|
---|
Category:REPORTABLE OCCURRENCE REPORT (SEE ALSO AO LER)
MONTHYEARML20115H7681996-07-17017 July 1996 Special Rept:On 960603,Unit 2 Vent Stack Wide Range Gas Radiation Monitor Sys Removed from Svc for Planned Mod.Sys Subsequently Returned to Svc on 960701.Mod Replaced ML20115H0111996-07-17017 July 1996 Special Rept:On 960703,main Stack Wide Range Gas Radiation Monitor Sys Removed from Svc for Planned Mod.Sys Expected to Be Returned to Svc by 960830 After Mod Work Completed ML20111B4751996-05-10010 May 1996 Special Rept:On 960422,vent Stack Wide Range Gas Radiation Monitor Sys Was Removed from Svc for Planned Mod.Field Survey Teams Would Be Dispatched to Monitor Radioactive Effluents as Defined in Plant Emergency Plan ML20092M1751995-09-22022 September 1995 Special Rept:On 950726,valid Failure of E-3 EDG Occurred Due to Dead Spot on Potentiometer Which Affected E-3 EDG Controller Output signal.E-3 EDG Returned to Operable Status Following Motor Operated Potentiometer Replacement ML20087H2511995-08-14014 August 1995 Special Rept:On 950726,non-valid Failure of E-3 EDG Occurred Due to Dead Spot on E-3 EDG Motor Operated Potentiometer (MOP).E-1 & E-3 EDG Mops Will Be Replaced W/New Type Mop During Future Mod Outages ML20086R5171995-07-25025 July 1995 Special Rept:On 950630,determined That Number 12 Cylinder on E-1 D/G Had Lower than Normal Operating Temps During Surveillance Test.Caused by Failure of Fuel Oil Injector Pump.Injector Pump Replaced & Satisfactorily Tested ML20078C1701994-10-24024 October 1994 Special Rept:On 940924,valid Failure of E-2 EDG Occurred. Caused by Problem w/4 Kv Breaker.Breaker Incorporated Into Preventive Maint Program to Replace Grease ML20071Q5771994-08-0202 August 1994 Special Rept:On 940706,valid Failure of E-4 Emergency Diesel Generator Occurred.Caused by Solenoid Valve Spuriously Sticking.Valves Replaced ML20064C3011994-02-28028 February 1994 Special Rept:On 940211,non Valid Failure of EDG E-4 Occurred When Voltage Shutdown Button Inadvertently Bumped.Maint Insp Initiated to Determine If Generator Damage May Have Occurred Due to Event.Remaining EDGs Were Operable ML20059A8271993-10-22022 October 1993 Special Rept:On 931012,valid Failure of EDG E-2 Occurred During Routine Monthly Test.Edg E-2 Declared Inoperable Due to High Fuel Oil Differential Pressure Condition.Edg E-2 Fuel Oil Filters Replaced ML20056G8701993-08-27027 August 1993 Special Rept:On 930803,discovered That Cylinder on 2-EDG Lower than Normal Operating Temps.Caused by Fuel Pin on Cylinder Injector Pump Not Fully Engaged ML20079L6291991-10-30030 October 1991 Special Rept:On 910916 & 23,cable Spreading & Computer Room CO2 Fire Protection Sys Out for Svc for More than 14 Days. Caused by Need to Provide for Worker Safety During Mod Work. Fire Detectors Verified Operable & Firewatch Stationed ML20077P9701991-08-15015 August 1991 Special Rept:On 910714,diesel Driven Fire Pump Out of Svc for More than Seven Days Due to Annual Preventative Maint Activities.Preventative Maint Completed & Pump Returned to Svc.Operability Testing Completed Satisfactorily on 910723 ML20064A4651990-08-27027 August 1990 Special Rept:On 900802,diesel-driven Fire Pump Declared Inoperable During Testing Due to Engine Overheating.Caused by Silt & Marine Biotic Life