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| {{#Wiki_filter:ACCpLERATED iSTRIBUTION DEMOTTIQN,Ji¥STEM . REGULATORY INFORMATION | | {{#Wiki_filter:ACCpLERATED iSTRIBUTION DEMOTTIQN,Ji¥STEM . |
| ~ISTRIBUTION SYSTEM (RIDS) ACCESSION NBR:9109190223 DOC.DATE: | | REGULATORY INFORMATION ~ISTRIBUTION SYSTEM (RIDS) |
| 91/09/13 NOTARIZED: | | ACCESSION NBR:9109190223 DOC.DATE: 91/09/13 NOTARIZED: NO DOCKET# |
| NO FACIL:50-281 Surry Power Station, Unit 2, Vi:rg.inia Electric.&
| | FACIL:50-281 Surry Power Station, Unit 2, Vi:rg.inia Electric.& Powe 05000281 AUTH.NAME AUTHOR AFFILIATION . |
| Powe AUTH.NAME AUTHOR AFFILIATION . STEWART,W.L. | | STEWART,W.L. Virginia Power (Virginia Elect~ic & Power Co.) |
| Virginia Power (Virginia Elect~ic & Power Co.) *. RECIP. NAME RECIPIENT AFFILIATION Document Control_Branch (Document Control.Desk) | | *. RECIP. NAME RECIPIENT AFFILIATION Document Control_Branch (Document Control.Desk) |
|
| |
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| ==SUBJECT:== | | ==SUBJECT:== |
| Special*rept:on 910815 & 24,quadrant-to-a:verage power tilt exceeded 2% for more than 24 h.Caused by blown fuse & . dropped rod runback.Cable w/insulation damage & rod control cabinet repaired. | | Special*rept:on 910815 & 24,quadrant-to-a:verage power tilt exceeded 2% for more than 24 h.Caused by blown fuse & . |
| * | | dropped rod runback.Cable w/insulation damage & rod control cabinet repaired. * |
| * DOCKET# 05000281 DISTRIBUTION CODE: IE22D COPIES RECEIVED:LTR | | * DISTRIBUTION CODE: IE22D COPIES RECEIVED:LTR / ENCL_, SIZE:_._3'----- |
| / ENCL_, | | TITLE: 5 o. 7 3/ 5 o . 9 Licensee Event Report ( LER) , Incident Rpt, . etc. . |
| TITLE: 5 o. 7 3 / 5 o . 9 Licensee Event Report ( LER) , Incident Rpt, . etc. . NOTES:lcy NMSS/IMSB/PM. | | NOTES:lcy NMSS/IMSB/PM. 05000281 RECIPIENT COPIES RECIPIENT COPIES |
| 05000281 RECIPIENT COPIES RECIPIENT COPIES *ID CODE/NAME LTTR ENCL ID CODE/NAME LTTR ENCL PD2-2 LA 1 1 PD2-2 PD. 1 1 BUCKLEY,B 1 1 INTERNAL: | | *ID CODE/NAME LTTR ENCL ID CODE/NAME LTTR ENCL PD2-2 LA 1 1 PD2-2 PD. 1 1 BUCKLEY,B 1 1 INTERNAL: ACNW 2 2 ACRS 2 2 AEOD/DOA 1 1 .AEOD/DSP/TPAB 1 1 AEOD/ROAB/DSP 2 *2 NRR/DET/ECMB 9H 1 1 NRR/DET/EMEB 7E 1 1 . NRR/DLPQ/LHFBlO 1 1 NRR/DLPQ/LPEBlO 1 1 NRR/DOEA/OEAB 1 1 NRR/DREP/PRPBll 2 2 NRR/DST/SELB SD 1 1 NRR/DST/SICB8H3 . 1 1 NRR:~~~B:8:llb 1 1 NRR/DST/SRXB .BE 1 1 REG,dr''* , 02 1 1 RES/DSIR/EIB 1 1 RGif-* *---~-*~FJ:-1:iE~*'o*i- 1 1 EXTERNAL: EG&G BRYCE,J.H 3 3 L ST LOBBY WARD 1 1 NRC PDR 1 1 NSIC MURPHY,G.A 1 1 NSIC POORE,W. 1 1 NUDOCS FULL TXT 1 1 NOTES: 1 1 NOTE TO ALL "RIDS" RECIPIET'\TS: |
| ACNW 2 2 ACRS 2 2 AEOD/DOA 1 1 .AEOD/DSP/TPAB 1 1 AEOD/ROAB/DSP 2 *2 NRR/DET/ECMB 9H 1 1 NRR/DET/EMEB 7E 1 1 . NRR/DLPQ/LHFBlO 1 1 NRR/DLPQ/LPEBlO 1 1 NRR/DOEA/OEAB 1 1 NRR/DREP/PRPBll 2 2 NRR/DST/SELB SD 1 1 NRR/DST/SICB8H3 . 1 1 NRR:~~~B:8:llb 1 1 NRR/DST/SRXB .BE 1 1 REG,dr''* , 0 2 1 1 RES/DSIR/EIB 1 1 RGif-* *---~-*~FJ:-1:iE~*'o*i-1 1 EXTERNAL: | | PLEASE HELP us T9 REDUCE \\"ASTE! CONTACT THE DOCUMP<T cm,ffROL DESK, R00'.\1 PJ-3, (EXT. 20079) TO ELI'.\11'.'i:\TE YOUR NAME FROJ\1 DISTRIBUTION LISTS FOR DOCUi\1ENTS YOU DQ"-:'T NEED! |
| EG&G BRYCE,J.H 3 3 L ST LOBBY WARD 1 1 NRC PDR 1 1 NSIC MURPHY,G.A 1 1 NSIC POORE,W. 1 1 NUDOCS FULL TXT 1 1 NOTES: 1 1 NOTE TO ALL "RIDS" RECIPIET'\TS: | | TOTAL NUMBER OF COPIES REQUIRED: LTTR 34 |
| PLEASE HELP us T9 REDUCE \\"ASTE! CONTACT THE DOCUMP<T cm,ffROL DESK, R00'.\1 PJ-3, (EXT. 20079) TO ELI'.\11'.'i:\TE YOUR NAME FROJ\1 DISTRIBUTION LISTS FOR DOCUi\1ENTS YOU DQ"-:'T NEED! TOTAL NUMBER OF COPIES REQUIRED: | | * ENCL 34 . |
| LTTR 34 | | |
| * ENCL 34 . I I , b, ')' *I e e VIRGINIA ELECTRIC AND POWER COMPANY RICHMOND, VIRGINIA 23261 September 13, 1991 United States Nuclear Regulatory Commission Attention: | | I , |
| Document Control Desk Washington, D. C. 20555 Gentlemen: | | e e VIRGINIA ELECTRIC AND POWER COMPANY b, |
| | ')' |
| | RICHMOND, VIRGINIA 23261 September 13, 1991 United States Nuclear Regulatory Commission Serial No. 91-532 Attention: Document Control Desk NO/RJS R1 Washington, D. C. 20555 Docket No. 50-281 License No. DPR.:37 Gentlemen: |
| VIRGINIA ELECTRIC AND POWER COMPANY SURRY POWER STATION UNIT 2 | | VIRGINIA ELECTRIC AND POWER COMPANY SURRY POWER STATION UNIT 2 |
| * SPECIAL REPORT -QUADRANT TO AVERAGE POWER TILT EXCEEDS 2.0% FOR GREATER THAN 24 HOURS Serial No. NO/RJS Docket No. License No. 91-532 R1 50-281 DPR.:37 Surry Technical Specification 3.12.8.7.a requires an evaluation be performed and a special report be issued to the Nuclear Regulatory Commission under certain conditions when the quadrant to average power tilt exceeds 2% for greater than 24 hours. On August 15, 1991 and August 24, 1991, the Surry Unit 2 quadrant to average power tilt exceeded 2% for greater than 24 hours. A description of the circumstances surrounding these events are provided in the att.achment to this letter. This report has been reviewed and approved by the Station Nuclear Safety and | | * SPECIAL REPORT - |
| | QUADRANT TO AVERAGE POWER TILT EXCEEDS 2.0% FOR GREATER THAN 24 HOURS Surry Technical Specification 3.12.8.7.a requires an evaluation be performed and a special report be issued to the Nuclear Regulatory Commission under certain conditions when the quadrant to average power tilt exceeds 2% for greater than 24 hours. On August 15, 1991 and August 24, 1991, the Surry Unit 2 quadrant to average power tilt exceeded 2% for greater than 24 hours. A description of the circumstances surrounding these events are provided in the att.achment to this letter. |
| | This report has been reviewed and approved by the Station Nuclear Safety and |
| * Operating Committee. | | * Operating Committee. |
| Should you have any questions or require additional information, please contact us. W. L. St art Senior Vice President | | Should you have any questions or require additional information, please contact us. |
