ML19268C172
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| ML19268C172 | |
| Person / Time | |
|---|---|
| Site: | North Anna  |
| Issue date: | 11/16/1979 |
| From: | VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.) |
| To: | |
| References | |
| NUDOCS 8001030602 | |
| Download: ML19268C172 (1) | |
Similar Documents at North Anna | |
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Category:REPORTABLE OCCURRENCE REPORT (SEE ALSO AO
MONTHYEARML20046C3661993-08-0505 August 1993
[Table view]Special Rept:On 930629,seven Blockout Type Penetration Fire Barriers & on 930713,six Sleeve Type Penetration Fire Barriers Determined to Be Nonfunctional.Repairs Completed & Fire Barriers Restored to Functional Status ML20044H3651993-06-0101 June 1993 Special Rept:On 930427,EDG Failed to Auto Start During Performance of Main Dam Auxiliary Power Diesel Periodic Test.Corroded Wires & Lugs Appeared to Be Loose.Control Wire Connections Cleaned & Aged Wires Replaced ML20024H6471991-05-31031 May 1991 Special Rept:On 910227,svc Water MOVs Associated W/ Recirculation Spray Heat Exchangers Exceeded Torgue Limits & Stopped in Mid Position While Being Opened During Test.Event Reported on Voluntary Basis to Provide Info to NRC ML20005E1601989-12-22022 December 1989 Special Rept:On 891218,heat Trace Sys for Kaman Vent Stack a Radiation Monitor RI-VG-179 Declared Inoperable.Sys Removed from Svc & Tech Spec 3.3.3.1 Action Statememt Entered.Sys Will Be Repaired & Returned to Svc by 900130 ML19332G0471989-12-11011 December 1989 Special Rept:On 891202,Kaman Process Vent Radiation Monitor Exceeded Action Statement of Tech Spec 3.3.3.1 Since Monitor Not Returned to Operable Status within 7 Days.On 891125, Monitor Alarmed in Control Room Every 15 to 30 Minutes ML20023D2181983-05-10010 May 1983 Ro:On 830509,w/unit at 100% Power,Severe Hydrogen Leak Discovered on Hydrogen inner-cooled Turbine Generator.Unit Rampdown Ordered & Hydrogen Vented to Atmosphere.Emergency Terminated When Pressure Reached Less than 10 Psig ML20009F9751981-03-26026 March 1981 Ro:On 810325,station Personnel Discharged 22,000 Gallons of Condensate Water Over 14-h Period.Samples Taken at Beginning & End of Discharge.Results Listed ML19329F8811980-07-11011 July 1980 RO 80-55/O1T-0:during Review of FSAR Safety Analyses for Boron Dilution Accident Potential,Nonconservatism in Cold Shutdown Analysis Determined.Cause Unknown.Accident Analysis Review Initiated ML19329F9701980-06-27027 June 1980 RO-80-029/01T-0:on 800627,pressurizer Power Operated Relief Valve PCV-2456 Inadvertently Opened in Mode 3 Following Valve Maint Activities.Corrective Action Will Be Taken Pending Completion of Investigation ML18139A2991980-06-0606 June 1980 Ro:Several Lines in Low Head & High Safety Injection Sys Were Not Analyzed for Effects of Fluid Temp Below 70 F. Review of New Nozzle Loads Showed Load on Pump Exceeded Vendor Allowable Load.Multiphase Program Proposed ML19312E5901980-06-0505 June 1980 RO 80-10/01T-0:on 800605,during Review of ECCS Piping, Loading on Low Head Safety Injection Pump Nozzles Was Discovered to Exceed Design Stress Allowable.Caused by Deficiency in Piping Sys Stress Analysis ML19290C6831980-02-0404 February 1980 RO 80-02/01T-0:during Review Required by IE Bulletin 79-14, Stress Discovered Over Design Allowable on Pipe Hangers & Snubbers.Caused by Incorrect Valve Weights Used in Design Calculations.Hangers & Snubbers Will Be Modified ML19270K2641980-01-25025 January 1980 RO-80-19:on 800124,during Equipment Qualification Review for IE Bulletin 79-01,qualification Discrepancy Discovered in Svc Water Radiation Pumps for Recirculation Spray Heat