11-13-2017 | On May 27, 2017, an attempt to start the red train High Pressure Injection ( HPI) pump [BJ] in accordance with normal operating procedures was initiated. Control Room operators received an annunciator, HPI PUMP TRIP, and observed no indication of the pump starting.
During investigative walk downs with the relay department, personnel discovered the HPI breaker was not fully racked up (trip pedal still in a tripped (down) condition and roller not free to roll). Operations personnel performed manual breaker operations to rack the 4160 V breaker [EB] further in the up direction. The pump was successfully started and declared operable.
The condition was the result of an inadequate risk evaluation.
The associated Operations Directive has been revised to require Operations management approval when waiving start-checks of vital 4160 VAC components following racking up of the respective breaker. The revision is expected to ensure appropriate personnel are involved when determining the risk associated with not testing components for functionality/operability following racking up evolutions of an associated breaker. |
---|
|
---|
Category:Letter
MONTHYEARML23326A0392024-01-24024 January 2024 Issuance of Amendment No. 281 Revision to Technical Specifications to Adopt TSTF-505, Revision 2, Provide Risk-Informed Extended Completion Times - RITSTF Initiative 4b ML24017A1582024-01-17017 January 2024 Submittal of Emergency Plan Revision 50 IR 05000313/20234202024-01-10010 January 2024 Security Baseline Inspection Report 05000313/2023420 and 05000368/2023420 IR 05000313/20234022024-01-0202 January 2024 Security Baseline Inspection Report 05000313/2023402 and 05000368/2023402 ML23349A1672023-12-21021 December 2023 Request for Withholding Information from Public Disclosure ML23354A0022023-12-21021 December 2023 Request for Withholding Information from Public Disclosure ML23348A3572023-12-14014 December 2023 Application to Revise Technical Specifications to Use Online Monitoring Methodology Slides and Affidavit for Pre-Submittal Meeting ML23340A1592023-12-13013 December 2023 Entergy Operations, Inc. - Entergy Fleet Project Manager Assignment ML23352A0292023-12-13013 December 2023 Entergy - 2024 Nuclear Energy Liability Evidence of Financial Protection IR 05000313/20234052023-12-12012 December 2023 Security Baseline Inspection Report 05000313/2023405 and 05000368/2023405 ML23341A0832023-12-11011 December 2023 Material Control and Accounting Program Inspection Report 05000313/368/2023404- Cover Letter ML23305A0922023-12-0707 December 2023 Summary of Regulatory Audit Regarding License Amendment Request to Revise Technical Specifications to Adopt TSTF-505, Revision 2, Provide Risk-Informed Extended Completion Times RITSTF Initiative 4b ML23333A1362023-11-29029 November 2023 Supplement to Request for Exemption from Enhanced Weapons, Firearms Background Checks, and Security Event Notifications Implementation ML23275A2072023-11-28028 November 2023 Issuance of Amendment No. 280 Removal of Technical Specification Condition Allowing Two Reactor Coolant Pump Operation IR 05000313/20230032023-11-21021 November 2023 Revised - ANO Revised Integrated Inspection Report 05000313/2023003 and 05000368/2023003 and Independent Spent Fuel Storage Installation Inspection Report 07200013/ 2023001 ML23325A1412023-11-21021 November 2023 Request for Exemption from Enhanced Weapons, Firearms Background Checks, and Security Event Notifications Implementation ML23313A0962023-11-13013 November 2023 Integrated Inspection Report 05000313/2023003 and 05000368/2023003 and Independent Spent Fuel Storage Installation Inspection Report 07200013/2023001 ML23243B0452023-11-13013 November 2023 Request for Withholding Information from Public Disclosure ML23311A2082023-11-0909 November 2023 Reassignment of U.S. Nuclear Regulatory Commission Branch Chief in the Division of Operating Reactor Licensing for Plant Licensing Branch IV IR 05000313/20230112023-10-10010 October 2023 Commercial Grade Dedication Inspection Report 05000313/2023011 and 05000368/2023011 IR 05000313/20230052023-08-21021 August 2023 Updated Inspection Plan for Arkansas Nuclear One, Units 1 and 2 (Report 05000313/2023005 and 05000368/2023005) - Mid Cycle IR 05000313/20243012023-08-14014 August 2023 Notification of NRC Initial Operator Licensing Examination 05000313/2024301 IR 05000313/20230022023-08-11011 August 2023 Integrated Inspection Report 05000313/2023002 and 05000368/2023002 and Notice of Violation ML23209A6022023-08-0909 August 2023 Regulatory Audit Plan in Support of License Amendment Request to Revise Technical Specifications to Adopt Risk- Informed Completion Times IR 05000416/20230022023-08-0808 August 2023 Integrated Inspection Report 05000416/2023002 and Independent Spent Fuel Storage Installation Inspection Report 07200050/2023001 ML23208A2132023-08-0303 August 2023 Regulatory Audit Summary Concerning Review of License Amendment Request to Remove Technical Specification Condition Allowing Two Reactor Coolant Pump Operation ML23208A2112023-07-27027 July 2023 Entergy Operations Inc., Application to Revise Technical Specifications to Adopt TSTF-205, Revision of Channel Calibration, Channel Functional Test, and Related Definitions ML23188A1732023-07-12012 July 2023 Request for Withholding Information from Public Disclosure ML23142A2022023-06-29029 June 2023 Issuance of Amendment Nos. 279 and 332 Emergency Plan Staffing Requirements IR 05000313/20234032023-06-28028 June 2023 Security Baseline Inspection Report 05000313/2023403 and 05000368/2023403 ML23178A0892023-06-26026 June 2023 August 2023 Emergency Preparedness Program Inspection-Request for Information ML23166B0902023-06-21021 June 2023 Request for Relief ANO1 ISI 036 Regarding Volumetric Examination Requirements ML23180A1082023-06-20020 June 2023 ANO Unit 1 SAR Amendment 31, TRM, TS Bases, 10 CFR 50.59 Report, and Commitment Change Summary Report IR 05000313/20234012023-06-13013 June 2023 Cyber Security Inspection Report 05000313/2023401 and 05000368/2023401 ML23130A2972023-05-17017 May 2023 Notification of Inspection (NRC Inspection Report 05000313/2023003) and Request for Information ML23114A3572023-05-10010 May 2023 Regulatory Audit Summary Concerning Review of Request for Alternative ANO-CISI-002 Regarding Containment Inservice Inspection Frequency ML23121A3012023-05-10010 May 2023 Regulatory Audit Plan in Support of License Amendment Request to Revise Technical Specifications to Adopt Risk - Informed Completion Times ML23130A2732023-05-10010 May 2023 and Waterford 3 Steam Electric Station - Response to Regulatory Issue Summary 2023-01, Preparation and Scheduling of Operator Licensing Examinations IR 05000313/20230012023-05-0909 May 2023 Integrated Inspection Report 05000313/2023001 and 05000368/2023001 ML23118A3202023-05-0808 May 2023 Notification of Biennial Problem Identification and Resolution Inspection and Request for Information (05000313;05000368/2023010) ML23117A2172023-05-0101 May 2023 Safety Evaluation for Quality Assurance Program Manual Reduction in Commitment IR 05000368/20233012023-05-0101 May 2023 NRC Examination Report 05000368/2023301 ML23108A1362023-04-24024 April 2023 Approval of Request for Half-Nozzle Repair of Reactor Vessel Closure Head Penetration No. 46 ML23110A1122023-04-20020 April 2023 Annual Report for Entergy Quality Assurance Program Manual Changes Under 10 CFR 50.54(a)(3), 10 CFR 71.106, and 10 CFR 72.140(d). Notification of Application of Approved Appendix B to 10 CFR 72 Subpart G 2024-01-24
[Table view] Category:Licensee Event Report (LER)
MONTHYEARML20135G7222020-05-14014 May 2020 Final ASP Analysis - ANO 1 (LER 313-96-005) 05000313/LER-2017-0022017-07-26026 July 2017 High Pressure Injection Pump Inoperable for Greater Than Technical Specification Completion Time, LER 17-002-00 for Arkansas Nuclear One, Unit 1, Regarding High Pressure Injection Pump Inoperable for Greater Than Technical Specification Completion Time 05000368/LER-2017-0022017-06-26026 June 2017 Automatic Start of an Emergency Diesel Generator Due to the Momentary Loss of Offsite Power due to Severe Weather, LER 17-002-00 for Arkansas Nuclear One, Unit 2, Regarding Automatic Start of an Emergency Diesel Generator Due to the Momentary Loss of Offsite Power due to Severe Weather 05000313/LER-2017-0012017-06-26026 June 2017 Automatic Start