On April 30, 2017, at 1818 hours0.021 days <br />0.505 hours <br />0.00301 weeks <br />6.91749e-4 months <br />, while the plant was at 100 percent rated thermal power, main turbine steam bypass valve number 1 partially opened. Power was subsequently lowered in an attempt to close the bypass valve. While lowering power the bypass valve would shut and then reopen and power would again be lowered. When power was lowered to approximately 74 percent the bypass valve remained closed. During the transient the reactor protection system ( RPS) trip functions for the main turbine stop valve closure and turbine control valve fast closure scram were declared inoperable due to the opening of the bypass valve, which changes the bypass setpoint for those RPS trips. With the loss of RPS trip capability. a loss of safety function existed intermittently for approximately 37 minutes. The manual reactor trip function and other RPS functions remained operable.
Both channels of the rod withdrawal limiter (RWL) and the end of cycle reactor recirculation pump trip (EOC-RPT) function were also declared inoperable. These functions are credited in accident analysis and this also resulted in a loss of safety function in accordance with the plants Technical Specification bases.
The direct cause of the bypass valve opening was degradation of the Primary Low Value Gate (PLVG) card in the main turbine speed control circuit.
The safety significance of this event is considered to be small. This event is not considered a safety system functional failure as the specific functions were maintained and never bypassed during the event. This event is being reported under 50.73(a)(2)(v)(A) and 50.73(a)(2)(v)(D) for a loss of safety function. |
Similar Documents at Perry |
---|
Category:Letter
MONTHYEARIR 05000440/20230042024-01-30030 January 2024 Integrated Inspection Report 05000440/2023004 L-23-207, License Amendment Request (LAR) for Adoption of TSTF-264-A Revision 0, 3.3.9 and 3.3.10 - Delete Flux Monitors Specific Overlap Requirement SRs2024-01-24024 January 2024 License Amendment Request (LAR) for Adoption of TSTF-264-A Revision 0, 3.3.9 and 3.3.10 - Delete Flux Monitors Specific Overlap Requirement SRs L-24-017, 30-Day Voluntary Report in Accordance with Industry Groundwater Protection Initiative2024-01-24024 January 2024 30-Day Voluntary Report in Accordance with Industry Groundwater Protection Initiative IR 05000440/20234022024-01-10010 January 2024 Cyber Security Inspection Report 05000440/2023402 ML24003A8032024-01-0303 January 2024 Notification of NRC Fire Protection Team Inspection Request for Information ML23321A0472023-12-20020 December 2023 Letter to Rod L. Penfield - Perry Nuclear Power Plant, Unit 1 - License Renewal Regulatory Audit Regarding the Environmental Review of the License Renewal Application L-23-171, CFR 50.55a Request Number VR-9. Revision 0, Feedwater Check Valve Exercising Test Frequency2023-12-0808 December 2023 CFR 50.55a Request Number VR-9. Revision 0, Feedwater Check Valve Exercising Test Frequency L-23-244, Request for Exemption from Enhanced Weapons, Firearms Background Checks, and Security Event Notifications Implementation2023-12-0606 December 2023 Request for Exemption from Enhanced Weapons, Firearms Background Checks, and Security Event Notifications Implementation IR 05000440/20230112023-11-28028 November 2023 Biennial Problem Identification and Resolution Inspection Report 05000440/2023011 IR 05000440/20234032023-11-27027 November 2023 Security Baseline Inspection Report 05000440/2023403 ML23292A2972023-11-17017 November 2023 Table of Contents LAR (L-2023-LLA-0111) L-23-238, Mid-Cycle Revision to the Core Operating Limits Report for Operating Cycle 202023-11-10010 November 2023 Mid-Cycle Revision to the Core Operating Limits Report for Operating Cycle 20 L-23-052, Submittal of the Updated Safety Analysis Report, Revision 232023-10-27027 October 2023 Submittal of the Updated Safety Analysis Report, Revision 23 ML23292A2482023-10-19019 