Exchangers.Cause Unknown ML19290C6841980-01-21021 January 1980 RO-80-01/01T-0:on 800121,excess Letdown Lines Had Several Pipe Stress Points Above Normal or Upset Allowables.Caused by Incorrect Use of Valve Weight for HCV-1201 Pipe Stress Calculations.Snubber Will Be Added to Line ML19270H7941979-12-14014 December 1979 Followup Suppl to Ler/Ro 79-15.Higher Pipe Stress Code Allowable Should Have Been Used by Teledyne.Pipe Stress on Kubes 1.5 inches-RC-105-1502-01 Not Over Code Allowable ML19257A3451979-12-12012 December 1979 RO 79-158/01T-0:during Review Required by IE Circular 78-08, S&W Discovered Pressure Differential Switches PDS-HV1228A & B Not Seismically Qualified.Cause Unknown.Problem Being Reviewed ML19257A3431979-12-12012 December 1979 RO 79-157/01T-0:during Review of Seismic Analyses Per IE Bulletin 79-14,nonconformance in Pipe Support Design Was Discovered by S&W.Caused by Incorrect Valve Weights Used in Support Calculations ML19268C1711979-11-27027 November 1979 Supplements RO 79-141/01T-0:while Reviewing Operation of Secondary Ventilation Sys,Sys Discovered to Operate in Manner Not in Keeping W/Accident Analyses.Cause Unknown. Matter Under Review ML19268C1701979-11-19019 November 1979 Supplements RO 79-141/1T-0:on 791114,determined,upon Review of Fsar,That Previously Reported Deficiency Re Nonautomatic Restart of Casing Cooling Pumps on Restoration of Onsite Emergency Power Is Not Deficiency ML19268C1741979-11-19019 November 1979 Followup to RO 79-152/01T-0:on 791118,Westinghouse Notified Util of Potential Reduction in Conservatism Re Error Allowances Assumed in Analysis for Power Range Neutron Flux High Negative Rate.Setpoints Will Be Changed ML19268C1721979-11-16016 November 1979 Supplements RO 79-141/01T-0:while Reviewing Operation, Recirculation Cooling Fans & Control Rod Drive Fans Found to Operate in Manner Not in Keeping W/Accident Analyses. Cause Unknown.Problem Being Reviewed by Engineering Svcs ML19268C1731979-11-14014 November 1979 Supplements RO 79-141/01T-0:while Reviewing Operation of Svc Water Sys,Casting Cooling Subsys & Recirculation Spray Sys, Sys Found to Operate Not in Keeping W/Accident Analyses. Cause Unknown.Discrepancies Under Review ML19308B1131979-11-14014 November 1979 Submits 24-h Reportable Event Written Followup Re Undetecable Failure of P-4 Contacts in Engineered Safety Features Actuation Sys.Caused by Westinghouse Design Error. Procedures for Testing P-4 Contacts Being Evaluated ML19268C1691979-11-0606 November 1979 RO-79-151/01T-0:during Review of Valve Weights in Conjunction W/Ie Bulletin 79-14,discovered That Incorrect Seismic Response Spectrum Was Used in Pipe Stress Analysis. Cause Not Known.Investigation in Progress ML19254F2701979-10-18018 October 1979 RO 79-142/01T-0:on 791018,during Pressurization of Steam Generator C,Channel IV Pressure Indications for Generators a & C Observed to Be Swapped.Caused by Piping Being Connected to Wrong Transmitters.Piping Will Be Changed ML19249E1141979-09-14014 September 1979 Ro:On 790914,ambient Temp Ranges Could Have Existed in Excess of Capability of Diesel Generator Fan Cooling Sys. Caused by Fan Blades Not Having Proper Pitch Setting to Provide Necessary Cooling at All Temps.Evaluation Underway ML19249E1001979-09-12012 September 1979 RO on 790912:while Performing Evaluation to Determine When to Secure Quench Spray Pumps After Loca,Error Discovered in Emergency Procedure 1-EP-2 Requiring Pumps Be Secured at Level of 28.1%.Error Corrected;Cause to Be Determined ML19208C4321979-09-12012 September 1979 Ro:On 790912,noted That Station Curve for Refueling Water Tank Was Incorrect,Resulting in Tech Spec Upper Tank