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Safety Evaluation Supporting Elimination of Arbitrary Intermediate Pipe Breaks in Feedwater SysML20127G742 |
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Vogtle |
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Issue date: |
06/13/1985 |
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NRC |
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Shared Package |
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ML20127G736 |
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References |
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NUDOCS 8506260059 |
Download: ML20127G742 (2) |
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Category:SAFETY EVALUATION REPORT--LICENSING & RELATED ISSUES
MONTHYEARML20206A6561999-04-21021 April 1999 Safety Evaluation Authorizing Licensee Re Rev 9 to First 10-year ISI Interval Program Plan & Associated Requests for Relief (RR) 65 from ASME Boiler & Pressure Vessel Code ML20202H9851999-01-29029 January 1999 Safety Evaluation Accepting Rev 8 to First 10-year Interval Inservice Insp Program & Associated Requests for Relief for Vogtle Electric Generating Plant,Unit 1 ML20198S1781998-12-31031 December 1998 SER Re Second 10-year Interval Inservice Insp Program Plan & Associated Requests for Relief for Southern Nuclear Operating Co,Inc Units 1 & 2 ML20217H7181998-04-0101 April 1998 Corrected Page 5 to 980324 SER Re Relief Requests Associated W/Second 10-year Interval Insp program.RR-21 in Error in That Component,Suction Damper Inadvertently Omitted. Corrected Page 7 of Technical Ltr Rept Also Encl ML20217B8831998-03-24024 March 1998 SER Accepting Relief Request RR-5,RR-19,RR-20,RR-21,RR-23 & RR-24 for Second 10-yr Interval ISI Program Plan ML20203H9551998-02-23023 February 1998 SER Denying Quality Assurance Program Description Change for Vogtle Electric Generating Plant,Units 1 & 2 ML20203C2811997-12-0909 December 1997 Safety Evaluation Authorizing Request for Relief of Second 10 Yr Interval Inservice Insp Program ML20198T3621997-10-24024 October 1997 Safety Evaluation Authorizing Supporting Second 10-year Interval ISI Program Requests for Relief RR-17 & RR-25 as Submitted by Southern Nuclear Operating Co on 970529 ML20210R2071997-08-27027 August 1997 Safety Evaluation Accepting Relief Requests for Pump & Valve Inservice Testing Program ML20058A3041993-11-19019 November 1993 Safety Evaluation Re Accumulator Pressure & Vol Instrumentation of Reg Guide 1.97 Environ Qualification Requirements,Per Generic Ltr 82-33.Category 3 Qualification of Instrumentation Acceptable ML20062J8641993-11-10010 November 1993 Safety Evaluation Denying Licensee 920617 Request for Amends to License Changing TS 3/4.6.1.7 & 4.6.1.2f for Plant ML20059J0061993-11-0303 November 1993 Safety Evaluation Supporting Rev 15 to Emergency Plan for Plant ML20057F8291993-10-12012 October 1993 Safety Evaluation Accepting Util Submittals of Rev 7 to IST Program for Unit 1 & Rev 4 to IST Program for Unit 2 ML20057E3021993-10-0404 October 1993 Safety Evaluation Accepting Proposed Changes to EAL in Rev 15 of Plant Emergency Plan ML20056H6441993-08-26026 August 1993 Safety Evaluation Denying TS Change for Surveillance of Emergency Core Cooling Sys ML20127B7051993-01-0606 January 1993 Safety Evaluation Supporting Rev 4 to First 10-yr Interval Inservice Insp Program for Facility ML20127B6901993-01-0606 January 1993 Safety Evaluation Supporting Rev 5 to First 10-yr Interval Inservice Insp Program for Facility ML20126F3331992-12-23023 December 1992 Safety Evaluation Accepting Licensee Schedule for Completing MOV Testing Program in Response to GL 89-10 ML20059E9171990-08-31031 August 1990 SER Supporting Util 890928 Request for Exemption from 10CFR20,App a & Authorizing Use of Radioiodine Protection Factor for Sorbent Canisters ML20206L6491988-11-22022 November 1988 Supplemental Safety Evaluation Concluding That Commitment & Schedule Re 14 Open Items Concerning SPDS Acceptable. Commitment to Complete 1000 H Availability Test by 881231 Acceptable.Requirements of License Condition 2.C.7(b) Met