October 2023 Fws to NRC, Federal Agency Coordination Under ESA Section 7 for Perry Nuclear Plant, Unit 1, License Renewal, and Concurrence with Not Likely to Adversely Affect Determination for Northern Long-eared Bat ML23292A2472023-10-19019 October 2023 Fws to NRC, Perry Nuclear Plant, Unit 1, License Renewal List of Threatened and Endangered Species That May Occur in Your Proposed Project Location or May Be Affected IR 05000440/20230032023-10-11011 October 2023 Integrated Inspection Report 05000440/2023003 ML23249A1032023-10-0303 October 2023 Letter to Rod L. Penfield, Site Vice President-Perry Nuclear Power Plant, Unit 1-Notice of Intent to Conduct Scoping Process and Prepare an Environmental Impact Statement ML23237B4222023-09-28028 September 2023 Energy Harbor Nuclear Corp. - Vistra Operations Company LLC - Letter Regarding Order Approving Transfer of Licenses and Draft Conforming License Amendments ML23269A1242023-09-27027 September 2023 Request for Withholding Information from Public Disclosure ML23261B0192023-09-25025 September 2023 Aging Management Audit Plan Regarding the License Renewal Application Review ML23261C3642023-09-25025 September 2023 License Renewal Application Online Reference Portal ML23256A3592023-09-22022 September 2023 Determination of Acceptability and Sufficiency for Docketing, Proposed Review Schedule, and Opportunity for a Hearing Regarding the Energy Harbor Nuclear Corp. Application for License Renewal L-23-206, Ohio National Pollutant Discharge Elimination System (NPDES) Permit 3IB00016 MD2023-09-12012 September 2023 Ohio National Pollutant Discharge Elimination System (NPDES) Permit 3IB00016 MD L-23-205, Supplement to Application for Order Consenting to Transfer of Licenses and Conforming License Amendments2023-09-12012 September 2023 Supplement to Application for Order Consenting to Transfer of Licenses and Conforming License Amendments L-23-172, Quality Assurance Program Manual2023-08-31031 August 2023 Quality Assurance Program Manual IR 05000440/20234012023-08-28028 August 2023 Public - Perry Nuclear Power Plant Security Baseline Inspection Report 05000440/2023401 ML23129A1722023-08-25025 August 2023 Request for Withholding Information from Public Disclosure for Beaver Valley Power Station, Units 1 and 2; Davis Besse Nuclear Power Station, Unit 1; and Perry Nuclear Power Plant, Unit 1 IR 05000440/20230052023-08-24024 August 2023 Updated Inspection Plan for Perry Nuclear Power Plant (Report 05000440/2023005) ML23172A2852023-08-23023 August 2023 Safety Evaluation Irradiated Fuel Management Plan and Preliminary Decommissioning Cost Estimate ML23227A2202023-08-15015 August 2023 Information Request to Support Upcoming Problem Identification and Resolution Inspection at Perry Nuclear Power Plant L-23-001, License Amendment Request to Remove the Table of Contents from the Technical Specifications2023-08-0707 August 2023 License Amendment Request to Remove the Table of Contents from the Technical Specifications L-23-188, Energy Harbor Nuclear Corp., Supplement to Application for Order Consenting to Transfer of Licenses and Conforming License Amendments2023-08-0707 August 2023 Energy Harbor Nuclear Corp., Supplement to Application for Order Consenting to Transfer of Licenses and Conforming License Amendments IR 05000440/20230022023-08-0202 August 2023 Integrated Inspection Report 05000440/2023002 L-23-174, 30-Day Voluntary Report in Accordance with Industry Groundwater Protection Initiative2023-07-19019 July 2023 30-Day Voluntary Report in Accordance with Industry Groundwater Protection Initiative ML23198A2842023-07-17017 July 2023 Information Request for the Cyber-Security Baseline Inspection, Notification to Perform Inspection L-23-146, License Renewal Application for the Perry Nuclear Power Plant2023-07-0303 July 2023 License Renewal Application for the Perry Nuclear Power Plant IR 05000440/20230102023-06-29029 June 2023 Comprehensive Engineering Team Inspection Report 05000440/2023010 