Level Limit Being Exceeded.Cause Unknown.Tank Level Lowered.Change to Station Curve Being Drafted ML19242A6651979-07-26026 July 1979 RO 79-091/01T-0 on 790725:followup Rept on Discovery That Component W-104 Dual Peripheral Driver in 7,300 Series Signal Comparator Cartds Could Fail,Causing Associated Bistable to Fail in Unsafe Mode ML19225C9471979-07-23023 July 1979 RO 79-089/01T:discovered Possiblity of Failure of Process Cards,Causing Adverse Effects on Associated Loop Actions. Process Card Failure Analysis Performed ML19270G6531979-04-25025 April 1979 RO 79-057/01T-0 on 790424:potential Overload exists;4,160 Volt Transfer Bus & Feeder Breakers Are Not Capable of Continually Carrying Full Load Current.Caused by Improper Sizing of Transfer Bus Equipment ML19263C9591979-02-0505 February 1979 Telcon Rept:Util Informed Region 2 of Potential Hydraulic Transient (Water Hammer) in Recirculation Spray Coolers During Operation in Post LOCA Environ.Magnitude of Transient & Applicability to Unit 1 Have Not Been Determined ML19294A5281978-11-14014 November 1978 RO 78-100 on 780803:rept Submitted Re Deficiency in Seismic Analysis of Reactor Vessel Insulation.Mod Made,But Was Not Seismically Analyzed 1993-08-05 Category:LER) MONTHYEARML20046C3661993-08-0505 August 1993
[Table view]Special Rept:On 930629,seven Blockout Type Penetration Fire Barriers & on 930713,six Sleeve Type Penetration Fire Barriers Determined to Be Nonfunctional.Repairs Completed & Fire Barriers Restored to Functional Status ML20044H3651993-06-0101 June 1993 Special Rept:On 930427,EDG Failed to Auto Start During Performance of Main Dam Auxiliary Power Diesel Periodic Test.Corroded Wires & Lugs Appeared to Be Loose.Control Wire Connections Cleaned & Aged Wires Replaced ML20024H6471991-05-31031 May 1991 Special Rept:On 910227,svc Water MOVs Associated W/ Recirculation Spray Heat Exchangers Exceeded Torgue Limits & Stopped in Mid Position While Being Opened During Test.Event Reported on Voluntary Basis to Provide Info to NRC ML20005E1601989-12-22022 December 1989 Special Rept:On 891218,heat Trace Sys for Kaman Vent Stack a Radiation Monitor RI-VG-179 Declared Inoperable.Sys Removed from Svc & Tech Spec 3.3.3.1 Action Statememt Entered.Sys Will Be Repaired & Returned to Svc by 900130 ML19332G0471989-12-11011 December 1989 Special Rept:On 891202,Kaman Process Vent Radiation Monitor Exceeded Action Statement of Tech Spec 3.3.3.1 Since Monitor Not Returned to Operable Status within 7 Days.On 891125, Monitor Alarmed in Control Room Every 15 to 30 Minutes ML20023D2181983-05-10010 May 1983 Ro:On 830509,w/unit at 100% Power,Severe Hydrogen Leak Discovered on Hydrogen inner-cooled Turbine Generator.Unit Rampdown Ordered & Hydrogen Vented to Atmosphere.Emergency Terminated When Pressure Reached Less than 10 Psig ML20009F9751981-03-26026 March 1981 Ro:On 810325,station Personnel Discharged 22,000 Gallons of Condensate Water Over 14-h Period.Samples Taken at Beginning & End of Discharge.Results Listed ML19329F8811980-07-11011 July 1980 RO 80-55/O1T-0:during Review of FSAR Safety Analyses for Boron Dilution Accident Potential,Nonconservatism in Cold Shutdown Analysis Determined.Cause Unknown.Accident Analysis Review Initiated ML19329F9701980-06-27027 June 1980 RO-80-029/01T-0:on 800627,pressurizer Power Operated Relief Valve PCV-2456 Inadvertently Opened in Mode 3 Following Valve Maint Activities.Corrective Action Will Be Taken Pending Completion of Investigation ML18139A2991980-06-0606 June 1980 Ro:Several Lines in Low Head & High Safety Injection Sys Were Not Analyzed for Effects of Fluid Temp Below 70 F. Review of New Nozzle Loads Showed Load on Pump