Plugging Y Strainer in Cooling Line.Strainer Cleaned & Retested ML20059B8991990-08-21021 August 1990 Special Rept:On 900802,diesel Driven Fire Pump Declared Inoperable During Testing Due to Engine Overheating.Diesel Generator E-2 Returned to Operable Status & motor-driven Fire Pump Declared Operable on 900807 ML20058N6651990-08-0808 August 1990 Special Rept:On 900802 & 07,diesel Driven & Motor Driven Fire Pumps,Respectively,Declared Administratively Out of Svc.Caused by Engine Overheating & Diesel Generator (DG) E-2 Out of Svc.Local Fire Depts Notified & DG E-2 Repaired ML20245H4461989-08-10010 August 1989 Ro:On 890710,diesel Driven Fire Pump Out of Svc for More than 7 Days.Caused by Disconnected Coolant Hose from Engine Block During Test,Draining Coolant from Engine & Heat Exchanger.Insp & Repair of Engine Performed ML20245J5571989-05-0101 May 1989 Ro:On 890331,motor Driven Fire Pump Out of Svc in Excess of 7 Days.Caused by Removal of Pump from Svc on 890324 to Allow Implementation of Electrical Mods.Diesel Driven Fire Pump Verified Operable & Tested Every 72 H ML20245B3391989-04-14014 April 1989 Special Rept:On 890303,seismic Monitoring Instruments Inoperable for More than 30 Days.Caused by Triaxial Accelerometer Cables Picking Up Electrical Noise Which Caused Spurious Alarms.Noise Filters Will Be Installed ML20195E5011988-11-0303 November 1988 Special Rept:On 881020,diesel Driven Fire Pump Failed to Start Automatically During Surveillance Test.Caused by Inadequate Test.Diesel Driven Fire Pump & auto-start Feature Tested & Rev of Fire Pumps Surveillance Tests in Process ML20205H2561988-10-21021 October 1988 Ro:On 881020,diesel Driven Fire Pump Failed to Start Automatically During Performance of Surveillance Test.Cause Under Investigation.Diesel Driven Fire Pump Subsequently Tested Successfully & Returned to Svc ML20154A7261988-09-0202 September 1988 Special Rept:On 880726,motor-driven Fire Pump Out of Svc for More than 7 Days.Caused by Action Taken to Allow Cleaning & Insp of of E-42 4 Kv bus.Motor-driven Fire Pump Restored to Operable Status on 880821 ML20154A9611988-09-0101 September 1988 Special Rept:On 880822,discharge Pressure Lost While Motor Driven Fire Pump in Operation.Caused by Crack That Formed in Column Pipe Flange Area Where It Bolts to Pump.Motor Driven Pump Removed from Pump Structure,Disassembled & Inspected ML20195B8501988-06-15015 June 1988 Special Rept:On 870215,packing Leak from RCIC Outboard Isolation Valve Reported to Operating Shift.Caused by Steam Leak.New Grease Replaced.On 870915,degradation to Motor Operator & Field Wiring Discovered.Components Replaced ML20154P3591988-05-27027 May 1988 Special Rept:On 880415,carbon Dioxide Fire Suppression Sys Taken Out of Svc for More than 14 Days.Caused by Continuous Fire Watch Required in Cable Spreading Room During Repair of Hole in Floor.Hole Repaired & Subj Sys Returned to Svc ML20153B4681988-03-16016 March 1988 Revised Special Rept Re Diesel Driven Fire Pump out-of-svc for More than Tech Spec Limit of 7 Days.On 871111,diesel Driven Fire Pump Declared Inoperable.Probably Caused by Battery Failures.Surveillance Procedure Revised ML20153B3101988-03-16016 March 1988 Special Rept:On 880302,E-224 440-volt Emergency Load Ctr Supply Breaker Tripped Open,Removing