07-11-2016 | On May 10, 2016, the Davis-Besse Nuclear Power Station ( DBNPS) was in Mode 1 and increasing power following refueling outage activities. At 0528 hours0.00611 days <br />0.147 hours <br />8.730159e-4 weeks <br />2.00904e-4 months <br />, it was identified that all four of the Anticipatory Reactor Trip System ( ARTS) channel switches were in the bypass position for the Main Turbine function while at approximately 53 percent power.
These switches are required by the Technical Specifications to be in the normal/enabled position when above 45 percent power. The switches were restored to Normal and the applicable Technical Specifications exited at 0552 hours0.00639 days <br />0.153 hours <br />9.126984e-4 weeks <br />2.10036e-4 months <br />.
An Operations Standing Order was issued to require paired periodic walk downs of all Control Room panels to ensure a comprehensive understanding of plant status awareness. Walk downs were also performed to independently identify any additional concerns or omissions in plant startup activities. The root cause of this event is the operators failed to effectively work as a team to ensure a safety system was in an operable condition when required. Corrective actions include implementation of the Operations Section Continuous Improvement Plan and revision of applicable procedures.
This event is being reported pursuant to 10 CFR 50.73(a)(2)(i)(B) as a condition prohibited by Technical Specifications. |
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Category:Letter
MONTHYEARIR 05000346/20243012024-02-0202 February 2024 NRC Initial License Examination Report 05000346/2024301 IR 05000346/20230042024-01-31031 January 2024 Integrated Inspection Report 05000346/2023004 ML23313A1352024-01-17017 January 2024 Authorization and Safety Evaluation for Alternative Request RP 5 for the Fifth 10 Year Interval Inservice Testing Program ML23353A1192023-12-19019 December 2023 Operator Licensing Examination Approval Davis Besse Nuclear Power Station, January 2024 L-23-260, Corrections to the 2022 Combined Annual Radiological Environmental Operating Report and Radioactive Effluent Release Report for the Davis-Besse Nuclear Power Station2023-12-0707 December 2023 Corrections to the 2022 Combined Annual Radiological Environmental Operating Report and Radioactive Effluent Release Report for the Davis-Besse Nuclear Power Station L-23-243, Independent Spent Fuel Storage Installation - Request for Exemption from Enhanced Weapons, Firearms Background Checks, and Security Event Notifications Implementation2023-12-0606 December 2023 Independent Spent Fuel Storage Installation - Request for Exemption from Enhanced Weapons, Firearms Background Checks, and Security Event Notifications Implementation ML23338A3172023-12-0606 December 2023 Notification of NRC Baseline Inspection and Request for Information; Inspection Report 05000346/2024001 IR 05000346/20234032023-11-0202 November 2023 Security Baseline Inspection Report 05000346/2023403 ML23293A0612023-11-0101 November 2023 Letter to the Honorable Marcy Kaptur, from Chair Hanson Responds to Letter Regarding Follow Up on Concerns Raised by Union Representatives During the June Visit to the Davis-Besse Nuclear Power Plant L-23-215, Changes to Emergency Plan2023-10-19019 October 2023 Changes to Emergency Plan 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 IR 05000346/20234012023-09-13013 September 2023 Security Baseline Inspection Report 05000346/2023401 (Public) 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 05000346/20230112023-08-30030 August 2023 Biennial Problem Identification and Resolution Inspection Report 05000346/2023011 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 05000346/20230052023-08-24024 August 2023 Updated Inspection Plan for Davis-Besse Nuclear Power Station (Report 05000346/2023005) 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 05000346/20230502023-08-0303 August 2023 Special Inspection Report 05000346/2023050 IR 05000346/20230902023-08-0101 August 2023 EA-23-002 Davis-Besse Nuclear Power Station - NRC Inspection Report No. 05000346/2023090 (Public) ML23178A2742023-08-0101 