| -Nuclear Attachment | | W. L. St art Senior Vice President - Nuclear Attachment - Special Report for Quandrant to Average Power Tilt Exceeding 2% for Greater than 24 Hours cc: U. S. Nuclear Regulatory Commission Region II 101 Marietta Street, N. W. |
| -Special Report for Quandrant to Average Power Tilt Exceeding 2% for Greater than 24 Hours cc: U. S. Nuclear Regulatory Commission Region II 101 Marietta Street, N. W. Suite 2900 Atlanta, Georgia 30323 Mr. M. W. Branch NRC Senior Resident Inspector Surry Power Station ifY\ *,)v' ' ,, ! | | Suite 2900 Atlanta, Georgia 30323 Mr. M. W. Branch NRC Senior Resident Inspector Surry Power Station ifY\ |
| * I l . e ATTACHMENT SPECIAL -REPORT FOR QUADRANT TO* AVERAGE POWER TILT EXCEEDING 2% FOR GREATER THAN 24 HOURS | | *,)v' ' ,, |
| . -.,. -II.II' on August 14, 1991 at 1753 hours with Unit 2 at 100% reactor power (795 MW), control rod D-4 in control bank C dropped into the core with blown fuse indications. | | *I ! |
| An | | * I e |
| * individual Rod Position Indication (IRPI) dropped rod runback occurred and the unit was stabilized at 54% power (420 MW). Applicable Abnormal Operating Procedures were implemented and technical specification requirements were reviewed. | | l . |
| Reactor power was verified to be less than 75% and initial Quadrant Power Tilt (OPT) from the excore detectors was determined to be 11.6% at 1825 hours. A shutdown margin calculation was also completed and verified to be satisfactory at 1828 hours. Following the determination that OPT was greater than 2.%, at 2059 hours the High Flux Trip Setpoints were reduced to 72% and rod stop setpoints were reduced to 68% to allow power operation with control rod D-4 inoperable and fully inserted and with OPT greater than 2%. This action was taken to comply with Technical Specification 3.12.8.6.b which requires the High Flux Trip Setpoint to be reduced at least 2% for every 1 % of OPT when hot channel factors are not determined within two hours. Following discussions held with the nuclear steam supply system vendor, Westinghouse, the rod control cabinet was inspected and tested and the rod drive cables were meggered satisfactorily. | | ATTACHMENT SPECIAL -REPORT FOR QUADRANT TO* AVERAGE POWER TILT EXCEEDING 2% |
| A cable (with suspected insulation damage) in the rod control cabinet was repaired. | | FOR GREATER THAN 24 HOURS |
| The fuses were replaced and control rod D-4 retrieval was performed in accordance with AP-1.01. The rod was fully withdrawn and rE3actor power was raised to 100% at a ramp rate limited to 3% per hour for reactor power levels greater than 68%. This limitation oh ramp rate was implemented in accordance_ | | |
| with Westinghouse fuel conditioning guidelines. | | .,. . |
| on August ~3. 1991 at 0435 hours with Unit 2 at 80% reactor power (625 MW), control rod D-4 in control bank C again dropped into the core. A second IRPI dropped rod runback occurred and the unit was stabilized at 50% power (370 MW). Applicable Abnormal Operating Procedures were implemented and actions similar to the first event were taken. Reactor power was verified to be less than 75% and a shutdown margin calculation was completed and verified to be satisfactory at 0503 hours. The High Flux Trip Setpoints were reduced to 72% and the rod stop setpoints were reduced to 68% at 0817 hours. Initial Quadrant Power Tilt (OPT) from the excore detectors was determined to be-14.5% at 1124 hours. Reactor operation continued at reduced power, in accordance with analyses performed, until September 7 when Unit 2 was shutdown to troubleshoot and make repairs to control rod D-4. The core asymmetry due to operation with control rod D-4 inserted, coupled with the xenon transients and changes in Tave associated with the dropped rod events, resulted in the observed excore tilts. For ea*ch of these events, manual OPT calculations were performed at least every two hours to monitor and trend the tilts. Following each event, preparations were also initiated to reduce Overpower | | - - |
| ~T and Overtemperature | | II.II' on August 14, 1991 at 1753 hours with Unit 2 at 100% reactor power (795 MW), |
| ~T trip setpoints. | | control rod D-4 in control bank C dropped into the core with blown fuse indications. An |
| These preparations were made to ensure the Technical Specification requirement to reduce these setpoints, if the excore tilt exceeded 2% for greater than 24 hours and either the hot channel factors had not been determined or had been exceeded, could be expeditiously implemented. | | *individual Rod Position Indication (IRPI) dropped rod runback occurred and the unit was stabilized at 54% power (420 MW). Applicable Abnormal Operating Procedures were implemented and technical specification requirements were reviewed. Reactor power was verified to be less than 75% and initial Quadrant Power Tilt (OPT) from the excore detectors was determined to be 11.6% at 1825 hours. A shutdown margin calculation was also completed and verified to be satisfactory at 1828 hours. |
| Prior to OPT exceeding 2% (but less than 10%) for greater than a 24 hour period, the nuclear engineering staff concluded from full core flux maps taken at 1124 on August 15 (D-4 inserted), 0248 on August 16 (D-4 withdrawn), at 1123 on August 17 (D-4 withdrawn), and at 1405 on August 23 (D-4 inserted) that the limits placed on core peal*dng factors by TS 3.12.B.1 were not exceeded during these events. Since the core peaking factors remained within limits, it was not necessary to reduce the Overpower | | Following the determination that OPT was greater than 2.%, at 2059 hours the High Flux Trip Setpoints were reduced to 72% and rod stop setpoints were reduced to 68% |
