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Category:REPORTABLE OCCURRENCE REPORT (SEE ALSO AO LER)
MONTHYEARML20148S3141997-06-30030 June 1997 Ro:On 970422,Oconee Unit 2 Was Shut Down Due to Leak in Rcs. Leak Was Caused by Crack in Pipe to safe-end Weld Connection at RCS Nozzle for HPI Sys A1 Injection Line.Unit 1 Was Shut Down to Inspect Hpis Injection Lines & Implement Ldst Mods ML20117A5981992-11-23023 November 1992 Special Rept:On 921119,ability of Control Battery Racks to Withstand Seismic Event Could Not Be Confirmed & Batteries Declared Inoperable.Batteries Expected to Be Restored in TS Required Time ML20236T0791987-11-25025 November 1987 Advises LER 269/87-09,re Degradation of More than One Functional Unit of Emergency Power Switching Logic for Units 2 & 3,in Preparation & Will Be Submitted by 871215. Incident Originally Discussed in Special Rept ML20210J6671987-02-0303 February 1987 Special Rept:On 861113-14,1206 & 23,spurious Fire Alarms Annunciated in Control Room.On 870118,unit Shut Down Due to Problems W/Detectors.Cause Undetermined.Technicians Investigating Potential Problem W/Detectors ML20215N4011986-10-20020 October 1986 Special Rept:On 860808,during Shutdown for Maint,Found Unidentified Wires in Environmentally Qualified Limitorque motor-operated Valves.Caused by Mfg Deficiency.Wires Replaced ML20209C1871986-08-13013 August 1986 Special Rept:On 860707,fire Barrier Penetration Nonfunctional.Caused by Design Deficiency Due to Ineffective Communication Between Design Groups.Fire Watch Established. Notice Initiated Requiring Installation of Fire Wall ML20212D2221986-07-29029 July 1986 Special Rept:On 860606,determined That Inadequate Assurance Existed Re Use of Qualified Grease in All Limitorque Operators.Appropriate Programs Not Updated to Reflect Revs. Lubrication Records Reviewed ML20210N5641986-04-14014 April 1986 Special Rept:On 860206,fire Wall Determined to Be Degraded. Caused by Personnel Failure to Recognize That Removing Small Amount of Pyrocrete Would Degrade Fire Wall.Fire Wall Repaired & Declared Fully Functional.Part 21 Related ML20137D6481985-11-22022 November 1985 Ro:On 851119,Keowee Hydro Unit 2 Inoperable Beyond Oconee Tech Spec Limit Due to Burned Out Laminated Copper Connection Between Two Coils.Caused by Cracked Brazement. Connector & Field Coils Will Be Replaced ML20135D7781985-08-21021 August 1985 Ro:On 850722,CRD Dc Breaker CB-1 Failed Trip Time Requirement During Channel C Reactor Protective Sys on-line Test.Cause of Failure Could Not Be Determined.Failed CB-1 Breaker Placed in Tripped Position ML20129G0441985-05-24024 May 1985 Ro:On 850425,batch of Powdex Resin from Powdex Cells 1A & 1D Transferred to Chemical Treatment Pond 2 Instead of Powdex Backwash Tank.Caused by Misalignment of Valve CTP-7.Valve Correctly Positioned ML20108E5341985-02-14014 February 1985 Special Rept:On 850114,CRD Dc Breaker Failed Slow During Channel D Reactor Protective Sys on-line Test.Caused by Sticking Trip Latch Roller Bearings & Excessive Trip Latch Operating Torque.Breaker Front Frame Replaced ML20112D0771984-12-14014 December 1984 Special Rept:On 841109,many Fire Barriers Did Not Meet Surveillance Insp Acceptance Criteria & Declared Inoperable. Caused by Const/Installation Deficiency,Component Failure/ Malfunction & Some Unknown Causes.Firestops Repaired ML20099E0241984-10-24024 October 1984 Special Rept:On 840927,discovered That Contaminated Oil Shipped to Lee Steam Station for Disposal by Incineration. Caused by Misinterpretation of Regulations.Shipments of Contaminated Oil Halted ML20093F1911984-10-0808 October 1984 RO 269/83-16,revising 831107 Commitment Re Completion Date of 850101 to Relocate Hydrogen Purge Unit Connection Near Permanent Hookup Connections on Each Unit for Hydrogen Recombiner ML20093L5061984-10-0505 October 1984 Special Rept:On 840906,batch of Powdex Resin from Powder Cells 2D & 2E Transferred from Plant to Chemical Treatment Pond 1 Instead of to Powdex Backwash