Power Supply for Motor Driven Fire Pump.Caused by Failure of Undervoltage Relay on E-22 Bus.Failed Relay Replaced ML20196G5521988-03-0707 March 1988 Ro:On 880302 & 05,motor Driven Fire Pumps Declared Inoperable.Caused by Level in Storage Tank Dropped Due to Oil Being Transferred from Storage to Day Tank.Diesel Fuel Added Storage Tank to Bring Level Above 300 Gallon Limit ML20147G1531988-03-0303 March 1988 Ro:On 880302,both Fire Pumps Became Inoperable When Breaker E-224 for Motor Driven Fire Pump Tripped.Diesel Driven Fire Pump Taken Out of Svc for Maint on 880301.Caused by Failure of Bus E-22 Undervoltage Relay.Temporary Jumpers Installed ML20147C2081988-01-11011 January 1988 Special Rept:On 871216,planned Release of Liquid Radwaste from Laundry Drain Tank B Made W/O Being Treated as Described in Limiting Condition of Operation 3.8.B.4.Caused by Procedural Deficiency.Procedure Revised ML20238C5071987-12-21021 December 1987 Special Rept:On 871111,diesel-driven Fire Pump Failed Surveillance Test & Declared Inoperable.Cause Unknown.Four Sets of Cells for Two Batteries Replaced & Charged W/Portable Charger.Surveillance Test Procedure Revised ML20236K9111987-08-0303 August 1987 Ro:On 870731,motor Driven Fire Pump Automatically Started on Decreasing Header Pressure at 140 Psig.Caused by Personnel Digging in Yard Directly Behind Radwaste Bldg.Affected Portion of Fire Header Isolated for Repair of Leak ML20214W7691987-06-0505 June 1987 Special Rept:On 870428,bus E22 Deenergized to Perform Series of outage-related Mods,Causing Motor Driven Fire Pump to Be out-of-svc for More than 7 Days,In Violation of Tech Specs. Motor Driven Fire Pump Restored to Svc on 870515 ML20214U0341987-06-0404 June 1987 Special Rept:During Update of Safe Shutdown Data Base, Conditions Re Unencapsulated Cables in Fire Areas Identified as Reportable Per Confirmatory Action Ltr 86-07 & App R. Caused by Exclusion from Previous Analysis.Fire Watch Begun 05000000/LER-1986-009, Ro:On 860312,discovered That LER 2-86-04 & LER 86-009 Not Submitted to Nrc.Caused by Misplaced Repts.Repts Telecopied to Nrc.Procedure for Distribution of Repts Revised1986-04-14014 April 1986 Ro:On 860312,discovered That LER 2-86-04 & LER 86-009 Not Submitted to Nrc.Caused by Misplaced Repts.Repts Telecopied to Nrc.Procedure for Distribution of Repts Revised ML20199F4401986-03-27027 March 1986 Special Rept:On 860216,during Cold Shutdown,Condensate Storage Tank (CST) Filled & Overflowed Into CST Moat & Outside Moat.Caused by Blown Fuse Resulting in Removal of Power from Hotwell Level Controllers.Fuse Mods Considered ML20093F1951984-09-21021 September 1984 RO MM-3-03:on 840823,routine Surveillance Testing Indicated Three Moisture Sensors in Recirculation Sys Moisture Monitoring Sys Functioning Improperly.Cause Not Determined. Hourly Monitoring Being Performed ML20096F4901984-08-14014 August 1984 RO-MM-3-02:on 840715,surveillance Test Revealed Malfunctioning of Moisture Sensors in Recirculation Sys Moisture Monitoring Sys.Cause Unknown.Hourly Monitoring of Drywell Sump Collection Initiated Until Next Outage ML20094F4451984-07-23023 July 1984 RO MM-3-01:on 840622 & 25,moisture Sensors in Recirculation Sys Moisture Monitoring Sys Functioned Improperly.Cause Unknown.Drywell Sump Collection Sys