Letter Sequence Approval |
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Results
Other: ML20137H372, ML20197B076, ML20204G924, ML20205T170, ML20206B329, ML20206B459, ML20206F887, ML20207K386, ML20207K441, ML20207K446, ML20207K506, ML20207K512, ML20207P779, ML20207P991, ML20207P993, ML20209E329, ML20209F187, ML20209G043, ML20210A740, ML20210A748, ML20210A757, ML20210T436, ML20210T655, ML20210T686, ML20211D992, ML20211E058, ML20211E084, ML20211E110, ML20211G583, ML20211N368, ML20212M102, ML20214Q988, ML20214Q998, ML20214S836, ML20214S958, ML20215G796, ML20215H964, ML20215H973, ML20215J855, ML20215J871, ML20215L534, ML20216D570, ML20216E230, ML20234C109, ML20235E520, ML20235F508, ML20245C018
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MONTHYEARML20137H3721985-11-26026 November 1985 Memorandum & Order Granting Extension of 851130 Deadline for Environ Qualification of Electrical Equipment to 860531 & Approving Proposal to Allow Operation w/35% Reactor Power Limit During Interim.Served on 851127 Project stage: Other ML20211E0841986-02-20020 February 1986 Issue a to Fort St Vrain:Delayed Firewater Cooldown;Effect of Liner Cooling on Orifice Valve Temps Project stage: Other ML20209F1871986-03-18018 March 1986 Fort St Vrain Steam Generator Temps During Interruption of Forced Cooling from 105% Power Project stage: Other ML20214S9581986-09-25025 September 1986 Requests That Util Take Listed Actions Re Three Repts Submitted Concerning Firewater Cooldown Analysis,Per NRC Review & 860917 Telcon.Response to Item 1 Requested within 15 Days of Ltr Date & Item 2 at Time Analysis Submitted Project stage: Other ML20211E0581986-09-30030 September 1986 Effect of Delayed Firewater Cooldown W/Loss of Liner Cooling on Pcrv Temps Project stage: Other ML20215G7961986-10-10010 October 1986 Advises That Info Requested in NRC Re Best Estimate Schedule for Resolution of Problems Encountered W/Firewater Cooldown Analysis Will Be Submitted as Part of Util Graduated rise-to-power Program Project stage: Other ML20197B0761986-10-22022 October 1986 Informs That Util Will Update & Submit Rept on Chernobyl Accident by 861126.Update Will Ctr on Graphite Related Concerns,Including Analysis of Worst Case Explosive Gas Mixtures & Comparison of Reactor Kinetics Behavior Project stage: Other ML20211G5831986-10-22022 October 1986 Anticipates Completion of Steam Generator Analysis & App R Modeling Reanalysis Work by Feb 1987,per 860918 Telcon W/Nrc Re Steam Generator Cool Down Studies for App R Project stage: Other ML20215L5341986-10-23023 October 1986 Staff Requirements Memo Re Commission Briefing in Washington,Dc on Status of Facility Project stage: Other ML20207K5121986-11-13013 November 1986 Fort St Vrain Calculations for Circulator Temp-Related Operating Limits Project stage: Other ML20207K5011986-12-0404 December 1986 Effect of Firewater Cooldown Using Economizer-Evaporator- Superheater (EES) Bundle on Steam Generator Structural Integrity. Draft Rept of Steam Generator Ability to Withstand post-App R Firewater Cooldown Transient Encl Project stage: Draft Other ML20207K4461986-12-12012 December 1986 Issue a to Effect of Firewater Cooldown Using Reheater on Steam Generator Structural Integrity Project stage: Other ML20211N3681986-12-12012 December 1986 Forwards Restart Interaction Schedule,Per 861205 Request Project stage: Other ML20207K5061986-12-22022 December 1986 Issue a to Effect of Intentional Depressurization on Cooldown from 39% Power Using One Reheater Module (1-1/2 H Delay) Project stage: Other ML20207K4411986-12-23023 December 1986 Issue a to Economizer-Evaporator-Superheater (EES) Cooldown from 39% & 78% Power Using Condensate or Firewater (1.5 H Delay) Project stage: Other ML20207K3861986-12-30030 December 