Tank.Caused by Misalignment of Valves of Chemical Treatment Ponds 5 & 6 ML20106B4791984-10-0303 October 1984 Special Rept:On 840928,power Circuit Breaker 22 Explosively Short Circuited,Causing Power Circuit Breaker 9 to Open, Isolating 230 Kv Overhead Line from Primary OL Power Source. Breaker Reclosed ML20096A1061984-08-22022 August 1984 Suppl to Rev 1 to RO-287/83-13:containment Isolation Valve 3CS-5 Declared Inoperable Due to Leakage Past Seat. Investigation Into Valve Failure Conducted & Diaphragm Replaced ML20094N8601984-07-27027 July 1984 RO 269/83-20 Re Trip Shaft & Bearing Assembly Portions of CRD Breaker Front Frame Assemblies.Nine of 17 GE Frames Defective.Util Awaiting Schedule for Delivery of New Frames ML20092A4291984-06-0606 June 1984 Special Rept:On 840419,during Fuel Reshuffling for Cycle 8, Fuel Assembly FA 0297 Became Stuck in Fuel Location E-10 During Insertion & Fuel Assembly FA 029Q Damaged.Caused by Inadequate Procedure Change ML20092A3841984-04-30030 April 1984 Updated RO-269/83-20 Submitted on 840111 Re Two CRD Breakers Experiencing Delay During Testing.Ge Will Ship CRD Breaker Front Frame Assemblies on 840514.Installation Will Be Complete on All Three Units by 840731 ML20084G4851984-04-18018 April 1984 Updated RO 269/83-17:seals at Conduit Connections Defective. Scotchcast 9 Epoxy Resin Will Be Utilized to Seal Conduit Connections,Dow Corning RTV 3145 Applied to Conduit Fittings & Conduit/Cable Seals Will Be Upgraded ML20082R7561983-12-0202 December 1983 Ro:On 831015-16,standby Bus 2 Deenergized to Verify Emergency Power Path & CT-3 Startup Transformer Locked Out. Caused by Failure of Two Insulators Causing Short to Ground. Info Supersedes 831101 Rept ML20082H5161983-11-21021 November 1983 Ro:Re Loss of Power on Both Standby Buses W/Both Units Out of Svc.Investigation Incomplete.Necessary Info Will Be Submitted by 831202 ML20082C6081983-11-14014 November 1983 Ro:On 831109,while Units Out of Svc for Planned Maint,Lee 6C Gas Turbine Tripped off-line,deenergizing Standby Buses & Placing Units in Degraded Mode Beyond Tech Spec Limit.Cause Undetermined.Next Rept by 831118 ML20078P9651983-11-0202 November 1983 Ro:On 831028,while Unit Out of Svc,Lee 6C Gas Turbine Tripped & Deenergized Both 4,160-volt Standby Buses.Cause Unknown.Lee 5C Turbine Placed on-line to Sys Grid. Investigation Continuing ML20081K0951983-11-0101 November 1983 Ro:On 831015-16,w/Unit 1 Out of Svc,Standby Bus 2 Deenergized to Allow Operability Verification of Underground Emergency Power Path in Accordance W/Tech Specs.On 831015, CT-3 Underwent Lockout.Caused by Bad Insulators ML20078P8841983-10-31031 October 1983 Ro:On 831026,w/unit Out of Svc for Maint,Lee Steam Station Gas Turbine Tripped,Deenergizing Both Standby Buses.Cause Not Determined.Redundant Buses Available ML20081B2521983-10-17017 October 1983 Ro:On 831012,standby Buses Deenergized to Allow for Operability Performance Testing of Standby Bus Breakers Per Tech Specs.Testing Caused Degraded Mode Beyond Tech Spec Limit ML20078H4121983-10-0404 October 1983 Ro:On 830929,while Energizing 4,160-volt Standby Buses,Lee 6C Gas Turbine Tripped off-line,deenergizing Both Standby Buses & Placing Two Operating Units in Degraded Mode.Cause Undetermined Since Unit Has No Event Recorder ML20080P3271983-09-27027 September 1983 Ro:On 830922,w/both Keowee Hydro Units Out of Svc for Planned Maint,Lee 6C Gas Turbine,Being Used to Energize Buses,Tripped Off Line.Both Standby Buses Deenergized & Units 1 & 3 Placed in Degraded Mode ML20080M0261983-09-16016 September 1983 Updated RO 287/83-07.Investigation Incomplete.Next Rept Expected by 831030 ML20080G2351983-09-0606 September 1983 RO 270/83-09:on 830802,hydraulic Snubber Noted Technically Inoperable for More than 72 H.Investigation Incomplete.Next Rept Will Be Submitted by 830912 ML20076C3291983-08-15015 August 1983 RO 287/83-07:followup to Rept Submitted on 830708. Investigation Incomplete.Supplemental Rept Expected by 830915 ML20072J2031983-06-24024 