ML23178A2422023-06-28028 June 2023 Reassignment of the U.S. Nuclear Regulatory Commission Branch Chief in the Division of Operating Reactor Licensing for Plant Licensing Branch III L-23-051, Plan, Nineteenth Inservice Inspection Summary Report2023-06-22022 June 2023 Plan, Nineteenth Inservice Inspection Summary Report L-23-050, 2022 Annual 10 CFR 50.46 Report of Changes to or Errors in Emergency Core Cooling System Evaluation Models2023-06-22022 June 2023 2022 Annual 10 CFR 50.46 Report of Changes to or Errors in Emergency Core Cooling System Evaluation Models L-22-249, License Amendment Request for Adoption of Technical Specification Task Force Traveler TSTF-276-A Revision 2, Change TS 3.8.1. AC Sources-Operating. to Clarify the Power Factor Requirements When Performing Diesel Gener2023-06-0505 June 2023 License Amendment Request for Adoption of Technical Specification Task Force Traveler TSTF-276-A Revision 2, Change TS 3.8.1. AC Sources-Operating. to Clarify the Power Factor Requirements When Performing Diesel Gener ML23144A3562023-05-25025 May 2023 Information Meeting with a Question and Answer Session to Discuss NRC 2022 End of Cycle Plant Performance Assessment of Perry Nuclear Power Plant, Unit 1 L-23-134, Response to NRC Regulatory Issue Summary 2023-01 Preparation and Scheduling of Operator Licensing Examinations2023-05-23023 May 2023 Response to NRC Regulatory Issue Summary 2023-01 Preparation and Scheduling of Operator Licensing Examinations L-23-065, Annual Financial Report2023-05-22022 May 2023 Annual Financial Report ML23124A1742023-05-17017 May 2023 Energy Harbor Fleet Vistra License Transfer - Request for Withholding Information from Public Disclosure for Commance Peak Plant, Units 1 & 2, Beaver Valley Station, Units 1 & 2, Davis Besse Station, Unit 1 and Perry Plant, Unit 1 ML23129A0112023-05-16016 May 2023 Notice of Consideration of Approval of Indirect and Direct License Transfer for Comanche Peak Plant, Units 1 & 2, Beaver Valley Station, Units 1 & 2, Davis Besse Station, Unit 1 and Perry Plant, Unit 1 (EPID L-2023-LLM-0000) (Letter) IR 05000440/20230012023-05-0404 May 2023 Integrated Inspection Report (05000440/2023001) L-23-121, Annual Radiological Effluent Release Report2023-04-26026 April 2023 Annual Radiological Effluent Release Report L-23-122, Annual Radiological Environmental Operating Report2023-04-26026 April 2023 Annual Radiological Environmental Operating Report 2024-01-30
[Table view] Category:Licensee Event Report (LER)
MONTHYEAR05000440/LER-2017-0062017-12-0101 December 2017 Loss of Safety Function due to the Inoperability of Both Trains of Motor Control Center Ventilation, LER 17-006-00 for Perry Nuclear Power Plant Regarding Loss of Safety Function due to the Inoperability of Both Trains of Motor Control Center Ventilation 05000440/LER-2017-0042017-10-0404 October 2017 Loss of Safety Function for High Pressure Core Spray Suppression Pool Level Instrumentation, LER 17-004-00 for Perry re Loss of Safety Function for High Pressure Core Spray Suppression Pool Level Instrumentation 05000440/LER-2017-0052017-10-0404 October 2017 Controller Malfunction results in Momentary Degradation of Secondary Containment Pressure, LER 17-005-00 for Perry Nuclear Power Plant Regarding Controller Malfunction Results in Momentary Degradation of Secondary Containment Pressure 05000440/LER-2017-0022017-06-27027 June 2017 Loss of Safety Function Due to Main Turbine Bypass Valve Opening, LER 17-002-00 for Perry Nuclear Power Plant Regarding Loss of Safety Function Due to Main Turbine Bypass Valve Opening 05000440/LER-2017-0032017-06-26026 June 2017 Annulus Exhaust Gas Treatment System Loss of Safety Function, LER 17-003-00 for Perry Nuclear Power Plant Regarding Annulus Exhaust Gas Treatment System Loss of Safety Function 05000440/LER-2016-0042017-02-24024 February 2017 Loss of Safety Function Due to Two Inoperable Standby Liquid Control Subsystems, LER 16-004-00 for Perry Regarding Loss of Safety Function Due to Two Inoperable