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Category:ABNORMAL OCCURRENCE REPORTS (SEE ALSO LER & RO)
MONTHYEARML20086B1731976-11-0909 November 1976 AO 50-267/74-20A:on 741116,during Low Power Physics Testing, Conflict Found Between Tech Specs 4.2.11 & 4.4.1 Re Moisture Limits.Caused by Last Minute Change in Tech Specs 4.2.11. Tech Specs Revised ML20086B1781976-11-0909 November 1976 AO 50-267/74-20A:on 741116,during Low Power Physics Testing, Conflict Found Between Tech Specs 4.2.11 & 4.4.1 Re Moisture Limits.Caused by Last Minute Change to Tech Specs 4.2.11. Tech Specs Revised ML20086B1001976-09-0303 September 1976 AO 50-267/74-21C:on 741121,high Pressure in Gas Waste Vacuum Tank Lifted Relief Valve Allowing Release of 700 Scf Uncontaminated Gas.Caused by Operator Error.Valves Will Be Replaced W/Kerotest Valves & Change Notice 91 Issued ML20086A0441976-05-28028 May 1976 Telecopy AO 76-012:on 760527,helium Circulator 1B Tripped Twice.Caused by Buffer Seal Malfunction.Sys Operating Procedure Will Be Revised ML20086A0691976-05-20020 May 1976 AO 76-011:on 760510,helium Circulator 1C Tripped Due to Negative buffer-midbuffer Differential Pressure.Cause Associated W/Test ML20086A0871976-05-0303 May 1976 Telecopy AO 76-010:on 760429 & 30,circulators 1A & 1B Tripped on Loss of Bearing Water.Caused by Operator Error ML20085M4351976-02-17017 February 1976 Telecopy AO 76/005:on 760227,loss of Essential 480-volt Bus 2 Caused Trip of Three Helium Circulators Due to Circulator Bearing Water Problems.Loss of 480-volt Bus Could Cause Temporary Loss of Forced Circulation ML20085M4731976-02-0606 February 1976 Telecopy AOs 76/03 & 76/04:on 760206,generator Set 1-B Load Breaker Would Not Close & Generator Set 1A Trouble Alarm Received,Indicating Partial Disconnection of Engine 1B from Generator.Causes Not Stated ML20085M5651975-12-22022 December 1975 AO 50-267/74/23A:on 741211,engine a of Standby Diesel Generator 1A Declutched During 2 H Surveillance Run & No Alarm Annunciated.Caused by Dirt Under Seat of Solenoid Valve.Plant Change Notice 12 Initiated ML20085M7181975-12-22022 December 1975 AO 50-267/75/15A:on 750709,during Repair of Minor Oil Leak on Gasoline Engine of Emergency Fire Pump,Inlet Manifold Piping Found Cracked.Caused by Component Failure.Manifold Repaired ML20086B1541975-12-18018 December 1975 AO 50-267/74-7A:on 740424,fuel Handling Machine Failed to Engage & Lift Reflector Element 09-06-R-01.Caused by Mfg Error.Reflectors de-burred & Ga Co Will Supply Two Column 1 Metal Clad Reflector Elements ML20085M5631975-11-18018 November 1975 AO 50-267/75/24:on 751108,static Seal on Helium Circulator B Inadvertently Released.Cause Presently Undetermined. Circulator B Brake & Seal Manually Set ML20085M6211975-10-21021 October 1975 AO 50-267/75/18A:on 750816,during Installation Preparation, Helium Circulation Damaged.Caused by Lack of Adherence to Approved Procedure.Personnel Counseled to Adhere to Approved Procedures & Supervision ML20085M5711975-09-26026 September 1975 AO 50-267/75/23:on 750916,essential Electrical Cable Discovered to Have Failed.Caused by Circumstances Associated W/Work in Progress.Damaged Cable Replaced ML20085M5771975-09-26026 September 1975 AO 50-267/75/22:on 750912,during Gas Waste Routine Release, Trouble W/Gas Vacuum Tank Observed by Reactor Operator.Cause of Malfunction Unknown.Failure Could Not Be Reproduced.No Further Action Planned ML20086B1151975-09-26026 September 1975 AO 50-267/74-21B:on 741121,high Pressure in Gas Waste Vacuum Tank Lifted Relief Valve Allowing Release of 700 Scf Uncontaminated Gas.Caused by Operator Error.Inlet Valve Seats Will Be Replaced W/Soft Seats ML20085M5821975-09-22022 September 1975 AO 50-267/75/21:on 750911,control Rod Drive Inserted Into Pcrv Rotated 180 Degrees from Required Orientation During