June 1983 Ro:On 830527,certain Containment Isolation Valves May Have Failed in non-ES Position Due to Loss of Dc Power. Investigation & Rept Will Be Completed & Reviewed by 830708 ML20073Q0121983-04-19019 April 1983 Corrected RO 269/83-07:on 830303,during Insp of Manual Containment Isolation Valves,Valve CF-19 Discovered Open. Caused by Personnel Error.Valve Closed.Core Flood Procedure & Reactor Bldg Manual Checklist Changed ML20069K4141983-04-15015 April 1983 Updated ROs 287/83-04,269/83-05 & 269/83-10:repts Being Reviewed & Will Be Submitted No Later than 830419 ML20072T7011983-03-30030 March 1983 RO-287/83-04 Will Not Be Submitted by 830331 as Planned.Rept Re Open Valve on Emergency Hatch Leak Rate Test Pressurization Line Incomplete.Rept to Be Submitted by 830414 ML20072T6971983-03-30030 March 1983 RO-269/83-10 Will Be Delayed Due to Continuing Investigation of Incident Re Partially Opened Interpersonnel Emergency Door Following Testing.Rept Should Be Submitted No Later than 830415 ML20073C4071983-03-25025 March 1983 Informs That RO-287/83-04 Not Reportable.Results of Seismic Analysis Indicate Letdown Line Was Seismically Operable W/Lead Blankets Attached.Pipe Stress,Support Restraint & Equipment Nozzle Loads within Allowable Limits ML20069E3741983-03-11011 March 1983 Ro:On 830225,reactor Protective Sys Pump Power Monitor Sys Failed to Meet Operability Requirements.Investigation Incomplete at Present Time.Rept Will Be Submitted by 830325 ML20070K5851982-12-23023 December 1982 Ro:On 821213,Region 2 Informed of Two Manual Containment Isolation Valves Discovered Open.Rept Providing Details Delayed Due to Investigation.Rept Will Be Completed & Submitted by 821231 ML20070K7311982-12-23023 December 1982 RO 287/82-14:primary to Secondary Leak Discovered in Steam Generator 3B.Rept Will Not Be Submitted Until 830107 Contrary to Previous Commitment ML20065L7761982-10-14014 October 1982 Ro:On 821014,Unit 2 Core Relief Valves Declared Inoperable Due to Analysis Prompted by B&W Safety Concern.Unit 3 Valves Were Offsite Undergoing Ring Adjustment.Immediate Shutdown of Unit 2 Commenced ML20063N2791982-09-0707 September 1982 Informs That RO-269/82-15 Re Electrically Inoperable Valve CCW-8 Will Be Submitted by 820921.Investigation Incomplete ML20063M0851982-09-0303 September 1982 Advises That RO-269/82-16 Re Separation of safety-related Cables Will Not Be Filed.Review & Evaluation Determined That Separation of Specified Cables Conforms to Established Criteria.No Further Action Required ML20063M1031982-09-0101 September 1982 Ro:On 820818,five Reactor Coolant Pump Closure Studs Determined to Be Degraded in Size Below Acceptable SAR limits.RO-287/82-09 Will Be Completed,Reviewed & Submitted by 820910 ML20062J1721982-08-0505 August 1982 RO 270/82-10:on 820722,util Informed NRC That Upper Surge Tank Indicator Read Below Tech Spec Min Required Water Level.Investigation & Preparation of Rept Incomplete.Final Review & Rept Expected by 820819 ML20071K3471982-07-20020 July 1982 RO 269/82-13:on 820706,emergency Feedwater Pump Declared Inoperable When Required Surveillance Testing Discovered Not Performed.Investigation & Rept Will Be Completed,Reviewed & Submitted by 820803 ML20058D8291982-07-16016 July 1982 RO 270/82-09:on 820616,valve 2FDW-316 Would Not Close Completely After Sampling & Affected Flow Path Declared Inoperable.Investigation & Rept Will Be Completed,Reviewed & Submitted on 820730 1997-06-30
[Table view] Category:TEXT-SAFETY REPORT
