07-25-2016 | At 1322 PDT on March 28, 2016, a manual reactor scram was initiated in response to a loss of Reactor Closed Cooling ( RCC). The loss of RCC was due to the opening of a Service Water ( SW) valve at the inlet side of the Fuel Pool Cooling heat exchanger during performance of a partial surveillance without proper isolation of the RCC system piping from the heat exchanger. The cross-connection of the two systems caused depressurization and loss of flow from the RCC system into the non-pressurized SW piping. The SW valve was closed and the reactor was scrammed. Safety system responses to the scram signal were normal, with all control rods being fully inserted. Reactor decay heat was removed via bypass valves to the Main Condenser. No safety relief valves lifted and no emergency core cooling systems injected following the reactor scram.
The root cause was determined to be that plant Operators did not properly evaluate plant configuration when performing a partial surveillance including the marking as "N/A" (not applicable) of procedural steps, in accordance with plant procedures. Human performance aspects of the event were quickly addressed and additional corrective actions include reinforcing and monitoring procedure standards, and updating work control procedures at the station.
26158 R6 NRC Form 366 (01-2014) |
---|
|
---|
Category:Letter
MONTHYEARGO2-24-004, License Amendment Request to Revise Emergency Plan2024-01-30030 January 2024 License Amendment Request to Revise Emergency Plan IR 05000397/20230042024-01-29029 January 2024 Integrated Inspection and Independent Spent Fuel Storage Installation Report 05000397/2023004 and 07200035/2023001 GO2-24-003, Relief Requests for the Columbia Generating Station Fifth Ten-Year Interval Inservice Testing2024-01-29029 January 2024 Relief Requests for the Columbia Generating Station Fifth Ten-Year Interval Inservice Testing ML24011A1522024-01-10010 January 2024 March 2024 Emergency Preparedness Exercise Inspection-Request for Information GO2-24-005, Docket No. 50-397 Supplement to Reply to a Notice of Violation; EA-21-1702024-01-0808 January 2024 Docket No. 50-397 Supplement to Reply to a Notice of Violation; EA-21-170 GO2-23-136, Guarantee of Payment of Deferred Premium2023-12-20020 December 2023 Guarantee of Payment of Deferred Premium GO2-23-135, Notice of Readiness for Supplemental Inspection2023-12-14014 December 2023 Notice of Readiness for Supplemental Inspection GO2-23-130, Reply to a Notice of Violation; EA-23-0542023-12-14014 December 2023 Reply to a Notice of Violation; EA-23-054 GO2-23-105, Licensing Basis Document Update and Biennial Commitment Change Report2023-12-12012 December 2023 Licensing Basis Document Update and Biennial Commitment Change Report ML23288A0002023-12-0707 December 2023 Issuance of Amendment No. 272 to Adopt TSTF-541, Revision 2, Add Exceptions to Surveillance Requirements for Valves and Dampers Locked in the Actuated Position GO2-23-107, Application to Revise Technical Specifications to Adopt TSTS-584, Eliminate Automatic RWCU System Isolation on SLC Initiation2023-12-0505 December 2023 Application to Revise Technical Specifications to Adopt TSTS-584, Eliminate Automatic RWCU System Isolation on SLC Initiation GO2-23-126, Docket No. 50-397 Voluntary Response to Regulatory Issue Summary 2023-012023-11-28028 November 2023 Docket No. 50-397 Voluntary Response to Regulatory Issue Summary 2023-01 GO2-23-121, Request for Exemption from Enhanced Weapons, Firearms Background Checks, and Security Event Notifications Implementation2023-11-27027 November 2023 Request for Exemption from Enhanced Weapons, Firearms Background Checks, and Security Event Notifications Implementation IR 05000397/20230122023-11-20020 November 2023 Commercial Grade Dedication Inspection Report 05000397/2023012 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 05000397/20230102023-11-0909 November 2023 Biennial Problem Identification and Resolution Inspection Report 05000397/2023010 IR 05000397/20230932023-11-0101 November 2023 Final Significance Determination of a White Finding, Notice of Violation and Follow-Up Assessment Letter; NRC Inspection Report 05000397/2023093 ML23299A2072023-10-26026 October 