Exceeded Vendor Allowable Load.Multiphase Program Proposed ML19312E5901980-06-0505 June 1980 RO 80-10/01T-0:on 800605,during Review of ECCS Piping, Loading on Low Head Safety Injection Pump Nozzles Was Discovered to Exceed Design Stress Allowable.Caused by Deficiency in Piping Sys Stress Analysis ML19290C6831980-02-0404 February 1980 RO 80-02/01T-0:during Review Required by IE Bulletin 79-14, Stress Discovered Over Design Allowable on Pipe Hangers & Snubbers.Caused by Incorrect Valve Weights Used in Design Calculations.Hangers & Snubbers Will Be Modified ML19270K2641980-01-25025 January 1980 RO-80-19:on 800124,during Equipment Qualification Review for IE Bulletin 79-01,qualification Discrepancy Discovered in Svc Water Radiation Pumps for Recirculation Spray Heat Exchangers.Cause Unknown ML19290C6841980-01-21021 January 1980 RO-80-01/01T-0:on 800121,excess Letdown Lines Had Several Pipe Stress Points Above Normal or Upset Allowables.Caused by Incorrect Use of Valve Weight for HCV-1201 Pipe Stress Calculations.Snubber Will Be Added to Line ML19270H7941979-12-14014 December 1979 Followup Suppl to Ler/Ro 79-15.Higher Pipe Stress Code Allowable Should Have Been Used by Teledyne.Pipe Stress on Kubes 1.5 inches-RC-105-1502-01 Not Over Code Allowable ML19257A3451979-12-12012 December 1979 RO 79-158/01T-0:during Review Required by IE Circular 78-08, S&W Discovered Pressure Differential Switches PDS-HV1228A & B Not Seismically Qualified.Cause Unknown.Problem Being Reviewed ML19257A3431979-12-12012 December 1979 RO 79-157/01T-0:during Review of Seismic Analyses Per IE Bulletin 79-14,nonconformance in Pipe Support Design Was Discovered by S&W.Caused by Incorrect Valve Weights Used in Support Calculations ML19268C1711979-11-27027 November 1979 Supplements RO 79-141/01T-0:while Reviewing Operation of Secondary Ventilation Sys,Sys Discovered to Operate in Manner Not in Keeping W/Accident Analyses.Cause Unknown. Matter Under Review ML19268C1701979-11-19019 November 1979 Supplements RO 79-141/1T-0:on 791114,determined,upon Review of Fsar,That Previously Reported Deficiency Re Nonautomatic Restart of Casing Cooling Pumps on Restoration of Onsite Emergency Power Is Not Deficiency ML19268C1741979-11-19019 November 1979 Followup to RO 79-152/01T-0:on 791118,Westinghouse Notified Util of Potential Reduction in Conservatism Re Error Allowances Assumed in Analysis for Power Range Neutron Flux High Negative Rate.Setpoints Will Be Changed ML19268C1721979-11-16016 November 1979 Supplements RO 79-141/01T-0:while Reviewing Operation, Recirculation Cooling Fans & Control Rod Drive Fans Found to Operate in Manner Not in Keeping W/Accident Analyses. Cause Unknown.Problem Being Reviewed by Engineering Svcs ML19268C1731979-11-14014 November 1979 Supplements RO 79-141/01T-0:while Reviewing Operation of Svc Water Sys,Casting Cooling Subsys & Recirculation Spray Sys, Sys Found to Operate Not in Keeping W/Accident Analyses. Cause Unknown.Discrepancies Under Review ML19308B1131979-11-14014 November 1979 Submits 24-h Reportable Event Written Followup Re Undetecable Failure of P-4 Contacts in Engineered Safety Features Actuation Sys.Caused by Westinghouse Design Error. Procedures for Testing P-4 Contacts Being Evaluated ML19268C1691979-11-0606 November 1979 RO-79-151/01T-0:during Review of Valve Weights in Conjunction W/Ie Bulletin 79-14,discovered That Incorrect Seismic Response Spectrum Was Used in Pipe Stress Analysis. Cause Not Known.Investigation in Progress ML19254F2701979-10-18018 October 1979 RO 79-142/01T-0:on 791018,during Pressurization of Steam Generator C,Channel IV Pressure Indications for Generators a & C Observed to Be