MONTHYEARML20206P1501999-01-0505 January 1999 LER 98-S03-00:on 981207,security Officer Discovered Uncontrolled Safeguards Info Drawing.Caused by Failure to Follow Established Procedures & Policies.Drawing Was Controlled by Site Security.With ML20216F9931998-12-31031 December 1998 Piedmont Municipal Power Agency 1998 Annual Rept ML20198E6381998-12-17017 December 1998 LER 98-S02-00:on 981130,security Access Was Revoked Due to Falsification of Criminal Record.Individual Was Escorted from Protected Area & Unescorted Access Was Restricted. with ML20153G4601998-09-30030 September 1998 USI A-46 Seismic Evaluation Rept, Vols 1-2 ML17354B0971998-09-0909 September 1998 Part 21 Rept Re Possible Machining Defect in Certain One Inch Stainless Steel Swagelok Front Ferrules,Part Number SS-1613-1.Caused by Tubing Slipping Out of Fitting at Three Times Working Pressure of Tubing.Notified Affected Utils ML15261A4681998-09-0404 September 1998 Safety Evaluation Supporting Amends 232,232 & 231 to Licenses DPR-38,DPR-47 & DPR-55,respectively ML20248F7441998-05-31031 May 1998 Reactor Vessel Working Group,Response to RAI Regarding Reactor Pressure Vessel Integrity ML20247L9041997-12-31031 December 1997 1997 Annual Rept for Duke Energy Corporation & Saluda River Electric Cooperative,Inc,Financial Statements as of Dec 1997 & 1996 Together W/Auditors Rept ML20198J7651997-10-15015 October 1997 Safety Evaluation Accepting 10-yr Interval Insp Program Plan Alternatives for Listed Plants Units ML20148S3141997-06-30030 June 1997 Ro:On 970422,Oconee Unit 2 Was Shut Down Due to Leak in Rcs. Leak Was Caused by Crack in Pipe to safe-end Weld Connection at RCS Nozzle for HPI Sys A1 Injection Line.Unit 1 Was Shut Down to Inspect Hpis Injection Lines & Implement Ldst Mods ML20148H2501997-06-0505 June 1997 Safety Evaluation Accepting Proposed Restructuring of Util Through Acquisition Of,& Merger W/Panenergy Corp ML20210E3591997-03-27027 March 1997 Part 21 Rept Re Sorrento Electronics Inc Has Determined Operation & Maint Manual May Not Adequately Define Requirements for Performing Periodic Surveillance of SR Applications.Caused by Hardware Failures.Revised RM-23A ML20134N7121997-02-20020 February 1997 Safety Evaluation Accepting Relief Request 96-04 for Plant ML20138L2151997-01-31031 January 1997 Monthly Operating Repts for Jan 1997 for Oconee Nuclear Station,Units 1,2 & 3 ML20138L2281996-12-31031 December 1996 Revised Monthly Operating Repts for Dec 1996 for Oconee Nuclear Station,Units 1,2 & 3 ML20133C1231996-12-23023 December 1996 Informs Commission of Staff Review of Request for License Amends from DPC to Perform Emergency Power Engineered Safeguards Functional Test on Three Oconee Nuclear Units ML20115F2471996-07-0303 July 1996 Part 21 Rept Re Piping (Small Portion of Unmelted Matl Drawn Lengthwise Into Bar During Drawing Process) Defect That Existed in Bar as Received from Mill.Addl Insp Procedure for Raw Matl Instituted ML20107M8931995-10-31031 October 1995 Nonproprietary DPC Fuel Reconstitution Analysis Methodology ML17353A4341995-10-31031 October 1995 Rev 1 to BAW-2245, Initial Rt of Linde 80 Welds Based on Fracture Toughness in Transition Range. ML17264A1181995-07-31031 July 1995 Response to Part (1) of GL 92-01,Rev 1,Suppl 1. ML20086M0851995-06-29029 June 1995 DPC TR QA Program ML20077R3631994-12-31031 December 1994 Monthly Operating Repts for Dec 1994 for Bfnpp ML20236L5971994-12-29029 December 1994 SER in Response to 940314 TIA 94-012 Requesting NRR Staff to Determine Specific Mod to Keowee Emergency Power Supply Logic Must Be Reviewed by Staff Prior to Implementation of Mod ML20064L2001994-01-31031 January 1994 Final Rept EPRI TR-103591, Burnup Verification Measurements on Spent-Fuel Assemblies at Oconee Nuclear Station ML20062K7481993-12-0101 December 1993 ISI Rept for Unit 2 McGuire 1993 Refueling Outage 8 ML20056E5171993-08-31031 August 1993 Technical Review Rept, Tardy Licensee Actions ML20046C1291993-08-0202 August 1993 LER 93-007-00:on 930701,determined That Unit 1 Ssf Rc Makeup Sys Inoperable in Past Due to Design Deficiency.Operations Procedures Revised to Reflect Newly Calculated Operating Limits for Rc Makeup Pump,Rcps & RCS.W/930802 Ltr ML20056G0131993-07-27027 July 1993 Rev 0 to ISI Rept Unit 2 Oconee 1993 Refueling Outage 13 ML20044G5311993-05-26026 May 1993 Suppl to 921207 Part 21 Rept Re Declutch Sys Anomaly in Certain Types of Valve Actuators Supplied by Limitorque Corp.Limitorque Designed New Declutch Lever Which Will Be