Control Rod Drive Mod.Caused by Design & Procedure Error. Procedures Modified ML20085M6181975-09-0505 September 1975 AO 50-267/75/19:on 750825,engine a of Standby Generator a Automatically Shut Down & Declutched During Cooldown Portion of Weekly Surveillance Test.Caused by Difference in Fuel Rack Setting.Setting Changed ML20085M6231975-09-0505 September 1975 AO 50-267/75/18:on 750816,during Installation Preparation, Helium Circulator Damaged.Caused by Lack of Adherence to Approved Procedure.Personnel Counseled to Adhere to Approved Procedures & Supervision ML20085M6121975-09-0505 September 1975 AO 50-267/75/20:on 750826,12 Cord Sets Connecting Process Controllers at I-05 & I-06 Control Board to Cable Rack in Auxiliary Electric Equipment Room Switched.Caused by Malicious Mischief ML20085M6781975-08-15015 August 1975 AO 50-267/75/17:on 750808,instrument Air Compressor 1C Observed Running Continuously in Unloaded Condition.Caused by Component Failure.Failed Unloader Actuator Replaced W/New Unloader Actuator & Tested ML20085M7021975-07-21021 July 1975 AO 50-267/75/16:on 750610,when Engine B of Standby Generator a Dissassembled,Broken Rings,Scored Cylinders & Cracked Pistons Found.Caused by Water Engine.Engines Inspected.Pistons,Liners & Rings Replaced ML20085M7251975-07-18018 July 1975 AO 50-267/75/15:on 750709,during Repair of Minor Oil Leak on Gasoline Engine of Emergency Fire Pump Inlet Manifold, Piping Found Cracked.Caused by Component Failure.New Manifold Ordered & Defective Casting Replaced ML20085M7401975-06-11011 June 1975 AO 50-267/75/14:on 750530,engine B of a Diesel Generator Oversped to 1,900 Rpm While Electrical Overspeed Trip Being Set.Caused by Procedure Error.Test Procedure Changed ML20085L6331975-05-27027 May 1975 AO 75-267/75/13:on 750519,I-B Engine of I-A Standby Diesel Generator Failed to Start.Caused by Failure to Transmit Info That Engine Was Out of Svc to Adjust Overspeed Switches ML20085L6481975-05-12012 May 1975 AO 50-267/75/10:on 750501,exam Revealed Pin on Declutching Mechanism of Engine D of Standby Diesel Generator D Sheared Off.Caused by Inadequate Lubrication.Pin Replaced & Lubrication Frequency Increased ML20085L6301975-05-12012 May 1975 AO 50-267/75/9:on 750404,valve HV-2188-8 Did Not Open When Circulator Seal Release Permissive Circuit Directed Valve to Open.Cause Not Stated.Air Solenoids Inspected & Cleaned ML20085L7871975-05-0707 May 1975 AO 50-267/74-25:on 741018,diesel Engine B of Standby Generator a Tripped from High Water Jacket Temp on Routine Test.Caused by Improper Filling of Water Jackets.Personnel Counseled ML20085L6411975-05-0707 May 1975 AO 50-267/75/11:on 750424,preliminary Calculations Indicated That Helium Bottles Supplying Reserve Shutdown Sys Did Not Have Adequate Restraint for Dbe.Cause Not Stated.New Bottle Racks Designed & Installed ML20085L7881975-04-16016 April 1975 AO 50-267/74/24A:on 741222,static Seal on Helium Circulator a Released During Removal of Temporary Jumpers.Caused by Jumper Contact W/Station Ground ML20085L7671975-04-0808 April 1975 AO 50-267/75/3A:on 750123,dew Point Moisture Monitor Failed to Initiate Reactor Scram When Moisture Content Exceeded Trip Setpoint.Caused by Design & Procedure Inadequacies.New Procedure Developed ML20085L6491975-04-0707 April 1975 AO 50-267/75/9:on 750329,leak in Mechanical Seal of Helium Circulator B Discovered.Caused by Foreign Matl on Sealing Surfaces.No Corrective Actions Planned ML20085L6831975-04-0202 April 1975 AO 50-267/75/6A:on 750202,gas Waste Vacuum Tank Rupture Disc Ruptured,Releasing Small Quantity of Gas.Caused by Improper Closure of Air Operated Drain Valve Due to Foreign Matl on Valve Seat.Seat Repaired ML20086E1651975-03-21021 March 1975 AO 50-267/74/6A:on 750202,gas Waste Vacuum Tank Rupture Disc Ruptured,Releasing Small Quantity of