Swapped.Caused by Piping Being Connected to Wrong Transmitters.Piping Will Be Changed ML19249E1141979-09-14014 September 1979 Ro:On 790914,ambient Temp Ranges Could Have Existed in Excess of Capability of Diesel Generator Fan Cooling Sys. Caused by Fan Blades Not Having Proper Pitch Setting to Provide Necessary Cooling at All Temps.Evaluation Underway ML19249E1001979-09-12012 September 1979 RO on 790912:while Performing Evaluation to Determine When to Secure Quench Spray Pumps After Loca,Error Discovered in Emergency Procedure 1-EP-2 Requiring Pumps Be Secured at Level of 28.1%.Error Corrected;Cause to Be Determined ML19208C4321979-09-12012 September 1979 Ro:On 790912,noted That Station Curve for Refueling Water Tank Was Incorrect,Resulting in Tech Spec Upper Tank Level Limit Being Exceeded.Cause Unknown.Tank Level Lowered.Change to Station Curve Being Drafted ML19242A6651979-07-26026 July 1979 RO 79-091/01T-0 on 790725:followup Rept on Discovery That Component W-104 Dual Peripheral Driver in 7,300 Series Signal Comparator Cartds Could Fail,Causing Associated Bistable to Fail in Unsafe Mode ML19225C9471979-07-23023 July 1979 RO 79-089/01T:discovered Possiblity of Failure of Process Cards,Causing Adverse Effects on Associated Loop Actions. Process Card Failure Analysis Performed ML19270G6531979-04-25025 April 1979 RO 79-057/01T-0 on 790424:potential Overload exists;4,160 Volt Transfer Bus & Feeder Breakers Are Not Capable of Continually Carrying Full Load Current.Caused by Improper Sizing of Transfer Bus Equipment ML19263C9591979-02-0505 February 1979 Telcon Rept:Util Informed Region 2 of Potential Hydraulic Transient (Water Hammer) in Recirculation Spray Coolers During Operation in Post LOCA Environ.Magnitude of Transient & Applicability to Unit 1 Have Not Been Determined ML19294A5281978-11-14014 November 1978 RO 78-100 on 780803:rept Submitted Re Deficiency in Seismic Analysis of Reactor Vessel Insulation.Mod Made,But Was Not Seismically Analyzed 1993-08-05 Category:TEXT-SAFETY REPORT MONTHYEARML20217N9281999-10-20020 October 1999
[Table view]Special Rept:On 991003,PZR PORV Actuation Mitigated RCS low- Temp Overpressure Transient.Caused by a RCP Facilitating Sweeping of Entrained Air Out of RCS Loops.Operating Procedure 2-OP-5.1 Will Be Revised ML20217H3631999-10-14014 October 1999 Rev 0 to COLR for North Anna 2 Cycle 14 Pattern Su ML18152A2811999-10-12012 October 1999 Technical Basis for Elimination of Nozzle Inner Radius Insps (for Nozzles Other than Reactor Vessel),Technical Basis for ASME Section XI Code Case N-619. ML20212J9251999-10-0101 October 1999 Safety Evaluation Accepting Licensee Relief Request IWE-3 for Second 10-year ISI for Plant ML20217D6851999-09-30030 September 1999 Monthly Operating Repts for Sept 1999 for North Anna Power Station,Units 1 & 2.With ML20211N2611999-09-0808 September 1999 Safety Evaluation Concluding That Proposed Irradiation of Fuel Rods Beyond Current Lead Rod Burnup Limit & Clarification of Terminology with Respect to Reconstituted Fuel Assemblies Acceptable ML20211J2561999-08-31031 August 1999 Safety Evaluation Accepting Elimination of Augmented ISI Program for Pressurizer Spray Lines at North Anna Unit 2 ML20216E5011999-08-31031 August 1999 Monthly Operating Repts for Aug 1999 for Naps,Units 1 & 2. with ML20211J2421999-08-31031 August 1999 Safety Evaluation Supporting Removal of Augmented Insp Program on RCS Bypass Lines from Licensing Basis of North Anna,Units 1 & 2 ML20210T0791999-08-13013 August 1999 Safety Evaluation Concluding That Revised Withdrawal Schedules for North Anna Units 1 & 2 Satisfy Requirements of App H to 10CFR50 & Therefore Acceptable