11-9-2017 | On September 12, 2017 at 1227 PDT, Secondary Containment became inoperable due to pressure increasing above the Technical Specification limit of -0.25 inches of water gauge. While the plant was at 100% power, a Reactor Building exhaust valve and supply valve unexpectedly lost power and closed, resulting in a loss of Secondary Containment for approximately one minute. While Technical Specification limits were exceeded for this short time period, the resulting pressure excursion was bounded by analytical results; and thus, there were no safety consequences for this condition. This event was reported under 10 CFR 50.72(b)(3)(v)(C) and 10 CFR 50.72 (b)(3)(v)(D) as Event Notification #52966.
The apparent cause of the event was that station personnel did not deliberately and conservatively perform work tasks. Workers failed to update work instructions when work was rescheduled, and did not verify power sources at the work site. Corrective actions for this event include conducting a workshop on management expectations of Maintenance, increased management oversight, and addressing human performance issues. |
---|
|
---|
Category:Letter
MONTHYEARML24290A1142024-10-17017 October 2024 CGS FPTI 2024011 IR 05000397/20244032024-10-0101 October 2024 Cybersecurity Inspection Report 05000397/2024403 Public GO2-24-088, Supplement to Response to Request for Additional Information Regarding License Amendment Request to Revise Columbia Emergency Plan2024-09-24024 September 2024 Supplement to Response to Request for Additional Information Regarding License Amendment Request to Revise Columbia Emergency Plan GO2-24-051, Application to Revise Technical Specifications to Adopt TSTF-592, Revise Automatic Depressurization System (ADS) Instrumentation Requirements2024-09-23023 September 2024 Application to Revise Technical Specifications to Adopt TSTF-592, Revise Automatic Depressurization System (ADS) Instrumentation Requirements ML24247A1572024-09-12012 September 2024 Withholding Determination Letter for Presentation Materials for Energy Northwest Pre-application Meeting 8-9-2024 ML24255A1012024-09-12012 September 2024 Request for Withholding Information from Public Disclosure Energy Northwest Regulatory Engagement Plan, Revision 0 GO2-24-082, Response to Request for Additional Information Regarding License Amendment Request to Revise Columbia Emergency Plan2024-09-10010 September 2024 Response to Request for Additional Information Regarding License Amendment Request to Revise Columbia Emergency Plan IR 05000397/20240052024-08-22022 August 2024 Updated Inspection Plan for Columbia Generating Station (Report 05000397/2024005) IR 07200035/20244012024-08-19019 August 2024 Security Baseline Inspection Report 07200035/2024401 IR 05000397/20244022024-08-13013 August 2024 Security Baseline Inspection Report 05000397/2024402 IR 05000397/20240022024-08-0909 August 2024 Integrated Inspection Report 05000397/2024002 GO2-24-060, Reply to a Notice of Violation, EA-21-170 and EA-23-0542024-07-30030 July 2024 Reply to a Notice of Violation, EA-21-170 and EA-23-054 GO2-24-070, Response to Request for Additional Information Regarding Fifth Interval Inservice Testing Program2024-07-29029 July 2024 Response to Request for Additional Information Regarding Fifth Interval Inservice Testing Program GO2-24-063, Notification of Extension to Columbias Fourth 10-Year Interval Inservice Testing Program Plan2024-07-15015 July 2024 Notification of Extension to Columbias Fourth 10-Year Interval Inservice Testing Program Plan IR 05000397/20240122024-07-10010 July 2024 – Safety Conscious Work Environment Issue of Concern Follow-up Inspection 05000397/2024012 ML24180A1482024-06-28028 June 2024 Notification of an NRC Fire Protection Baseline Inspection (NRC Inspection Report 05000397/2024011) and Request for Information IR 05000397/20244202024-06-27027 June 2024 – Security Baseline Inspection Report 05000397 2024420 Cover Letter GO2-24-057, Notice of Readiness for Supplemental Inspection2024-06-19019 June 2024 Notice of Readiness for Supplemental Inspection ML24099A2232024-06-12012 June 2024 Issuance of Amendment No. 