Gas.Caused by Failure of Air Operated Drain Valve to Close Properly.Valve Repaired & Reinstalled ML20085L7071975-03-14014 March 1975 AO 50-267/75-4-A:on 750125,tritium Leaked from Secondary Closure of Refueling Region 1.Caused by Normal Presence of Tritium in Pressurizing Gas ML20085L6511975-03-0707 March 1975 AO 50-267/75/8:on 750224,diesel Engine B of Standby Generator a Failed to Function Properly During Weekly Test. Caused by Defective Temp Thermocouple.New Thermocouple Installed & Preventive Maint Program Instigated ML20085L6581975-03-0404 March 1975 AO 50-267/75/7:on 750121-23,reactivity Anamoly Occurred Due to Release of Hopper of Reserve Shutdown Mall Into Core. Cause Not Stated.Valve Seats Modified ML20086B0681975-02-26026 February 1975 AO 50-267/74-22A:on 741129,high Pressure in Gas Waste Vacuum Tank Blew Rupture Disc & Lifted Relief Valve Allowing Release of 750 Scf Uncontaminated Gas.Caused by Design Inadequacy.Pressure Indicator Installed ML20085L6851975-02-18018 February 1975 AO 50-267/75/6:on 750202,gas Waste Vacuum Tank Rupture Disc Ruptured,Releasing Small Quantity of Gas.Caused by Improper Closure of Air Operated Drain Valve.Valve Will Be Disassembled for Insp ML20085L7011975-02-17017 February 1975 AO 50-267/75/5:on 750127,gas Vacuum Tank Rupture Disc Ruptured,Releasing Small Quantity of Gas.Caused by Inadequate Procedures.Procedure Rewritten ML20085L7121975-02-14014 February 1975 AO 50-267/75/4:on 750125,tritium Leaked from Secondary Closure of Refueling Region 1.Cause Will Be Determined When Vessel Pressure Dropped to Atmospheric or Below ML20085L7721975-02-12012 February 1975 AO 50-267/75/3:on 750123,dew Point Moisture Monitors Failed to Initiate Reactor Scram When Moisture Content Exceeded Trip Setpoint.Caused by Failure of Sample of Primary Coolant to Reach Monitor.Tech Specs Revised ML20086B1231975-02-12012 February 1975 AO 50-267/74-21A:on 741121,high Pressure in Gas Waste Vacuum Tank Lifted Relief Valve Allowing Release of 700 Scf Uncontaminated Gas.Caused by Procedural Error.Inlet Valve Seats Will Be Replaced & Interim Procedure Modified ML20085L7401975-02-0707 February 1975 AO 50-267/75/1:on 750118,230-kV Breaker Tripped Due to High Winds,Causing Standby Diesel Generator a to Receive Start Signal.Generator B Did Not Receive Start Signal.Caused by Sensitive Relay Setting.Relay Recalibr ML20085L7271975-01-31031 January 1975 AO 50-267/75/2:on 750113,reactor Bldg Exhaust Charcoal Filters Failed to Meet Tech Spec Leak Rate Requirements. Caused by Use of oil-based Paint & Organic Solvents.Filters Changed Out ML20085L6501975-01-25025 January 1975 AO 50-267/75/24A:on 741222,static Seal on C-2101 (Helium Circulator C) Released During Removal of Temporary Jumpers. Caused by Blown Fuse & Seal Release Valve Leak.All Circulator Brake & Seal Vent Valves Checked ML20085L7341975-01-24024 January 1975 Telecopy Ao:Charcoal in Reactor Bldg Exhaust Filters Failed to Meet Tech Spec Requirements ML20085L7901975-01-14014 January 1975 AO 50-267/74/24:on 741222,static Seal on C-2101 (Helium Circulator C) Released During Removal of Temporary Jumpers.Caused by Jumper Across Logic Circulator a Coming in Contact W/Station Ground ML20086B0501974-12-23023 December 1974 AO 50-267/74-23:on 741211,engine a of Standby Diesel Generator 1-A Declutched & No Alarms Annunciated.Caused by Cylinder Air Pressure Decay Due to Dirt Under Solenoid Valve Seat.Change Notice 11 Re in-line Filters Approved ML20086B0641974-12-19019 December 1974 Telecopy AO 50-267/74-23:on 741211,diesel Engine a of Standby Generator 1-A Declutched 1976-09-03
[Table view] Category:TEXT-SAFETY REPORT