Standby Liquid Control Subsystems L-16-366, LER 16-03-001 for Perry Nuclear Power Plant Loss of Safety Related Electrical Bus Results in a Loss of Shutdown Cooling2016-12-21021 December 2016 LER 16-03-001 for Perry Nuclear Power Plant Loss of Safety Related Electrical Bus Results in a Loss of Shutdown Cooling L-16-365, LER 16-01-001 for Perry, Unit 1, Regarding Pressure Boundary Leakage, Level 8 Automatic SCRAM, and APRM Loss of Safety Function2016-12-21021 December 2016 LER 16-01-001 for Perry, Unit 1, Regarding Pressure Boundary Leakage, Level 8 Automatic SCRAM, and APRM Loss of Safety Function ML16138A3342016-05-17017 May 2016 ASP Analysis - Reject Perry Nuclear Power Plant, Unit 1 (440-2014-005) ML16138A3362016-05-17017 May 2016 ASP Analysis - Reject Perry Nuclear Power Plant, Unit 1 (440-2014-004) 05000440/LER-2016-0032016-04-0808 April 2016 Loss of Safety Related Electrical Bus Results in a Loss of Shutdown Cooling, LER 16-003-00 for Perry Regarding Loss of Safety Related Electrical Bus Results in a Loss of Shutdown Cooling 05000440/LER-2016-0022016-04-0808 April 2016 Manual Reactor SCRAM Due to Spurious Opening of Safety Relief Valves, LER 16-002-00 for Perry Regarding Manual Reactor SCRAM Due to Spurious Opening of Safety Relief Valve 05000440/LER-2016-0012016-03-23023 March 2016 Pressure Boundary Leakage, Level 8 Automatic SCRAM, and APRM Loss of Safety Function, LER 16-001-00 for Perry Nuclear Power Plant Regarding Drywell Leakage, Level 8 Automatic SCRAM and APRM Loss of Safety Function L-13-194, LER 13-S02-01 for Perry, Unit 1 Regarding Security Weapon Left Unattended2013-06-25025 June 2013 LER 13-S02-01 for Perry, Unit 1 Regarding Security Weapon Left Unattended L-13-143, LER 13-S02-00, for Perry Nuclear Power Plant, Unit 1, Regarding Security Weapon Left Unattended2013-04-30030 April 2013 LER 13-S02-00, for Perry Nuclear Power Plant, Unit 1, Regarding Security Weapon Left Unattended L-13-119, LER 13-S01-00 for Perry Nuclear Power Plant, Unit 1, Regarding Local Power Range Monitors Delivered to the Incorrect Address2013-03-15015 March 2013 LER 13-S01-00 for Perry Nuclear Power Plant, Unit 1, Regarding Local Power Range Monitors Delivered to the Incorrect Address L-12-114, LER 12-S02-00, for Perry Nuclear Power Plant, Unit 1, Regarding Potential Vulnerability in a Safeguards Security System2012-03-22022 March 2012 LER 12-S02-00, for Perry Nuclear Power Plant, Unit 1, Regarding Potential Vulnerability in a Safeguards Security System L-12-083, LER 12-S01-00, Latent Software Error Resulted in Improperly Authorized Visitor Access Into Protected Area2012-02-29029 February 2012 LER 12-S01-00, Latent Software Error Resulted in Improperly Authorized Visitor Access Into Protected Area L-08-052, LER 07-04-001 for Perry Nuclear Power Plant Re Automatic Reactor Protection System Actuation Due to Feedwater Control Power Supply Failure2008-02-15015 February 2008 LER 07-04-001 for Perry Nuclear Power Plant Re Automatic Reactor Protection System Actuation Due to Feedwater Control Power Supply Failure ML0533301242005-11-18018 November 2005 LER 05-03-00 for Perry Nuclear Power Plant Lack of Suction Flow Path Causes High Pressure Core Spray to Be Inoperable ML0509602632004-12-17017 December 2004 Final Precursor Analysis - Perry Grid Loop 2017-06-27
[Table view] |
Estimated buraen per response to comply th.s mandatory collection request 3 0 hours0 days <br />0 hours <br />0 weeks <br />0 months <br />. Reportec lessons learned are .ncorporated into the licensing process and fed back to industry. Senc comments regarding burden estimate to the Irtrmation Services Branca (T-2 F431 U.S Nuclear Regulatory Commission, Washington. DC 20555-0001. or by e-mail to NEOB-10202. (3150-0104). Office of Management and Budget. Wash rigton. DC 20503. If a means used to impose an information collection does not display a currently valid OME control number. the NRC nay not conduct or sponsor, ana a person is not recuired to resperd to. the information co ec.on.
