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Category:LICENSEE EVENT REPORT (SEE ALSO AO
MONTHYEARML20045B3551993-06-11011 June 1993 LER 93-001-00:on 930429,refueling Jib Crane Moved in Vicinity of Spent Fuel Pool Using vendor-supplied Lifting Eye in Violation of NUREG-0612.Caused by Failure to Identify Crane as Heavy Load.Meetings held.W/930611 Ltr ML20024G7171991-04-22022 April 1991 LER 91-001-00:on 910324,RB Normal Ventilation Sys (Rbnvs) Outboard Exhaust Valve Closed for No Apparent Reason.Cause Inconclusive.Sys Restored to Normal Lineup & Rbnvs Outboard Valve Will Be Stroked on Routine basis.W/910422 Ltr ML20028H0231990-09-28028 September 1990 LER 90-007-00:on 900907,unplanned Actuation of ESF Sys Occurred During I&C Surveillance Test.Caused by Inadequate procedure.SP44.650.16 Revised to Require That Leads Lifted & Individually separated.W/900928 Ltr ML20012C5131990-03-16016 March 1990 LER 86-029-02:on 860718,19,21 & 870508,loss of Reactor Protection Sys Power Occurred Due to Spurious Tripping of Alternate Feed EPA Breakers.Caused by Low Output Voltage of Alternate Feed Transformer.Output adjusted.W/900316 Ltr ML20006E1571990-02-0909 February 1990 LER 90-001-00:on 900117,unplanned Actuation of ESF Reactor Bldg Standby Ventilation Sys B Occurred,Causing Interlocking Relays in Control Circuits to Deenergize.Caused by Transient Voltage Dip.Procedures Re Bus Loads modified.W/900209 Ltr ML19354D8331990-01-12012 January 1990 LER 89-011-00:on 891222,unplanned Actuation of ESF Primary Containment Isolation Sys Occurred When Performing Sys Layup Implementation Package for Hpci.Caused by Inadequate Procedure.Breaker Positions changed.W/900112 Ltr ML20005F8641990-01-11011 January 1990 LER 89-010-00:on 891212,unplanned Actuation of ESF Control Room Air Conditioning Train a Occurred.Caused by Removal of Leads from Relay During Test to Prevent ESF Sys Actuations. Electrical Relay Replaced & Wiring Mod made.W/900111 Ltr ML20011D2371989-12-15015 December 1989 LER 89-009-00:on 891115,notification Received of Potential Failure Mechanism of Four 3-way Solenoid Operated Pilot Valves.Caused by Incorrect Mounting of Valves.Valves Remounted Vertically & Field Walkdown done.W/891215 Ltr ML19332C5591989-11-15015 November 1989 LER 89-008-00:on 891016,control Room Alarms Received Indicating Fire Pump Had Started & Deluge Valve Had Opened. Caused by Actuation of Manual Pull Station.Deluge Sys Restored to Normal & Personnel interviewed.W/891115 Ltr 1993-06-11
[Table view] Category:RO)
MONTHYEARML20045B3551993-06-11011 June 1993 LER 93-001-00:on 930429,refueling Jib Crane Moved in Vicinity of Spent Fuel Pool Using vendor-supplied Lifting Eye in Violation of NUREG-0612.Caused by Failure to Identify Crane as Heavy Load.Meetings held.W/930611 Ltr ML20024G7171991-04-22022 April 1991 LER 91-001-00:on 910324,RB Normal Ventilation Sys (Rbnvs) Outboard Exhaust Valve Closed for No Apparent Reason.Cause Inconclusive.Sys Restored to Normal Lineup & Rbnvs Outboard Valve Will Be Stroked on Routine basis.W/910422 Ltr ML20028H0231990-09-28028 September 1990 LER 90-007-00:on 900907,unplanned Actuation of ESF Sys Occurred During I&C Surveillance Test.Caused by Inadequate procedure.SP44.650.16 Revised to Require That Leads Lifted & Individually separated.W/900928 Ltr ML20012C5131990-03-16016 March 1990 LER 86-029-02:on 860718,19,21 & 870508,loss of Reactor Protection Sys Power Occurred Due to Spurious Tripping of Alternate Feed EPA Breakers.Caused by Low Output Voltage of Alternate Feed Transformer.Output adjusted.W/900316 Ltr ML20006E1571990-02-0909 February 1990 LER 90-001-00:on 900117,unplanned Actuation of ESF Reactor Bldg Standby Ventilation Sys B Occurred,Causing Interlocking Relays in Control Circuits to Deenergize.Caused by Transient Voltage Dip.Procedures Re Bus Loads