Available in First Quarter 1993 ML20126J5961992-12-31031 December 1992 Part 21 Rept Re Potential Loss of RHR Cooling During Nozzle Dam Removal.Nozzle Dams May Create Trapped Air Column Behind Cold Leg Nozzle Dam.Mod to Nozzle Dams Currently Underway. Ltrs to Affected Utils Encl ML20117A5981992-11-23023 November 1992 Special Rept:On 921119,ability of Control Battery Racks to Withstand Seismic Event Could Not Be Confirmed & Batteries Declared Inoperable.Batteries Expected to Be Restored in TS Required Time ML20097G0421992-05-31031 May 1992 Analysis of Capsule OCIII-D Duke Power Company Oconee Nuclear Station Unit-3 ML20077D0671991-11-15015 November 1991 Nonproprietary Version of Rev 0 to Boric Acid Corrosion of Oconee Unit 1 Upper Tubesheet ML20067A5241990-12-31031 December 1990 Final Submittal in Response to NRC Bulletin 88-011, 'Pressurizer Surge Line Thermal Stratification.' ML20042F3541990-04-30030 April 1990 Special Rept Re Failure to Prevent Performance Degradation of Reactor Bldg Cooling Units.Caused by Mgt Deficiency & Inadequate Program.Cooling Unit Declared Inoperable & Removed from Svc for Cleaning & Placed Back in Operation ML17348A1621990-03-27027 March 1990 Part 21 Rept Re Matls W/Programmatic Defects Supplied by Dubose Steel,Inc.Customers,Purchase Order,Items & Affected Heat Numbers Listed ML19332D5391989-10-31031 October 1989 Core Thermal-Hydraulic Methodology Using VIPRE-01. ML20042F2321989-08-31031 August 1989 Nonproprietary DCHF-1 Correlation for Predicting Critical Heat Flux in Mixing Vane Grid Fuel Assemblies. ML20205F3211988-10-10010 October 1988 Part 21 Rept Re Potential Deviation from Tech Spec Concerning Ry Indicators Due to Operating Temp Effect on Analog Meter Movement.Initially Reported on 881006.Customers Verbally Notified on 881006-07 ML20154K2091988-09-0909 September 1988 Rev 0 to Response to NRC Bulletin 88-005,Nonconforming Matls Supplied by Piping Supplies,Inc at Folsom,Nj & West Jersey Mfg Co.... Proprietary Procedure 1404.1, Leeb Hardness Testing (Equotip).... Encl.Procedure Withheld ML20245D9541988-09-0606 September 1988 Part 21 Rept Re Condition Involving Inconel 600 Matl Used to Fabricate Steam Generator Tube Plugs & Found to Possess Microstructure Susceptible to Stress Corrosion Cracking ML20245B6061988-08-31031 August 1988 Inadequate NPSH in HPSI Sys in Pwrs, Engineering Evaluation Rept ML20239A6991987-11-30030 November 1987 Addendum 1 to Rev 2 to Integrated Reactor Vessel Matl Surveillance Program (Addendum) ML20236T0791987-11-25025 November 1987 Advises LER 269/87-09,re Degradation of More than One Functional Unit of Emergency Power Switching Logic for Units 2 & 3,in Preparation & Will Be Submitted by 871215. Incident Originally Discussed in Special Rept ML20236Q9491987-10-31031 October 1987 Monthly Operating Repts for Oct 1987 ML20235W9611987-09-30030 September 1987 Monthly Operating Repts for Sept 1987 ML20234B1861987-08-31031 August 1987 Monthly Operating Repts for Aug 1987 ML20237K4761987-07-31031 July 1987 Monthly Operating Repts for Jul 1987 ML20236Y0221987-07-0808 July 1987 Safety Evaluation Clarifying Determination of Acceptability of Test Duration for Performance of Integrated Leak Rate Test at Plant ML20235S6311987-06-30030 June 1987 Monthly Operating Repts for June 1987 1999-01-05
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DUKE POWER GOMPANY P.O. BOX 33180 CHARLOTTE, N.C. 28242 HAL B. TUCKER ML3' NOM
==ree. men (704) GM801 nuotsaa racotwson July 2', 1986 ,
u
'3 Dr. J. Nelson Grace, Regional Administrator 7, U. S. Nuclear Regulatory Comunission E-3 Region II --
101 Marietta Street, NW, Suite 2900 cr.
Atlanta, Georgia 30323 C~
Subject:
Oconee Nuclear Station Docket Nos. 50-269, 270, 287
Dear Dr. Grace:
Please find attached a Special Report concerning the utilization of unqualified lubrication within in-containment Limitorque Valve operators. j This Special Report is being submitted pursuant to a comunituent made by Duke to j provide a report regarding this event.