1986 Forwards Analyses Supporting Power Operation Up to 39% Power Based on Safe Shutdown Cooling Following 90 Min Interruption of Forced Circulation.Conclusions of Repts Listed.Corrective Actions for LERs 86-020 & 86-026 Also Listed Project stage: Other ML20207P7791987-01-0707 January 1987 Forwards Current Integrated Schedule for Restart & Power Ascension Activities.Schedule Incorporates Consolidated Schedular Info on Both Interaction Activities.Updates Will Be Provided Twice Per Month.W/One Oversize Graph Project stage: Other ML20207P9931987-01-13013 January 1987 SAR for Tech Spec Limiting Condition for Operation 4.3.1 Change Permitting Safe Shutdown Cooling W/Evaporator- Economizer-Superheater Project stage: Other ML20207P9911987-01-15015 January 1987 Proposed Tech Specs,Requiring Both evaporator-economizer Superheater Sections & Both Reheater Sections to Be Available During Operation at Power as Min Number of HXs Project stage: Other ML20207P9891987-01-15015 January 1987 Application for Amend to License DPR-34,requiring Both evaporator-economizer Superheater Sections & Both Reheater Sections to Be Available During Operation at Power as Min Number of Operable HXs Project stage: Request ML20207P9871987-01-15015 January 1987 Forwards Application for Amend to License DPR-34,changing Tech Specs to Require Both evaporator-economizer Superheater Sections & Both Reheater Sections to Be Available During Operation at Power.Fee Paid Project stage: Request ML20211E1101987-01-26026 January 1987 Rev a to Engineering Evaluation of Procedure to Recover from Actuation of Steam Line Rupture Detection/Isolation Sys for Power Levels Through P2 Project stage: Other IR 05000267/19870021987-01-30030 January 1987 Partially Withheld Insp Rept 50-267/87-02 on 870106-09 (Ref 10CFR73.21).No Violations or Deviations Noted.Major Areas Inspected:Matl Control & Accounting Project stage: Request ML20210A7571987-01-30030 January 1987 Fort St Vrain 1987 Power Ascension Plan Project stage: Other ML20210A7481987-01-30030 January 1987 Requests Concurrence to Start Up & Operate Facility Through Graduated Rise to Power Up to 100% of Rated Power,Subj to Listed Constraints. Fort St Vrain 1987 Power Ascension Plan Encl Project stage: Other ML20210A7401987-02-0202 February 1987 Forwards Updated Nrc/Public Svc Co of Colorado Restart Interaction Schedule, Reflecting Current Target Dates & Recently Completed Items Project stage: Other ML20209G0431987-02-0202 February 1987 Forwards Current Integrated Schedule for Plant Restart & Power Ascension Activities.W/One Oversize Encl Project stage: Other ML20210N8831987-02-0303 February 1987 Forwards Request for Addl Info on 861230 & 870115 Submittals Re Analysis of Firewater Cooldown from 82% of Full Power Project stage: RAI ML20210P0191987-02-0505 February 1987 Summary of 870113 Meeting W/Util Re Completion of Equipment Qualification Program & Program & Approvals Required for Plant Restart Project stage: Meeting ML20210T6861987-02-0505 February 1987 Rev a to Engineering Evaluation of Reanalysis of FSAR Accidents/Transients Relying on EES Cooling. W/Four Oversize Drawings Project stage: Other ML20211D9921987-02-0505 February 1987 Issue a to Economizer-Evaporator-Superheater Cooldowns for Equipment Qualification & App R Events W/Vent Lines (1.5 H Delay) Project stage: Other ML20210T6551987-02-0606 February 1987 Provides Results of Confirmatory Analyses for FSAR Accidents Which Utilize Either EES or Reheater Section of Steam Generator for DHR Project stage: Other ML20210T4361987-02-11011 February 1987 Requests Publication of Fr Notice of Consideration of Issuance of Amend to License DPR-34 & Proposed NSHC Determination & Opportunity for Hearing on 870115 Request Re Operation of evaporator-economizer-superheater