August 2023 Letter to the Honorable Marcy Kaptur from Chair Hanson Responds to Letter Regarding the License Transfer Application for the Davis-Besse Nuclear Power Station L-23-175, Submittal of Fifth Ten Year Inservice Testing Program2023-08-0101 August 2023 Submittal of Fifth Ten Year Inservice Testing Program IR 05000346/20230022023-07-27027 July 2023 Integrated Inspection Report 05000346/2023002 ML23193A7842023-07-13013 July 2023 Information Request for the Cyber-Security Baseline Inspection, Notification to Perform Inspection 05000346/2023402 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 ML23160A2342023-06-13013 June 2023 Confirmation of Initial License Examination L-23-034, 2022 Annual 10 CFR 50.46 Report of Changes to or Errors in Emergency Core Cooling System Evaluation Models2023-06-13013 June 2023 2022 Annual 10 CFR 50.46 Report of Changes to or Errors in Emergency Core Cooling System Evaluation Models IR 05000346/20235012023-06-13013 June 2023 Emergency Preparedness Biennial Exercise Inspection Report 05000346/2023501 L-23-135, Response to Regulatory Issue Summary 2023-01, Preparation and Scheduling of Operator Licensing Examinations2023-05-31031 May 2023 Response to 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) ML23131A2732023-05-15015 May 2023 Notification of NRC Supplemental Inspection 95001 and Request for Information L-23-101, Combined Annual Radiological Environmental Operating Report and Radioactive Effluent Release Report for the Davis-Besse Nuclear Power Station - 20222023-05-12012 May 2023 Combined Annual Radiological Environmental Operating Report and Radioactive Effluent Release Report for the Davis-Besse Nuclear Power Station - 2022 L-23-131, Readiness for Resumption of NRC Supplemental Inspection2023-05-12012 May 2023 Readiness for Resumption of NRC Supplemental Inspection IR 05000346/20230102023-05-0909 May 2023 Commercial Grade Dedication Inspection Report 05000346/2023010 ML23123A1272023-05-0303 May 2023 Information Request to Support Upcoming Problem Identification and Resolution Inspection at Davis-Besse Nuclear Power Station IR 05000346/20230012023-05-0101 May 2023 Integrated Inspection Report 05000346/2023001 and 07200014/2022001 L-23-092, Occupational Radiation Exposure Report for Year 20222023-04-27027 April 2023 Occupational Radiation Exposure Report for Year 2022 ML23111A1972023-04-26026 April 2023 Information Meeting with Question and Answer Session to Discuss NRC 2022 End-of-Cycle Plant Performance Assessment of Davis-Besse Nuclear Power Plant Station ML23114A1062023-04-25025 April 2023 Information Request to Support the NRC Annual Baseline Emergency Action Level and Emergency Plan Changes Inspection CP-202300181, ISFSI, Beaver Valley, Units 1 and 2, ISFSI, Davis-Besse, Unit 1, ISFSI, Perry, Unit 1, ISFSI, Corrected Affidavit for Application for Order Consenting to Transfer of Licenses and Conforming License Amendments2023-04-20020 April 2023 ISFSI, Beaver Valley, Units 1 and 2, ISFSI, Davis-Besse, Unit 1, ISFSI, Perry, Unit 1, ISFSI, Corrected Affidavit for Application for Order Consenting to Transfer of Licenses and Conforming License Amendments CP-202300157, ISFSI, Beaver Valley, Units 1 and 2, ISFSI, Davis-Besse, Unit 1, ISFSI, Perry, Unit 1, and ISFSI, Application for Order Consenting to Transfer of Licenses and Conforming License Amendments2023-04-14014 April 2023 ISFSI, Beaver Valley, Units 1 and 2, ISFSI, Davis-Besse, Unit 1, ISFSI, Perry, Unit 1, and ISFSI, Application for Order Consenting to Transfer of Licenses and Conforming License Amendments ML23096A1382023-04-11011 April 2023 Review of the Spring 2022 Steam Generator Tube Inspection Report L-23-061, Submittal of the Decommissioning Funding Status Reports2023-03-31031 March 2023 Submittal of the Decommissioning Funding Status Reports L-23-037, and Perry Nuclear Power Plant - Independent Spent Fuel Storage Installation Changes, Tests, and Experiments2023-03-29029 March 2023 and Perry Nuclear Power Plant - Independent Spent Fuel Storage Installation Changes, Tests, and Experiments L-23-066, Annual Notification of Property Insurance Coverage2023-03-21021 March 2023 Annual Notification of Property Insurance Coverage ML23066A2892023-03-14014 March 2023 Request for Threshold Determination Under 10 CFR 50.80 and 10 CFR 72.50 for an Amendment to the Voting Agreement ML23066A2592023-03-14014 March 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 2024-02-02