modified.W/900209 Ltr ML19354D8331990-01-12012 January 1990 LER 89-011-00:on 891222,unplanned Actuation of ESF Primary Containment Isolation Sys Occurred When Performing Sys Layup Implementation Package for Hpci.Caused by Inadequate Procedure.Breaker Positions changed.W/900112 Ltr ML20005F8641990-01-11011 January 1990 LER 89-010-00:on 891212,unplanned Actuation of ESF Control Room Air Conditioning Train a Occurred.Caused by Removal of Leads from Relay During Test to Prevent ESF Sys Actuations. Electrical Relay Replaced & Wiring Mod made.W/900111 Ltr ML20011D2371989-12-15015 December 1989 LER 89-009-00:on 891115,notification Received of Potential Failure Mechanism of Four 3-way Solenoid Operated Pilot Valves.Caused by Incorrect Mounting of Valves.Valves Remounted Vertically & Field Walkdown done.W/891215 Ltr ML19332C5591989-11-15015 November 1989 LER 89-008-00:on 891016,control Room Alarms Received Indicating Fire Pump Had Started & Deluge Valve Had Opened. Caused by Actuation of Manual Pull Station.Deluge Sys Restored to Normal & Personnel interviewed.W/891115 Ltr 1993-06-11
[Table view] Category:TEXT-SAFETY REPORT
MONTHYEARML20140G4481997-05-0101 May 1997 Part 21 Rept Re Potential Defect in Component of Dsrv & Dsr Enterprise Standby Diesel Generator Sys.Recommends That Springs Be Inspected on Periodic Basis,Such as During Refueling Outages ML20135D8011996-11-26026 November 1996 Part 21 Rept Re Two Safety Related Valves Supplied by Velan Valve Corp Were Not in Compliance W/Originally Supplied QA Documentation.Returned Valves to Velan in May 1996 & on 961120 Velan Advised That Valves Had Been Misplaced ML20080G4691995-01-26026 January 1995 Record of Telcon W/Nrc & Licensees 950126 to Clarify Position Re Dispositioning of Exempt Sources Listed in Section 6.3.3 of Shoreham Termination Survey Final Rept Dtd Oct 1994 ML20069F0001994-01-24024 January 1994 Vols 1-4 to Shoreham Decommissioning Project Termination Survey Final Rept ML20058K3841993-12-0909 December 1993 Part 21 Rept Re Potential Defect in Component of Dsrv & Dsr Enterprise Standby DG Sys,Regarding Potential Problem W/ Subcover Assembled Atop Power Head ML20057F2261993-09-30030 September 1993 Safety Evaluation Supporting Exemption Request from Requirements of 10CFR50.54(q) for License NPF-82 ML20056C7181993-07-14014 July 1993 SE Supporting Amend 10 to License NPF-82 ML20045B3551993-06-11011 June 1993 LER 93-001-00:on 930429,refueling Jib Crane Moved in Vicinity of Spent Fuel Pool Using vendor-supplied Lifting Eye in Violation of NUREG-0612.Caused by Failure to Identify Crane as Heavy Load.Meetings held.W/930611 Ltr ML20045C8881993-06-0808 June 1993 Vols 1 & 2 to Refueling Jib Crane 1T31-CRN-008A Incident Root Cause Analysis. W/One Oversize Encl ML20044C1181993-02-28028 February 1993 Shoreham Nuclear Power Station Updated Decommissioning Plan. ML20128P6451993-02-28028 February 1993 Snps Decommissioning Project Termination Survey Final Rept for Steam Turbine Sys (N31) ML20128P7431993-02-19019 February 1993 Rev 3 to 93X027, Nuclear QA Surveillance Rept ML20127H2301993-01-15015 January 1993 Part 21 Rept Re Potential Defeat in Component of Dsrv & Dsr Enterprise Standby DG Sys.Starting Air Distributor Housing Assemblies Installed as Replacement Parts at Listed Sites ML20126B0421992-12-17017 December 1992 Final Part 21 Rept Re Potential Problem W/Steel Cylinder Heads.Initially Reported on 921125.Caused by Inadequate Cast Wall Thickness at 3/4-inch-10 Bolt Hole.Stud at Location Indicated on Encl Sketch Should Be Removed ML20125C7161992-12-0707 December 1992 Part 21 Rept Re Possibility for Malfunction of Declutching Mechanisms in SMB/SB-000 & SMB/SB/SBD-00 Actuators. Malfunction Only Occurs During Seismic Event.Balanced Levers May Be Purchased from Vendor.List of Affected Utils Encl