Monitored Hourly Until Next Outage ML20083Q0231984-03-23023 March 1984 Ro:On 840224,during Verification of Moisture Monitoring Sys,Point 7 Failed.Cause Will Be Determined During Next Outage W/Drywell Deinerted.Drywell Sump Collection Sys Will Be Monitored Hourly ML20083P9631984-03-12012 March 1984 Ro:On 840209,CO2 Fire Protection Sys,Serving Cable Spreading Room & Computer Room,Declared Inoperable.Caused by Ground in One of Two Cables from Smoke Detector Control Panel.Cables Replaced & Sys Available for Svc ML20083P8201984-03-0505 March 1984 Ro:On 840125,moisture Sensor in Recirculation Sys Moisture Monitoring Sys Functioned Improperly & Sys Declared Inoperable.Caused by Failed Techmark Limited Moisture Sensor Circuit Card.Sensor Replaced ML20080A7731984-01-16016 January 1984 Ro:On 831128,from 830830-1128,seismic Monitoring Sys Inoperable.Caused by Personnel Oversight.Startup check-off List Modified to Require Maint Request ML20069L3171983-04-11011 April 1983 Corrected RO 3-83-11/1P:on 830407,full-in Position Signal Jumpered Into Probe Buffer Cards.Control Rods Could Have Been Withdrawn W/O Initiating Single Control Rod Interlock. Caused by Personnel Error.Jumpers Removed ML20079L2681983-02-15015 February 1983 RO 3-83-08/1P:on 830214,three of Eight MSIVs Failed to Pass Tech Spec Limit of 11.5 Scfh & Containment Isolation Valve Mo 2-74 Failed Leak Rate Test.Caused by Abnormal Wear of Valve Internals.Valves to Be Inspected & Repaired ML20066A5811982-10-28028 October 1982 RO 2-82-36/1P:on 821024,71J Safety Relief Valve Opened When Pressure Reached 832 Psig.Cause Unknown.Valve to Be Sent to Vendor.Two Vacuum Breakers Replaced.Fatigue Analysis Determined Downstream Piping Not Overstressed ML20066A9391982-10-25025 October 1982 Ro:Response Spectrum Analyzer Component of Seismic Monitoring Sys Intermittently Inoperable Since 820909.Caused by Malfunctioning Power Control Card.Card Will Be Replaced. Component to Be Returned to Svc by 821130 ML20058B7101982-07-14014 July 1982 Ro:On 820619,during Scheduled Loss of Power Test on Unit 2, Inadvertent Startup of ECCS on Unit 3 Initiated While at Full Power.Caused by Defective Elma Dc Power Supply to 24-volt Dc Logic Circuit ML20055B5181982-07-13013 July 1982 RO Advising That Triaxial Accelerometer Devices in Reactor Core Isolation Cooling Sys Pump Room Inoperable for More than 30 Days.Replacement Detector to Be Installed by 820831 ML20126L1441981-05-20020 May 1981 RO 2-81-32/1P:on 810520,w/units in Shutdown Condition, re-evaluation of Concrete Block Walls Identified Four Walls Unstable Under Effects of Tornado Depressurization & Cardox Injection.Caused by Const or Design Error 1996-07-17
[Table view] Category:TEXT-SAFETY REPORT
MONTHYEARML20217K9931999-10-14014 October 1999 Safety Evaluation Supporting Amend 234 to License DPR-56 ML20217B4331999-10-0505 October 1999 Safety Evaluation Supporting Amend 233 to License DPR-56 ML20217G3541999-09-30030 September 1999 Monthly Operating Repts for Sept 1999 for Pbaps,Units 2 & 3. with ML20216H7091999-09-24024 September 1999 Safety Evaluation Supporting Amends 229 & 232 to Licenses DPR-44 & DPR-56,respectively ML20212D1281999-09-17017 September 1999 Safety Evaluation Supporting Proposed Alternatives CRR-03, 05,08,09,10 & 11 ML20212A5871999-08-31031 August 