of an Emergency Diesel Generator Due to the Loss of Offsite Power due to Severe Weather, LER 17-001-00 for Arkansas Nuclear One, Unit 1, Regarding Automatic Start of an Emergency Diesel Generator Due to the Loss of Offsite Power due to Severe Weather 05000313/LER-2016-0032017-06-0909 June 2017 Tornado Missile Vulnerabilities Resulting in Unanalyzed Condition, LER 16-003-01 for Arkansas Nuclear One, Unit 1 Regarding Tornado Missile Vulnerabilities Resulting in Unanalyzed Condition 05000368/LER-2017-0012017-05-30030 May 2017 Inadequate Protection from Tornado Missiles Identified Due to Nonconforming Design Conditions, LER 17-001-00 for Arkansas Nuclear One, Unit 2, Regarding Inadequate Protection from Tornado Missiles Identified Due to Nonconforming Design Conditions 05000313/LER-2016-0042016-11-29029 November 2016 Decay Heat Removal System Socket Weld Leak due to a Vibration-Induced Fatigue Crack, LER 16-004-00 for Arkansas Nuclear One, Unit 1, Regarding Decay Heat Removal System Socket Weld Leak Due to a Vibration-Induced Fatigue Crack 05000368/LER-2016-0012016-11-15015 November 2016 Failure of One Emergency Diesel Generator and Subsequent Required Shutdown of Arkansas Nuclear One, Unit 2, LER 16-001-00 for Arkansas Nuclear One, Unit 2, Regarding Failure of One Emergency Diesel Generator and Subsequent Required Shutdown 05000313/LER-2016-0022016-08-11011 August 2016 Tornado Missile Vulnerability Resulting in Condition Prohibited By Technical Specifications, LER 16-002-00 for Arkansas Nuclear One, Unit 1, Regarding Tornado Missile Vulnerability Resulting in Condition Prohibited By Technical Specifications 05000313/LER-2016-0012016-05-18018 May 2016 Non-Functional External Penetration Flood Seals, LER 16-001-00 for Arkansas Nuclear One, Unit 1, Regarding Non-Functional External Penetration Flood Seals 05000313/LER-2015-0012016-02-12012 February 2016 Manual Reactor Trio Due to Oscillations in the Feedwater System, LER 15-001-00 for Arkansas Nuclear One, Unit 1, Regarding Manual Reactor Trip Due to Oscillations in the Feedwater System 2CAN051405, LER 14-01-00 for Arkansas Nuclear One, Unit 2 Regarding Operation of Switchgear Rooms Ventilation Prohibited by Technical Specifications2014-05-15015 May 2014 LER 14-01-00 for Arkansas Nuclear One, Unit 2 Regarding Operation of Switchgear Rooms Ventilation Prohibited by Technical Specifications 0CAN050202, LER 02-S01-00 for Arkansas Nuclear One Units 1 and 2, Compensatory Measures Were Removed While a Security Perimeter Intrusion Detection Microwave Field Remained Disarmed2002-05-10010 May 2002 LER 02-S01-00 for Arkansas Nuclear One Units 1 and 2, Compensatory Measures Were Removed While a Security Perimeter Intrusion Detection Microwave Field Remained Disarmed 2020-05-14
[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.
A. PLANT STATUS
Arkansas Nuclear One, Unit 1 (ANO-1) was operating at 100% rated thermal power in Mode 1 when this condition was discovered. There were no other structures, systems, or components (SSCs) that were inoperable at the time that contributed in the event.
B. EVENT DESCRIPTION
On May 11, 2017, all four High Pressure Injection (HPI) pump breakers were racked up to support ANO-1 startup from a unit outage. Operations elected to not cycle each of the breakers (start each pump individually) because the realignments required are relatively complex and would introduce the potential for human error.
On May 27, 2017, Operations attempted to place the red train HPI pump in service in accordance with normal operating procedures, in order to secure the swing HPI pump for upcoming maintenance. Annunciator, HPI PUMP TRIP, was received in the Control Room and operators observed that the pump failed to start.
During investigative walk downs, the red train HPI pump breaker was observed to not be fully racked up (trip pedal still in a tripped (down) condition and roller not free to roll). Operations personnel performed manual breaker operations to rack the 4160 V breaker further in the up direction. The red train pump was successfully started and declared operable. The green train HPI loop and pump and the swing HPI pump were not impacted by this condition.