| ~T and Overtemperature | | to allow power operation with control rod D-4 inoperable and fully inserted and with OPT greater than 2%. This action was taken to comply with Technical Specification 3.12.8.6.b which requires the High Flux Trip Setpoint to be reduced at least 2% for every 1% of OPT when hot channel factors are not determined within two hours. |
| ~T trip setpoints during either event.}} | | Following discussions held with the nuclear steam supply system vendor, Westinghouse, the rod control cabinet was inspected and tested and the rod drive cables were meggered satisfactorily. A cable (with suspected insulation damage) in the rod control cabinet was repaired. The fuses were replaced and control rod D-4 retrieval was performed in accordance with AP-1.01. The rod was fully withdrawn and rE3actor power was raised to 100% at a ramp rate limited to 3% per hour for reactor power levels greater than 68%. This limitation oh ramp rate was implemented in accordance_ with Westinghouse fuel conditioning guidelines. |
| | on August ~3. 1991 at 0435 hours with Unit 2 at 80% reactor power (625 MW), control rod D-4 in control bank C again dropped into the core. A second IRPI dropped rod runback occurred and the unit was stabilized at 50% power (370 MW). Applicable Abnormal Operating Procedures were implemented and actions similar to the first event were taken. Reactor power was verified to be less than 75% and a shutdown margin calculation was completed and verified to be satisfactory at 0503 hours. The High Flux Trip Setpoints were reduced to 72% and the rod stop setpoints were reduced to 68% at 0817 hours. Initial Quadrant Power Tilt (OPT) from the excore detectors was determined to be-14.5% at 1124 hours. Reactor operation continued at reduced power, in accordance with analyses performed, until September 7 when Unit 2 was shutdown to troubleshoot and make repairs to control rod D-4. |
| | The core asymmetry due to operation with control rod D-4 inserted, coupled with the xenon transients and changes in Tave associated with the dropped rod events, resulted in the observed excore tilts. For ea*ch of these events, manual OPT calculations were performed at least every two hours to monitor and trend the tilts. |
| | Following each event, preparations were also initiated to reduce Overpower ~T and Overtemperature ~T trip setpoints. These preparations were made to ensure the Technical Specification requirement to reduce these setpoints, if the excore tilt exceeded 2% for greater than 24 hours and either the hot channel factors had not been determined or had been exceeded, could be expeditiously implemented. Prior to OPT exceeding 2% (but less than 10%) for greater than a 24 hour period, the nuclear engineering staff concluded from full core flux maps taken at 1124 on August 15 (D-4 inserted), 0248 on August 16 (D-4 withdrawn), at 1123 on August 17 (D-4 withdrawn), and at 1405 on August 23 (D-4 inserted) that the limits placed on core peal*dng factors by TS 3.12.B.1 were not exceeded during these events. Since the core peaking factors remained within limits, it was not necessary to reduce the Overpower ~T and Overtemperature ~T trip setpoints during either event.}} |
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Category:REPORTABLE OCCURRENCE REPORT (SEE ALSO AO
MONTHYEARML18153B1351994-11-0303 November 1994 Ro:On 941028,total Suspended Solids Concentration in Spoil Discharge Reached 820 Mg/L.Permit Limitations Expressed as Values Exceeding Ambient Levels ML18153B4111993-12-15015 December 1993 Ro:On 931215,discovered Fault in Control Rod Drive Sys, Rendering Control Rod Assemblies in Shutdown Bank a Immovable W/Group 2 at 222 Steps & Group 1 Rods of Control Banks a & C Immovable by Faulted Conditions ML18153D1311992-09-15015 September 1992 Update to 920703 Special Rept Re Operational Difficulties W/ Waste Gas Decay Tank Hydrogen Monitors.Operability Intermittent & Reliability Not Yet Achieved.Ts Change to Delete Requirement to Monitor Hydrogen Sent on 920628 ML18153D0561992-07-0303 July 1992 Special Rept:Waste Gas Decay Tank Monitoring Instrumentation Out of Svc for More than 30 Days as Result of Replacement of Pressure Sensors Due to Instrument Drift.Replacement Pumps Received in June 1992.Updated Rept to Be Sent by 920731 ML18153D0221992-06-0303 June 1992 Special Rept:On 920503,quadrant to Average Power Tilt Exceeded 2% for Greater than 24 H.Caused by Loop Inlet Temp Imbalance.Power Range Nuclear Instruments Recalibr ML18153C9071992-02-24024 February 1992 Ro:On 920106,discovered That Portion of Wall Separating Cable Vault & Auxiliary Bldg Was of 4-inch Block Const Instead of Being Designated as Separate Fire Areas.Fire Watches Established Per Station Operating Procedures ML18153C7371991-09-13013 September 1991 Special Rept:On 910815 & 24,quadrant-to-average Power Tilt Exceeded 2% for More than 24 H.Caused by Blown Fuse & Dropped Rod Runback.Cable W/Insulation Damage & Rod Control Cabinet Repaired ML18153C5441991-02-15015 February 1991 Special Rept:On 901220,spurious Alarms Received Shortly After Placing ATWS Mitigation Sys Actuation Circuitry in Svc.From 901222-28,spurious Trouble Alarms Received.On 901231,improper Voltage Ratings Found on Relay Modules ML18153C5071991-01-23023 January 1991 Special Rept:On 901224,quadrant to Average Power Tilt Exceeded 2.0% for Greater than 24 H.Caused by Xenon Transient & Change in Tave Coupled w/pre-existing Core Asymmetry.Isophase Bus Duct Shunts Repaired ML18152B1331988-05-0505 May 1988 Ro:Safety Evaluation of Steam Generator Tube Rupture Accident.Continued Operation of Station Based on Continuing Reanalysis of Impact of Steam Generator Tube Uncovery Justified for Listed Reasons ML18150A1631987-06-0909 June 1987 Ro:On 870516,automatic Shutdown on Low Reactor Coolant Flow in One Loop Experienced.Caused by Mechanical Failure of Reactor Coolant Loop Stop Valve.Effects of Event from Core DNB Standpoint Evaluated,Per 870527 Telcon W/Nrc ML18139B9881982-08-0505 August 1982 Ro:On 