ML20155C9901988-10-0303 October 1988 Safety Evaluation Concluding That ATWS Design Proposed by Util Meets 10CFR50.62 Requirements,Subj to Successful Completion of Certain Noted Human Factors Engineering Reviews ML20151E0421988-07-18018 July 1988 Sser Supporting Electrical Cable & Raceway Configurations for Plant ML20236S5251987-11-20020 November 1987 Safety Evaluation Supporting Util 870121,0522,0720 & 0929 Submittals Re Seismic Adequacy for Spent Fuel Pool Racks ML20236D2941987-10-28028 October 1987 Safety Evaluation Supporting Fire Suppression Sys Changes for Facility ML20236A8521987-10-15015 October 1987 Safety Evaluation Concluding That Util 870713,0930 & 1015 Submittals in Support of License Condition 2.C(8) Provide Acceptable Justification That Inorganic Zinc Coating on Fuel Oil Storage Tanks Will Not Adversely Affect Generators ML20235S8101987-10-0707 October 1987 Safety Evaluation Supporting Proposed Redesign of Steam Generator Upper Support of Reactor Coolant Loop Sys for Unit 2 & Proposed Revised FSAR ML20235G7371987-09-22022 September 1987 Safety Evaluation Supporting Rev 2 to Inservice Testing Program,Providing Cold Shutdown Valve Testing Justifications & Addl Relief Requests ML20237H3011987-08-19019 August 1987 Safety Evaluation Accepting 870601 Proposed Deletion of Electrical Penetration Filter & Exhaust Sys NUREG-1137, Safety Evaluation Supporting Util 870601 Proposal Re Pipe Break Criteria Used for Flooding Analyses & Addition of Moderate Energy non-seismic Category I Piping to Exceptions List.Nrc Does Not Entirely Agree W/Util Justification1987-08-14014 August 1987 Safety Evaluation Supporting Util 870601 Proposal Re Pipe Break Criteria Used for Flooding Analyses & Addition of Moderate Energy non-seismic Category I Piping to Exceptions List.Nrc Does Not Entirely Agree W/Util Justification ML20236H1151987-07-30030 July 1987 Safety Evaluation Supporting Util long-term Proposal for Support of Cable in Vertical Cable Trays Through Use of Stainless Steel Cable Ties ML20236F3591987-07-29029 July 1987 Safety Evaluation Re Util Response to Generic Ltr 83-28,Item 2.1 Re Identification of safety-related Reactor Trip Sys Components.Util Response Adequate ML20235J9441987-07-0707 July 1987 Safety Evaluation Supporting Supplemental Responses to Generic Ltr 83-28,Items 3.1.1,3.1.2,3.2.1,3.2.2 & 4.5.1 Per NUREG-1000 ML20212F5381987-01-0808 January 1987 Safety Evaluation of Water Hammer Events & Corrective Actions Taken to Ensure Nuclear Svc Water Cooling Water Sys Integrity & long-term Operability.Sys Functional Integrity & long-term Operability Capability Adequate ML20214P3971986-09-15015 September 1986 SER Supporting Environ Qualification of Asco Solenoid Valves ML20205F2731986-08-0808 August 1986 Safety Evaluation Re Operability & Reliability of Tdi Emergency Diesel Generators.Submittal Concludes Technical Resolution of Generic Tdi Generator Issues ML20215A7521986-07-0707 July 1986 SER Supporting Util 860523 Proposed Changes to Tech Specs Re Reactor Trip Sys Instrumentation & Surveillance in Response to Generic Ltr 85-09.SALP Input Also Encl ML20215A9671986-05-22022 May 1986 SER Re Util 851207 Proposed Changes to Tech Specs Pertaining to Reactor Trip Sys Instrumentation & Surveillance,Per Generic Ltr 85-09.Proposed Tech Specs Should Be Submitted for Review,Per Generic Ltr.Salp Input Also Encl ML20215A7821986-05-0808 May 1986 Sser Re Util Response to Generic Ltr 83-28,Item 4.3, Reactor Trip Breaker Automatic Shunt Trip. Licensee Should Submit Proposed Tech Specs Consistent W/Generic Ltr 85-09 Guidance for NRC Review.Salp Input Also Encl ML20215G1131986-04-11011 April 1986 SER Re Util 830414,850315,0620,0906 & 860121 Responses to Reg Guide 1.97.Design Acceptable W/Respect to Conformance to Reg Guide 1.97,Rev 2,w/exception of Containment Sump Water Temp ML20127G7421985-06-13013 June 1985 Safety Evaluation Supporting Elimination of Arbitrary Intermediate Pipe Breaks in Feedwater Sys 1999-04-21
[Table view] Category:TEXT-SAFETY REPORT