2023 Biennial Requalification Inspection Request for Information IR 05000397/20230032023-10-25025 October 2023 Integrated Inspection Report 05000397/2023003 IR 05000397/20230112023-10-0404 October 2023 License Renewal Phase 2 Report 05000397/2023011 IR 05000397/20234012023-09-11011 September 2023 Security Baseline Inspection Report 05000397/2023401 GO2-23-097, In-Service Inspection Summary Report for the Twenty-Sixth Refueling Outage (R26)2023-09-0606 September 2023 In-Service Inspection Summary Report for the Twenty-Sixth Refueling Outage (R26) ML24032A2182023-09-0101 September 2023 Information Request, Security IR 2024401 GO2-23-100, Technical Specification Section 5.6.4 Post Accident Monitoring Instrumentation 14-Day Report for Inoperable Suppression Pool Level Indication2023-08-31031 August 2023 Technical Specification Section 5.6.4 Post Accident Monitoring Instrumentation 14-Day Report for Inoperable Suppression Pool Level Indication GO2-23-056, Application to Revise Technical Specifications to Adopt TSTF-230, Add New Condition B to LCO 3.6.2.3, RHR Suppression Pool Cooling2023-08-29029 August 2023 Application to Revise Technical Specifications to Adopt TSTF-230, Add New Condition B to LCO 3.6.2.3, RHR Suppression Pool Cooling IR 05000397/20230052023-08-22022 August 2023 Updated Inspection Plan for Columbia Generating Station (Report 05000397/2023005) - Mid Year Letter IR 05000397/20230022023-08-0101 August 2023 Integrated Inspection Report 05000397/2023002 GO2-23-093, Supplement to Reply to a Notice of Violation: EA-21-1702023-07-27027 July 2023 Supplement to Reply to a Notice of Violation: EA-21-170 ML23206A2442023-07-25025 July 2023 Energy Northwest Columbia Generating Station, Response to Apparent Violation in NRC Inspection Report 05000397/2023092; EA-23-054 GO2-23-068, Notification of Completion of Commitments Required Prior to Entry Into the Period of Extended Operation2023-07-19019 July 2023 Notification of Completion of Commitments Required Prior to Entry Into the Period of Extended Operation GO2-23-090, Reply to a Notice of Violation2023-07-12012 July 2023 Reply to a Notice of Violation ML23143A1202023-06-27027 June 2023 Request Number 4ISI-11 to the American Society of Mechanical Engineers Boiler and Pressure Vessel Code Regarding Alternate Examination of Reactor Vessel Welds GO2-23-073, Notification of NPDES Permit Issuance2023-06-26026 June 2023 Notification of NPDES Permit Issuance ML23163A2502023-06-12012 June 2023 Summary of Changes and Analysis for Revision 41 of Plant Procedures Manual 13.8.1 Emergency Dose Projection System Operations GO2-23-072, Cycle 27 Core Operating Limits Report2023-06-0505 June 2023 Cycle 27 Core Operating Limits Report ML23157A2702023-06-0101 June 2023 4-2022-011 -022 Letter - OI Closure to Licensee IR 05000397/20230922023-06-0101 June 2023 NRC Inspection Report 05000397/2023092 and Preliminary White Finding IR 05000397/20230902023-06-0101 June 2023 Final Significance Determination of a White Finding, Notice of Violation and Follow-Up Assessment Letter; NRC Inspection Report 05000397/2023090 GO2-23-055, Independent Spent Fuel Storage Installation, 2022 Annual Radiological Environmental Operating Report2023-05-15015 May 2023 Independent Spent Fuel Storage Installation, 2022 Annual Radiological Environmental Operating Report IR 05000397/20230012023-05-0505 May 2023 Integrated Inspection Report 05000397/2023001 - April 26, 2023 GO2-23-006, License Amendment Request to Clean-Up Operating License and Appendix a Technical Specifications2023-05-0101 May 2023 License Amendment Request to Clean-Up Operating License and Appendix a Technical Specifications IR 05000397/20233012023-05-0101 May 2023 NRC Examination Report 05000397/2023301 GO2-23-053, 2022 Annual Environmental Operating Report2023-04-26026 April 2023 2022 Annual Environmental Operating Report GO2-23-057, 2022 Annual Radioactive Effluent Release Report2023-04-25025 April 2023 2022 Annual Radioactive Effluent Release Report ML23110A2642023-04-20020 April 2023 Request for Information License Renewal Phase 2 Inspection GO2-23-012, Application to Revise Technical Specifications to Adopt Tstf-541, Add Exceptions to Surveillance Requirements for Valves and Dampers