Sections Project stage: Other ML20211E9791987-02-12012 February 1987 Forwards Proposed Agenda & Slides for 870226 Meeting W/ Commission & Staff to Secure Commission Approval for Full Power Operation of Facility Project stage: Meeting ML20211D8901987-02-17017 February 1987 Forwards Response to NRC 870203 Request for Addl Info Re Firewater Cooldown from 82% of Full Power,Per Util 861230 & s Project stage: Request ML20207Q7941987-03-0303 March 1987 Forwards Second Request for Addl Info Re Util Analysis of Firewater Cooldown from 82% of Full Power Operation,Based on Review of 861230,870115 & 0217 Submittals Project stage: Approval ML20212M1021987-03-0505 March 1987 Forwards Assessment of Addl Concerns Per 870226 Request Re Restart of Facility.Events & Circumstances Involving Contracts Had No Adverse Impacts Re Plant Safety or Safe Plant Operations Project stage: Other ML20204G9241987-03-20020 March 1987 Forwards Restart & Power Ascension Schedule,Incorporating Consolidated Schedular Info on NRC-util Interaction Activities.Brief Narrative Description of Scope of Each Line Item Activity Also Encl.W/One Oversize Encl Project stage: Other ML20205B3441987-03-20020 March 1987 Forwards Response to NRC 870303 Second Request for Addl Info Re Firewater Cooldown from 82% of Full Power (Safe Shutdown Cooling) Project stage: Request ML20205M8901987-03-30030 March 1987 Forwards Third Request for Addl Info Re Util 861230,870115 & 0217 Submittals Concerning Analysis of Firewater Cooldown from 82% of Full Power.Major Concerns Re Effects of Transient Loading Due to Seismic Motion or Flow Project stage: RAI ML20205T1701987-04-0101 April 1987 Forwards Oversize Current Integrated Schedule for Facility Restart & Power Ascension Activities Required for Equipment Qualification Completion Certification,Startup/Plant Criticality & Power Ascension to 82%.Related Info Encl Project stage: Other ML20206B6031987-04-0101 April 1987 Forwards Comments Re Implication of Chernobyl Reactor Accident.Design Differences Between Fort St Vrain & Chernobyl Preclude Accident Similar to Chernobyl from Occurring at Fort St Vrain Project stage: Approval ML20206B4591987-04-0303 April 1987 Forwards Summary of Equipment Qualification (EQ) Insp Conducted by NRR & IE on 870126-30.EQ Program Approved. Detailed Results of Insp Will Be Provided Project stage: Other ML20206B3291987-04-0707 April 1987 Submits Daily Highlight.Public Svc Co of Colorado Authorized to Restart & Operate Facility HTGR at Level of Up to 35% Full Power.Facility Out of Operation Since 860531,when Shut Down for Equipment Qualification Mods Project stage: Other ML20206F8871987-04-10010 April 1987 Submits Requested Addl Info for Analysis of Firewater Cooldown for 82% Power Operation,Per Project stage: Other ML20209E3291987-04-27027 April 1987 Provides Written Authorization to Operate Reactor at Up to 35% Full Power,Per Section IV of 870406 Confirmatory Order Modifying License DPR-34 Project stage: Other ML20215H9641987-04-30030 April 1987 Forwards Updated Ga Technologies Procedure 909410, Buckle Users Manual, Per 870330 Request.Manual Updated to Include Revs to Computer Code Required by High Temps & Short Times Assumed for Steam Generator Tube Stress Analysis Project stage: Other ML20215H9731987-04-30030 April 1987 Revised Buckle Users Manual:Creep Collapse of Thin-Walled Circular Cylindrical Shells Subj to Radial Pressure & Thermal Gradients Project stage: Other ML20215J8711987-05-0404 May 1987 Rev a to Evaluation of Test Data for Confirmation of Fire Water Flow Rate to Circulator Water Turbine During EES Cooldown for Safe Shutdown Cooling Project stage: Other ML20215J8551987-05-0404 May 1987 Forwards Rev a to EE-EQ-0057, Evaluation of Test Data for Confirmation of Fire Water Flow Rate to Circulator Water Turbine During EES Cooldown for Safe Shutdown Cooling Project stage: Other 1987-01-07