MONTHYEARML20217K4591999-09-30030 September 1999 Monthly Operating Repts for Sept 1999 for Vogtle Electric Generating Plant,Units 1 & 2.With ML20217K8041999-09-30030 September 1999 Rev 1 to Vegp,Unit 2 Cycle 7 Colr ML20217K7741999-09-30030 September 1999 Rev 1 to Vegp,Unit 1 Cycle 9 Colr ML20216E5061999-08-31031 August 1999 Monthly Operating Repts for Aug 1999 for Vegp,Units 1 & 2. with ML20210P9841999-07-31031 July 1999 Monthly Operating Repts for July 1999 for Vogtle Electric Generating Plant,Units 1 & 2.With ML20209H1211999-06-30030 June 1999 Monthly Operating Repts for June 1999 for Vogtle Electric Generating Plant,Units 1 & 2.With ML20196F9711999-05-31031 May 1999 Owner Rept for ISI for Vogtle Electric Generating Plant, Unit 1 Eighth Maint/Refueling Outage ML20195G1731999-05-31031 May 1999 Monthly Operating Repts for May 1999 for VEGP Units 1 & 2. with ML20206N2141999-04-30030 April 1999 Monthly Operating Repts for Apr 1999 for Vogtle Electric Generating Plant,Units 1 & 2.With ML20206A6561999-04-21021 April 1999 Safety Evaluation Authorizing Licensee Re Rev 9 to First 10-year ISI Interval Program Plan & Associated Requests for Relief (RR) 65 from ASME Boiler & Pressure Vessel Code ML18016A9011999-04-12012 April 1999 Part 21 Rept Re Defect in Component of DSRV-16-4,Enterprise DG Sys.Caused by Potential Problem with Connecting Rod Assemblies Built Since 1986,that Have Been Converted to Use Prestressed Fasteners.Affected Rods Should Be Inspected ML20206C2291999-03-31031 March 1999 Revised Monthly Operating Repts for Mar 1999 for Vogtle Electric Generating Plant,Units 1 & 2 ML20205Q8081999-03-31031 March 1999 Monthly Operating Repts for Mar 1999 for Vegp,Units 1 & 2. with ML20205A9581999-03-31031 March 1999 Rev 0 to VEGP Unit 1 Cycle 9 Colr ML20207K6051999-02-28028 February 1999 Monthly Operating Repts for Feb 1999 for Vogtle Electric Generating Plant,Units 1 & 2.With ML20209H3951999-02-15015 February 1999 Rev 2 to ISI Program Second 10-Year Interval Vogtle Electric Generating Plant Units 1 & 2 ML20209H4091999-02-15015 February 1999 Rev 1 to ISI Program Second 10-Year Interval Vogtle Electric Generating Plant Units 1 & 2 ML20202H9851999-01-29029 January 1999 Safety Evaluation Accepting Rev 8 to First 10-year Interval Inservice Insp Program & Associated Requests for Relief for Vogtle Electric Generating Plant,Unit 1 ML20199F8041999-01-13013 January 1999 Corrected Pages to VEGP-2 ISI Summary Rept for Spring 1998 Maint/Refueling Outage ML20199E7561998-12-31031 December 1998 Monthly Operating Repts for Dec 1998 for Vogtle Electric Generating Plant,Units 1 & 2.With ML20198S1781998-12-31031 December 1998 SER Re Second 10-year Interval Inservice Insp Program Plan & Associated Requests for Relief for Southern Nuclear Operating Co,Inc Units 1 & 2 ML20196E5221998-12-0101 December 1998 Rev 8 to ISI-P-014, ISI Program for VEGP-2 ML20198B8571998-11-30030 November 1998 Monthly Operating Repts for Nov 1998 for Vogtle Electric Generating Plant,Units 1 & 2.With ML20195H2131998-10-31031 October 1998 Monthly Operating Repts for Oct 1998 for Vogtle Electric Generating Station,Units 1 & 2.With ML20154L5681998-09-30030 September 1998 Monthly Operating Repts for Sept 1998 for Vegp,Units 1 & 2 ML20151W3681998-08-31031 August 1998 Monthly Operating Repts for Aug 1998 for Vogtle Electric Generating Plant Units 1 & 2.With ML20154L5721998-08-31031 August 1998 Corrected Page from MOR for Aug 1998 for Vegp,Unit 2 ML20237D2051998-07-31031 July 1998 Monthly Operating Repts for July 1998 for Vogtle Electric Generating Plant Units 1 & 2 ML20236V3121998-07-29029 July 1998 Final Part 21 Rept Re Enterprise DSR-4 & DSRV-4 Edgs.Short Term Instability Was Found During post-installation Testing & Setup as Part of Design mod/post-work Testing Process. Different Methods Were Developed to Correct Problem ML20236P6991998-06-30030 June 1998 Monthly Operating Repts for June 1998 for Vogtle Electric Generating Plant,Units 1 & 2 ML20236Q3051998-06-30030 June 1998 Owner'S Rept for ISI for Sixth Maint/Refueling Outage of Vogtle Electric Generating Plant,Unit 2 ML20249A3911998-05-31031 May 1998 Monthly Operating Repts for May 1998 for Vogtle Electric Generating Plant ML20248A1671998-05-22022 May 