275 to Adopt TSTF-230, Revision 1, Add New Condition B to LCO 3.6.2.3, RHR Suppression Pool Cooling GO2-24-056, Relief Request for the Columbia Generating Station Fourth Ten-Year Interval Inservice Testing2024-06-11011 June 2024 Relief Request for the Columbia Generating Station Fourth Ten-Year Interval Inservice Testing ML24128A2242024-05-31031 May 2024 Issuance of Amendment No. 274 to Revise Technical Specifications to Adopt TSTF-584, Eliminate Automatic RWCU System Isolation on SLC Initiation GO2-24-049, 2023 Annual Radiological Environmental Operating Report2024-05-13013 May 2024 2023 Annual Radiological Environmental Operating Report GO2-24-050, Annual Environmental Operating Report2024-04-30030 April 2024 Annual Environmental Operating Report IR 05000397/20240012024-04-24024 April 2024 Integrated Inspection Report 05000397/2024001 GO2-24-042, 2023 Annual Radioactive Effluent Release Report2024-04-22022 April 2024 2023 Annual Radioactive Effluent Release Report ML24089A2282024-04-15015 April 2024 – Acceptance of Requested Licensing Action License Amendment Request to Revise Columbia Generating Station Emergency Plan ML24074A4532024-04-11011 April 2024 Request for Withholding Information from Public Disclosure GO2-24-044, Voluntary Response to Regulatory Issue Summary 2024-012024-04-11011 April 2024 Voluntary Response to Regulatory Issue Summary 2024-01 IR 05000397/20244012024-04-0202 April 2024 – Security Baseline Inspection Report 05000397/2024401 (Cover Letter Only) GO2-24-034, Supplement to License Amendment Request to Revise Columbia Generating Station Emergency Plan2024-03-20020 March 2024 Supplement to License Amendment Request to Revise Columbia Generating Station Emergency Plan ML24058A0692024-03-14014 March 2024 Supplemental Information Needed for Acceptance of Requested Licensing Action Amendment Request for Emergency Plan ML24044A0492024-03-12012 March 2024 Exemption from Select Requirements of 10 CFR Part 73 (EPID L-2023-LLE-0064 (Security Notifications, Reports, and Recordkeeping and Suspicious Activity Reporting)) GO2-24-041, Level of Financial Protection - Annual Reporting Requirement2024-03-12012 March 2024 Level of Financial Protection - Annual Reporting Requirement GO2-24-036, Presentation Information for Pre-Application Meeting Regarding Columbia’S Replacement Steam Dryer Evaluation Approach for Extended Power Uprate2024-03-11011 March 2024 Presentation Information for Pre-Application Meeting Regarding Columbia’S Replacement Steam Dryer Evaluation Approach for Extended Power Uprate GO2-24-039, Report of Changes or Errors in Emergency Core Cooling System Loss of Coolant Accident Analysis Models Pursuant to 10 CFR 50.462024-03-11011 March 2024 Report of Changes or Errors in Emergency Core Cooling System Loss of Coolant Accident Analysis Models Pursuant to 10 CFR 50.46 ML24047A0422024-03-0707 March 2024 Issuance of Amendment No. 273 Renewed Facility Operating License and Technical Specification Clean Up IR 05000397/20230062024-02-28028 February 2024 Annual Assessment Letter for Columbia Generating Station (Report 05000397/2023006) IR 05000397/20253012024-02-14014 February 2024 Notification of NRC Initial Operator Licensing Examination 05000397/2025301 GO2-24-004, 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 GO2-24-014, Independent Spent Fuel Storage Installation, Supplement to Request for Exemption from Enhanced Weapons, Firearms Background Checks, and Security Event Notifications Implementation2024-01-15015 January 2024 Independent Spent Fuel Storage Installation, Supplement to Request for Exemption from Enhanced Weapons, Firearms Background Checks, and Security Event Notifications Implementation 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 2024-09-24
[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] |
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 Columbia Generating Station 05000- 397 2017 - 005 - 00
Plant Conditions
At the time of the event, the plant was operating in Mode 1 at 100% power. There were no structures, systems, or components that were inoperable at the start of the event that contributed to the event.