ML20127P5861992-11-23023 November 1992 Followup to 921005 Part 21 Rept Re Potential Defect in SB/SBD-1 Housing Cover Screws.Procedure Re Replacement of SBD-1 Spring Cover Bolts Encl.All Fasteners Should Be Loosened & Removed.List of Affected Utils Encl ML20128B9641992-10-31031 October 1992 Rev 0 to Shoreham Decommissioning Project Termination Survey Plan ML20118B4391992-09-11011 September 1992 Part 21 Rept Re Degradation in Abb Type 27N Undervoltage Relays Used in Electrical Switchgear.Recommends That Users Review Applications Requiring Exposures Greater than 1E03 Rads TID W/Time Delay Function Option ML20099H5781992-07-31031 July 1992 Rev 4 to Shoreham Defueled Sar ML20114A6311992-07-28028 July 1992 Shoreham Decommissioning Plan ML20101K5791992-06-25025 June 1992 Long Island Power Authority Shoreham Decommissioning Project,Shoreham Nuclear Power Station,Technical Rept on Water Processing & Water Mgt Activities for Reactor Pressure Vessel & Wet Cutting Station ML20094L1271992-03-13013 March 1992 Amend 1 to Part 21 Rept 159 Re Potential Defect in Power Cylinder Liner.Initially Reported on 920115.Caused by Liner/ Block Fit & Localized Matl Microstructure.All Drawings & Specs Revised to Address Matl Design Requirements ML20082M5081991-08-26026 August 1991 Rev 3 to Shoreham Defueled Sar PM-91-125, Monthly Operating Rept for Jul 1991 for Shoreham Nuclear Power Station1991-07-31031 July 1991 Monthly Operating Rept for Jul 1991 for Shoreham Nuclear Power Station PM-91-112, Monthly Operating Rept for Jun 1991 for Shoreham Nuclear Power Station1991-06-30030 June 1991 Monthly Operating Rept for Jun 1991 for Shoreham Nuclear Power Station PM-91-075, Monthly Operating Rept for Apr 1991 for Shoreham Nuclear Power Station1991-04-30030 April 1991 Monthly Operating Rept for Apr 1991 for Shoreham Nuclear Power Station ML20024G7171991-04-22022 April 1991 LER 91-001-00:on 910324,RB Normal Ventilation Sys (Rbnvs) Outboard Exhaust Valve Closed for No Apparent Reason.Cause Inconclusive.Sys Restored to Normal Lineup & Rbnvs Outboard Valve Will Be Stroked on Routine basis.W/910422 Ltr SNRC-1806, Revised Pages 2 & 6 to Encl a of 10CFR50.59 Annual Rept for 19901991-04-15015 April 1991 Revised Pages 2 & 6 to Encl a of 10CFR50.59 Annual Rept for 1990 PM-91-058, Monthly Operating Rept for Mar 1991 for Shoreham Nuclear Power Station1991-03-31031 March 1991 Monthly Operating Rept for Mar 1991 for Shoreham Nuclear Power Station PM-91-037, Monthly Operating Rept for Feb 1991 for Shoreham Nuclear Power Station1991-02-28028 February 1991 Monthly Operating Rept for Feb 1991 for Shoreham Nuclear Power Station PM-91-016, Monthly Operating Rept for Jan 1991 for Shoreham Nuclear Power Station1991-01-31031 January 1991 Monthly Operating Rept for Jan 1991 for Shoreham Nuclear Power Station SNRC-1797, 10CFR 50.59 Annual Rept of Facility Changes,Procedure Changes,Tests & Experiments for Jan-Dec 19901990-12-31031 December 1990 10CFR 50.59 Annual Rept of Facility Changes,Procedure Changes,Tests & Experiments for Jan-Dec 1990 SNRC-1794, Shoreham Nuclear Power Station Annual Operating Rept,19901990-12-31031 December 1990 Shoreham Nuclear Power Station Annual Operating Rept,1990 SNRC-1799, Lilco 1990 Annual Rept1990-12-31031 December 1990 Lilco 1990 Annual Rept ML20069Q3901990-12-31031 December 1990 Shoreham Nuclear Power Station Decommissioning Plan. (Filed in Category P) ML20028H0231990-09-28028 September 1990 LER 90-007-00:on 900907,unplanned Actuation of ESF Sys Occurred During I&C Surveillance Test.Caused by Inadequate procedure.SP44.650.16 Revised to Require That Leads Lifted & Individually separated.W/900928 Ltr ML20056A2001990-07-31031 July 1990 Safety Evaluation Supporting Amend 6 to License NPF-82 PM-90-097, Monthly Operating Rept for June 1990 for Shoreham Nuclear Power Station1990-06-30030 