Very truly yours, b J Hal B. Tucker PFG/40/ sib Attachment xc: Mrs. Helen Pastis Office of Nuclear Reactor Regulation l
U. S. Nuclear Regulatory Commission Washington, D. C. 20555 Mr. J. C. Bryant NRC Resident Inspector Oconee Nuclear Station n
8608120441 860729 PDR ADOCK 05000269 p Np M /c)
l DUKE POWER COMPANY ;
OCONEE NUCLEAR STATION SPECIAL REPORT
, Utilization of Unqualified Lubrication Within In-Containment Limitorque Valve Operators i
Abstract On June 6,1986, at 1130 hours0.0131 days <br />0.314 hours <br />0.00187 weeks <br />4.29965e-4 months <br />, Units 1, 2, and 3 were operating at 100% full power when it was determined by NRC Inspectors that adequate assurance did not exist that qualified grease was being used in all Limitorque Operators required to be environmentally qualified.
The immediate corrective action was to review lubrication records of the equipment in question, determine the type of grease being used, and submit j justification to the NRC for continued operation.
i This event is classified as a Management / Quality Assurance Deficiency in that
~
appropriate Duke documents, manuals and procedures were not updated to reflect a revision that occurred to a vendor manual (Limitorque Operator Manual) and that the original Limitorque Qualification test report and maintenance manual were not interpreted to be restrictive concerning lubrication substances.
1 For complete valve operability, under all postulated conditions, i environmentally qualified lubrication is a requirement. Although the qualification of the lubrication used was not clearly substantiated, Duke's evaluation has shown that the combinations of grease will provide the necessary lubrication, and thus, will not degrade the capability of the valve to perform its safety-related function. Therefore, the safety and health of j the public were not affected by this incident.
BACKCROUND i
! Environmental qualification of electrical equipment in nuclear power plants is specified by 10 CFR 50.49, which requires each nuclear power plant to develop j a program for qualifying certain electric equipment installed in postulated j harsh environments. Certain valve operators are environmentally qualified as
) a unit, which includes the grease in the gear box.
1 i Specification Number CS-3-27-1 dated October 25, 1967, and written by Babcock j and Wilcox (B&W) required radiation, temperature, humidity, and pressure effects on the lubricant to be considered in selecting the gear train l lubricant.
} Exxon Nebula EPO and EP1 was the grease tested in Limitorque Valve Operators.
Test Report OM-245-0979 described the grease as being serviceable and
, acceptable after testing, but did not specify the type of grease being used in the test. It was learned from other records that Exxon Nebula was the only grease tested. Other gresses were tested and qualified for other Limitorque j operator applications such as limit switch gear train and motor bearings.
j On June 6, 1986, all three units were operating at 100% full power. An NRC
- team of inspectors was on site. During this review the NRC team discovered
- that Duke could not demonstrate that the qualified lubricant was being used to lubricate the main gear train of Limitorque Valve Operators required to be j environmentally qualified.
t l
2
DESCRIPTION OF OCCURRENCE Initial environmental qualification requirements were provided in 10 CFR 50 Appendix A in 1967. In 1968, B&W supplied Limitorque Operators with Exxon Nebula EPO or EP1 grease, qualified by tests for valve operators located in harsh environments. Exxon Nebula is a general use grease and was listed in the Limitorque Operator Manual (1966-1971), along with several other brands, including MarFak 0, as an acceptable lubricant for the Limitorque Operator main gear train. When Duke Power started the lubrication and maintenance program at Oconee, Texaco products were selected as an acceptable. grease for the main gear train of Limitorque Valve Operators.
Maintenance and operations used Limitorque Operator Manual-(1966-1971) to develop a Repair Procedure and a Lubrication Manual respectively. Texaco grease was the specified grease in both of these applications. A compatibility study and laboratory tests was judged to be sufficient to l qualify the Texaco grease as an acceptab3e substitute for in-containment valves.
Subsequently, Texaco was requested to do compatibility studies, laboratory testing and make recommendations for substitute greases for Oconee. The study and tests were completed by Texaco in 1975, and recommendations were made for substitute greases. Texaco lubricants were then selected for use in Limitorque Valve Operators at Oconee. The Oconee lubrication program met the grease requirements as stated in the Limitorque Manual dated 1966-1971.
Prior to Texaco completing the requested compatibility studies and laboratory testing, a Maintenance procedure was written in 1974, to repair Limitorque Operators, which referenced the Limitorque manual dated 1971. This manual gave grease specifications but did not distinguish between grease brands.
In 1975, a new safety related Limitorque Operator Repair Procedure, was developed referencing Texaco products as lubricants for the main gear train of the Limitorque Operators. At this time it was perceived that the grease requirements as stated in the Limitorque Manual (dated 1966-1971) were being met.
