the 22 MBFP in accordance with the MBFPT speed control trouble ARP and main feedwater system SOP in an effort to further stabilize pump speed. Taking local pneumatic control allows for direct input of a steady air signal to the control oil system speed changer valves to control the turbine steam supply via the LP governor valves. After establishing local pneumatic control, LP governor valve operation initially stabilized, but about two minutes later the governor valves went to full closed. An automatic main turbine {TA} runback signal should have been generated on a low speed signal (less than 3300 rpm) when the 22 MBFP tripped (governor valves closed). However, there was no indication that the main turbine runback feature actuated. The turbine runback feature is designed to reduce main turbine load to approximately 76.5 percent. This allows secondary steam flow and feed flow to reach a new equilibrium state and, thus, decrease the probability of a reactor trip.
With the rapid reduction in speed following the 22 MBFP trip, the pump was no longer delivering feedwater flow to the SGs. In response, the CCR operators commenced a manual runback to reduce main turbine load as directed by the loss of main feedwater AOP. The operators closely monitored SG levels and established a predetermined level threshold of 15 percent to manually trip the reactor (7 percent above the automatic reactor trip setpoint). At 1531 hours0.0177 days <br />0.425 hours <br />0.00253 weeks <br />5.825455e-4 months <br />, the decreasing SG levels reached the 15 percent threshold and the CCR operators initiated a manual reactor trip. All control rods {AA} fully inserted and all required safety systems functioned properly. The plant was stabilized in hot standby with decay heat being removed by the main condenser {SG}. There was no radiation release. The emergency diesel generators {EK, DG} did not start, as offsite power remained available. The Auxiliary Feedwater System (AFWS) {BA} automatically started as expected due to SG low level as a result of void fraction (shrink) effect. As required, on June 26, 2017, at 1839 hours0.0213 days <br />0.511 hours <br />0.00304 weeks <br />6.997395e-4 months <br />, a 4-hour non-emergency notification was made to the NRC for an actuation of the Reactor Protection System {JC} while critical, and included an 8-hour notification for a valid actuation of the AFWS under 10 CFR 50.72(b)(3)(iv)(A) (Event Log No. 52829). This event notification also satisfied the 10 CFR 50.72(b)(2)(xi) notification requirement for Entergy's planned press release/news release regarding the IP2 reactor trip event.
During the initial investigation, when the housing cover for the LP governor valve servomotor (LP servomotor) was removed, the shoulder screws that secure the fulcrum bar to the piston shaft link pin (linkage) were found detached and laying in the bottom of the servomotor housing. The male threads on the shoulder screws and the female threads on the fulcrum bar were inspected, and both the male and female threads were found to be in good condition with minimal wear to the threads. There was sufficient thread engagement to allow the screws to be engaged back into the fulcrum bar with no looseness. Wear was found on the fulcrum bar at the mating surface of the fulcrum bar and piston shaft link pin.
Siemens, the original equipment manufacturer, was contacted to analyze the failure of the LP servomotor and assist in the servomotor repairs. Siemens Field Services personnel are contracted by Entergy during outages to perform overhaul work on major plant components, including the main turbine generator and MBFPTs. Entergy provides oversight of the work and Siemens personnel. Siemens performed an overhaul of the 22 MBFP LP governor valve servomotor during the IP2 Spring 2016 (2R22) refueling outage, which consisted of a complete servomotor disassembly, inspection, replacement of worn components, and reassembly. During the investigation to determine why the LP servomotor failed, it was identified that the piston shaft appeared to be very slightly twisted and not in its correct alignment. With the piston shaft misaligned, uneven forces were placed on the fulcrum bar, link pin, and shoulder screws, and this was evident by the wear found on the fulcrum bar. In addition, based on a Siemens/Westinghouse proprietary drawing of the LP servomotor, the threads for the shoulder screws - 001 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.
e Nor Indian Point 2 05000-247 2017 -001 - 00 should have been staked to securely retain the screws. Contrary to the drawing, Siemens personnel had not staked the screws during the 2R22 refueling outage overhaul of the LP servomotor, or in any previous outage overhauls. If the shoulder screws become detached from the LP servomotor linkage fulcrum bar and piston shaft link pin, the MBFP LP governor valves fail in the closed direction. This was the direct cause of the rpm swings and eventual loss of the 22 MBFP, and subsequent manual reactor trip that occurred on June 26, 2017.