1999 Monthly Operating Repts for Aug 1999 for Peach Bottom,Units 2 & 3.With ML20211D5501999-08-23023 August 1999 Safety Evaluation Supporting Amends 228 & 231 to Licenses DPR-44 & DPR-56,respectively ML20212H6311999-08-19019 August 1999 Rev 2 to PECO-COLR-P2C13, COLR for Pbaps,Unit 2,Reload 12 Cycle 13 ML20210N7641999-07-31031 July 1999 Monthly Operating Repts for Jul 1999 for PBAPS Units 2 & 3. with ML20209H1121999-06-30030 June 1999 Monthly Operating Repts for June 1999 for Pbaps,Units 2 & 3. with ML20195H8841999-05-31031 May 1999 Monthly Operating Repts for May 1999 for Pbaps,Units 2 & 3. with ML20206N1661999-04-30030 April 1999 Monthly Operating Repts for Apr 1999 for Pbaps,Units 2 & 3. with ML20206A2921999-04-20020 April 1999 Safety Evaluation Concluding That Proposed Changes to EALs for PBAPS Are Consistent with Guidance in NUMARC/NESP-007 & Identified Deviations Meet Requirements of 10CFR50.47(b)(4) & App E to 10CFR50 ML20205K7411999-04-0707 April 1999 Safety Evaluation Supporting Amends 227 & 230 to Licenses DPR-44 & DPR-56,respectively ML20205P5851999-03-31031 March 1999 Monthly Operating Repts for Mar 1999 for Peach Bottom Units 2 & 3.With ML20207G9971999-02-28028 February 1999 Monthly Operating Repts for Feb 1999 for Peach Bottom Units 2 & 3.With ML20199E3471998-12-31031 December 1998 Monthly Operating Repts for Dec 1998 for Peach Bottom,Units 1 & 2.With ML20205K0381998-12-31031 December 1998 PECO Energy 1998 Annual Rept. with ML20206P1651998-12-31031 December 1998 Fire Protection for Operating Nuclear Power Plants, Section Iii.F, Automatic Fire Detection ML20206D3651998-12-31031 December 1998 1998 PBAPS Annual 10CFR50.59 & Commitment Rev Rept. with ML20206D3591998-12-31031 December 1998 1998 PBAPS Annual 10CFR72.48 Rept. with ML20196G7021998-12-0202 December 1998 SER Authorizing Proposed Alternative to Delay Exam of Reactor Pressure Vessel Shell Circumferential Welds by Two Operating Cycles ML20196E8261998-11-30030 November 1998 Response to NRC RAI Re Reactor Pressure Vessel Structural Integrity at Peach Bottom Units 2 & 3 ML20198B8591998-11-30030 November 1998 Monthly Operating Repts for Nov 1998 for Pbaps,Units 2 & 3. with ML20206R2571998-11-17017 November 1998 PBAPS Graded Exercise Scenario Manual (Sections 1.0 - 5.0) Emergency Preparedness 981117 Scenario P84 ML20198C6751998-11-0505 November 1998 Rev 3 to COLR for PBAPS Unit 3,Reload 11,Cycle 12 ML20195E5341998-10-31031 October 1998 Monthly Operating Repts for Oct 1998 for Pbaps,Units 2 & 3. with ML20155C6071998-10-26026 October 1998 Safety Evaluation Supporting Amend 226 to License DPR-44 ML20155C1681998-10-22022 October 1998 Safety Evaluation Accepting Proposed Alternative Plan for Exam of Reactor Pressure Vessel Shell Longitudinal Welds ML20155H7721998-10-12012 October 1998 Rev 1 to COLR for Peach Bottom Atomic Power Station Unit 2, Reload 12,Cycle 13 ML20154J2401998-10-0505 October 1998 Safety Evaluation Supporting Amends 224 & 228 to Licenses DPR-44 & DPR-56,respectively ML20154H4771998-10-0505 October 1998 Safety Evaluation Supporting Amends 225 & 229 to Licenses DPR-44 & DPR-56,respectively ML20154G6821998-10-0101 October 1998 SER Related to Request for Relief 01A-VRR-1 Re Inservice Testing of Automatic Depressurization Sys Safety Relief Valves at Peach