820721,rate of Exchange of Condenser Cooling Water Outlet Temp Reached Max of 12 F/Hour Exceeding Max Rate of Change of 3 F/Hour Per Tech Spec 4.14.A.3.Caused by Loss of Electrical Power to Four of Eight Circulating Water Pumps ML18139B8461982-04-16016 April 1982 Ro:On 820403,average Rate of Change of Condenser Cooling Water Outlet Temp Exceeded Permitted Rate.Caused by Operator Error.Personnel Reinstructed ML18139B8271982-03-26026 March 1982 Ro:On 820212,w/Unit 1 at 100% Power & Unit 2 at Hot Shutdown,Average Rate of Change of Condenser Cooling Water Outlet Temp Exceeded Tech Specs.Caused by Failure of Vacuum Priming Sys at River Intake.Sys Repaired ML18139B7241982-02-0505 February 1982 Ro:On 820122,average Rate of Change of Condenser Cooling Water Outlet Temp Exceeded Tech Spec Limit.Caused by Throttling of Water Flow Through Condenser Boxes to Preserve Reduced Canal Water Due to Vacuum Priming Pump Failure ML18139B4991981-08-25025 August 1981 Ro:On 810813,condenser Cooling Water Outlet Temp Exceeded Max Rate of Change of 3 F Per Hour Permitted by Tech Spec 4.14.A.3.Caused by Sheared Pin on Condenser Inlet Screen.No Damage to River Environ Found During Search ML18139B4971981-08-25025 August 1981 Ro:On 810810,rate of Change of Condenser Cooling Water Outlet Temp Reached Max of 7 F/Hr Exceeding Tech Specs, & Causing Loss of Electrical Svc to 4 of 8 Circulating Water Pumps.Loss of Svc Caused by Ground Fault in Transformer ML18139B3261981-05-13013 May 1981 Ro:On 810428,condenser Cooling Water Outlet Temp Exceeded Max Average Rate of Change.Caused by Lack of Svc Water Flow. Event Caused No Detrimental Effect on River Environ ML18139B2871981-05-0101 May 1981 Ro:On 810418,condenser Cooling Water Outlet Temp Exceeded Max Average Rate of Change of 3F/hr Per Tech Spec 4.14.A.3. Lack of Svc Water Flow Believed to Be Contributing Factor. Tube Leaks Repaired.River Environ Not Affected ML18139B2501981-04-16016 April 1981 Ro:On 810406,condenser Cooling Water Outlet Temp Exceeded Max Average Rate of Change Permitted by Tech Specs.Lack of Svc Water Flow Believed to Be Contributing Factor.Search Conducted to Determine Temp Change Effect on River Environ ML18139B2311981-04-0101 April 1981 Ro:On 810322,condenser Cooling Water Outlet Temp Exceeded Tech Spec Limit.Caused by Lack of Svc Water Flow. Investigation Is in Progress ML18139A9641981-01-0505 January 1981 Ro:On 801220 at Full Power,Condenser Cooling Water Outlet Temp Exceeded Max Rate of Change Per Tech Specs.Cause Not Stated.Temp Decreased When Waterbox Outlet Valves Throttled Due to Vacuum Priming Problems ML18139A8481980-11-19019 November 1980 Ro:On 801102,during Cold Shutdown,Condenser Cooling Water Outlet Temp Exceeded Max Rate of Change of 3 F/Hr.Caused by Lack of Svc Water Flow Through Unit 1.No Detrimental Evidence Found Re River Environ 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 ML18139A2741980-05-23023 May 1980 Ro:On 800512,condenser Cooling Water Outlet Temp Exceeded Temp Change Rate of 3 F/H.During Power Escalation W/Only Three Circulating Water Pumps in Operation,Canal Intake Level Dropped & Groin Temp Reached Change Rate of 5.5 F/H ML18139A1731980-04-22022 April 1980 Ro:While Conducting PT 25.12,pump 1-FP-P2 in Fire Protection Sys Failed to Meet Acceptance Criteria of 250 Ft at 2500 Gallons Per Minute.Cause Not Determined.Vendor Will Participate in Insp.Local Fire Depts Will Supply Assistance ML18136A4031980-01-18018 January 1980 Ro:On 800108,while Unit 1 Was Operating at 50% Power,Cooling Water Outlet Temp Exceeded 3 F/Hour Change Rate.While Returning Unit 1 to Svc,Discharge Coolant Temp Increased to 7 F/Hour.No Temp Effects on River ML18136A4591980-01-16016 January 1980 Ro:On 800116,during Power Operation,Boric Acid Flow in One of Two Required Flow Paths to Core Was Blocked for Approx 3-h.Caused by Inadvertent Closing of Discharge Valve.Valve Immediately Opened & Boric Acid Flow Verified ML18136A3371979-12-27027 December 1979 Ro:On 791217,condenser Cooling Water Outlet Temp Exceeded Max Temp Rate Change Permitted by Tech Specs.Caused by Removing Waterbox from Svc Too Rapidly.No Adverse Impact on Environ ML18136A3471979-12-10010 December 1979 Ro:On 791207,when Radiation Alarm Setpoint Reached in Discharge Line of Air Ejectors,Trip Valves Diverted Air Into Containment.Caused by Improper Initial Design Concept.Mods to Maintain Valve Closed Initiated ML18136A2311979-11-26026 November 1979 Ro:On 791110,condenser Cooling Water Outlet Temp Exceeded Temp Change Rate of 3 F/H While Unit 1 Was at 100% Power & Unit 2 Was in Cold Shutdown.Caused by Valve Misalignment Permitting Sodium Fluid to Enter Sys ML18136A1781979-11-0909 November 1979 Ro:On 791026 & 27,condenser Cooling Water Outlet Temp Exceeded Temp Change Rate of 3 F/H.Caused When Waterbox Was Removed from Svc on 791026 & When Returned to Svc on 791027.No Detrimental Effects Found on River Environ ML18116A1741979-06-25025 June 1979 RO on 790622:radiography of Facility Steam Generator Feedwater Nozzles & Reducers Revealed Crack Indications at Counterbore Region.Westinghouse & Util to Evaluate Problem ML18116A1751979-06-22022 June 1979 RO on 790621:Westinghouse Notified Util of Nonconservatism in Accident Analysis.Increase in Steam Generator Ref Resulted from Rise in Containment Temp Not Properly Accounted For.Corrective Action Being Evaluated ML18114A6981979-06-0606 June 1979 RO on 790606:abnormal Degradation of Cable Insulation in Emergency Power Sys Battery Charges.Cause Unknown But Manufacturer Will Be Contacted 1994-11-03
[Table view] Category:LER)