June 1990 Monthly Operating Rept for June 1990 for Shoreham Nuclear Power Station ML20055E3911990-06-25025 June 1990 Safety Evaluation Supporting Amend 5 to License NPF-82 PM-90-083, Monthly Operating Rept for May 1990 for Shoreham Nuclear Power Station1990-05-31031 May 1990 Monthly Operating Rept for May 1990 for Shoreham Nuclear Power Station 05000322/LER-1988-0151990-05-16016 May 1990 LER 88-015-02:on 880916,seismic Monitoring Instrumentation, Including Peak Acceleration Recorders,Removed from Svc for More than 30 Days Due to Corrosion on Scratch Plates.Cover Gasket Replaced & Thermal Barrier Mount to Be Installed 05000322/LER-1986-0391990-05-16016 May 1990 LER 86-039-01:on 861006,unplanned Initiation of Reactor Bldg Standby Ventilation Sys Occurred W/All Rods Inserted in Core.Caused by Faulty Design of Retaining Device.Warning Signs Attached to Valve Actuator & Valve Mod Initiated 05000322/LER-1986-0321990-05-16016 May 1990 LER 86-032-01:on 860728,RWCU Isolated on High Differential Flow Sensed by Steam Leak Detection Sys While Placing Filter Demineralizers in Operation.Cause Not Determined. Operating Procedures Revised to Monitor RWCU Sys 05000322/LER-1987-0091990-05-16016 May 1990 LER 87-009-01:on 870203,full Reactor Trip Occurred Due to Perturbation in Ref Leg.Caused by Spurious Low Level Reactor Pressure Vessel Water Level Signal.Existing Level & Pressure Transmitters Replaced W/Newer Models 05000322/LER-1987-0221990-05-16016 May 1990 LER 87-022-01:on 870604,HPCI Test Valve to Condensate Storage Tank,Globe Valve & Hpci/Rcic Test Valve to Condensate Storage Tank Failed to Close Against Sys Operating Pressure.Disc of motor-operated Valve 37 Modified 05000322/LER-1989-0051990-05-16016 May 1990 LER 89-005-01:on 890321,results of Local Leak Rate Test of Core Spray Suction Valve a Determined That Leakage,When Combined W/All Type B & C Penetration Leakages,Exceeded Tech Spec Limit.Caused by Normal Valve Degradation 05000322/LER-1989-0031990-05-16016 May 1990 LER 89-003-01:on 890310,emergency Diesel Generator (EDG) 102 Manually Shutdown During 18-month Surveillance Test Due to Failure of EDG Output Breaker.Cause Not Determined. Replacement Breaker Installed in Cubicle 102-8 05000322/LER-1985-0591990-05-16016 May 1990 LER 85-059-01:on 851219,half Reactor Trip,Full NSSS Shutoff Sys Isolation & Reactor Bldg Standby Ventilation Sys Initiation Occurred Due to Loss of Power to Reactor Protection Sys Bus B.Assembly Breaker Reset 05000322/LER-1987-0351990-05-16016 May 1990 LER 87-035-02:on 871221,880106 & 0330,high Energy Line Break Logic Isolations of RWCU & Main Steam Line Drain Valves Occurred.Caused by Problems W/Temp Monitoring Units. Grounding Scheme Changed & Transformers Rewired 05000322/LER-1988-0031990-05-16016 May 1990 LER 88-003-01:on 880322,unplanned Automatic Initiation of Reactor Bldg Standby Ventilation Sys Side a Occurred During Deenergization of Relay.Caused by Close Placement of Relay Terminals.Wiring Inside Electrical Panels Reworked 1997-05-01
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. event and the NRC was notified at 1426 per 100FR50.72(b)(2)(ii).
A definite cause for the outboard exhaust valve closing could not be determined. The exhaust valve itself, its control circuit and the components that vent air off the valve to assist it in closing were all inspected or tested but nothing abnormal was found.
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IDENTIFICATION OF THE EVENT Unplanned automatic actuations of ESF Systems (Control Room Air Conditioning [VI) "A" and Reactor Building Standby Ventilation System
[BH] "A") due to low Reactor Building Differential Pressure.
Event Date: 03/24/91 Report Date: 04/22/91 CONDITIONS PRIOR TO THE EVENT Reactor Defueled - All fuel assemblies stored in the Spent Fuel Pool.