As part of the cause investigation, the 2R22 LP servomotor overhaul Work Order (WO) was reviewed to determine why the shaft and linkage were left slightly twisted. While reviewing the WO, it was observed that a step text document was used in place of the Entergy MBFPT inspection procedure. The step text reduced the complete overhaul of the LP servomotor (i.e., visual inspection, disassembly, cleaning, replacement of worn parts, reassembly) down to only two steps. Siemens personnel are not accustomed to using Entergy procedures, so the step text document was created to eliminate the confusion. However, many of the notes, caution statements, and required measurements were not transferred from the Entergy MBFPT inspection procedure to the 2R22 LP servomotor overhaul WO step text document. Consequently, vital information was not included in the 2R22 WO.
Specifically, the caution statement regarding the use of excessive force or the twisting of mechanical linkages during assembly potentially causing equipment damage or malfunction was not transferred over to the 2R22 WO.
The omitted caution statement may have contributed to the condition identified during the inspection of the LP servomotor where the piston shaft and linkage appeared to be slightly twisted.
An investigation was conducted to determine the cause of the apparent failure of the main turbine runback feature when the 22 MBFP was tripped. There are two independent main turbine runback circuits, with each circuit controlling one load limit valve (LLV1 or LLV2) {TG, FCV}. The LLVs restrict steam to the main turbine in order to runback (lower) turbine load. The turbine runback function is armed when the runback permissive bistable (PC- 412B-1 or PC-412A-1) {RLY} within an LLV circuit is actuated (contact closes) on a loss of the MBFP (speed drops below 3300 rpm) coincident with turbine power above 76.5 percent, and the Arm/Defeat switch must be in the Armed position. Actuation of either of the two bistables will initiate a turbine runback via its respective LLV circuit.
As part of the functional checks performed during the investigation, the PC-412B-1 bistable for LLV1 was tested and found to be not functioning, and the PC-412A-1 bistable for LLV2 was found with an out of tolerance setting and needed adjustment. Both circuit bistables were replaced and the other circuit components were tested and verified to be functioning properly. Considering these results, it was concluded that LLV1 would not have performed its turbine runback function. It was indeterminate whether LLV2 would have functioned properly with the PC-412A-1 bistable as-found out of tolerance setting; however, the PC-412A-1 bistable was replaced to eliminate the vulnerability. Proper function of the alarm, time delay relays, and the arming of the circuit via the control switch were all verified. The tachometer relays for both circuits were functionally tested and verified to be operating properly. Additionally, the drive motors for both LLVs were checked and the results were compared against the design for number of turns to stroke and stroke speed. The results were verified to be in agreement with the intended design. Thus, all of the turbine runback circuit components were functionally tested and verified to be operating as designed following the replacement of the bistables.
An extent of condition (EOC) investigation was conducted and it was determined that the conditions identified on the 22 MBFP involving the shoulder screws used to secure the fulcrum bar and piston shaft link and the LP servomotor component alignment issue extend to the 21, 31, and 32 MBFP LP servomotors. The LP servomotor for the 21 MBFP was disassembled, inspected, and reassembled during the forced outage for this reactor trip event. The shaft and linkage were found to be aligned correctly with no twists, and all but one of the shoulder screws were staked. The one shoulder screw not staked was inaccessible due to the LP servomotor linkage being already reassembled. Station management elected not to remove the LP servo motor housing covers on the 31 and 32 MBFPs to perform visual inspections of the shoulder screws, as Indian Point Unit 3 (IP3) was operating at 100 percent power at the time of the IP2 forced outage. The EOC corrective actions are: (1) to perform semi- annual preventive maintenance (PM) inspections of the 21, 22, 31, and 32 MBFP LP servomotor shoulder screws 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.
Indian Point 2 05000-247 2017 -001 -00 to ensure no backing out is occurring and (2) to install and stake the 21, 22, 31, and 32 MBFP LP servomotor shoulder screws using Loctite 609 during their next scheduled overhaul, and all future outage overhauls (corrective action to revise 0-TUR-402-MFW).
CAUSE OF EVENT
The direct cause of the 800 rpm swings on the 22 MBFP, and erratic operation of the LP steam supply governor valves, was that the shoulder screws, which secure the LP servomotor fulcrum bar to the piston shaft link pin, backed out over time and detached from the assembly. This caused the 22 MBFP LP governor valves to fail closed.