[Table view] Category:Licensee Event Report (LER)
MONTHYEAR05000346/LER-2017-0022017-11-27027 November 2017 Auxiliary Feed Water Pump Turbine Bearing Damaged due to Improperly Marked Lubricating Oil Sight Glass, LER 17-002-00 For Davis-Besse Nuclear Power Station, Unit 1, Regarding Auxiliary Feed Water Pump Turbine Bearing Damaged due to Improperly Marked Lubricating Oil Sight Glass 05000346/LER-2017-0012017-09-18018 September 2017 Emergency Diesel Generator Fuel Oil Storage Tank Vents Not Adequately Protected from Tornado-Generated Missiles, LER 17-001-00 for Davis-Besse, Unit 1, Regarding Emergency Diesel Generator Fuel Oil Storage Tank Vents Not Adequately Protected from Tornado-Generated Missiles 05000346/LER-2016-0082017-02-27027 February 2017 Application of Technical Specification for the Safety Features Actuation System Instrumentation, LER 16-008-01 for Davis-Besse Nuclear Power Station Unit 1 Regarding Application of Technical Specification for the Safety Features Actuation System Instrumentation 05000346/LER-2016-0092016-11-0909 November 2016 Reactor Trip due to Rainwater Intrusion and Auxiliary Feedwater Actuation on High Steam Generator Level, LER 16-009-00 for Davis-Besse Nuclear Power Station, Unit 1 Regarding Reactor Trip due to Rainwater Intrusion and Auxiliary Feedwater Actuation on High Steam Generator Level 05000346/LER-2016-0072016-08-22022 August 2016 Pressurizer Code Safety Valve Setpoint Test Failures, LER 16-007-00 for Davis-Besse, Unit 1 Regarding Pressurizer Code Safety Valve Setpoint Test Failures 05000346/LER-2016-0062016-08-15015 August 2016 Potential to Trip Emergency Diesel Generator on High Crankcase Pressure, LER 16-006-00 for Davis-Besse Nuclear Power Station Unit 1 RE: Potential to Trip Emergency Diesel Generator on High Crankcase Pressure 05000346/LER-2016-0052016-07-11011 July 2016 - , Plant Startup with Anticipatory Reactor Trip System in Main Turbine Bypass, LER 16-005-00 for Davis-Besse, Unit 1, Regarding Plant Startup with Anticipatory Reactor Trip System in Main Turbine Bypass 05000346/LER-2016-0042016-06-0606 June 2016 Reactor Coolant System Hot Leg Resistance Temperature Detector Wire Insulation Degradation, LER 16-004-00 for Davis-Besse Nuclear Power Station, Unit 1 Regarding Reactor Coolant System Hot Leg Resistance Temperature Detector Wire Insulation Degradation 05000346/LER-2016-0032016-05-31031 May 2016 Leak from Reactor Coolant Pump Seal Piping Flexible Hose due to Undetected Manufacture Weld Defect, LER 16-003-00 for Davis-Besse Nuclear Power Station, Unit 1 Regarding Leak from Reactor Coolant Pump Seal Piping Flexible Hose due to Undetected Manufacture Weld Defect 05000346/LER-2016-0022016-03-29029 March 2016 Unanticipated Steam and Feedwater Rupture Control System Actuation, LER 16-002-00 for Davis-Besse Nuclear Power Station, Unit 1, Regarding Unanticipated Steam and Feedwater Rupture Control System Actuation 05000346/LER-2016-0012016-03-29029 March 2016 1 OF 7, LER 16-001-00 for Davis-Besse Nuclear Power Station Unit 1 Regarding Reactor Trip During Nuclear Instrumentation Calibrations and Steam Feedwater Rupture Control System Actuation on High Steam Generator Level ML0409003422004-03-26026 March 2004 LER 97-004-01 for Davis-Besse, Unit 1 Regarding Reactor Coolant Pump Motor Oil Piping Not Protected from Leakage as Required Per 10CFR50, Appendix R ML0404901932004-02-13013 February 2004 LER 99-003-01 for Davis-Besse, Unit 1 Regarding Failure to Perform Engineering Evaluation for Pressurizer Cooldown Rate Exceeding Technical Specification Limit ML0331701982003-11-0707 November 2003 LER 98-002-01 for Davis-Besse Unit 1 Regarding Plant Trip Due to High Pressurizer Level as a Result of Loss of Letdown Capability 2017-09-18
[Table view] |
Energy Industry Identification System (EIIS) codes are identified in the text as [XX].