Mode Switch - Refuel RPV Drained DESCRIPTION OF THE EVENT On March 24, 1991, at approximately 1221, Reactor Building Normal Ventilation Exhaust Valve (1T46*AOV-037B) closed for no apparent reason. Since the Reactor Building is maintained at a negative pressure, the loss of exhaust flow caused the Reactor Building pressure to rise above .30" W.G. This caused pressure differential switches to trip and annunciators to alarm in the Control Room. The Control Room Operators responded by dispatching an Equipment Operator to the Reactor Building and by checking the control panel. They noticed that 1T46*AOV-037B was closed and reopened it. However, before the Reactor Building pressure could be restored to below .30" W.G., a 30 second time delay elapsed on the A side logic and this caused the Reactor Building Standby Ventilation System (RBSVS) A and Control Room Air Conditioning (CRAC) A subsystems to actuate. This was an unplanned actuation of Engineered Safety Feature systems and is reportable per 100FR50.72(b)(2)(ii) and 50.73(a)(2)(iv). The two affected systems were reset at 1225. Plant Management personnel were informed of the event and the NRC was notified at 1426.
At the time of this event, the Reactor Building Normal Ventilation System (RBNVS) war being operated in a recirculation mode. In this 1 mode, both RBNVS supply valves are closed and the air inside the '
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CAUSE QF THE EVENT The RBSYS and CRAC A subsystems initiated on Low Reactor Building Differential Pressure. The low differential pressure resulted from isolation of the exhaust flow path plus normal air in-leakage. To determine why this valve closed the following actions were taken:
- 1. At the exhaust valve control circuit, Technicians checked wiring terminations for tightness, checked for continuity and verified proper resistance to ground.
- 2. At the exhaust valve, Technicians checked the associated solenoid operated pilot valve's (SOV) junction box terminations for tightness. They also verified that the plunger in the SOV was f ree to move.
- 3. Other components that vent air off the cylinder to assist the exhaust valve in closing were also inspected but nothing abnormal was found.
- 4. The exhaust valve was stroked repeatedly and verified to have operated normally.
- 5. The pressure differential transmitters and pressure differential switches were inspected. Time Delay relay 63X-1T46B30, which initiates the RBSYS and CRAC "B" subsystems on Low Reactor Building D/P after a 30 second time delay was found to be inoperable. This is likely the reason the "B" subsystems were not actuated. However, nothing was found that would have caused the exhaust valve to close.
- 6. A recorder was used to monitor the voltage supplied to the outboard exhaust valve's SOV. This recorder was in place for one week but no voltage fluctuations were observed.
In spite of the above actions, no definite cause could be found for the outboard exhaust valve closing.
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0l0 0 l4 or 015 Two potential causes have been suggested. The first concerns the fact that the outboard exhaust valve did not close when an operator tried to manually close it on February 5, 1991. This exhaust valve's
- control switch has three positions: Close, Auto and Open. If, after the unsuccessful attempt to close the valve, the switch was only allowed to return to the Auto position without momentarily being placed in Open, then a close signal would have remained sealed in.
If this was the case, then the valve would have had to have remained in the open position from February 5th to March 24th with a close signal applied.
This scenario was found to be creditable since a review of maintenance records shcwed that on at least seven occasions during the last five years one of the four supply or exhaust valves have failed to close when either a manual close signal or an isolation signal was applied. Also, since RBNVS has been operating in the recirculation mode, monthly stroking of these valves has been discontinued.
A second potential cause could have been a momentary voltage dip on the 120 V AC bus supplying power to the outboard exhaust valve's control circuit. This voltage dip may have deenergiaed and then sealed out the interlocking relay in the valve control circuit. This would have caused the outboard exhaust valve to close. Because of differences in relay drop-out voltages and because many valves are deenergized, it is conceivable that this particular control circuit was the only one affected by a voltage dip.
ANALYSIS OF THE EVERI There was no safety significance to this event. The plant is shutdown and has been defueled since August 1989.
Since RBSVS has not been required to be operable in the plant's current operational. condition, the Reactor Building Normal Ventilation System has been operated in a recirculation mode in order to reduce Reactor Building humidity to help protect equipment from corrosion and also to reduce building heating costs.
@RRECTIVE ACTIONS
- 1. Time delay relay 63X-1T46B30 was replaced with a spare.
- 2. The voltage supplied to the outboard exhaust valve's SOV was '
monitored on a recorder for one week. Additionally, the outboard exhaust valve was cycled daily during this time but nothing abnormal was found.
3.
The RBNVS outboard exhaust valve will be stroked on a routine basis.
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- 4. Operator training will be revised to remind operators that a closing signal is sealed in on the type of switch used for IT46*A9V-037B, whenever the switch is moved from the Close to the Auto position.
ADDITIONAL INFORMATION a, liannf,arturer and model number of f ailed component (s)
Agastat Relay Co.
Model E70240K002
- b. LER numbers of previous similar events LER 90-002 NRC Perue WA (SA9s
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