3. LER NUMBER
Perry Nuclear Power Plant Unit 1 05000-440 YEAR 2017 - 002 - 00 Energy Industry Identification System (EIIS) codes are identified in the text as [XX].
INTRODUCTION
On April 30, 2017, at 1818 hours0.021 days <br />0.505 hours <br />0.00301 weeks <br />6.91749e-4 months <br />, while the plant was at 100 percent rated thermal power, main turbine steam bypass [JI] valve number 1 partially opened. Power was subsequently lowered in an attempt to close the bypass valve. While lowering power the bypass valve would shut and then reopen and power would again be lowered. When power was lowered to approximately 74 percent the bypass valve remained closed.
During the transient the reactor protection system (RPS) [JC] trip functions for the main turbine stop valve closure and turbine control valve fast closure scram were declared inoperable due to the opening of the bypass valve which changes the bypass setpoint for those RPS trips. With the loss of RPS trip capability for this function a loss of safety function existed intermittently for approximately 37 minutes. The manual reactor trip function and other RPS functions remained operable.
Both channels of the rod withdrawal [AA] limiter (RWL) and the end of cycle reactor recirculation pump [AD] trip (EOC-RPT) function were also declared inoperable in accordance with the plants Technical Specification (TS) bases. These functions are credited in accident analysis. this also resulted in a loss of safety function.
On April 30. 2017, at 1910 hours0.0221 days <br />0.531 hours <br />0.00316 weeks <br />7.26755e-4 months <br />, the action statements for TS 3.3.1.1 "Reactor Protection System (RPS) Instrumentation"; 3.3.2.1 Control Rod Block Instrumentation", and 3.3.4.1 "End of Cycle Recirculation Pump Trip (EOC-RPT) Instrumentation" were exited following confirmation of bypass valve closure. On May 3, 2017, at 1259 hours0.0146 days <br />0.35 hours <br />0.00208 weeks <br />4.790495e-4 months <br />. event notification 52727 was made to the NRC Operations Center in accordance with 10CFR50.72(b)(3)(v)(A) and 10CFR50.72(b)(3)(v)(D) for the loss of safety function.
EVENT DESCRIPTION
On April 30, 2017. at 1818 hours0.021 days <br />0.505 hours <br />0.00301 weeks <br />6.91749e-4 months <br />, while the plant was at 100 percent rated thermal power main turbine steam bypass valve number 1 partially opened. Power was subsequently lowered in an attempt to close the bypass valve. While lowering power the bypass valve would shut and then reopen and power would again be lowered. When power was lowered to approximately 74 percent the bypass valve remained closed.
Certain TS functions are automatically bypassed based upon certain sensed reactor power levels. Four of those functions rely on the pressure in the first stage of the turbine to correlate reactor power. With a bypass valve open. the pressure in the first stage of the turbine may not be representative of true reactor power so these functions are declared inoperable. The following functions use the first stage pressure:
Turbine Stop Valve (TSV) Closure and Turbine Control Valve (TCV) Fast Closure Scram — TS 3.3.1.1:
Closure of the TSVs and TCVs results in the loss of a heat sink and produces reactor pressure. neutron flux.
and heat flux transients that must be limited. Therefore, a reactor scram is initiated at the start of TSV and TCV closure in anticipation of the transients that would result from the closure of these valves. This function must be enabled at thermal power greater than or equal to 38 percent. This is normally accomplished automatically by pressure switches sensing turbine first stage pressure; therefore, to consider this function operable. the turbine bypass valves must remain shut at power greater than or equal to 38 percent.