ML20210S1411999-07-31031 July 1999 Monthly Operating Repts for July 1999 for North Anna Power Station.With ML20210Q9931999-07-31031 July 1999 Rev 1 to COLR for North Anna Power Station,Unit 2 Cycle 13 Pattern Ud ML20209E5641999-06-30030 June 1999 Monthly Operating Repts for June 1999 for North Anna Power Stations,Units 1 & 2.With ML20195G1901999-05-31031 May 1999 Monthly Operating Rept for May 1999 for NAPS Units 1 & 2. with ML20206L4831999-05-10010 May 1999 SER Accepting Request to Delay Submitting Plant,Unit 1 Class 1 Piping ISI Program for Third Insp Interval Until 010430, to Permit Development of Risk Informed ISI Program for Class 1 Piping ML20206Q6671999-04-30030 April 1999 Monthly Operating Repts for Apr 1999 for North Anna Power Station,Units 1 & 2.With ML20205S0391999-04-21021 April 1999 SER Accepting Request for Relief IWE5,per 10CFR50.55a(a)(3) & Proposed Alternatives for IWE2,IWE4,IWE6 & IWL2 Authorized Per 10CFR50.55a(a)(3)(ii) ML20205K3041999-03-31031 March 1999 Monthly Operating Repts for Mar 1999 for North Anna Power Station,Units 1 & 2.With ML20207K5921999-02-28028 February 1999 Monthly Operating Repts for Feb 1999 for North Anna Power Station,Units 1 & 2.With ML20207E1731999-02-18018 February 1999 Informs Commission of Status of Preparations of IAEA Osart Mission to North Anna Nuclear Power Plant Early Next Year ML20205A0241998-12-31031 December 1998 Summary of Facility Changes,Tests & Experiments,Including Summary of SEs Implemented at Plant During 1998,per 10CFR50.59(b)(2).With ML20199C8781998-12-31031 December 1998 Monthly Operating Repts for Dec 1998 for North Anna Power Station,Units 1 & 2.With ML20198H9541998-12-0303 December 1998 Safety Evaluation Authorizing Proposed Alternative for Remainder of Second 10-yr Insp Interval for Plant ML20198J5561998-12-0303 December 1998 ISI Summary Rept for North Anna Power Station,Unit 1 1998 Refueling Outage Owner Rept for Inservice Insps ML20197G8551998-11-30030 November 1998 Monthly Operating Repts for Nov 1998 for North Anna Power Station,Units 1 & 2.With ML20196G1381998-11-0303 November 1998 Safety Evaluation Authorizing Rev to Relief Request NDE-32 for Remainder of Second 10-yr Insp Interval for Each Unit ML20195D0571998-10-31031 October 1998 Monthly Operating Repts for Oct 1998 for North Anna Power Station,Units 1 & 2.With ML20154L0691998-10-14014 October 1998 COLR for North Anna Power Station Unit 1 Cycle 14 Pattern Xy ML20155J6911998-10-0909 October 1998 Staff Response to Tasking Memorandum & Stakeholder Concerns ML20154H4001998-09-30030 September 1998 Monthly Operating Repts for Sept 1998 for North Anna Power Station,Units 1 & 2.With ML20151X8011998-09-10010 September 1998 Special Rept:On 980622,groundwater Level at Piezometer P-22 Was Again Noted to Be Above Max Water Level by 0.71 Feet. Increased Frequency of Piezometer Monitoring & Installed Addl Piezometers at Toe of Slope Along Southwest Section ML20151W4711998-08-31031 August 1998 Monthly Operating Repts for Aug 1998 for North Anna Power Station Units 1 & 2.With ML20237A4341998-07-31031 July 1998 Monthly Operating Repts for July 1998 for North Anna Power Station,Units 1 & 2 ML20236V1251998-07-14014 July 1998 ISI Summary Rept for Naps,Unit 2,1998 Refueling Outage Owners Rept of Isis ML20236K5531998-07-0707 July 1998 SER Accepting Request for Change in ISI Commitment on Protection Against Pipe Breaks Outside Containment ML20236M3381998-06-30030 June 1998 Monthly Operating Repts for June 1998 for North Anna Power Station,Units 1 & 2 ML20248M1011998-05-31031 May 1998 Monthly Operating Repts for May 1998 for North Anna Power Station,Units 1 & 2 ML20248C8831998-05-29029 May 1998 SER