System Description:
At the Davis-Besse Nuclear Power Station (DBNPS), 'the purpose of the Anticipatory Reactor Trip System (ARTS) is to initiate .a reactor trip on a loss of main feedwater [SI] event or a trip of the Main Turbine [TA] at power in order to reduce the magnitude of pressure and temperature transients on the Reactor Coolant , System [AB]. This lowers the probability of the Pressurizer Pilot Operated Relief Valve (PORV) [AB-RV] actuation during these events. The ARTS was added to the Babcock and Wilcox (B&W) designed plants following the Three Mile Island Unit 2 accident, but is not credited to mitigate the consequence of any accident in the Updated Final Safety Analysis Report (UFSAR).
The ARTS consists of four separate redundant protection channels that receive inputs of Main Feedwater (MFW) pump [SI-P] status and Main Turbine status.. Each protection channel contains a logic trip module, which transmits trip signals to its own two-out-of-four logic and to the two-out-of-four logic of the 'logic trip modules in the other three ARTS protective channels. Whenever any two ARTS channels transmit channel trip signals, the logic trip module in each channel actuates to remove power from its associated Control Rod Drive trip breaker [AA-BKR].
Technical Specifications:
Technical Specification (TS) Limiting Condition for Operation (LCO) 3.3.16 requires three channels of the ARTS instrumentation Turbine Trip function be Operable when greater than 45 percent Rated Thermal Power. With one required channel inoperable, Condition A requires the channel be restored to Operable status within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />. If the Required Action and associated. Completion Time is not met, Condition B requires reactor thermal power to be reduced to less than 45 percent power within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />. TS LCO 3.3.16 also requires three channels of the Trip of Both Main Feed Pump Turbines instrumentation function and four channels of the Output Logic function be operable when in Mode 1.
DESCRIPTION OF EVENT:
On May 9, 2016, the unit entered Mode 1 at 1524 hours0.0176 days <br />0.423 hours <br />0.00252 weeks <br />5.79882e-4 months <br /> following refueling outage activities. One of the projects completed during the outage was replacement of the Control Rod Drive System with a digital system per Engineering Change Package (ECP) 12-0272.
On May 10, 2016, with the unit at approximately 53 percent power, it was identified during review of Control Room Annunciators at 0528 hours0.00611 days <br />0.147 hours <br />8.730159e-4 weeks <br />2.00904e-4 months <br /> that the ARTS test trip bypass annunciator was lit. The status of the ARTS Trip Bypass switches was reviewed and it was identified that all four ARTS channels were in Steam Feed Rupture Control System (SFRCS) [JB] bypass and Main Turbine bypass vice the expected "Normal" 2 condition.
CAUSE OF EVENT:
Operating Procedure DB-OP-06902, Power Operations, provides operating instructions for Main Turbine startup at 18 percent power through full power operation as well as reactor shutdown. Step 4.6.5 of DB-OP- 06902 instructs the operator to verify ARTS is enabled prior to reaching 45 percent power. The direct cause for the ARTS Trip Bypass being left in bypass for SFRCS and Main Turbine during startup is the reactor operator failed to fully read and understand procedure DB-OP-06902 step 4.6.5 prior to verifying ARTS enabled at approximately 40 percent power. The operator did not preview/review the task/procedure before performance.
The root cause of this event is the operators failed to effectively work as a team to ensure a safety system was in an operable condition prior to the mode of applicability for plant startup. The operators were ineffective in their advocacy to understand why ARTS was in bypass and failed to get a critical review of assumptions they made that plant startup procedures would, at some point, restore ARTS.
A contributing cause to this event is some procedures were not developed in accordance with approved processes and did not contain specific guidance for restoration of ARTS after all 'four channels of all parameters were placed in bypass. This was evident in temporary Test Procedure DB-TP-10405, Digital Control Rod Drive System (DCRDCS) Post Installation Testing for ECP 12-0272 as well as other operating procedures.