1998 Interim Part 21 Re Enterprise DSR-4 & DSRV-4 Emergency diesel.Post-installation Testing Revealed,High Em/Rfi Levels Affected New Controllers,Whereas Original Controllers Were unaffected.Follow-up Will Be Provided No Later than 980731 ML20249A3931998-04-30030 April 1998 Revised MOR for Apr 1998 for Vogtle Electric Generating Plant Unit 1 ML20247F3841998-04-30030 April 1998 Monthly Operating Repts for Apr 1998 for Vogtle Electric Generating Plant,Units 1 & 2 ML20154Q9721998-04-20020 April 1998 10CFR50.59(B) Rept of Facility Changes,Tests & Experiments for Vogtle Electric Generating Plant,Units 1 & 2 ML20217H7181998-04-0101 April 1998 Corrected Page 5 to 980324 SER Re Relief Requests Associated W/Second 10-year Interval Insp program.RR-21 in Error in That Component,Suction Damper Inadvertently Omitted. Corrected Page 7 of Technical Ltr Rept Also Encl ML20216D6141998-03-31031 March 1998 Monthly Operating Repts for Mar 1998 for Vogtle Electric Generating Plant,Units 1 & 2 ML20217Q1301998-03-31031 March 1998 Rev 0 to Vepc Unit 2 Cycle 7,COLR ML20217B8831998-03-24024 March 1998 SER Accepting Relief Request RR-5,RR-19,RR-20,RR-21,RR-23 & RR-24 for Second 10-yr Interval ISI Program Plan ML20216E2421998-02-28028 February 1998 Monthly Operating Repts for Feb 1998 for Vogtle Electric Generating Plant,Units 1 & 2 ML20203H9551998-02-23023 February 1998 SER Denying Quality Assurance Program Description Change for Vogtle Electric Generating Plant,Units 1 & 2 ML20203E4831998-02-11011 February 1998 Rev 1 to Vogtle Electric Generating Plant,Units 1 & 2 Second Ten-Yr Interval Pump Inservice Test Program ML20198T1211998-01-31031 January 1998 Owners Rept for Inservice Inspection for Seventh Maintenance/Refueling Outage ML20202G5441998-01-31031 January 1998 Monthly Operating Repts for Jan 1998 for Vogtle Electric Generating Plant,Units 1 & 2 ML20199E5431998-01-31031 January 1998 Rev 3 to WCAP-14720, Vogtle Units 1 & 2 Spent Fuel Rack Criticality Analysis W/Credit for Soluble Boron ML20198L6471997-12-31031 December 1997 Monthly Operating Repts for Dec 1997 for Vogtle Electric Generating Plant,Units 1 & 2 ML20203C2811997-12-0909 December 1997 Safety Evaluation Authorizing Request for Relief of Second 10 Yr Interval Inservice Insp Program ML20202B7881997-12-0101 December 1997 Rev 8 to ISI-P-006, ISI Program for Gpc Vogtle Electric Generating Plant Unit 1 ML20203H0601997-11-30030 November 1997 Monthly Operating Repts for Nov 1997 for Vegp,Units 1 & 2 1999-09-30
[Table view] |
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i Enclosure i
V0GTLE ELECTRIC GENERATING PLANT UNITS 1 AND 2 SAFETY EVALUATION FOR ELIMINATING ARBITRARY INTERMEDIATE PIPE BREAKS IN FEEDWATER SYSTEMS I. INTRODUCTION In Reference 1 the applicant for the Vogtle plant, Georgia Power Co. (GPC),
, requested the NRC approval for adopting an alternate approach to the i existing guidelines in SRP 3.6.2 Branch Technical Position (BTP) MEB 3-1 regarding the postulation of intermediate pipe breaks (Ref. 2). The alternate approach proposed to eliminate from design considerations those
, breaks generally referred to as " arbitrary intermediate breaks" that are defined as those break locations, which, based on piping stress analysis 4
results, are below the stress and fatigue limits specified in BTP MEB 3-1 but are selected to provide a minimum of two postulated breaks between the terminal ends of a piping system. After reviewing the applicant's request, the staff approved the alternative pipe break criteria pro applicant except for the breaks in the main feedwater (FW) piping posed Ref. by(the
, 3). The applicant has now provided additional technical information regarding the safety features incorporated into the design of the Vogtle plant to minimize the potential for water hammer in the main FW system (Ref. 4). Reference 4 also discusses the stress analyses performed to ,
determine the effects of water hammer, and the ability of the piping system to withstand such a transient. The staff has reviewed the applicant's recent submittal (Ref. 4) and the FSAR.Section 10.4.7 and summarizes its findings below.