End of Cycle Recirculation Pump Trip (EOC-RPT) — TS 3.3.4.1:
Estimated burden per response :o comply with this mandatory co!lec: on recuest: 82 hours9.490741e-4 days <br />0.0228 hours <br />1.35582e-4 weeks <br />3.1201e-5 months <br />. Reported comments regarding burden est mate to the Information Services Branch (T-2 F43). U.S Nuclear Regulatory Commission. Washington DC 20555-0001 or by 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 informabor collection aces not display a currently valid OMB control number. the NRC may not conduct or sponsor and a person is not rem, red to respond to. the rfiormanon collection.
To mitigate pressurization transient effects of a main turbine trip the EOC-RPT must trip the recirculation pumps from fast speed operation after initiation of initial closure movement of either the TSVs or the TCVs.
The combined effects of this trip and a scram reduce fuel bundle power more rapidly than does a scram alone, resulting in an increased margin to the Minimum Critical Power Ratio (MCPR) safety limit. The EOC- RPT function is automatically disabled when turbine first stage pressure is less than 38 percent power. To consider this function operable, the turbine bypass valves must remain shut at power greater than or equal to 38 percent.
Rod Withdrawal Limiter (RWL) —TS 3.3.2.1:
The RWL is designed to prevent violation of the MCPR safety limit and the cladding 1 percent plastic strain fuel design limit that may result from a single control rod withdrawal error (RWE) event. The RWL is assumed to mitigate the consequences of an RWE event when operating greater than 33.3 percent power.
With any bypass valve open both channels of the listed functions are inoperable resulting in a loss of safety function. During the transient the following TS action statements were entered: TS 3.3.1.1 conditions A, B and C, 3.3.2.1 condition A and 3.3.4.1 conditions A and B. The required action for TS 3.3.1.1 C.1 requires restoration of RPS trip capability within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />. TS 3.3.2.1 Action A.1 requires immediate suspension of control rod withdrawal and verification of no rod motion by 2 licensed operators. 3.3.4.1 Action B.1 requires restoration of EOC-RPT capability within 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />.
On April 30, 2017, at 1910 hours0.0221 days <br />0.531 hours <br />0.00316 weeks <br />7.26755e-4 months <br />. the action statements for TS 3.3.1.1. 3.3.2.1, and 3.3.4.1 were exited following confirmation of bypass valve closure. On May 3. 2017, at 1259 hours0.0146 days <br />0.35 hours <br />0.00208 weeks <br />4.790495e-4 months <br /> event notification 52727 was made to the NRC Operations Center in accordance with 10CFR50.72(b)(3)(v)(A) and 10CFR50.72(b)(3)(v)(D) for the loss of safety function.
CAUSE
The direct cause of the bypass valve opening was degradation of the Primary Low Value Gate (PLVG) card in the main turbine speed control circuit [SC].
The problem solving team assembled for this issue evaluated monitoring equipment attached to the speed control portion of the Electro-Hydraulic system in order to determine the source of the inadvertent opening of the bypass valve. The failure mode was narrowed down to the turbine speed control portion of the circuitry based upon the alarms received during the transient. The decision was made to replace the Primary Low Value Gate and the Primary Frequency to Voltage Converter Speed Control cards. After the replacement was completed, the turbine was re-synchronized to the electrical grid. The installed monitoring equipment showed no evidence of an issue within the Electro-Hydraulic control systems and there were no further openings of the bypass valves.
The analysis of the removed cards is not yet completed, and if a change to the primary cause is warranted a LER revision will be submitted. Preliminary testing found a degradation of the PLVG card. During bench checks of the card it was discovered that an intermittent varying output signal was created with no changes to the input of the card. This intermittent change in output of the card would have caused the opening of the bypass valve. The second card that was replaced was the Primary Frequency to Voltage Converter card although initial analysis has identified no issues with this card.