MONTHYEARML20196G6731997-07-0101 July 1997 Informs Commission That Decommissioning Process Has Been Completed at PSC of Colorado Fsvngs,Unit 1 Located in Town of Platteville in Weld County,Co ML20141K9961997-05-0505 May 1997 Safety Evaluation Supporting Amend 89 to License DPR-34 ML20140E1121997-04-10010 April 1997 Confirmatory Survey of Group Effluent Discharge Pathway Areas for Fsv Nuclear Station,Platteville,Co ML20134D1661997-01-30030 January 1997 Rev 1,Vol 6 to Final Survey Rept,Final Survey of Group E (Book 2A of 2) ML20137S6111996-12-31031 December 1996 Annual Rept Pursuant to Section 13 or 15(d) of Securities Exchange Act 1934, for Fy Ended Dec 1996 ML20134G6401996-10-29029 October 1996 Rev 0,Volume 6,Books 1 & 2 of 2 to Final Survey of Group E ML20134G6171996-10-29029 October 1996 Rev 2,Volume 1,Books 1 & 2 of 2 to Final Survey Description & Results ML20134G7271996-10-29029 October 1996 Rev 0,Volume 11,Book 1 of 1 to Final Survey of Group J ML20134G6861996-10-29029 October 1996 Rev 0,Volume 8,Books 1 & 2 of 2 to, Final Survey of Group G ML20134G6321996-10-26026 October 1996 Rev 1,Volume 5,Books 2 & 3 of 3 to Final Survey of Group D ML20133D7831996-10-22022 October 1996 Preliminary Rept - Orise Support of NRC License Insp at Fsv on 960930-1003 ML20116A4661996-07-19019 July 1996 Fsv Final Survey Exposure Rate Measurements ML20112J6861996-05-31031 May 1996 June 1996 Quarterly 10CFR50.59 Rept of Changes,Tests & Experiments for Fsv Decommissioning.Rept Covers Period of 960216-0531 ML20112C1531996-05-17017 May 1996 Fsv Final Survey Exposure Rate Measurements ML20101G5521996-03-21021 March 1996 Confirmatory Survey Activities for Fsv Nuclear Station PSC Platteville,Co, Final Rept ML20097E3201996-01-31031 January 1996 Nonproprietary Fort St Vrain Technical Basis Documents for Piping Survey Instrumentation ML20095K4131995-12-26026 December 1995 Rev 3 to Decommissioning Plan ML20095H7211995-12-20020 December 1995 Revs to Fort St Vrain Decommissioning Fire Protection Plan Update ML20095K9751995-12-15015 December 1995 Fort St Vrain Project Update Presentation to NRC, on 951207 & 15 ML20096C1671995-12-13013 December 1995 Rev 4 to Decommissioning Fire Protection Plan ML20094M1651995-11-30030 November 1995 Nonproprietary Fsv Technical Basis Documents for Piping Survey Implementation ML20092F3461995-09-14014 September 1995 Quarterly 10CFR50.59 Rept of Changes,Tests & Experiments for Fsv Decommissioning, Covering Period of 950516-0815.W/ ML20137H3531994-12-31031 December 1994 Partially Withheld, Rept of Independent Counsel Investigation Concerning Issues at Fort St Vrain Nuclear Generating Station Decommissioning Project, App D,Comments by Mkf & Westinghouse Team & Responses ML20137S2331994-12-31031 December 1994 Rept of Independent Counsel Investigation Concerning Issues at Fort St Vrain Nuclear Generating Station Decommissioning Project, Dec 1994 ML20029C6031993-12-31031 December 1993 1993 Annual Rept Public Svc Co of Colorado. W/940405 Ltr ML20058Q3791993-12-21021 December 1993 Rev 1 to Decommissioning Plan for Fort St Vrain Nuclear Generating Station ML20045B3641993-06-30030 June 1993 June 1993 Quarterly 10CFR50.59 Rept of Changes,Tests & Experiments for Fsv Decommissioning. ML20045A4291993-06-0303 June 1993 LER 93-003-00:on 930505,new Source of Natural Gas Introduced within 0.5 Miles of ISFSI & Reactor Bldg W/O Prior NRC Approval.Caused by Field Routing of Natural Gas Pipe.Well Isolated by Well operator.W/930603 Ltr ML20077D1631993-05-10010 May 1993 Enforcement Conference, in Arlington,Tx 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 ML20128D7191992-12-0101 December 1992 Safety Evaluation Approving Exemption from Requirement of 10CFR50.54(q) to Change to Biennial Emergency Plan Exercise Rather than Annual Following Completion of Next Scheduled Exercise at Plant 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 ML20127F5691992-11-0303 November 1992 Informs Commission of Intent to Issue Order Approving Plant Decommissioning