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Category:SAFETY EVALUATION REPORT--LICENSING & RELATED ISSUES
MONTHYEARML20141K9961997-05-0505 May 1997 Safety Evaluation Supporting Amend 89 to License DPR-34 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 ML20246J3261989-08-30030 August 1989 Safety Evaluation Supporting Amend 72 to License DPR-34 ML20245J3781989-08-14014 August 1989 Safety Evaluation Supporting Amend 71 to License DPR-34 ML20245J4511989-08-0808 August 1989 Safety Evaluation Responding to Issues Re Tech Spec Upgrade & Plant Defueling.Stated Tech Spec Sections Should Be Upgraded ML20246J3131989-07-0707 July 1989 Safety Evaluation Concluding That Operators Role in Mitigating High Energy Line Break at Facility Acceptable ML20247R2261989-05-26026 May 1989 Final Safety Evaluation Re LER 87-20 Concerning Interactions Between Steamline Rupture Detection/Isolation Sys,Plant Protective Sys & Control Sys at Facility ML20245C5031989-04-18018 April 1989 Safety Evaluation Supporting Amend 70 to License DPR-34 ML20248D6501989-03-31031 March 1989 Safety Evaluation Supporting Amend 69 to License DPR-34 ML20236A1401989-02-27027 February 1989 Safety Evaluation Supporting Amend 68 to License DPR-34 ML20235T4511989-02-24024 February 1989 Safety Evaluation Re Facility Core Support Flow Vent Sys. Continued Operation of Facility W/Current Core Support Flow Sys Configuration Acceptable ML20235J3421989-02-16016 February 1989 Safety Evaluation Supporting Util Action in Response to Generic Ltr 83-28,item 2.1 (Part 2) Confirming Establishment of Interface W/Either NSSS Vendor or Vendors of Each Component in Reactor Trip Sys ML20235J3841989-02-13013 February 1989 Safety Evaluation Concluding That Continued Operation of Facility Not Affected by Steam Generator Tube Failures Experienced by Advanced gas-cooled Reactors ML20195D3911988-10-27027 October 1988 Safety Evaluation Supporting Corrective Actions of LER 86-017 ML20205G0021988-10-24024 October 1988 Safety Evaluation Supporting Amend 65 to License DPR-34 ML20154J8021988-09-15015 September 1988 Safety Evaluation Supporting Amend 64 to License DPR-34 ML20154J4621988-09-15015 September 1988 Safety Evaluation Supporting Amend 63 to License DPR-34 ML20207F0571988-08-10010 August 1988 Safety Evaluation Supporting Util 870206 Submittal Re Safe Shutdowns During Postulated Accident Conditions ML20207F0431988-08-0505 August 1988 Safety Evaluation Supporting Amend 61 to License DPR-34 ML20207F2411988-08-0505 August 1988 Safety Evaluation Supporting Amend 62 to License DPR-34 ML20151M1601988-07-21021 July 1988 Safety Evaluating Supporting Requirements for Redundancy in Responding to Rapid Depressurization Accident ML20151A9961988-06-20020 June 1988 Safety Evaluation Supporting Amend 60 to License DPR-34 ML20195K0651988-06-15015 June 1988 SER Concurring W/Util Proposed Corrective Actions in Engineering Rept Entitled, Rept of Helium Circulator S/N 2101 Damage & Inlet Piping S/N 2001 Repair & Mod Activities ML20195F9661988-06-15015 June 1988 Safety Evaluation Re Destructive Exam Rept for Fuel Test Assembly-2.Fuel Represented by Fuel Test Assembly-2 Predicted to Be Safe for Operation in Facility for 1,800 EFPDs ML20154F8891988-05-10010 May 1988 Safety Evaluation Re Proposed Safe Shutdown Sys & Exemption Requests Concerning 10CFR50,App R.Licensee Request for Exemptions in Listed Areas Should Be Granted.Concept for Providing post-fire Shutdown Acceptable ML20148S6031988-04-0707 April 1988 Safety Evaluation Supporting Amend 59 to License DPR-34 ML20151B6651988-04-0101 April 1988 Supplemental Safety Evaluation Supporting Util Compliance