Letter Sequence Other |
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Initiation
- Request, Request, Request, Request, Request, Request, Request, Request, Request, Request, Request, Request, Request, Request, Request, Request, Request, Request, Request, Request, Request, Request, Request, Request, Request, Request, Request, Request, Request, Request, Request
- Acceptance...
- Supplement, Supplement, Supplement, Supplement, Supplement, Supplement
Administration
- Withholding Request Acceptance, Withholding Request Acceptance, Withholding Request Acceptance, Withholding Request Acceptance, Withholding Request Acceptance, Withholding Request Acceptance, Withholding Request Acceptance, Withholding Request Acceptance, Withholding Request Acceptance, Withholding Request Acceptance, Withholding Request Acceptance, Withholding Request Acceptance, Withholding Request Acceptance, Withholding Request Acceptance
- Meeting, Meeting, Meeting, Meeting, Meeting, Meeting, Meeting, Meeting, Meeting, Meeting, Meeting, Meeting, Meeting, Meeting, Meeting, Meeting, Meeting, Meeting, Meeting, Meeting, Meeting, Meeting
Results
Other: ML070370281, ML073100027, ML073510180, ML080360067, ML080430700, ML080500171, ML080530256, ML081010450, ML081010451, ML081120502, ML081700294, ML081720078, ML081760295, ML082040065, ML082050462, ML082100425, ML082810470, ML083120308, ML083240224, ML083250083, ML090130718, ML090340528, ML090720951, ML090760630, ML091320366, ML092020345, ML092430520, ML092440518, ML092460495, ML092460496, ML092460497, ML092460498, ML092460500, ML092540483, ML092680057, ML12319A076, ML13044A498
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MONTHYEARML0711503712007-04-24024 April 2007 Technical Specifications (TS) Changes TS-431 and TS-418 - Extended Power Uprate (EPU) - Steam Dryer Evaluations Project stage: Request ML0712905652007-05-16016 May 2007 Withholding Information from Public Disclosure, Response to Nuclear Regulatory Commission (NRC) Request for Additional Information - Round 12 for Browns Ferry EPU: Supplemental to SBWB-64 Project stage: RAI ML0716303492007-06-15015 June 2007 Meeting with the Tennessee Valley Authority Concerning the Status of Browns Ferry Nuclear Plant, Units 1, 2 and 3, Steam Dryer Review Project stage: Meeting ML0718700242007-07-0303 July 2007 Technical Specifications (TS) Change TS-461 - Modification of Restart Large Transient Testing License Condition 2. (G) 2 - Supplement 1 Project stage: Request ML0717801902007-07-0505 July 2007 Request for Additional Information for Extended Power Uprate - Round 13 (TS-431 and TS-418 (TAC Nos. MD5262, MD5263, and MD5264) Project stage: RAI ML0719004762007-07-10010 July 2007 Meeting with the Tennessee Valley Authority (TVA) Concerning the Pending ACRS Meeting on the Browns Ferry Extended Power Uprate Project stage: Meeting ML0721501562007-07-18018 July 2007 Slides from Meeting with Tennessee Valley Authority on the Browns Ferry Power Uprate ACRS Presentation Project stage: Meeting ML0721303712007-07-27027 July 2007 Technical Specifications Changes TS-431 and TS-418, Extended Power Uprate - Steam Dryer Evaluations Project stage: Request ML0721400442007-08-0808 August 2007 Summary of Meeting with Tennessee Valley Authority on the Browns Ferry Power Uprate ACRS Presentation Project stage: Meeting ML0724805472007-08-31031 August 2007 Technical Specifications (TS) Changes TS-431 and TS-418 - Extended Power Uprate (EPU) - Response to Round 13 Request for Additional Information (RAI) - Containment Overpressure Project stage: Request ML0727606602007-10-0909 October 2007 