MONTHYEARML18153B1351994-11-0303 November 1994 Ro:On 941028,total Suspended Solids Concentration in Spoil Discharge Reached 820 Mg/L.Permit Limitations Expressed as Values Exceeding Ambient Levels ML18153B4111993-12-15015 December 1993 Ro:On 931215,discovered Fault in Control Rod Drive Sys, Rendering Control Rod Assemblies in Shutdown Bank a Immovable W/Group 2 at 222 Steps & Group 1 Rods of Control Banks a & C Immovable by Faulted Conditions ML18153D1311992-09-15015 September 1992 Update to 920703 Special Rept Re Operational Difficulties W/ Waste Gas Decay Tank Hydrogen Monitors.Operability Intermittent & Reliability Not Yet Achieved.Ts Change to Delete Requirement to Monitor Hydrogen Sent on 920628 ML18153D0561992-07-0303 July 1992 Special Rept:Waste Gas Decay Tank Monitoring Instrumentation Out of Svc for More than 30 Days as Result of Replacement of Pressure Sensors Due to Instrument Drift.Replacement Pumps Received in June 1992.Updated Rept to Be Sent by 920731 ML18153D0221992-06-0303 June 1992 Special Rept:On 920503,quadrant to Average Power Tilt Exceeded 2% for Greater than 24 H.Caused by Loop Inlet Temp Imbalance.Power Range Nuclear Instruments Recalibr ML18153C9071992-02-24024 February 1992 Ro:On 920106,discovered That Portion of Wall Separating Cable Vault & Auxiliary Bldg Was of 4-inch Block Const Instead of Being Designated as Separate Fire Areas.Fire Watches Established Per Station Operating Procedures ML18153C7371991-09-13013 September 1991 Special Rept:On 910815 & 24,quadrant-to-average Power Tilt Exceeded 2% for More than 24 H.Caused by Blown Fuse & Dropped Rod Runback.Cable W/Insulation Damage & Rod Control Cabinet Repaired ML18153C5441991-02-15015 February 1991 Special Rept:On 901220,spurious Alarms Received Shortly After Placing ATWS Mitigation Sys Actuation Circuitry in Svc.From 901222-28,spurious Trouble Alarms Received.On 901231,improper Voltage Ratings Found on Relay Modules ML18153C5071991-01-23023 January 1991 Special Rept:On 901224,quadrant to Average Power Tilt Exceeded 2.0% for Greater than 24 H.Caused by Xenon Transient & Change in Tave Coupled w/pre-existing Core Asymmetry.Isophase Bus Duct Shunts Repaired ML18152B1331988-05-0505 May 1988 Ro:Safety Evaluation of Steam Generator Tube Rupture Accident.Continued Operation of Station Based on Continuing Reanalysis of Impact of Steam Generator Tube Uncovery Justified for Listed Reasons ML18150A1631987-06-0909 June 1987 Ro:On 870516,automatic Shutdown on Low Reactor Coolant Flow in One Loop Experienced.Caused by Mechanical Failure of Reactor Coolant Loop Stop Valve.Effects of Event from Core DNB Standpoint Evaluated,Per 870527 Telcon W/Nrc ML18139B9881982-08-0505 August 1982 Ro:On 820721,rate of Exchange of Condenser Cooling Water Outlet Temp Reached Max of 12 F/Hour Exceeding Max Rate of Change of 3 F/Hour Per Tech Spec 4.14.A.3.Caused by Loss of Electrical Power to Four of Eight Circulating Water Pumps ML18139B8461982-04-16016 April 1982 Ro:On 820403,average Rate of Change of Condenser Cooling Water Outlet Temp Exceeded Permitted Rate.Caused by Operator Error.Personnel Reinstructed ML18139B8271982-03-26026 March 1982 Ro:On 820212,w/Unit 1 at 100% Power & Unit 2 at Hot Shutdown,Average Rate of Change of Condenser Cooling Water Outlet Temp Exceeded Tech Specs.Caused by Failure of Vacuum Priming Sys at River Intake.Sys Repaired ML18139B7241982-02-0505 February 1982 Ro:On 820122,average Rate of Change of Condenser Cooling Water Outlet Temp Exceeded Tech Spec Limit.Caused by Throttling of Water Flow Through Condenser Boxes to Preserve Reduced Canal Water Due to Vacuum Priming Pump Failure ML18139B4991981-08-25025 August 1981 Ro:On 810813,condenser Cooling Water Outlet Temp Exceeded Max Rate of Change of 3 F Per Hour Permitted by Tech Spec 4.14.A.3.Caused by Sheared Pin on Condenser Inlet Screen.No Damage to River Environ Found During Search ML18139B4971981-08-25025 August 1981 Ro:On 810810,rate of Change of Condenser Cooling Water Outlet Temp Reached Max of 7 F/Hr Exceeding Tech Specs, & Causing Loss of Electrical Svc to 4 of 8 Circulating Water Pumps.Loss of Svc Caused by Ground Fault in Transformer ML18139B3261981-05-13013 May 1981 Ro:On 810428,condenser Cooling Water Outlet Temp Exceeded Max Average Rate of Change.Caused by Lack of Svc Water Flow. Event Caused No Detrimental Effect on River Environ ML18139B2871981-05-0101 May 1981 Ro:On 810418,condenser Cooling Water Outlet Temp Exceeded Max Average Rate of Change of 3F/hr Per Tech Spec 4.14.A.3. Lack of Svc Water Flow Believed to Be Contributing Factor. Tube Leaks Repaired.River Environ Not Affected ML18139B2501981-04-16016 April 1981 Ro:On 810406,condenser Cooling Water Outlet Temp Exceeded Max Average Rate of Change Permitted by Tech Specs.Lack of Svc Water Flow Believed to Be Contributing Factor.Search Conducted to Determine Temp Change Effect on River Environ ML18139B2311981-04-0101 April 1981 Ro:On 810322,condenser Cooling Water Outlet Temp Exceeded Tech Spec Limit.Caused by Lack of Svc Water Flow. Investigation Is in Progress ML18139A9641981-01-0505 January 1981 Ro:On 801220 at Full Power,Condenser Cooling Water Outlet Temp Exceeded Max Rate of Change Per Tech Specs.Cause Not Stated.Temp Decreased When Waterbox Outlet Valves Throttled Due to Vacuum Priming Problems ML18139A8481980-11-19019 November 1980 Ro:On 801102,during Cold Shutdown,Condenser Cooling Water Outlet Temp Exceeded Max Rate of Change of 3 F/Hr.Caused by Lack of Svc Water Flow Through Unit 1.No Detrimental Evidence Found Re River Environ 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 ML18139A2741980-05-23023 May 1980 Ro:On 800512,condenser Cooling Water Outlet Temp Exceeded Temp Change Rate of 3 F/H.During Power Escalation W/Only Three Circulating Water Pumps in Operation,Canal Intake Level Dropped & Groin Temp Reached Change Rate of 5.5 F/H ML18139A1731980-04-22022 April 1980 Ro:While Conducting PT 25.12,pump 1-FP-P2 in Fire Protection Sys Failed to Meet Acceptance Criteria of 250 Ft at 2500 Gallons Per Minute.Cause Not Determined.Vendor Will Participate in Insp.Local Fire Depts Will Supply Assistance ML18136A4031980-01-18018 January 1980 Ro:On 800108,while Unit 1 Was Operating at 50% Power,Cooling