w/10CFR50.App R Re Safe Shutdown DHR Capacity ML20150C4541988-03-10010 March 1988 Safety Evaluation Concluding That Seismic Analysis Methods for Bldg 10 & Walkover Structure Conservative.Gaps Provided Adequate to Accommodate Relative Motions Which Occur Between Subj Structures & Walkover Structure & Turbine Bldg ML20147C8181988-02-25025 February 1988 Safety Evaluation Supporting Changes to Interim Tech Specs 3/4.1.7, Reactivity Change W/Temp NUREG-1220, Safety Evaluation Accepting Plant Special Senior Licensed Fuel Handler Initial & Requalification Operator Training Program,Per NUREG-1220, Training Review Criteria & Procedures1988-01-13013 January 1988 Safety Evaluation Accepting Plant Special Senior Licensed Fuel Handler Initial & Requalification Operator Training Program,Per NUREG-1220, Training Review Criteria & Procedures ML20237D7631987-12-18018 December 1987 Safety Evaluation Updating 861118 Fire Protection Sys Safety Evaluation.Util Alternate Fire Protection Configuration Acceptable ML20149E1621987-12-18018 December 1987 Marked-up Safety Evaluation Re Proposed Safe Shutdown Sys & Exemption Requests Concerning 10CFR50,App R ML20236U6961987-11-23023 November 1987 Safety Evaluation Supporting Amend 57 to License DPR-34. Addendum to Review of Proposed Tech Spec Change:Core Inlet Valves/Min Helium Flow & Max Core Region Temp Rise,Limiting Condition for Operation..., Technical Evaluation Rept Encl ML20236U5761987-11-20020 November 1987 Safety Evaluation Re Helium Circulator S/N C-2101 Damage. Util Corrective Action Program Initiated ML20236R3001987-11-13013 November 1987 Safety Evaluation Supporting Util Responses to Generic Ltr 83-28,Item 2.2.1 Re Equipment Classification Programs for All safety-related Components ML20238C7621987-09-0202 September 1987 Safety Evaluation Concurring W/Util 870702 & 27 Ltrs & 870818 Telcon Re Elimination or Reduction of Maint Requirements on Certain Fire Seals ML20235N6491987-07-13013 July 1987 Safety Evaluation Supporting Amend 56 to License DPR-34 ML20235F5281987-07-0202 July 1987 Safety Evaluation Re Safe Shutdown of Steam Generator Matls. Under Severe Transient Conditions,Fuel Temp Can Be Maintained Under Accepted Temp Limits & Plant Can Be Safely Shutdown ML20235F5151987-07-0202 July 1987 Safety Evaluation Re Safe Emergency Shutdown of Reactor Sys. Operation at 82% Acceptable ML20235F5441987-07-0202 July 1987 Safety Evaluation Re Effect of Firewater Cooldown on Steam Generator Structural Integrity.All Tests Acceptable ML20235E5281987-06-29029 June 1987 Safety Evaluation Supporting Amend 55 to License DPR-34 ML20216G9511987-06-24024 June 1987 Revised Safety Evaluation Re Steam Line Rupture Detection & Isolation Sys (Slrdis).Slrdis Meets Requirements of 10CFR50, App A,Gdc 20 & GDC 4 ML20216G9911987-06-24024 June 1987 Supplemental Safety Evaluation Supporting Application for Amend to License DPR-34 Re Tech Specs for Steam Line Rupture Detection & Isolation Sys ML20215J5401987-06-22022 June 1987 Draft Safety Evaluation Re Safe Emergency Shutdowns.Facility Operation at 82% Power Acceptable ML20216J1921987-06-17017 June 1987 Safety Evaluation Re Mods to Reduce Moisture Ingress Into Reactor Vessel.Periodic Insps & Preventive Maint Should Be Performed on Pertinent Components.Operational Performance Should Be Continuously Upgraded ML20214M4681987-05-20020 May 1987 Safety Evaluation Supporting Amend 54 to License DPR-34 ML20215J8271987-05-0505 May 1987 Safety Evaluation Supporting Amend 53 to License DPR-34 ML20209D7561987-04-22022 April 1987 Safety Evaluation Supporting Util 870211 Submittal Re Performance Enhancement Program,Finding 4-10 ML20206J9331987-04-0606 April 1987 Safety Evaluation Supporting Amend 52 to License DPR-34 ML20205S1141987-03-31031 March 1987 Safety Evaluation Accepting Util 831104 Response to Generic Ltr 83-28,Item 4.5.2, Reactor Trip Sys Reliability On-Line Testing. Facility Designed to Permit on-line Functional Testing,Including Testing of Reactor Trip Contactors 1997-05-05