The cause of the failure of the main turbine runback feature was indeterminate. The discovered failure of-the PC- 412B-1 bistable would have prevented LLV1 from performing the runback. However, it could not be established with certainty whether the as-found out of tolerance setting found on the PC-412A-1 bistable would have prevented LLV2 from performing the runback.
Causal factors which may have contributed to this event are:
1. The LP servomotor shoulder screws were not staked by the vendor as required by Siemens/Westinghouse proprietary design drawings.
2. The piston shaft and LP servomotor linkage were found very slightly twisted and worn during initial investigation, which placed slight uneven forces on the shoulder screws due to vendor workmanship issues that may have contributed to loosening.
3. A step text was created to perform the 2R22 LP servomotor PM inspection which omitted vital instructions, notes, and caution statements on how to reassemble the LP servomotor that were included in the MBFPT inspection procedure (0-TUR-402-MFW).
CORRECTIVE ACTIONS
The following corrective actions have been or will be performed under the Entergy Corrective Action Program to address the causes of this event.
- Repair 22 MBFP LP servomotor during forced outage. Reassemble 22 MBFP LP servomotor with shoulder screws staked as required by propriety drawings and secure screws with Loctite 609 to ensure no backing out occurs while operating.
- Verify proper function of the main turbine runback alarm, time delay relays, and arming circuit.
- Replace runback permissive bistables PC-412B-1 and PC-412A-1.
- Revise procedure 0-TUR-402-MFW for detail on LP Servomotor shoulder screw assembly. This is to include staking of the shoulder screw threads per Siemens drawings 634J5 and 634J4, and applying Loctite 609 to the threads per EC-72905.
- Perform review of LP servomotor failure with Siemens personnel who performed work in 2R22 to obtain their recollection of why requirement to stake shoulder screws was not performed, and perform a rework investigation per procedure EN-MA-123.
- For step texts that are elected to be used to perform work instead of site specific procedures, ensure all vital instructions, notes, and cautions statements are transferred from the procedure over to the step texts so all required information is captured and provided to those performing the work. This applies to all MBFP and main turbine generator (MTG) work for the IP2 2018 (2R23) and IP3 2019 (3R20) refueling outages.
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.
Indian Point 2 05000-247 2017
- Create a PM for IP2 and IP3 to perform semi-annual inspections and match marking of the MBFP LP servomotor shoulder screws to ensure no backing out of the screws is occurring while operating.
EVENT ANALYSIS
The event is reportable under 10 CFR 50.73(a)(2)(iv)(A). The licensee shall report any event or condition that resulted in manual or automatic actuation of any of the systems listed under 10 CFR 50.73(a)(2)(iv)(B). Systems to which the requirements of 10 CFR 50.73(a)(2)(iv)(A) apply for this event include the Reactor Protection System (RPS) {JC} including reactor trip and AFWS actuation'. This event meets the reporting criteria because the RPS was actuated by manual operator action at 1531 hours0.0177 days <br />0.425 hours <br />0.00253 weeks <br />5.825455e-4 months <br /> on June 26, 2017 in response to decreasing SG water levels, and the AFWS was automatically actuated on a valid low SG water level signal.
PAST SIMILAR EVENTS
A review was performed of the past three years for Licensee Event Reports (LERs) that involved a reactor trip caused by a MBFP speed control malfunction. One LER (IP3 LER 2015-007-01) was identfied that reported a miswired 31 MBFP Track and Hold board in the Lovejoy speed control system. This condition caused a minimum speed control signal to the 31 MBFP that resulted in lowering SG water levels, and a manual reactor trip was initiated at 15 percent SG level. The root cause was that the procurement for the MBFP Lovejoy Track and Hold boards was at an insufficient quality level commensurate with its criticality. As such, the corrective actions for this past similar event would not have prevented the event reported in this LER.
SAFETY SIGNIFICANCE
This event had no effect on the health and safety of the public. There were no actual safety consequences for the event because it was an uncomplicated manual reactor trip with no other transients or accidents, and the required primary safety systems performed as designed. The AFWS actuation was an expected reaction to low the SG water level caused by SG void fraction (shrink). This occurs after a reactor trip due to main steam {SB} back pressure that results from the rapid reduction of steam flow following turbine control valve closure. A reactor trip with the reduction in SG level and AFWS actuation are conditions for which the plant is analyzed. This event was bounded by the analyzed event described in IP2 Updated Final Safety Analysis Report (UFSAR) Section 14.1.9, Loss of Normal Feedwater. The AFWS has adequate redundancy to provide the minimum required flow assuming a single failure.