Plan & Corresponding Amend to License DPR-34 ML20101E5761992-05-31031 May 1992 Monthly Defueling Operations Rept for May 1992 for Fort St Vrain ML20096E8221992-04-30030 April 1992 Monthly Operating Rept for Apr 1992 for Fort St Vrain.W/ ML20095E9601992-04-17017 April 1992 Rev to Fort St Vrain Proposed Decommissioning Plan ML20100R7431992-03-31031 March 1992 Monthly Operating Rept for Mar 1992 for Fort St Vrain.W/ ML20090L0621992-02-29029 February 1992 Monthly Operating Rept for Feb 1992 for Fort St Vrain Unit 1 ML20092D0081992-01-31031 January 1992 Monthly Operating Rept for Jan 1992 for Fort St Vrain Nuclear Generating Station ML20102B2241992-01-22022 January 1992 Fort St Vrain Station Annual Rept of Changes,Tests & Experiments Not Requiring Prior Commission Approval Per 10CFR50.59, for Period 910123-920122 ML20094N6701991-12-31031 December 1991 Public Svc Co Annual Financial Rept for 1991 ML20091J6251991-12-31031 December 1991 Monthly Operating Rept for Dec 1991 for Fort St Vrain.W/ ML20094D6711991-11-30030 November 1991 Monthly Operating Rept for Nov 1991 for Fort St Vrain Unit 1 ML20090M1871991-11-20020 November 1991 FOSAVEX-91 Scenario for 1991 Plant Exercise of Defueling Emergency Response Plan ML20086D6891991-11-15015 November 1991 Proposed Decommissioning Plan for Fort St Vrain Nuclear Generating Station ML20085N1451991-11-0505 November 1991 Revised Ro:Operability Date of 910830 for Electric Motor Driven Fire Water Pump P-4501 Not Met.Pump Not Actually Declared Operable Until 911025.Caused by Unforseen Matl & Testing Problems.Equivalent Pump Available ML20086C5451991-10-31031 October 1991 Monthly Operating Rept for Oct 1991 for Fort St Vrain.W/ ML20085H6611991-10-10010 October 1991 Assessment of Mgt Modes for Graphite from Reactor Decommissioning ML20091D7671991-10-0101 October 1991 Rev B to Engineering Evaluation of Prestressed Concrete Reactor Vessel & Core Support Floor Structures for Proposed Sys 46 Temp Change ML20085D9861991-09-30030 September 1991 Monthly Operating Rept for Sept 1991 for Fort St Vrain.W/ 1997-07-01
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Information Report No. 1 Facility: Fort St. Vrain Nuclear Generating Station
Subject:
Control Rod Drive Serial No. 30 - Mechanical Failure Report Date: February 12, 1974
- 1. Scope This report is submitted to describe the mechanical failure in Control Rod Drive Serial No. 30 and the conditions leading up to the discovery of the failure. This report will also describe the steps taken to determine the cause of the mechanical failure. and a change in an associated procedure made to prevent one possible cause of the failure from occuring in the future, i 2. Description During the early evening hours of Wednesday, February 6,1974,
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activities preparatory to closing the reactor vessel were proceeding on.
the reactor refueling floor. One of these activities was bolting and torquing the primary closures in the refueling penetrations. As the bolts were being run in .on the No. 30 Control Rod Drive (CRE) in the No.11 penctration, one bolt failed to engage the threads of the flange in the penetration.
To investigate the cause of this problem, it was necessary to remove the CRD from the penetration. To facilitate.its removal the breaker to the drive motor was racked in and the special by-pass box, required for CRD removal, installed in the instrument cabeling at the penetration. The control rod pair was withdrawn, per procedures, to the normal out-limit, at 190" withdrawn. At this point, the normal up-limit was bypassed and the control rods were withdrawn to the extreme up-limit,~236". At this time the " shipping stop" tool was inserted to lock the control rods in position to prevent their moving during.CRD transport to storage.