Estimated bu
- den per response to comply with this mandatory collection request: 80 hours9.259259e-4 days <br />0.0222 hours <br />1.322751e-4 weeks <br />3.044e-5 months <br />. Reported comments regarding burden estimate to the Information Services Branch (T-2 F43). U.S Nuclear Regulatory Commission. Washirgton, DC 20555-0001, or by e-mail to Infocollects Resou
- ce@nrc.gcv, and to the Desk Ofce
- . Offce of Information and Regulatory Alairs.
NEOB-10202, (3150-0104). Office of Management ano Budget. Washington. DO 20503. If a means used to impose an information collection does not display a currently valid OMB contra number the NRC may not conduct or sponsor. and a person is not requ red to respond to the .1-formation col.ection.
05000-440
3. LER NUMBER
EVENT ANALYSIS
The event is of small safety significance from the Probabilistic Risk Assessment (PRA) perspective as no PRA related mitigative components or strategies were affected by this event. While the corresponding functions were declared inoperable from a Technical Specification perspective. functionality was maintained and the plant was correspondingly controlled via proper actions to reduce power. The event did not result in an automatic trip.
With no transient and no impact to any PRA related components or functions, there would be no corresponding change (delta) in core damage frequency (CDF). and no corresponding change (delta) in the large early release frequency (LERF). The delta CDF and delta LERF values would therefore be well below the acceptable thresholds of 1.0E-06/yr and 1.0E-07/yr. respectively. as discussed in Regulatory Guide 1.174. The risk of this event is therefore considered small in accordance with the Regulatory Guidance.
During the transient. the sensed reactor pressure at the turbine first stage did not drop low enough to impede the ability for the listed parameters to perform their function, therefore, this is not considered a safety system functional failure.
CORRECTIVE ACTIONS
The PLVG card was replaced following discovery of the failure. No other issues have been noted since replacement.
In addition to the card replacement, the mitigation strategy for the control system will be reviewed.
PREVIOUS SIMILAR EVENTS
A review of LERs and the corrective action database for the past three years identified no similar events.
COMMITMENTS
There are no regulatory commitments contained in this report. Actions described in this document represent intended or planned actions, are described for the NRC's information, and are not regulatory commitments.
|
---|
|
|
| | Reporting criterion |
---|
05000440/LER-2017-001 | Implementation of Enforcement Guidance Memorandum (EGM) 11-003, Revision 3 | 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications | 05000440/LER-2017-002 | Loss of Safety Function Due to Main Turbine Bypass Valve Opening LER 17-002-00 for Perry Nuclear Power Plant Regarding Loss of Safety Function Due to Main Turbine Bypass Valve Opening | 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 | 05000440/LER-2017-003 | Annulus Exhaust Gas Treatment System Loss of Safety Function LER 17-003-00 for Perry Nuclear Power Plant Regarding Annulus Exhaust Gas Treatment System Loss of Safety Function | 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 10 CFR 50.73(a)(2)(v), Loss of Safety Function | 05000440/LER-2017-004 | Loss of Safety Function for High Pressure Core Spray Suppression Pool Level Instrumentation LER 17-004-00 for Perry re Loss of Safety Function for High Pressure Core Spray Suppression Pool Level Instrumentation | 10 CFR 50.73(a)(2)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident | 05000440/LER-2017-005 | Controller Malfunction results in Momentary Degradation of Secondary Containment Pressure LER 17-005-00 for Perry Nuclear Power Plant Regarding Controller Malfunction Results in Momentary Degradation of 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 | 05000440/LER-2017-006 | Loss of Safety Function due to the Inoperability of Both Trains of Motor Control Center Ventilation LER 17-006-00 for Perry Nuclear Power Plant Regarding Loss of Safety Function due to the Inoperability of Both Trains of Motor Control Center Ventilation | 10 CFR 50.73(a)(2)(v)(B), Loss of Safety Function - Remove Residual Heat 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 | 05000440/LER-2017-007 | 1 OF | 10 CFR 50.73(a)(2)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident |
|