On February 8,1979, the NRC Office of Inspection and Enforcement issued IE Bulletin (IEB) 79-01 " Environmental Qualification of Class IE Equipment".
This bulletin, together with IE Circular 78-08, issued on May 31, 1978, required Duke to perform reviews to assess the adequacy of their Equipment Environmental Qualification programs.
The NRC issued orders, dated August 29, 1980, requiring licensees to' provide a report by November 1,1980, documenting the qualifications of safety-telated electrical equipment.
An Equipment Qualification Criteria Manual was developed by Duke to define the harsh environments in which the equipment was located in. All equipment affected by this bulletin were verified to be qualified or were to be replaced with qualified equipment.
During the course of Duke's correspondence with the NRC concerning IEB 79-01
, A, B, it was stated by Duke that the lubricating grease used in the main gear power train of the Limitorque Operators at Oconee Nuclear Station was Chevron SRI-2 and that this grease had been tested in a continuous-run motor type
1 l
test. However, this was in error because the grease initially supplied in the Limitorque Operators main gear train was Exxon Nebula EPO or EP1 and, as indicated earlier, Texaco products were r,ubsequently selected as an acceptable substitute. It should be noted that Chevron SRI-2 is the permanent grease used in the bearings of the reliance motors supplied with limitorque motor operatored valves.
A new Limitorque Operator Manual (1982) was issued by Limitorque, which was approved by Duke and stamped QA condition 1 on March 15, 1984. This manual ,
had specific guidance for types of grease to be used in Limitorque Operators, '
with Exxon Nebula listed as the only acceptable lubricant for in-containment applications. All appropriate Station Lubrication Programs were not updated to reflect the new information contained within the new Limitorque Operator Manual.
In parallel with the issuance of the new manual by Limitorque, the Equipment Qualification Reference Index (EQRI) Manual was developed by Duke in September 1984. The purpose of the EQRI manual was to clarify qualification mandated maintenance requirements for nuclear safety related equipment located in postulated harsh environments.
The manual contained equipment qualification sheets that listed specific maintenance requirements co maintain equipment qualification, including those for Limitorque Operators. In the remarks column of the qualification sheet for Limitorque Operators, the original OM-245-0979 Test Report referenced did ;
not contain specific grease requirements. The Test Report did describe the grease as being serviceable and acceptable after testing. The specific guidance provided within the new Limitorque Operator manual ragarding which grease to be used for in-containment applications was not specified within the EQRI Manual.
Subsequently, upon implementation of the EQRI Manual, the grease requirements were not identified and were not considered.
On June 6, 1986, an NRC team discovered the possible use of unqualified grease in the environmentally qualified Limitorque Valve Operators.
CAUSE OF OCCURRENCE This incident has been classified as a Management / Quality Assurance deficiency in that appropriate programs were not updated to reflect revisiona made by Limitorque to their operator manual, which provided specific guidance on the type of grease to be utilized for in-containment environmentally qualified valve operators and that the original Limitorque Qualification test report and maintenance manual were not interpreted to be restrictive concerning lubrication substance. In addition, existing administrative controls were not adequate at the time, to assure that the changes to the Limitorque Operator Manual was properly reviewed and incorporated into the EQRI Manual and into appropriate operations and maintenance procedures. The following three factors also contributed to the root cause of the above identified deficiency.
(1) The Limitorque Operator Manual (1966-1971) did not restrict which Lubricants could be used as is the case in the new Limitorque Operator Manual. The initial Manual provided a list of acceptable Lubricants, which included MarFax 0.
l
_4_
(2) The compatibility studies and laboratory tests were judged to be sufficient to qualify the selected Lubricant as being acceptable due to the information provided in the initial operator manual issued by Limitorque, (as noted in Item 1, above) .
(3) Test report OM-245-0979 described the grease as beirs serviceable and acceptable after testing, but did not state the type of Lubricant used in the test. It was learned from other records that Exxon Nebula grease was the only grease tested.
In regard to the error concerning the use of Chevron SRI-2 as reported in Duke submittals to NRC in response to IEB 79-01, the cause was due to a misunderstanding of terminology.
CORRECTIVE ACTIONS The immediate corrective action was to review Lubrication records to determine the type of grease used. In addition, a " Justification for Continued Operation" (JCO) was prepared and submitted to the NRC by a Duke letter dated June 6, 1986. A number of accessible in-containment Limitorque Operators were, also, visually inspected for grease condition.
Duke has initiated a valve refurbishment program, and upon recommendations of a consultant, has also, elected to use Exxon Nebula exclusively in all Limitorque Operators. Subsequently, many valve operators have been completely rebuilt with use of Exxon Nebula grease.