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4 To check proper shipping tool insertion into the drive mechanism, the brake fuse was removed and the instrumentation checked for control rod movement. The position instrumentation was observed for movement for approximately two (2) minutes with no movement detected. At this time the breaker was racked out and both the power and instrument cable were dis--
connected. Because of the hour, the crew went-to dinner,' leaving.the CRD in_the penetration. Approximately 45 minutes later, as the CRD was being hoisted from the penetration, one of the men noticed the control rods were fully' extended -from the drive and not withdrawn as they were supposed to be.
Withdrawal of the CRD was immediately's. topped.
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To be assured the extended control rods were still in the control rod channels in the core, one man entered the reactor vessel to investigate.
The control rods were found to be engaged. The CRD was then lowered into the penetration to its normal position and all electrical cables reattached.
Position instrumentation indicated the control rods were fully inserted. The shipping tool was removed and the brake fuse inserted and an attempt made to withdraw the control rods. The rods withdrew approximately 0.5" when the out-limit light came on. The control rods were then reinserted.
The reactor remained in a shut down condition through the entire exercise.
- 3. Cause Determination and Resultant Damage On Thursday, February 7,1974, a procedure was developed to verify proper gear train rotation and to verify position indications. Gear train rotation was verified but position indication proved to be erratic and unreliable.
The control rods were then withdrawn for a given length of time which would locate the top of the control rods within the guide tubes of the CRD. The shipping tool was inserted and the CRD hoisted approximately two feet by the reactor building crane. Core entry was made for' visual inspection.
It vis found that the control rods were still fully inserted. The CRD was lowered to its normal position.
It was decided to remove the CRD with the control rods extended.
Necessary control room / refueling floor communications were established and the CRD removed using the reactor building oyerhead crane. Upon removal, the control rods were disconnected and stored and the CRD positioned for disassembly. A spare CRD was installed in penetration No. 11 and the control rods inserted.
Upon partial disassembly of the CRD drive end, it was found that the three bolts and two dowel pins that mount the gear that engages the shipping tool to the cab' e drum hub casting were broken, allowing the cable reel to turn with the shipping tool engaged. The coupling between the position indicating potentiometers and limit switches and the drive mechanism was also broken.
- 4. Analysis of Damage The potentiometer coupling failure _is explained as follows:
As the control rods fell into the core, their.
travel was not controlled by dynamic braking because the CRD had been disconnected electrically.
.As the rods reached the bottom of their travel, the drive mechanism continued.to rotate and rewind the cables in reverse on the drum, driving the wiper of the POT's against their stop, causing the coupling
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Closer visual investigation of the gear that was sheared loose revealed one cracked tooth.
The failure of the three cap screws and two pins and the impli-cations of the failure is still under investigation.
The supplier of the CRD's (General Atomic) has been requested to make an analysis of the failed area'to determine if the cap screws and dowel pins would fail in shear should the CRD drive motor be energized with the shipping tool in place. An independent analysis will also be made.
General Atomic has also been requested to consider a redesign of the shipp'ing tool so that it would fail before any part in the gear train.
J A review of the procedure used to remove and insert the CRD s in the penetrations nas made and the procedure sequence revised to prevent possible energizing of the CRD drive motor with the shipping tool inserted.
We are also inspecting a representative number.of CRD's that'have been through the Preltsinary Operating Test program for any sign of damage, as an assessment of the condition of other rods and to ensure that we do not experience a generic problem.
Our analysis of the incident indica'tes the health and. safety of the public was at no time compromised by the failure. The reactor remained in a shut down condition throughout the incident. The mechanical failure _
in the CRD did not prevent the control rods from being inserted into the core nor was the CRD rendered inoperable.
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February 13, 1974 Mr. John O' Leary, Director Directorate of Licensing United States Atomic Energy Commission Washington, D. C. 20545
Subject:
Information Report No. 1 Control Rod Drive Serial No. 30 Mechanical Failure Fort St. Vrain' Station
Dear Mr. O' Leary:
The attached report is submitted as an informational report only to keep the AEC apprised of the status of Fort St. Vrain.
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Very truly yours, j':
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(7 m Nw )s. $wdh Frederic E. Swart Superintendent
. Fort St. Vrain Nuclear Generating Station FES:11 cc: Director, Region IV, Denver r
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MY M1' REGIO i .
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