ANALYSIS OF EVENT:
With the ARTS channels in bypass, the anticipatory reactor trip signal on a Main Turbine Trip would not have been provided. The reactor trip output function of SFRCS, since it uses the ARTS trip as its means of tripping the reactor, would likewise have been disabled. All of the other features of the SFRCS (e.g., start Auxiliary Feedwater Pumps [AB-P], align valves to isolate and/or feed water to the, Steam Generators [AB-SG]) would still have functioned. As stated above, the ARTS, including the SFRCS reactor trip function to ARTS, is 'not credited to mitigate the consequences of any UFSAR accident.
The Davis-Besse Probabilistic Risk Assessment (PRA) model does not model ARTS or credit it for tripping the reactor or mitigating any accidents or transients. All of the SFRCS functions which are modeled in the PRA were still available (e.g., start Auxiliary Feedwater Pumps, align valves to isolate and/or feed water to the Steam Generators). Other protective systems such as the Reactor Protection System [JC] and the Safety Features Actuation System [JE] were functional, and the Immediate Action for an SFRCS trip indication is for the Control Room Operators to manually trip the reactor.
The switch mispositioning occurred while the plant was at a reduced power level of 53 percent and with minimal decay heat in the core, as it occurred during startup from a refueling outage. The plant was in this condition for approximately 54 minutes. Therefore, the bypass of the ARTS channels while above 45 percent reactor power is qualitatively evaluated as having very low safety significance.
ANALYSIS OF EVENT: (continued) Reportability Discussion:
The unit attained 45 percent power at approximately 0458 hours0.0053 days <br />0.127 hours <br />7.572751e-4 weeks <br />1.74269e-4 months <br /> on May 10, 2016. The discovery that all four channels of ARTS were in SFRCS Bypass and Turbine-Generator Bypass occurred at 0528 hours0.00611 days <br />0.147 hours <br />8.730159e-4 weeks <br />2.00904e-4 months <br /> with the plant at approximately 53 percent power. 10 CFR 50.73(a)(2)(i)(B) requires reporting of any operation or condition which was prohibited by the plant's Technical Specifications. TS Table 3.3.16-1 states that three channels ARTS instrumentation Turbine Trip function are required to be Operable when greater than 45 percent Reactor Power, so LCO 3.3.16 was not met. TS LCO 3.0.4 states that when an LCO is not met, entry into a Mode or other specified condition in the Applicability shall only be made when the listed conditions (a, b, or c) are met. Because these conditions were not met, the unit should not have increased power above 45 percent power with 3 instrumentation channels of ARTS inoperable. Therefore, this issue is reportable as a Licensee Event Report (LER) per 10 CFR 50.73(a)(2)(i)(B). Because the ARTS is not credited to mitigate the consequences of any accident as described in the UFSAR, this issue does not represent a loss of safety function.
CORRECTIVE ACTIONS:
Completed Actions:
LCO 3.3.16 Condition A and LCO 3.0.3 were entered at the time of discovery. ARTS Channels 1 through 4 bypass switches were restored to Normal for both SFRCS and Main Turbine Trip functions per plant operating procedures, and LCO 3.3.16 and LCO 3.0.3 were exited at 0552 hours0.00639 days <br />0.153 hours <br />9.126984e-4 weeks <br />2.10036e-4 months <br /> on May 10, 2016.
Knowledgeable station personnel were paired in teams to perform walk downs of safety and environmentally significant systems and field conditions in an effort to independently identify concerns or omissions in plant startup activities.
Active Control Room and in-field local alarm panel annunciator windows were reviewed for an understanding of status and the alarming input. The Senior Reactor Operator turnover sheet was updated to accurately reflect these conditions.
An Operations Standing Order was developed and issued on the day of the event to require paired periodic walk downs of all Control Room panels to ensure a comprehensive understanding of plant status awareness.
This Standing Order remains in place pending establishment of further corrective actions.
Scheduled Actions:
Preventive actions have been developed to address the root cause of this event. However, since it involves crew/team behaviors, it is recognized that these actions may not be fully effective in precluding all future events attributed to less than adequate teamwork. It is expected that implementation of the Operations Section Cycle 20 Continuous Improvement Action Plan will act to minimize subsequent events where challenges in team behaviors may lead to a gap in compliance with technical specifications.