Locked in the Actuated Position2023-03-27027 March 2023 Application to Revise Technical Specifications to Adopt Tstf-541, Add Exceptions to Surveillance Requirements for Valves and Dampers Locked in the Actuated Position GO2-23-041, Generation Station - Level of Financial Protection - Annual Reporting Requirement2023-03-15015 March 2023 Generation Station - Level of Financial Protection - Annual Reporting Requirement GO2-23-038, Plant Decommissioning Fund Status Report2023-03-15015 March 2023 Plant Decommissioning Fund Status Report ML23013A0812023-03-15015 March 2023 Issuance of Amendment No. 270 Revision to Technical Specifications to Adopt TSTF 505, Revision 2, Provide Risk-Informed Extended Completion Times-RITSTF Initiative 4B GO2-23-034, Report of Changes or Errors in Emergency Core Cooling System Loss of Coolant Accident Analysis Models Pursuant to 10 CFR 50.462023-03-13013 March 2023 Report of Changes or Errors in Emergency Core Cooling System Loss of Coolant Accident Analysis Models Pursuant to 10 CFR 50.46 2024-01-08
[Table view] Category:Licensee Event Report (LER)
MONTHYEAR05000397/LER-2017-0072017-11-30030 November 2017 Valve Closure Results in Momentary Increase in Secondary Containment Pressure, LER 17-007-00 for Columbia Generating Station Regarding Valve Closure Results in Momentary Increase in Secondary Containment Pressure 05000397/LER-2017-0062017-11-0909 November 2017 CONDITION PROHIBITED BY TECHNICAL SPECIFICATIONS DUE TO INCOMPLETE ACTION STATEMENT, LER 17-006-00 for Columbia Generating Station for Condition Prohibited by Technical Specifications Due to Incomplete Action Statement 05000397/LER-2017-0052017-11-0909 November 2017 Valve Closure Results in Momentary Increase in Secondary Containment Pressure, LER 17-005-00 for Columbia Generating Station Regarding Valve Closure Results in Momentary Increase in Secondary Containment Pressure 05000397/LER-2017-0042017-10-18018 October 2017 MANUAL REACTOR SCRAM DUE TO HIGH MAIN CONDENSER BACK PRESSURE, LER 17-004-00 for Columbia Generating Station Regarding Manual Reactor Scram Due to High Main Condenser Back Pressure 05000397/LER-2016-0022017-09-27027 September 2017 1 OF 3, LER 16-002-01 for Columbia Generating Station Regarding Valve Closure Results in Momentary Increase in Secondary Containment Pressure 05000397/LER-2016-0032017-08-29029 August 2017 Failure of Fan to Start Results in Momentary Increase in Secondary Containment Pressure, LER 16-003-01 for Columbia Regarding Failure of Fan to Start Results in Momentary Increase in Secondary Containment Pressure 05000397/LER-2017-0032017-08-24024 August 2017 Momentary loss of Secondary Containment due to Weather, LER 17-003-00 for Columbia Generating Station Regarding Momentary Loss of Secondary Containment due to Weather 05000397/LER-2017-0022017-07-10010 July 2017 Implementation of Enforcement Guidance Memorandum 11-003, Revision 3, LER 17-002-00 for Columbia Generating Station re Implementation of Enforcement Guidance Memorandum 11-003, Revision 3 05000397/LER-2016-0042017-06-0808 June 2017 1 OF 3, LER 16-004-01 for Columbia Generating Station Regarding Automatic Scram Due to Off-site Load Reject 05000397/LER-2017-0012017-03-20020 March 2017 Contactor Coil Failure Results in Tripping of HPCS Diesel Mixed Air Fan, LER 17-001-00 for Columbia Generating Station Regarding Contactor Coil Failure Results in Tripping of HPCS Diesel Mixed Air Fan 05000397/LER-2016-0052017-02-15015 February 2017 Leak in Minimum Flow Line Makes HPCS and Primary Containment Inoperable, LER 16-005-00 for Columbia Generating Station Regarding Leak in Minimum Flow Line Makes HPCS and Primary Containment Inoperable 05000397/LER-2016-0012016-05-24024 May 2016 MANUAL REACTOR SCRAM FOLLOWING LOSS OF REACTOR CLOSED COOLING, LER 16-001-00 for Columbia Regarding Manual Reactor Scram Following Loss of Reactor Closed Cooling 05000397/LER-2015-0072016-01-0707 January 2016 REACTOR BUILDING PRESSURE GREATER THAN TECHNICAL SPECIFICATIONS REQUIREMENT, LER 15-007-00 for Columbia Regarding Reactor Building Pressure Greater Than Technical Specifications Requirement 2017-09-27
[Table view] |
Reported lessons learned are incorporated into the licensing process and fed back to industry.