Water Outlet Temp Exceeded 3 F/Hour Change Rate.While Returning Unit 1 to Svc,Discharge Coolant Temp Increased to 7 F/Hour.No Temp Effects on River ML18136A4591980-01-16016 January 1980 Ro:On 800116,during Power Operation,Boric Acid Flow in One of Two Required Flow Paths to Core Was Blocked for Approx 3-h.Caused by Inadvertent Closing of Discharge Valve.Valve Immediately Opened & Boric Acid Flow Verified ML18136A3371979-12-27027 December 1979 Ro:On 791217,condenser Cooling Water Outlet Temp Exceeded Max Temp Rate Change Permitted by Tech Specs.Caused by Removing Waterbox from Svc Too Rapidly.No Adverse Impact on Environ ML18136A3471979-12-10010 December 1979 Ro:On 791207,when Radiation Alarm Setpoint Reached in Discharge Line of Air Ejectors,Trip Valves Diverted Air Into Containment.Caused by Improper Initial Design Concept.Mods to Maintain Valve Closed Initiated ML18136A2311979-11-26026 November 1979 Ro:On 791110,condenser Cooling Water Outlet Temp Exceeded Temp Change Rate of 3 F/H While Unit 1 Was at 100% Power & Unit 2 Was in Cold Shutdown.Caused by Valve Misalignment Permitting Sodium Fluid to Enter Sys ML18136A1781979-11-0909 November 1979 Ro:On 791026 & 27,condenser Cooling Water Outlet Temp Exceeded Temp Change Rate of 3 F/H.Caused When Waterbox Was Removed from Svc on 791026 & When Returned to Svc on 791027.No Detrimental Effects Found on River Environ ML18116A1741979-06-25025 June 1979 RO on 790622:radiography of Facility Steam Generator Feedwater Nozzles & Reducers Revealed Crack Indications at Counterbore Region.Westinghouse & Util to Evaluate Problem ML18116A1751979-06-22022 June 1979 RO on 790621:Westinghouse Notified Util of Nonconservatism in Accident Analysis.Increase in Steam Generator Ref Resulted from Rise in Containment Temp Not Properly Accounted For.Corrective Action Being Evaluated ML18114A6981979-06-0606 June 1979 RO on 790606:abnormal Degradation of Cable Insulation in Emergency Power Sys Battery Charges.Cause Unknown But Manufacturer Will Be Contacted 1994-11-03
[Table view] Category:TEXT-SAFETY REPORT
MONTHYEARML18152A2811999-10-12012 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. ML18152B3531999-09-30030 September 1999 Monthly Operating Repts for Sept 1999 for Surry Power Station,Units 1 & 2.With 991012 Ltr ML18152B6651999-08-31031 August 1999 Monthly Operating Repts for Aug 1999 for Surry Power Station Units 1 & 2.With 990915 Ltr ML18152B4421999-08-27027 August 1999 LER 99-006-00:on 990802,determined That Plant Was Outside of App R Design Basis Due to Fire Barrier Deficiencies. Caused by Original Plant Design Deficiencies.Fire Watches Were Established & Mods Have Been Completed.With 990827 Ltr ML18152B4411999-08-27027 August 1999 LER 99-005-00:on 990731,effluent Radiation Monitors Were Declared Inoperable.Caused by Degraded Heat Trace Circuits for Monitors Sample Suction Line.Degraded Heat Trace Circuit Was Replaced & Addl Heat Trace Is Being Installed ML18151A3981999-08-13013 August 1999 SPS Unit 2 ISI Summary Rept for 1999 Refueling Outage. ML18152B3771999-08-13013 August 1999 LER 99-004-00:on 990714,TS Violation Due to non-safety Related Fans Effect on CR Boundary Was Noted.Cause of Event Has Not Yet Been Determined.Cable Spreading Room Doors Were Operned to Reduce Pressure in Rooms ML18152B3791999-07-31031 July 1999 Monthly Operating Repts for July 1999 for Surry Power Station,Units 1 & 2.With 990811 Ltr ML18152B3911999-06-30030 June 1999 Monthly Operating Repts for June 1999 for Surry Power Station,Units 1 & 2.With 990713 Ltr ML18152B4341999-05-31031 May 1999 Monthly Operating Repts for May 1999 for Surry Power Station,Units 1 & 2.With 990614 Ltr ML20195E2401999-05-31031 May 1999 Rev 2 to COLR for SPS Unit 2 Cycle 16 Pattern Ag ML18152B4181999-05-18018 May 1999 LER 99-002-00:on 990425,MSSVs Tested Out of Tolerance for as Found Setpoint.Caused by Minor Setpoint Drift.No Immediate Action Required.Deviation Rept Submitted for Each Valve.With 990518 Ltr ML18152B4161999-04-30030 April 1999 Monthly Operating Repts for Apr 1999 for Surry Power Station Units 1 & 2.With 990512 Ltr ML18152B4111999-04-28028 April 1999 LER 99-003-00:on 990331,potential Loss of Charging Pumps Was Noted.Caused by Main CR Fire.Station Deviation Was Issued on 990331.With 990428 Ltr ML18152B6511999-03-31031 March 1999 Monthly Operating Repts for Mar 1999 for Surry Power Station Units 1 & 2 ML18153A2741999-03-29029 March 1999 LER 99-002-00:on 990301,prematurely Released Fire Watches Resulted in Violation of TS 3.21.B.7.Caused by Inadequate Procedure.Procedure for Opening & Sealing Fire Stops Was Revised on 990212 ML18153A2681999-03-19019 March 1999 LER 98-013-01:on 981122,turbine/reactor Tripped on High Due to Short Circuit in Summator for MSL C Loop Channel III Flow Transmitter.Replaced 1-MS-FT1494 Summator & Module Repair Procedure Revised.With 9903190 Ltr ML18152B7331999-02-28028 February 1999 Monthly Operating Repts for Feb 1999 for Surry Power Station,Units 1 & 2.With 990310 Ltr ML18152B5421999-01-31031 January 1999 Monthly Operating Repts for Jan 1999 for Surry Power Station,Units 1 & 2.With 990210 Ltr ML18151A3031999-01-29029 January 1999 ISI Summary Rept for 1998 Refueling Outage,Including Form NIS-1, Owners Rept for ISIs & Form NIS-2, Owners Rept for Repairs & Replacements. ML18152B7261999-01-21021 January 1999 LER 99-001-00:on 981222,auxiliary Feedwater Pipe Support Missed Surveillance.Caused by Personnel Error.Station Deviation Rept Was Submitted.Two Supports in Question Received Required Code Insp & Were Found Acceptable ML18152B6011998-12-31031 December 1998 Monthly Operating Repts for Dec 1998 for Surry Power Station,Units 1 & 2.With 990115 Ltr ML18152B5781998-12-16016 December 1998 LER 98-014-00:on 981126,manual Reactor Trip in Response to Main Feedwater Regulating Valve Failure Occurred.Caused by Dislocation of Retaining Clip in Positioner.Control Room Operators