The following are corrective actions that Duke intends to pursue in response to this incident:
e All Limitorque Valve Operator Procedures will be revised to state the exact type of grease to be used and a clear description of where it should be used.
e The Equipment Qualification Reference Index Manual (EQRI) will be revised to identify, within the manual, the exact type of grease to be used in each application, and to reference only documents that are available in Oconee site document control.
e Lubrication in all in-containment environmentally qualified Limitorque Valve Operators will be replaced with qualified grease (Exxon Nebula EPO) during any cold shutdown outage which begins after September 1, 1986.
e Lubrication in all outside containment environmentally qualified Limitorque Valve Operators will be replaced with qualified grease (Exxon Nebula EPO) during each unit's next scheduled refueling outage.
e The Oconee Valve Lubrication Program will be reviewed for accuracy and completeness by September 1, 1986.
e Vendor Document Upgrade Program with a scheduled completion date of 1987 is i
currently ongoing. The program will have provisions to insure changes to Equipment Manuals are flagged to the appropriate personnel. This program was initiated in response to an Action item within Generic Letter 83-28.
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i ANALYSIS OF OCCURRENCE The deficiency in this incident is that the qualification of the grease used for Limitorque Valve Operators was not clearly substantiated. This assessment addresses the operability concern for those valves. The assessment is ,
twofold, with one portion addressing the in-containment valves and the other addressing all other environmentally qualified valves.
l The environmental conditions within the reactor building af ter an accident are
$ of such extreme nature that certain specifications for valve operators are required. High temperature and high radiation conditions are considered to be the most detrimental to lubricants. Therefore, lubricants for valve operators must meet standards regarding dropping temperature (i.e., point at which the base would begin separating from the oil). The lubricants must also withstand high radiation effects.
It is assumed that all Limitorque Operators in all three reactor buildings may :
have a mixture of Exxon Nebuls EP0/EP1 and Texaco Marfak 0 or Marfak 2. The j operaters could also contain the unqualified Marfak 0 or Marfak 2 entirely.
An investigation has determined that these are the only three types of grease that could be present in the operators. All of these valves are containment j isolation valves whose post-accident position is closed.
4 The containment isolation function is achieved in less than 30 minutes, and these valves have been evaluated to be fully operable during this time period, based on the following:
(a) Exxon Nebula EPO and EP1 is compatible with the Texaco Marfak 0 and 2.
It has been determined that some of the valves in question have both types of grease in the operator.
(b) The total integrated dose 30 minutes post-accident is less than 9.2 ES l rads. The threshold for any radiation effects for the Marfak grease is l 5.5 E6 rads. The initial effects above this threshold are softening {
with no failures of fluids predicted below 1 E8 rads. i (c) The peak post-accident temperature is 286 degrees F. While the Marfak is rated for continuous use at 200 degrees F., the dropping temperature is 320 degrees F.
(d) Oconee's stroke tLse tests for the subject valves have shown no trends that would indicate any lubricant degradation.
(e) The combined radiation and temperature effects, at most, would produce some softening of the grease. Being that the grease is totally i
encapsulated by a sealed gear box, the softening would not adversely affect operation.
Further, two of the in-containment valves are required to be active after an accident, specifically LP-1 and LP-2. These valves are located on the decay heat drop lines which would have to be opened to establish Low Pressure Injection Cooling. The valves on Units 1 and 2 have been replaced during the last refueling outage (Unit 2 - March 85, Unit 1 - March 86), and each have the qualified Nebula lubricant only. The same vales on Unit 3 have Rotork Operators and contain qualified lubricant. All other post-accident in-containment active valves have Rotork Operators with qualified lubricant or are electrical solenoid valves.
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In summary, any unqualified grease is present in only the post-accident passive isolation valves, and, as discussed above, the presence cf the unqualified grease would not adversely affect the capability of the valves
- to provide their intended safety function.
For the outside containment valves, this portion of the assessment assumes '
that the environmental conditions within containment would be the most extreme and would bound any conditions possible outside containment.
Therefore the assessment for in-containment post-accident passive valves is viable for the valves outside-containment, provided the types and combinations of lubricants are the same. An investigation has shown this to be the case. The operability of any valves outside the building is not t in question since the environmental conditions are not as severe as inside the building. The fact that the grease in these operators is totally encapsulated and would still be able to provide some lubrication after any softening lends more assurance to the operability of the valves.In addition, any active valves located outside the containment would also be accessible except in the most severe accident conditions which have minimal probability of occurrence.
While it is understood that environmentally qualified lubrication is a requirement for complete valve operability under all pcstulated conditions, this investigation has not found any reason to suspect the present lubrication in any EQ valve will prevent operator function. To the contrary, it has shown that the possible combinations of grease will provide the necessary lubrication to allow the valve to carry out its intended safety function.
Therefore, the safety and health of the public were not affected by this incident.
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