C. BACKGROUND – SYSTEM DESIGN The HPI system is an integral part of the Makeup and Purification system which uses two of the three makeup pumps (P-36A, P-36B, P-36C) for injection of coolant from the Borated Water Storage Tank (BWST). The HPI, Low Pressure Injection [BO], and the Core Flooding systems are collectively designed as an Emergency Core Cooling System (ECCS) which, for the entire spectrum of RCS break sizes, terminates the core thermal transient, limits the amount of zirconium-water reaction, and assures that core integrity is maintained. P-36A is the dedicated red train HPI pump, P-36C the dedicated green train HPI pump, and HPI pump P-36B can be aligned to support either train. One HPI pump train is required to satisfy accident analysis assumptions.
During accident conditions, injection of borated water is initiated by a low RCS pressure or high reactor building pressure signal, which automatically starts one HPI pump in each train. Automatic actuation of the associated valves and pumps switches the system from its normal operating makeup mode to the emergency operating mode of operation, in order to deliver water from the BWST into the reactor vessel through the reactor coolant lines. HPI pumps are powered from one of two train-specific 4160 VAC vital switchgear which are backed by train specific safety-related Emergency Diesel Generators.
In light of single failure considerations, the ANO-1 Technical Specifications (TSs) require two ECCS trains to be operable in Modes 1, 2, and Mode 3 when RCS temperature is greater than 350 °F. With one HPI train inoperable, restoration is required within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> or the unit must be placed in Mode 3 within the following 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and RCS temperature reduced to ≤ 350 °F within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> of expiration of the 72 hour8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> restoration Completion Time.
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.
In addition, plant mode changes with one train of HPI inoperable may only be made following completion of a risk assessment addressing inoperable systems and components, consideration of the results, determination of the acceptability of entering the mode in the Applicability, and the establishment of risk management actions, if appropriate, in accordance with ANO-1 TS 3.0.4.b.
D. EVENT CAUSE
The direct cause of the red train HPI pump not starting was that its 4160 V supply breaker was not fully and properly racked up. The cause of HPI train inoperability was the failure to effectively assess risk associated with the decision to waive the start-check of the HPI pump following the breaker racking evolution.
E. CORRECTIVE ACTIONS
The associated Operations Directive has been revised to require Operations management approval when waiving start-checks of vital 4160 VAC components following racking up of the respective breaker. The revision is expected to ensure appropriate personnel are involved when determining the risk associated with not testing components for functionality/operability following racking up evolutions of an associated breaker.
The red train HPI pump receives 4160 VAC power from the red train vital switchgear A-3 via a breaker manufactured by Siemens. All other A-3 Switchgear Siemens breakers were inspected (no Siemens breakers are installed on A-4 Switchgear) and no issues with the foot pedal or roller alignment were identified.
F. SAFETY SIGNIFICANT EVALUATION
The red train HPI pump was inoperable for approximately thirteen days prior to the condition being discovered and corrected. However, the pump was only required to be operable to meet TS requirements for five of the thirteen days.
While this condition resulted in exceeding the associated TS 3.5.2 Completion Time and resulted in plant mode changes being made without assessing station risk in accordance with TS 3.0.4.b, the green HPI train remained operable and available during this time period. Because one train of HPI remained operable at all times, the accident mitigation function of the system remained available over the relevant time period. Therefore, this event did not create a safety significant condition at ANO-1.
G. BASIS FOR REPORTABILITY
This event is reportable pursuant to the following criteria:
10 CFR 50.73(a)(2)(i)(B) Any operation or condition which was prohibited by Technical Specifications The guidance provided in NUREG 1022 states under 10 CFR 50.73(a)(1):
The holder of an operating license for a nuclear power plant (licensee) shall submit a Licensee Event Report (LER) for any event of the type described in this paragraph within 60 days after the discovery of the event.
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.
Arkansas Nuclear One, Unit 1 05000-313 2017 - 002 - 01
H. ADDITIONAL INFORMATION
10 CFR 50.73(b)(5) states that this report shall contain reference to “any previous similar events at the same plant that are known to the licensee.” NUREG 1022 reporting guidance states that term “previous occurrences” should include previous events or conditions that involved the same underlying concern or reason as this event, such as the same root cause, failure, or sequence of events.
A review of the ANO corrective action program and LERs for the previous three years was performed. There were no similar events identified at ANO during this time period.
Energy Industry Identification System (EIIS) codes and component codes are identified in the text of this report as [XX].