Send comments regarding burden estimate to the FOIA, Privacy and Information Collections Branch (T-5 F53), U.S. Nuclear Regulatory Commission, Washington, DC 20555-0001, or by intemet e-mail to Infocollects.Resource@nrc.gov, and to the Desk Officer, Office of Information and Regulatory Affairs, NEOB-10202, (3150-0104), Office of Management and Budget, Washington, DC 20503. If a means 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.
Columbia Generating Station
2. DOCKET
05000 397
Plant Conditions
The reactor was at 100% power before the event. There were no structures, systems or components that malfunctioned or that were out of service that contributed to this event. One of the four reactor source range detectors failed to insert during the scram, with no impact on safety functions.
Event Description
On March 28, 2016, Operators performed a partial surveillance of the Fuel Pool Cooling (FPC) System [DA] to satisfy Post Maintenance Testing (PMT) for a Service Water (SW) [BI] to FPC isolation valve. Per PMT instructions, sections of the surveillance procedure had been marked as Not Applicable (N/A) for steps not considered necessary for the partial surveillance. The steps marked as N/A included closing Reactor Closed Cooling (RCC) [CC] isolation valves on the downstream side of the heat exchanger that isolate SW from RCC. Opening the SW valve without isolating RCC resulted in loss of pressurized RCC inventory into depressurized SW piping.
Operators recognized the loss of RCC from Control Room indications and took appropriate actions to manually scram the reactor as required by abnormal operating procedures. All plant systems responded as expected during the scram transient. The SW valve was closed after approximately 2 minutes of being opened and RCC inventory recovered quickly.
This event was reported (EN # 51826 — 4 hour4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> notification) under criterion 10 CFR 50.72(b)(2)(iv)(B) — Actuation of Reactor Protection System (RPS) [JC] when the reactor is critical. The event also requires a 60-day report, or Licensee Event Report (LER), under criterion 10 CFR 50.73(a)(2)(iv)(A) as applicable to condition 50.73(a)(2)(iv)(B)(1) — An event or condition that resulted in manual or automatic actuation of the RPS system including: reactor scram or reactor trip.
Event Precursors The SW valve maintenance was originally scheduled to be performed concurrent with the quarterly surveillance of FPC. A change to the schedule moved the maintenance to after the surveillance. As a result a partial surveillance was performed. Work control reviews and pre job briefs failed to recognize the significance of some of the steps being bypassed (N/A'd) in the partial surveillance such as closing the RCC isolation valves.
Cause
The root cause was determined to be that plant Operators did not properly evaluate plant configuration when performing a partial surveillance including the marking as "N/A" (not applicable) of procedural steps, in accordance with plant's Procedure and Work Instruction Use and Adherence requirements.
26158A R3 Contributing Causes were that Work Control did not follow procedures when revising the work instructions, Technical Specification tracking log, and the work order impact statement, and that the Work Management process per the Integrated Risk Management procedure does not ensure that PMT tasks (and potentially other tasks on the same work order) are adequately evaluated for risk as stand-alone activities.
Corrective Actions
Human performance aspects of the event were immediately addressed, including coaching to the individuals involved. A Stand Down was conducted with oncoming day and night shift crews on the event, and instructions were issued requiring appropriate levels of reviews and peer checks when bypassing procedure steps for partial performance of procedures. Expectations were communicated to place keep all Notes, Cautions and Warnings in Continuous Use procedures even when steps in a section are bypassed (N/A'd).
Additional Corrective Actions include reinforcing and monitoring procedure standards, updating work control procedures, and revising the Integrated Risk Management procedure to require evaluation of each task on a work order for risk, as well as aggregate risk of the entire work order, and document this evaluation in a summary on the impact statement.
Previous Occurrences
Previous occurrences or events where improper application of N/A to work documents was a contributing factor to a plant event were investigated. There were no noteworthy examples where the improper use of N/A required issuance of an LER.
Assessment of Safety Consequences
This event resulted in a reactor trip and associated loss of generation. The loss of RCC resulted in the loss of cooling to several components, including Reactor Recirculation Pumps, the Non- Regenerative Heat Exchanger, and Drywell Cooling. There were no adverse effects to those systems due to the temporary loss of cooling. There were no undesired radiological or industrial safety aspects resulting from this event. This event did not challenge the ability of Columbia Generating Station to safely shutdown, and all plant systems responded as designed.
Energy Industry Identification System Information Energy Industry Identification System information codes from IEEE Standards 805-1984 and 803- 1983 are represented in brackets as [X] and [)0(] throughout the body of the narrative.
26158A R3