Request for Additional Information for Extended Power Uprate - Round 14 (TS-418) Project stage: RAI ML0728902372007-10-18018 October 2007 Request for Withholding Information from Public Disclosure Concerning Round 13 Request for Additional Information for Browns Ferry Nuclear Plant (Tac Nos. MD5262, MD5263 and MD5264) Project stage: RAI ML0729603112007-10-22022 October 2007 Technical Specification (TS) Changes TS-431 & TS-418, Extended Power Uprate - EPU Large Transient Testing Project stage: Request ML0731000272007-11-0909 November 2007 Request for Schedule Regarding Analysis for Steam Dryers on Extended Power Uprate Amendment Requests (TAC Nos. MD5262, MD5263, and MD5264) (TS-431 and TS-418-S) Project stage: Other ML0732303482007-11-15015 November 2007 Units 1, 2, and 3 - Technical Specifications (TS) Changes TS-431 and TS-418 - Extended Power Uprate (EPU) - Response to Round 13 Request for Additional Information (RAI) - Containment Overpressure APLA-35/37 Project stage: Request ML0733304832007-11-21021 November 2007 Technical Specifications (TS) Changes TS-431 and TS-418 - Extended Power Uprate (EPU) - Response to Preliminary Findings on Steam Dryer Stress Analysis Project stage: Request ML0735101802007-12-14014 December 2007 Technical Specifications Changes TS-431 and TS-418 - Extended Power Uprate - Schedule Regarding Analysis for Steam Dryers Project stage: Other ML0734607572007-12-19019 December 2007 Request for Withholding Information from Public Disclosure for Browns Ferry Nuclear Plant (Tac No. MD5262, MD5263 and MD5264) Project stage: Withholding Request Acceptance ML0735400102008-01-25025 January 2008 Summary of Meeting with Tennessee Valley Authority on Steam Dryer Portion of the Extended Power Uprate Review (TAC Nos. MD5262, MD5263, and MD5264), Browns Ferry Units 1, 2, and 3 Project stage: Meeting ML0801504182008-01-25025 January 2008 Plants, Units 1, 2, and 3 - (Public Version) - Summary of December 10, 2007 Meeting with TVA on Steam Dryer Portion of the Extended Power Uprate Review Project stage: Meeting ML0803205212008-01-25025 January 2008 Technical Specifications (TS) Changes TS-431 and TS-418 - Extended Power Uprate (EPU) Response to Round 15 Request for Additional Information (RAI) - APLA-38/40, SRXB-71, and SRXB-72 Project stage: Request ML0803600672008-01-25025 January 2008 Steam Dryer RAI 15 Status, Slides Project stage: Other ML0802501652008-01-30030 January 2008 Request for Withholding Information from Public Disclosure for Browns Ferry Nuclear Plant (Tac Nos. MD5262, MD5263, and MD5264) Project stage: Withholding Request Acceptance ML0803805602008-01-31031 January 2008 Technical Specifications (TS) Change TS-431 and TS-418 - Extended Power Uprate (EPU) - Response to Round 15 Request for Additional Information (RAI) Regarding Steam Dryer Analyses Project stage: Request ML0804307002008-02-11011 February 2008 Technical Specifications (TS) Changes TS-431 and TS-418 - Extended Power Uprate (EPU) - Schedule Regarding EPU Project stage: Other ML0803503812008-02-14014 February 2008 Summary of Meeting with Tennessee Valley Authority - on Extended Power Uprate Review Project stage: Meeting ML0805302562008-02-21021 February 2008 Unit 1 - Technical Specifications (TS) Change TS-431 - Extended Power Uprate (EPU) - Fuels Methods Commitments Project stage: Other ML0806501012008-02-21021 February 2008 Response to Round 16 Request for Additional Information SRXB-73 Project stage: Request ML0804506472008-02-27027 February 2008 Request for Withholding Information from Public Disclosure Project stage: Withholding Request Acceptance