Accepting Alternatives Proposed by Licensee for Use of Code Case N-535,pursuant to 10CFRa(a)(3)(i) in ASME Section XI Inservice Insp Program ML20247K9281998-05-15015 May 1998 Special Rept:On 980428,letdown PCV Exhibited Slow Response When C RCP Was Started.Cause to Be Determined.Review of Operating Procedure Will Be Performed to Determine If Enhancements Are Necessary ML20216A8971998-05-0606 May 1998 Rev 0 to Cycle 13 Pattern Ud COLR for North Anna Unit 2 ML20247F4441998-04-30030 April 1998 Monthly Operating Repts for Apr 1998 for North Anna Power Station,Units 1 & 2 ML20217B5321998-04-20020 April 1998 Safety Evaluation Supporting Proposed Alternative to ASME Code for Surface Exam of Seal Welds on Threaded Caps for Plant Reactor Vessel Head Penetrations for part-length CRDMs ML20217H9611998-04-0707 April 1998 Special Rept:On 980216,groundwater Level at Piezometer P-22, Again Noted to Be Above Max Water Level by 0.41 Feet.Design Package for Installation of Addl Standpipe Piezometers at Toe of Slope Southeast Section,Developed ML20216B1891998-03-31031 March 1998 Monthly Operating Repts for Mar 1998 for North Anna Power Station,Units 1 & 2 ML20216E8801998-03-0606 March 1998 Safety Evaluation Authorizing Licensee Request for Relief from ASME Code Requirements,Paragraph IWA-2400(c) (Summer Edition W/Summer 1983 Addenda),For Upcoming Naps,Unit 1 Outage,Per 10CFR50.55a(a)(3)(ii) ML20216E2561998-02-28028 February 1998 Monthly Operating Repts for Feb 1998 for North Anna Power Station,Units 1 & 2 ML20199J6431998-02-0202 February 1998 Safety Evaluation Approving Request for Approval to Repair Flaws in Accordance W/Gl 90-05 for ASME Code Class 3 SW Piping for North Anna,Unit 1,as Submitted in ISI Relief Request NDE-46 on 971218 ML20202D5811998-01-31031 January 1998 Monthly Operating Repts for Jan 1998 for North Anna Power Station,Units 1 & 2 ML20198S7571998-01-15015 January 1998 Safety Evaluation Accepting Licensee Request for Approval to Repair Flaws IAW GL-90-05 for ASME Code Class 3 Svc Water Piping ML20198P1351997-12-31031 December 1997 Monthly Operating Repts for Dec 1997 for North Anna Power Station,Units 1 & 2 1999-09-08 |
Text
'l USNRC REE- '
e v;u , v Virginia Electric and Power Company North Anna Power Station, Unit fl. MPF-4 Docket No. 50-338 8 13 L'0V 16 P l,30 24 Hour Reportable Event Written Follow-Up (supplement)
Event: ESF Systens Returning to Non-Safety Mode Upon Reset of CDA Signal LER/R0 79-141/01T-C While reviewing system operation. it was discovered that the recircu-lation cooling fans and the control red drive fans operate in a manner less conservative than that assumed in the accident analyses in the safety analysis report.
Specificall Actuation (CDA)signa].
- y. the fans When triptheupon CCA receipt of is signal a Containment reset, the fanDepressurization will autena-tically restart.
The return of Emergency Safety Features (ESF) equipment to a non-safety mode without deliberate operator action is not consistent with FSAR Ccerunt 7.4 which states that two acticas are required to return a device to the non-safety featurs mode. As stated in the FSAR. the return of ESF equipment to a non-safety mode is acecap11shed by resetting the appropriate actuation signal and subsequently operating the control switch for the device.
The cause of this discrepancy is unknown at this time.
This problen is presently being reviewed by engineering services.
There has been no effect on the. plant because of this discrepancy. The 4mit is presently in refueling shutdown mode. This event is similar to LER/KD 79-141 and w1]] be jncluded in that 13 day report.
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