CORRECTIVE ACTIONS: (continued) In support of the Operations Continuous Improvement Action Plan, operating crews will document at least one example of the Operator Fundamental Aspects of inquiry (validate assumptions) and advocacy from the Shift Crew Critiques. The Shift Manager will discuss these documented results during the End of Cycle Crew Performance Evaluation Meetings.
The Temporary Test Procedure DB-TP-10405 has been voided, and operating procedures that manipulate/verify the ARTS Trip Bypass switches (such as DB-OP-06902) will be modified to provide more specific guidance for the operation of the switches.
PREVIOUS SIMILAR EVENTS
There have been no LERs at the DBNPS in the past three years involving the inoperability of the ARTS.
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05000346/LER-2016-001 | 1 OF 7 LER 16-001-00 for Davis-Besse Nuclear Power Station Unit 1 Regarding Reactor Trip During Nuclear Instrumentation Calibrations and Steam Feedwater Rupture Control System Actuation on High Steam Generator Level | 10 CFR 50.73(a)(2)(iv)(A), System Actuation 10 CFR 50.73(a)(2)(iv), System Actuation | 05000346/LER-2016-002 | Unanticipated Steam and Feedwater Rupture Control System Actuation LER 16-002-00 for Davis-Besse Nuclear Power Station, Unit 1, Regarding Unanticipated Steam and Feedwater Rupture Control System Actuation | 10 CFR 50.73(a)(2)(iv)(A), System Actuation | 05000346/LER-2016-003 | Leak from Reactor Coolant Pump Seal Piping Flexible Hose due to Undetected Manufacture Weld Defect LER 16-003-00 for Davis-Besse Nuclear Power Station, Unit 1 Regarding Leak from Reactor Coolant Pump Seal Piping Flexible Hose due to Undetected Manufacture Weld Defect | 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications 10 CFR 50.73(a)(2)(ii)(A), Seriously Degraded | 05000346/LER-2016-004 | Reactor Coolant System Hot Leg Resistance Temperature Detector Wire Insulation Degradation LER 16-004-00 for Davis-Besse Nuclear Power Station, Unit 1 Regarding Reactor Coolant System Hot Leg Resistance Temperature Detector Wire Insulation Degradation | 10 CFR 50.73(a)(2)(v)(A), Loss of Safety Function - Shutdown the Reactor 10 CFR 50.73(a)(2)(vii), Common Cause Inoperability 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications | 05000346/LER-2016-005 | - , Plant Startup with Anticipatory Reactor Trip System in Main Turbine Bypass LER 16-005-00 for Davis-Besse, Unit 1, Regarding Plant Startup with Anticipatory Reactor Trip System in Main Turbine Bypass | 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications | 05000346/LER-2016-006 | Potential to Trip Emergency Diesel Generator on High Crankcase Pressure LER 16-006-00 for Davis-Besse Nuclear Power Station Unit 1 RE: Potential to Trip Emergency Diesel Generator on High Crankcase Pressure | 10 CFR 50.73(a)(2)(ii)(B), Unanalyzed Condition 10 CFR 50.73(a)(2)(v)(A), Loss of Safety Function - Shutdown the Reactor 10 CFR 50.73(a)(2)(v), Loss of Safety Function 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications | 05000346/LER-2016-007 | Pressurizer Code Safety Valve Setpoint Test Failures LER 16-007-00 for Davis-Besse, Unit 1 Regarding Pressurizer Code Safety Valve Setpoint Test Failures | 10 CFR 50.73(a)(2)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications | 05000346/LER-2016-008 | Application of Technical Specification for the Safety Features Actuation System Instrumentation LER 16-008-01 for Davis-Besse Nuclear Power Station Unit 1 Regarding Application of Technical Specification for the Safety Features Actuation System Instrumentation | 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications | 05000346/LER-2016-009 | Reactor Trip due to Rainwater Intrusion and Auxiliary Feedwater Actuation on High Steam Generator Level LER 16-009-00 for Davis-Besse Nuclear Power Station, Unit 1 Regarding Reactor Trip due to Rainwater Intrusion and Auxiliary Feedwater Actuation on High Steam Generator Level | 10 CFR 50.73(a)(2)(iv)(A), System Actuation |
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