Bottom Atomic Power Station,Units 2 & 3 ML20154G6631998-10-0101 October 1998 Safety Evaluation Supporting Amends 223 & 227 to Licenses DPR-44 & DPR-56,respectively ML20154H5541998-09-30030 September 1998 Monthly Operating Repts for Sept 1998 for Pbaps,Units 2 & 3. with ML20153B9651998-09-14014 September 1998 Safety Evaluation Supporting Amend 9 to License DPR-12 ML20151Y2901998-08-31031 August 1998 Monthly Operating Repts for Aug 1998 for Pbaps,Units 2 & 3. with ML20238F2661998-08-24024 August 1998 Safety Evaluation Supporting Amend 222 to License DPR-44 ML20237B9531998-08-10010 August 1998 Specification for ISI Program Third Interval,Not Including Class Mc,Primary Containment for Bpaps Units 2 & 3 ML20237A7761998-08-10010 August 1998 SER Accepting Licensee Response to NRC Bulleting 95-002, Unexpected Clogging of RHR Pump Strainer While Operating in Suppression Pool Cooling Mode ML20237A5351998-07-31031 July 1998 Monthly Operating Repts for July 1998 for Pbaps,Units 2 & 3 ML20236R8281998-07-15015 July 1998 Safety Evaluation Approving Proposed Alternative (one-time Temporary non-Code Repair) Pursuant to 10CFR50.55a(a)(3) (II) ML20236M3471998-06-30030 June 1998 Monthly Operating Repts for June 1998 for Pbaps,Units 2 & 3 ML20249C4791998-06-0202 June 1998 Rev 6 to COLR for PBAPS Unit 2 Reload 11,Cycle 12 ML20248F4781998-06-0101 June 1998 Corrected Page 1 to SE Supporting Amends 221 & 226 to Licenses DPR-44 & DPR-56,respectively.Original Page 1 of SE Had Three Typos ML20248F7441998-05-31031 May 1998 Reactor Vessel Working Group,Response to RAI Regarding Reactor Pressure Vessel Integrity ML20248M3001998-05-31031 May 1998 Monthly Operating Repts for May 1998 for Pbaps,Units 2 & 3 ML20247N5351998-05-11011 May 1998 SER Accepting Third 10-year Interval Inservice Program for Pump & Valves for Plant,Units 2 & 3 ML20249C4751998-05-0707 May 1998 Rev 5 to COLR for PBAPS Unit 2 Reload 11,Cycle 12 ML20247G0721998-04-30030 April 1998 Monthly Operating Repts for Apr 1998 for Pbaps,Units 2 & 3 1999-09-30
[Table view] |
Text
. .
PHILADELPHIA ELECTRIC COMPANY 23O1 MARKET STREET P.O. BOX 8699 PHILADELPHI A. PA.19101 (215)841 4000 June 15, 1988 Docket No. 50-277 Mr. William T. Russell, Administrator Region I U.S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555
Subject:
Special Report - Degradation of Motor Operated Isolation Valves due to Steam Leak Peach Bottom Atomic Power Station Unit 2
Dear Mr. Russell:
This special report is submitted to notify you of accelerated degradation of the motor operators of two isolation valves (MO 2-13-16, MO 2-13-15), which was caused by steam leaks from the valve stem packings. Although the events are distinct, common corrective actions are appropriate and have been taken.
This report is being submitted for information, and not pursuant to any regulatory reporting requirements, but does address NRC Open Item 50-277/87-07-01.
Descriptior. (MO 2-13-16)
On February 15, 1987, with Unit 2 at 85% power, a packing leak from the RCIC outboard isolation valve was reported to the operating shift. After failing to stop the leak by backseating the valve, the inboard isolation valve was closed to stop the leak and permit corrective maintenance / The valve stem was repacked, but the valve failed the subsequent stroke tests.