[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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Enclosure 1 SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATING TO SAFE EMERGENCY SHUT 00WNS (REACTOR SYSTEMS)
PUBLIC SERVICE COMPANY OF COLORADO FORT ST. VRAIN NUCLEAR GENERATING STATION DOCKET NO. 50-267
- 1. 0 INTRODUCTION In Fort St. Vrain License Event Report (LER) #86-026, dated October 17, 1986, the Public Service Company of Colorado (PSC) reported that the Safe Shutdown
' Cooling System for removing the decay heat following the postulated " Design Basis Earthquake" or " Maximum Tornado" accidents was inadequate. PSC stated in this LER that if one of these two accidents were to occur while the reactor was operating at 105% power, and if, as postulated in Section 10.3.9 of the FSAR, the functions of all non-seismic, non-Category 1 components were lost and the primary helium coolant flow was assumed interrupted for 90 minutes to allow for manual realignments, the safe shutdown cooling system would be unable to keep the fuel temperature below the 2900' F limit.
Further this LER states that the analysis for the removal of decay heat by the Safe Shutdown Cooling System, "did not consider firewater pump capacity nor the associated steam generator inlet or discharge piping configurations." j For the corrective action in the LER, the PSC committed to reanalyzing this Safe Shutdown Cooling System and providing an acceptable method to remove the decay heat and cool the plant without fuel temperatures exceeding 2900*F. ]
In the two-loop Fort St. Vrain plant each loop has six steam generator modules which have parallel secondary coolant flow paths. Each steam generator has two sections, i.e., an economizer-evaporator-superheater '
(EES) section and a reheater section.
The reheater sections of the steam generators are much smaller than the EES l sections; so their use seemed logical for removing the smaller decay heat load. However, the reheaters are designed for steam, not water, so their 4 cross sectional flow area is relatively high. The consequence of this is that the firewater pumps have only enough flow capacity to flood one or two reheater sections, rather than all six as previously assumed. PSC's re-analysis showed that this partial flooding would not provide enough heat transfer area; so PSC concluded that the reheater sections should not be used for the Safe Shutdown Cooling.
Instead, PSC proposed to use the EES sections by initially venting them to the atmosphere. However, the available vent path was not redundant or seismically qualified, so new 6 inch vent lines had to be installed. Even 8707130423 870702 7 DR ADOCK 050
(
1 l'
. s
+ . j e l l
with these new vent lines PSC found that the fuel temperature could not be l kept below the 2900 F limit for the Safe Shutdown Cooling accident scenario from 105% reactor power.
PSC had analyses done to determine from what power level safe, emergency shutdowns could be accomplished for all of these accident scenarios. These analyses, which PSC submitted to the NRC, showed that, depending on the accident scenario, the fuel temperature can be kept below the 2900 F limit during emergency shutdowns after long-term operation at power levels up to and including 82 percent power.
- 2. 0 EVALUATION l l
The NRC had the Oak Ridge National Laboratory evaluate all of these sub-mittals. The technical evaluation report (TER) on this evaluation is Enclosure 4. Three parts of the TER pertain to this Safety Evaluation (SE).