Event Description
On September 12, 2017 at 1227 PDT, Operations personnel received trouble alarms for the Off Gas System [WF], Fuel Pool Cooling System [DA], and Condensate Blowdown System [SD]. A Reactor Building [NG] exhaust valve [ISV] and supply valve [ISV] closed due to a loss of power. Concurrently, station electricians called to report an electrical spark while replacing the motor control center bucket [MCC] for the Reactor Core Isolation Cooling [BN] vacuum pump [P]. For a time period of approximately one minute, Secondary Containment differential pressure increased above -0.25 inches of water gauge (inwg), resulting in Technical Specification (TS) Surveillance Requirement 3.6.4.1.1 not being met.
This event is reportable as an event that could have prevented fulfillment of safety functions needed to control the release of radiation, and mitigate the consequences of an accident per 10 CFR 50.73(a)(2)(v)(C) and 10 CFR 50.73(a)(2)(v)(D).
This condition was reported under 10 CFR 50.72(b)(3)(v)(C) and 10 CFR 50.72(b)(3)(v)(D) via Event Notification #52966 for an event or condition that could have prevented fulfillment of a safety function needed to control the release of radioactive material, and needed to mitigate the consequences of an accident.
Immediate Corrective Actions
Operations personnel took manual control of the Reactor Building exhaust air controller [DCC] and restored Reactor Building differential pressure to normal. Both the supply and exhaust valves were re-opened, and the Reactor Building exhaust air controller was then returned to automatic function.
Assessment of Safety Consequences
This event resulted in an unplanned entry into TS Action Statement 3.6.4.1.A, in which Secondary Containment pressure was greater than -0.25 inwg for approximately one minute. The peak pressure during this event was -0.18 inwg. While the actual pressure was beyond the range allowed by Technical Specifications, the purpose of maintaining a slight vacuum is to assist in drawdown of secondary containment to support accident response of the safety related Standby Gas Treatment [BH] (SGT) system. Existing engineering analysis demonstrates that for this event, the drawdown credited in Columbia's accident analysis could have been attained using either of the two available trains of the SGT system, thus there were no potential safety consequences. There was no actual safety consequence associated with this event since there was no loss of safety function and no potential for radiological release.
Cause of Event
The apparent cause of the event was that station personnel did not deliberately and conservatively perform work tasks.
Workers failed to update work instructions when work was rescheduled, and did not verify power sources at the work site.
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 Columbia Generating Station 05000- 397 2017 - 005 - 00 Similar Events A loss of the ability to maintain Secondary Containment pressure greater than required by Technical Specifications has occurred at Columbia Generating Station four times in the past two years. One event was due to inclement weather, one event was due to degraded lubrication on a circuit breaker [52] fan [FAN], and two events were due to latent errors from initial construction of the plant. Energy Northwest has implemented corrective actions for these previous events.
Further Corrective Actions A Maintenance workshop will be held to strengthen understanding and knowledge of standards, and management's expectations of Maintenance personnel. Focused observations will be conducted to determine the effectiveness of the workshop. Additionally, human performance issues will be addressed.
Energy Industry Identification System (EIIS) Information codes from IEEE Standards 805-1984 and 803-1983 are represented in brackets as [XX] and [XXX] throughout the body of the narrative.
|
---|
|
|
| | Reporting criterion |
---|
05000397/LER-2017-001 | 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 | 10 CFR 50.73(a)(2)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident | 05000397/LER-2017-002 | 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 | 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications | 05000397/LER-2017-003 | 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 | 10 CFR 50.73(a)(2)(v)(C), Loss of Safety Function - Release of Radioactive Material 10 CFR 50.73(a)(2)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident | 05000397/LER-2017-004 | 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 | 10 CFR 50.73(a)(2)(iv)(A), System Actuation | 05000397/LER-2017-005 | 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 | 10 CFR 50.73(a)(2)(v)(C), Loss of Safety Function - Release of Radioactive Material 10 CFR 50.73(a)(2)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident | 05000397/LER-2017-006 | 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 | 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications | 05000397/LER-2017-007 | 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 | 10 CFR 50.73(a)(2)(v)(C), Loss of Safety Function - Release of Radioactive Material 10 CFR 50.73(a)(2)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident |
|