Placed Unit in Safe,Shutdown Condition ML18152B5811998-12-16016 December 1998 LER 98-013-00:on 981122,turbine/reactor Trip on High SG Level Occurred.Caused by Instrument Failure.Control Room Operators Placed Unit in Safe,Shutdown Condition ML18152B7121998-12-0404 December 1998 LER 98-S01-00:on 981105,noted Failure to Deactivate Station Access Badge.Caused by Human Error.Licensee Will Now Deactivate Station Badges Before Clearance Is Revoked & Process for Badge Deactivations Have Been Strengthened ML18152B7041998-12-0101 December 1998 LER 98-012-00:on 981102,noted That EDGs Were Concurrently Inoperable.Caused by Required Testing Per TS 3.16.B.1.a.2. Redundant EDG Was Returned to Svc within Two Hour Period, Following Satisfactory Testing.With 981201 Ltr ML18152B7081998-11-30030 November 1998 Rev 0 to COLR for Surry 1 Cycle 16,Pattern Un. ML18152B5721998-11-30030 November 1998 Monthly Operating Repts for Nov 1998 for Surry Power Station,Units 1 & 2.With 981214 Ltr ML18152B6161998-11-0606 November 1998 LER 98-011-00:on 981008,diesel Driven Fire Pump Failed to Start During Performance of Monthly Operability Test.Caused by Faulty Overspeed Trip Device Failure.Diesel Driven Fire Pump Declared Inoperable ML18152B6241998-10-31031 October 1998 Monthly Operating Repts for Oct 1998 for Surry Power Station Units 1 & 2.With 981111 Ltr ML18152B6081998-10-23023 October 1998 LER 98-010-01:on 980715,intake Canal Level Probes Were Inoperable Due to Marine Growth.Caused by Design of Canal Level Instrumentation.Canal Level Probes Will Continue to Be Monitored More Closely ML18152B6881998-09-30030 September 1998 Monthly Operating Repts for Sept 1998 for Surry Power Station Units 1 & 2.With 981012 Ltr ML18153A3271998-08-31031 August 1998 Monthly Operating Repts for Aug 1998 for Surry Power Station,Units 1 & 2 ML18152B7811998-07-31031 July 1998 LER 98-010-00:on 980715,low Intake Canal Level Instrument Channel I Was Declared Inoperable to Allow Testing of Intake Canal Level Probe 1-CW-LE-102.Subject Probe Was Cleaned by Diver,Tested & Channel I Was Returned to Operable Status ML18153A3161998-07-31031 July 1998 Monthly Operating Repts for July 1998 for Surry Power Station Units 1 & 2.W/980807 Ltr ML18152B7621998-06-30030 June 1998 Monthly Operating Repts for June 1998 for Surry Power Station,Units 1 & 2.W/980707 Ltr ML18153A2581998-06-0303 June 1998 LER 98-009-00:on 980509,nonisolable Leak of Reactor Coolant Pump Seal Injection Line Weld,Was Discovered.Caused by Lack of Fusion or Thermal Fatigue Coupled W/Vibration Stress Due to Loose Rod Hanger.Rcp Seal Injection Line Removed ML20248F7441998-05-31031 May 1998 Reactor Vessel Working Group,Response to RAI Regarding Reactor Pressure Vessel Integrity ML18153A3141998-05-31031 May 1998 Monthly Operating Repts for May 1998 for Surry Power Station,Units 1 & 2.W/980610 ML18152B8241998-05-22022 May 1998 LER 98-008-00:on 980228,auxiliary Ventilation Fans Were Noted in Condition Outside of Design Basis.Caused by Failure to Recognize Potential Impact of Certain Design Basis Accident Scenarios.No Corrective Actions Needed ML18152B8161998-04-30030 April 1998 Monthly Operating Repts for Apr 1998 for Surry Power Station Units 1 & 2.W/980508 Ltr ML18152B7951998-04-29029 April 1998 LER 98-007-00:on 980330,radiation Monitors Were Declared Inoperable.Caused by Change in Operating Temperature Range. Preplanned Alternate Method of Monitoring Was Initiated IAW TS Table 3.7-6 ML18153A2511998-04-22022 April 1998 LER 98-006-00:on 980324,unisolable Through Wall Leak of RCP Thermowell Was Noted.Cause of Leak Is Unknown.Rtd Will Be Replaced ML18153A2521998-04-22022 April 1998 LER 98-005-01:on 980212,fire Watch Insp Exceeded One Hour. Caused by Lack of Attention to Detail by Individual Involved.Individual Involved Was Coached on Requirement to Perform Fire Watch Patrols within Required Time Frame ML20217P9941998-04-0707 April 1998 Safety Evaluation Granting Licensee Third 10-yr Inservice Insp Program Relief Requests SR-018 - Sr-024 ML18153A2951998-03-31031 March 1998 Monthly Operating Repts for Mar 1998 for Sps,Units 1 & 2.W/ 980408 Ltr ML18153A2391998-03-13013 March 1998 LER 98-005-00:on 980212,fire Watch Insp Frequency Exceeded One H Occurred.Category 2 Root Cause Evaluation Being Conducted to Determine Cause of Event.Station Deviation Issued ML18153A2341998-03-0909 March 1998 LER 98-003-00:on 980226,no Procedural Guidance for Maintaining EDG Minimum Fuel Supply During Loop,Was Identified.Caused by Absence of Procedural Instructions. Deviation Rept Submitted to Document Deviating Condition ML18153A2301998-03-0606 March 1998 LER 98-004-00:on 980206,fire Watch Was Released Prematurely Resulting in Violation of Ts.Caused by Inadequate Planning of Repair Activity.Work Orders Will Include Ref to Applicable Procedures Developed to Assist in Repairs ML18153A2251998-03-0404 March 1998 LER 98-002-00:on 980202,automatic Turbine Trip Resulted in Automatic Reactor Trip.Caused Degraded Generator Voltage Regulator sub-component Failure.Placed Plant in Safe Hot SD & Replaced Intermittent Relay & Relay Socket 1999-09-30
[Table view] |
Text
ACCpLERATED iSTRIBUTION DEMOTTIQN,Ji¥STEM .
REGULATORY INFORMATION ~ISTRIBUTION SYSTEM (RIDS)
ACCESSION NBR:9109190223 DOC.DATE: 91/09/13 NOTARIZED: NO DOCKET#
FACIL:50-281 Surry Power Station, Unit 2, Vi:rg.inia Electric.& Powe 05000281 AUTH.NAME AUTHOR AFFILIATION .
STEWART,W.L. Virginia Power (Virginia Elect~ic & Power Co.)
- . RECIP. NAME RECIPIENT AFFILIATION Document Control_Branch (Document Control.Desk)
SUBJECT:
Special*rept:on 910815 & 24,quadrant-to-a:verage power tilt exceeded 2% for more than 24 h.Caused by blown fuse & .
dropped rod runback.Cable w/insulation damage & rod control cabinet repaired. *
- DISTRIBUTION CODE: IE22D COPIES RECEIVED:LTR / ENCL_, SIZE:_._3'-----
TITLE: 5 o. 7 3/ 5 o . 9 Licensee Event Report ( LER) , Incident Rpt, . etc. .