The fourth part, which is on possible structural and metallurgical failures in the steam generators, is the subject of a separate safety evaluation.
The NRC staff has reviewed the ORNL TER and agrees with ORNL's evaluations l and conclusions, except as addressed below.
l The first of the three parts is the evaluation of the calculations of the maximum fuel temperature that will be obtained after these postulated accidents. This evaluation was made by using the Oak Ridge developed ORECA
! computer program to independently calculate these temperatures. As can be i
seen in the TER the ORECA calculations show that 82% is a conservative power l level for a limiting fuel temperature of 2900 F. We concur with this finding in the ORNL TER that the 82% power limit proposed by the licensee l is acceptable.
The second of the three parts in the ORNL TER that pertain to this SE is the evaluation of the ability of the existing systems to supply sufficient water flow to both the helium circulator pelton wheel drives and the EES sections of the steam generators during these emergency cooldowns. The final con-clusion of this lengthy review is that for these scenarios, "there is substantial margin in the existing cooling systems to provide-for a safe shutdown." This conclusion is contingent on several items, two of which with we concur and restate as follows:
- 1. There are operating procedures for these accidents and that the operators have been trained to follow them.
- 2. PSC should perform an explicit analysis to demonstrate that the original Class I firewater flow path can accommodate a single active failure in the new Class I firewater flow path when the required EES pre-cooling times and the long term cooling are accounted for.
Another contingency in the ORNL TER findings is for the NRC to perform an audit or do confirmatory analyses of the PSC flow calculations. However, the staff believes that with the satisfactory agreement between PSC's cal-culated results and the results of the firewater flow test, which are m
s.
y reported in Reference 2 and mentioned on page 7 of the TER, no confirmatory I analyses are required. (However, the staff has requested NRC Region IV to (
perform an audit of the licensee's independent verification of these ;
i calculations.) l The remaining contingency in the TER findings and conclusions is concerned with a passive failure after 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> of cooling. However, PSC's calcu-I lations show that after 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> of cooling adequate flow can be obtained from a redundant flow path. Based upon these calculations, the staff finds that a passive failure can be accommodated.
t By letter dated June 24, 1987, the licensee has stated that: l (1) operating procedures have been provided for the postulated " Design Basis Earthquake," " Maximum Tornado," and " Appendix R Fire" accidents and the operators are trained to follow them; and (2) all of the redundant firewater flow paths can accommodate a single active failure up to 83.2 percent power. (This includes EES pre-cooling times and long-term cooling.)
On this basis we conclude that the first, second, and fourth conditions described above provide an acceptable basis to satisfying the requirements of the second part of the ORNL TER, and that the licensee has shown that the existing systems can supply sufficient water during emergency cooldowns.
The third of the three parts in the TER that pertain to this SE is the evaluation of the possibility of water hammer that would prevent these emergency cooldowns. The ORNL TER agrees with the licensee's con-clusions that a water hammer is unlikely because of the steam generator design, and water hammer forces would be reduced by the restriction of the tube entrances. The staff further notes that steam generator modules are designed for an inlet pressure of about 3180 psia (Table 4.2-7 of the FSV FSAR). By contrast, the firewater pumps have a total design head of only 140 psia (Section 9.12.3.3 of the FSV FSAR).
It is difficult to conceive how the low pressure output of the pump can cause damage to a system designed for over 20 times that pressure.
Hence, the staff concludes that it is highly unlikely that a water hammer )
will preclude a safe shutdown. ;
3.0 CONCLUSION
S The staff finds that the Fort St. Vrain reactor can be shutdown after prolonged operation at 82 percent of the licensed power without having the fuel temperature exceed the 2900* F limit. Thus the staff finds that operation at 82 percent power is acceptable.
d
4.0 REFERENCES
- 1. SECY-77-439 dated August 17, 1979.
- 2. Letter from H. L. Brey, Public Service Company of Colorado, to J. A. Calvo, USNRC, dated May 4, 1987.
Principal contributor: E. Lantz, RSB Dated: July 2,1987 1
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