It was then decided to replace the motor and the upper valve stem packing. While removing the motor operator, approximately one pint of water spilled from the motor clutch housing. The source of the water was the steam leak. The grease, which had been
' saturated with water, was replaced with new grease. The blocking permits were cleared and the valve passed the stroke time test.
The inboard isolation valve was opened, no leakage was observed and the outboard isolation valve passed the stroke time test.
8806220016 880615 I PDR ADOCK 05000277 '
S DCD
.Mro W. T. Russell, Administrator June 15, 19G8 Page 2 of 4 Inspection of the original notor began on February 19, 1987. Once disassembled, a rust deposit was observed in the motor lead channel. The insulation on some of the motor leads was degraded, and the locations of the degradation match the rust location on the housing as shown on Figures 1 and 2, attached.
Since this area had been wet, it was determined that a ground had developed in the motor at that point. Upon testing of the individual motor leads, the insulation of one was found to be ineffective.
On September 15, 1987, the motor operator was disassembled to permit inspection in response to IE Bulletin 85-03, "Motor-Operated Valve Common Mode Failures During Plant Transients Due to Improper Switch Setting". During this inspection, degradation to the motor operator and field wiring wi.s discovered. The damaged components, two of which are shown or. Figures 1 and 2, were replaced.
Description (MO 2-13-15):
In April, 1986, high drywell sump pump-out rates indicated that a leak existed within the drywell. After identifying the leak to be associated with the RCIC inboard isolation valve, it was determined that the steam leakage was three gallons per minute (3gpm). The determination was made by l
backseating the valve and monitoring sump pump-out rates, then calculating the corresponding steam flow. In July, 1986, PECo l
engineers calculated that the temperature which would exist near the motor operator would be 192 degrees F, based on a 3gpm steam leak from the stem packing area. The calculation was based on accepted industry standards and assumptions (American Society of Mechanical Engineers, and American Society of Heating, Refrigeration and Air Conditioning Engineers). Using the results l of this calculation, the qualified life of the motor was calculated to be 8.3 years, thus providing a justification for continued operation (JCO). These calculations only addressed the i motor and did not address the limit switch compartment or the field connection conduit. Subsequent inspections revealed that the wire insulation in the conduit appeared to experience the worst degradation.
During the months following the calculations (August-December 1986), corrective maintenance was performed to replace and repair electrical parts of the motor operator and repack the valve stem to correct the leak. Despite the corrective maintenance, the packing leak remained.
On April 17, 1987, with Unit 2 in the Refueling mode, the RCIC Steam Line was tagged out-of-service to permit motor operator inspection and testing in response to IE Bulletin 85-03.
During the inspection of the RCIC inboard isolation valve motor operator on April 27, 1987, accelerated degradation of the wiring insulation in the motor operator limit switch compartment and the associated conduit was discovered. The damage to the insulation l
_ _ . . _ . _ . _ . - _m - __ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ . .
.Mr. W. T. Russell, Administrator June 15, 1988 Page 3 of 4 caused sections of some wires to crumble when they were removed from the conduit. Refer to Figures 3 and 4, attached. The damage was caused by the environmental effects of steam from packing leaks. The valve remained tagged out-of-service until May 20, 1987, when repairs were completed.
Cause of the Events:
The damage to the motor operators and conduit wiring resulted from the steam environment. The source of steam in each case was a steam leak from the associated valve stem packing.
The steam provided the heat which caused the degradation.
Consequences of the Events:
During normal operating conditions, the inboard isolation valve (MO 2-13-15) could have performed its safety function. This conclusion is based on a review of surveillance test records from January, 1986 to March, 1987. This review shows that the inboard valve.and outboard valve stroke times were consistent and acceptable. Neither surveillance testing nor external inspection revealed any evidence of degradation, thus an elapsed inoperability time is not known. The RCIC steam line was tagged out of service on April 17, 1987, which was approximately 36 days after the refueling outage had begun. However, based on inspection results, the degraded wiring could have shorted during a seismic event, and thereby rendered the valve inoperable.