NOTES:lcy NMSS/IMSB/PM. 05000281 RECIPIENT COPIES RECIPIENT COPIES
- ID CODE/NAME LTTR ENCL ID CODE/NAME LTTR ENCL PD2-2 LA 1 1 PD2-2 PD. 1 1 BUCKLEY,B 1 1 INTERNAL: ACNW 2 2 ACRS 2 2 AEOD/DOA 1 1 .AEOD/DSP/TPAB 1 1 AEOD/ROAB/DSP 2 *2 NRR/DET/ECMB 9H 1 1 NRR/DET/EMEB 7E 1 1 . NRR/DLPQ/LHFBlO 1 1 NRR/DLPQ/LPEBlO 1 1 NRR/DOEA/OEAB 1 1 NRR/DREP/PRPBll 2 2 NRR/DST/SELB SD 1 1 NRR/DST/SICB8H3 . 1 1 NRR:~~~B:8:llb 1 1 NRR/DST/SRXB .BE 1 1 REG,dr* , 02 1 1 RES/DSIR/EIB 1 1 RGif-* *---~-*~FJ:-1:iE~*'o*i- 1 1 EXTERNAL: EG&G BRYCE,J.H 3 3 L ST LOBBY WARD 1 1 NRC PDR 1 1 NSIC MURPHY,G.A 1 1 NSIC POORE,W. 1 1 NUDOCS FULL TXT 1 1 NOTES: 1 1 NOTE TO ALL "RIDS" RECIPIET'\TS:
PLEASE HELP us T9 REDUCE \\"ASTE! CONTACT THE DOCUMP<T cm,ffROL DESK, R00'.\1 PJ-3, (EXT. 20079) TO ELI'.\11'.'i:\TE YOUR NAME FROJ\1 DISTRIBUTION LISTS FOR DOCUi\1ENTS YOU DQ"-:'T NEED!
TOTAL NUMBER OF COPIES REQUIRED: LTTR 34
I ,
e e VIRGINIA ELECTRIC AND POWER COMPANY b,
')'
RICHMOND, VIRGINIA 23261 September 13, 1991 United States Nuclear Regulatory Commission Serial No.91-532 Attention: Document Control Desk NO/RJS R1 Washington, D. C. 20555 Docket No. 50-281 License No. DPR.:37 Gentlemen:
VIRGINIA ELECTRIC AND POWER COMPANY SURRY POWER STATION UNIT 2
QUADRANT TO AVERAGE POWER TILT EXCEEDS 2.0% FOR GREATER THAN 24 HOURS Surry Technical Specification 3.12.8.7.a requires an evaluation be performed and a special report be issued to the Nuclear Regulatory Commission under certain conditions when the quadrant to average power tilt exceeds 2% for greater than 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. On August 15, 1991 and August 24, 1991, the Surry Unit 2 quadrant to average power tilt exceeded 2% for greater than 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. A description of the circumstances surrounding these events are provided in the att.achment to this letter.
This report has been reviewed and approved by the Station Nuclear Safety and
Should you have any questions or require additional information, please contact us.
W. L. St art Senior Vice President - Nuclear Attachment - Special Report for Quandrant to Average Power Tilt Exceeding 2% for Greater than 24 Hours cc: U. S. Nuclear Regulatory Commission Region II 101 Marietta Street, N. W.
Suite 2900 Atlanta, Georgia 30323 Mr. M. W. Branch NRC Senior Resident Inspector Surry Power Station ifY\
l .
ATTACHMENT SPECIAL -REPORT FOR QUADRANT TO* AVERAGE POWER TILT EXCEEDING 2%
FOR GREATER THAN 24 HOURS
.,. .
- -
II.II' on August 14, 1991 at 1753 hours0.0203 days <br />0.487 hours <br />0.0029 weeks <br />6.670165e-4 months <br /> with Unit 2 at 100% reactor power (795 MW),
control rod D-4 in control bank C dropped into the core with blown fuse indications. An
- individual Rod Position Indication (IRPI) dropped rod runback occurred and the unit was stabilized at 54% power (420 MW). Applicable Abnormal Operating Procedures were implemented and technical specification requirements were reviewed. Reactor power was verified to be less than 75% and initial Quadrant Power Tilt (OPT) from the excore detectors was determined to be 11.6% at 1825 hours0.0211 days <br />0.507 hours <br />0.00302 weeks <br />6.944125e-4 months <br />. A shutdown margin calculation was also completed and verified to be satisfactory at 1828 hours0.0212 days <br />0.508 hours <br />0.00302 weeks <br />6.95554e-4 months <br />.
Following the determination that OPT was greater than 2.%, at 2059 hours0.0238 days <br />0.572 hours <br />0.0034 weeks <br />7.834495e-4 months <br /> the High Flux Trip Setpoints were reduced to 72% and rod stop setpoints were reduced to 68%
to allow power operation with control rod D-4 inoperable and fully inserted and with OPT greater than 2%. This action was taken to comply with Technical Specification 3.12.8.6.b which requires the High Flux Trip Setpoint to be reduced at least 2% for every 1% of OPT when hot channel factors are not determined within two hours.
Following discussions held with the nuclear steam supply system vendor, Westinghouse, the rod control cabinet was inspected and tested and the rod drive cables were meggered satisfactorily. A cable (with suspected insulation damage) in the rod control cabinet was repaired. The fuses were replaced and control rod D-4 retrieval was performed in accordance with AP-1.01. The rod was fully withdrawn and rE3actor power was raised to 100% at a ramp rate limited to 3% per hour for reactor power levels greater than 68%. This limitation oh ramp rate was implemented in accordance_ with Westinghouse fuel conditioning guidelines.
on August ~3. 1991 at 0435 hours0.00503 days <br />0.121 hours <br />7.19246e-4 weeks <br />1.655175e-4 months <br /> with Unit 2 at 80% reactor power (625 MW), control rod D-4 in control bank C again dropped into the core. A second IRPI dropped rod runback occurred and the unit was stabilized at 50% power (370 MW). Applicable Abnormal Operating Procedures were implemented and actions similar to the first event were taken. Reactor power was verified to be less than 75% and a shutdown margin calculation was completed and verified to be satisfactory at 0503 hours0.00582 days <br />0.14 hours <br />8.316799e-4 weeks <br />1.913915e-4 months <br />. The High Flux Trip Setpoints were reduced to 72% and the rod stop setpoints were reduced to 68% at 0817 hours0.00946 days <br />0.227 hours <br />0.00135 weeks <br />3.108685e-4 months <br />. Initial Quadrant Power Tilt (OPT) from the excore detectors was determined to be-14.5% at 1124 hours0.013 days <br />0.312 hours <br />0.00186 weeks <br />4.27682e-4 months <br />. Reactor operation continued at reduced power, in accordance with analyses performed, until September 7 when Unit 2 was shutdown to troubleshoot and make repairs to control rod D-4.
The core asymmetry due to operation with control rod D-4 inserted, coupled with the xenon transients and changes in Tave associated with the dropped rod events, resulted in the observed excore tilts. For ea*ch of these events, manual OPT calculations were performed at least every two hours to monitor and trend the tilts.
Following each event, preparations were also initiated to reduce Overpower ~T and Overtemperature ~T trip setpoints. These preparations were made to ensure the Technical Specification requirement to reduce these setpoints, if the excore tilt exceeded 2% for greater than 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> and either the hot channel factors had not been determined or had been exceeded, could be expeditiously implemented. Prior to OPT exceeding 2% (but less than 10%) for greater than a 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> period, the nuclear engineering staff concluded from full core flux maps taken at 1124 on August 15 (D-4 inserted), 0248 on August 16 (D-4 withdrawn), at 1123 on August 17 (D-4 withdrawn), and at 1405 on August 23 (D-4 inserted) that the limits placed on core peal*dng factors by TS 3.12.B.1 were not exceeded during these events. Since the core peaking factors remained within limits, it was not necessary to reduce the Overpower ~T and Overtemperature ~T trip setpoints during either event.