II EVALUATION OF THE APPLICANT"5 SUBMITTAL ON WATER HAMMER As stated in FSAR Section 10.4.7, the FW sys' tem is designed with features to preclude the potential for damaging flow instabilities (water hammer).
The Vogtle units have a steam generator (SG) design (Westinghouse Model F) that has top discharge feedrings with J-tubes. The applicant has described in Reference 4 the various features that minimize water hammer potential.
During normal power operation, approximately 92 per cent of the feedwater is supplied through the 16-inch main FW line, and the remainder is supplied through the 6-inch bypass (auxiliary) feedwater (AFW) line that has its own inlet nozzle on the SG. This split flow scheme provides a continuous flow
- through the bypass piping to the bypass nozzle which effectively prevents the backflow of steam or hot water from the SG. During heatup, cooldown and l hot standby (flow less than 15 per cent of rated flow and temperature less
- than 250*F), feedwater is supplied only through the 6-inch bypass (auxiliary) nozzle. Unheated feedwater, whether from the main FW system or from the auxiliary FW system, will be supplied to the SG through the 6-inch bypass auxiliary FW nozzle, thus reducing the likelihood of water hammer occurring j in the main FW piping and the SG main feed nozzle and feedring.
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I The arrangement of both the feedwater piping and the auxiliary FW system is such as to reduce the probability of draining the feedwater into the SG as described in Reference 4. Also, the applicant has introduced design features that will prevent or monitor backleakage. A check valve, located between the main FW' isolation valve and the main FW nozzle, will be closed to isolate the main FW nozzle when not in use. Temperature sensors are provided in the main and auxiliary FW system piping close to their respective nozzles so as to alann and alert the operator of backleakage so that prompt corrective action can be taken. Forward flow will be maintained through the 6-inch bypass nozzle as much as possible even during heatup, hot standby and cooldown. Temperature sensors are also provided on the discharge piping close to each auxiliary FW pump to alann and alert the operator of backleakage so that corrective action can be taken.
The applicant will perform preoperational testing (as stated in the FSAR Section 10.4.7) when it will use the plant operating procedures, and verify that the prescribed operating procedures for each unit do not result in water hammer in the main or auxiliary FW system.
III CONCLUSION Based on a review of the applicant's submittal (Ref. 4) regarding the special features built into the design and operation of the FW systems and the FSAR Section 10.4.7, the staff finds that there is a sufficient basis for concluding that an adequate level of safety exists in the applicant's provisions for minimizing the potential for water hammer in the FW systems. Therefore, the staff concludes that the pipe rupture postulation and the associated effects are adequately considered in the design of the Vogtle plant, and thus finds the proposed deviation from the SRP acceptable.
IV REFERENCES
- 1. Letter from D. O. Foster, GPC, to H. Denton, NRC, subject, Vogtle Electric Generating Plant, Units 1 & 2, Arbitrary Intermediate Pipe Breaks, April 26, 1984.
- 2. Standard Review Plan for the Review of Safety Analysis Reports for Nuclear Power Plants, NUREG-0800 (Rev. 1), July 1981.
- 3. Letter from T. M. Novak, NRC, to D. O. Foster, GPC, subject, Vogtle Electric Generating Plant, Units 1 and 2, Arbitrary Intermediate Pipe Breaks, June 28, 1984.
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- 4. Letter from D. O. Foster, GPC, to E. G. Adensam, NRC, subject, Vogtle Electric Generating Plant, Units 1 and 2, April 24, 1985.
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