The UFSAR analysis demonstrates that the AFWS is capable of removing the stored and residual heat plus reactor coolant pump waste heat following a loss of normal feedwater event, thereby preventing over pressurization of the Reactor Coolant System (RCS) {AB} and preserving reactor coolant inventory.
An automatic turbine load runback signal is generated on a trip of one of the two MBFPs to initiate an automatic main turbine load runback. An automatic main turbine runback was not actuated during this event. The turbine runback is a design feature, and is not required for reactor protection. The UFSAR Section 14.1.4 analysis for rod cluster control assembly (RCCA) {AA, ROD} drop no longer credits turbine runback, nor is it credited in any other licensing basis analysis. For this event, rod control was in automatic and all rods inserted upon initiation of the manual reactor trip.
The AFWS actuated and provided required feedwater flow to the SGs. RCS pressure remained below the setpoint for pressurizer power operated relief valve (PORV) {AB, RV} or code safety valve {AB, RV} operation, and above the setpoint for automatic safety injection {BQ} actuation. Following the reactor trip, the plant was stabilized in hot standby with decay heat being removed by the main condenser.
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05000286/LER-2017-001 | Single Flow Barrier Access Point Found Unbolted LER 17-001-00 for Indian Point, Unit 3 Regarding Single Flow Barrier Access Point Found Unbolted | 10 CFR 50.73(a)(2)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident 10 CFR 50.73(a)(2)(v), Loss of Safety Function 10 CFR 50.73(a)(2)(vii), Common Cause Inoperability | 05000247/LER-2017-001 | Manual Reactor Trip Due to Decreasing Steam Generator Levels Caused By Main Boiler Feedwater Pump Turbine Low Pressure Governor Valves Failed Closed LER 17-001-00 for Indian Point, Unit 2 Regarding Manual Reactor Trip Due to Decreasing Steam Generator Levels Caused By Main Boiler Feedwater Pump Turbine Low Pressure Governor Valves Failed Closed | 10 CFR 50.73(a)(2)(iv)(A), System Actuation | 05000286/LER-2017-002 | Manual Isolation of Chemical and Volume Control System Normal Letdown to Stop a Valve Leak Resulted in an Exceedance of Technical Specification 3.4.9 Condition A Limit for Pressurizer Level LER 17-002-00 for Indian Point, Unit 3 re Manual Isolation of Chemical and Volume Control System Normal letdown to Stop a Valve Leak Resulted in an Exceedance of Technical Specification 3.4.9 Condition A Limit for Pressurizer Level | 10 CFR 50.73(a)(2)(v)(A), Loss of Safety Function - Shutdown the Reactor 10 CFR 50.73(a)(2)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident 10 CFR 50.73(a)(2)(v), Loss of Safety Function | 05000247/LER-2017-002 | Auxiliary Feedwater Flow Indication Inoperable for Longer Than the Allowed Technical Specification Completion Time Due to Failure of Complete Restoration Following Calibration LER 17-002-00 for Indian Point, Unit 2 Regarding Auxiliary Feedwater Flow Indication Inoperable for Longer Than the Allowed Technical Specification Completion Time Due to Failure of Complete Restoration Following Calibration | 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications | 05000286/LER-2017-003 | Condensate Storage Tank Declared Inoperable Per Technical Specification LER 17-003-00 for Indian Point, Unit 3, Regarding Condensate Storage Tank Declared Inoperable Per Technical Specification | 10 CFR 50.73(a)(2)(v)(B), Loss of Safety Function - Remove Residual Heat 10 CFR 50.73(a)(2)(V)(B) | 05000247/LER-2017-003 | Technical Specification Violation of Section 3.3.1 RPS Instrumentation LER 17-003-00 for Indian Point Unit 2, Regarding Technical Specification Violation of Section 3.3.1 RPS Instrumentation | 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications | 05000286/LER-2017-004 | Reactor Trip Due to Main Generator Loss of Field LER 17-004-00 for Indian Point Unit 3, Regarding Reactor Trip Due to Main Generator Loss of Field | 10 CFR 50.73(a)(2)(iv)(A), System Actuation |
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