The outboard isolation valve (MO 2-13-16) was operable during the months prior to the discovery of the damage, as evidenced by the surveillance tests, and, therefore the redundancy fulfilled the safety function. The inboard isolation l valve failure also demonstrated that the JCO calculations should l have been expanded to include the field wiring in addition to the l motor operator.
Actions Taken to Prevent Recurrence:
The inboard isolation valve (MO 2-13-15) remained out-of-service from April 17, 1987, until the motor operator was replaced on May 20, 1987. Photograohs of the motor operator and conduit wiring were taken for future reference of the damage and copies of four are included with this report. Future JCO calculations for this type of event will address the
! qualification of the notor operator and any other component whose integrity is required to assure valve operability, including the field wiring. Post-shutdown inspections of all wiring which l could have been affected by the leak is now required.
. .Mr. Wo T. Russell, Administrator June 15, 1988 Page 4 of 4 PECo is in the progress of inspecting, refurbishing and appropriately testing all active safety-related motor operated valves. This program includes the inspection of field wiring for damage, thereby helping to assure the reliability of all safety-related motor operated valves. The program for Unit 2 will be completed by August 1, 1988. The program for Unit 3 is underway and will be completed prior to the Unit 3 restart. A modification has been approved to replace valve packing with graphite and live-loading the packing chambers on safety-related steam line talves, where physical limitations permit. This modification is designed to improve valve packing reliability, thereby reducing packing leak-related damage, and is scheduled to be installed over the next several refueling outages.
If you have any questions, or require more information, please do not hesitate to contact us.
Very truly urs,
. -a l.
R. H. Logu Iff Assistant to the Manager Nuclear Support Division cc: Addressee T. P. Johnson, USNRC Senior Resident Inspector T. E. Magette, State of Maryland l
l l
l l
l l .
V i
9 *
-=
7 ' - Y t _r ' , .
I 'j ,[ ,
y cy ., / i l (::$/ '
, l' r g 2 -16 r
l '
./
4
\
I q '
A N
t 9 ,
O l
.{
as g4
~
e
~s ,A .
,s.
f -
9 mi -< ,,q - g - - ..,c,> - c > p,T ,.7, Lli , L,n v I -
4 [f f
, f)
F l'IGl:I;E 4 E
NO 2-13-]3 a
i b
t
+
t
. w V , .
y 4 .
~
4,h .
g g
'Y yk ..a ue 4
~ , ;w a % )
. :vM .;r.
x' n:-7_ .
9 .#
-4 f . _ _
?' 7iff u
f .- . . ' &_ Y,'-l .'. . cG
,6 Q E W. '
2: i ., .: ~ . .
- a. d o Y y
- z. -, m. .
[
~
,, 1 _ .
x
' i ~$j ,
~'
A
[. , - x ,
h -
l
~
l s
's
~
- 1. ,f
.crQ..,
'!Q s/5
. G. 4 ,y'
~
~
\
l,, *a q ,,^ ,
f / m.
'//lp.'/
s r.{' /
j ..
l
/,,
~
//
i
! l ,
O
/
O Y
l t
gl c,w
?;' l i
/
W x
z
n _
S n en L. s - a a a "-e. -
) , - -
6 k
ll 1
~
4..- ,
t FIGURE 3 MO 2-13-15 0
0 .
l '
( .
e
. 'g-h t ~, . ,
. $g ' . ' ,$
- v. .
y
. 77 .
9.. '
4 ,
y -
. r ,; ; +; .
l ,
4.' < :,' g '. .. .
.c:.c.,.. .
J ag., t; y **. ,. .
.. . ;9 ."y..,]..
g .
');'., ,
S ' ,
t ,
' ~
. b. .
..'e v.8