ML0803506982008-02-29029 February 2008 Request for Additional Information for Extended Power Uprate - Round 16 (TS-431 and TS-418) (TACs MD5262, MD5263, MD5264) Project stage: RAI ML0807104982008-03-0606 March 2008 (BFN) - Units 1, 2, and 3 - Technical Specifications (TS) Change TS-418 and TS-431 - Extended Power Uprate (EPU) - Response to Round 16 Request for Additional Information (RAI) - SRXB-74/86 and SRXB-87 Through SRXB-90 Project stage: Request ML0811205102008-03-20020 March 2008 Summary of March 20, 2008, Meeting with Tennessee Valley Authority Regarding Steam Dryer Portion of the Extended Power Uprate Review (TAC Nos. MD5262, MD5263, and MD5264) - Slides Project stage: Meeting ML0810104512008-04-0404 April 2008 Technical Specifications (TS) Changes TS-431 and TS-418 Extended Power Uprate (EPU) BFN Steam Monitoring Plan Project stage: Other ML0810104502008-04-0404 April 2008 (BFN) - Units 1, 2, and 3 - Technical Specifications (TS) Changes TS-431 and TS-418 - Extended Power Uprate (EPU) - Response to Round 15 and Round 16 Requests for Additional Information (RAI) Regarding Steam Dryer Analyses Project stage: Other ML0817602952008-04-0909 April 2008 Units 1, 2, & 3 - Technical Specifications Changes TS-431 and TS-418 - Extended Power Uprate - Confirmation of Commitment Completions Project stage: Other ML0811205022008-04-16016 April 2008 CDI Incoming Letter Dated April 16, 2008 Regarding NRC Presentation Entitled, Tennessee Valley Authority Browns Ferry Nuclear Plant - Extended Power Uprate Steam Dryers. Project stage: Other ML0811302312008-04-17017 April 2008 Public Slides - Summary of April 17, 2008, Meeting Regarding Steam Dryer Portion of the Extended Power Uprate Review, Project stage: Meeting ML0811200332008-04-30030 April 2008 Accumulation in Emergency Core Cooling, Decay Heat Removal, and Containment Browns Ferry Nuclear Plant, Units 1, 2, and 3 - Request for Withholding Information from Public Disclosure for Round 15 Fuels Responses Project stage: Withholding Request Acceptance ML0812806272008-05-0101 May 2008 Technical Specifications Change TS-418, Extended Power Uprate Supplemental Response to Round 16 Request for Additional Information - SRXB-87 & SRXB-89 Project stage: Supplement ML0813502222008-05-0202 May 2008 Request for Additional Information for Extended Power Uprate - Round 17 (TS-431 and TS-410) Project stage: RAI ML0805001712008-05-0202 May 2008 - Schedule Regarding Analysis for Steam Dryers on Extended Power Uprate Amendment Requests (TAC Nos. MD5262, MD5263, and MD5264) (TS-431 and TS-418) Project stage: Other ML0812804712008-05-0202 May 2008 Request for Additional Information for Extended Power Uprate - Round 17 Project stage: RAI ML0813602912008-05-22022 May 2008 Summary of April 17, 2008, Meeting Regarding Steam Dryer Portion of the Extended Power Uprate Review Project stage: Meeting ML0815805532008-05-22022 May 2008 Summary of 5/22/08 Meeting Regarding Containment Overpressure Portion of the Extended Power Uprate Review - Browns Ferry - Handouts Project stage: Meeting ML0810604452008-06-0202 June 2008 Request for Withholding Information from Public Disclosure for Partial Round 13 Responses (Tacs. MD5262, MD5263 and MD5264) Project stage: Withholding Request Acceptance ML0810606162008-06-0202 June 2008 Request for Withholding Information from Public Disclosure for Browns Ferry Nuclear Plant Project stage: Withholding Request Acceptance ML0810607222008-06-0202 June 2008 Request for Withholding Information from Public Disclosure for Partial Response to Round 13 Project stage: Withholding Request Acceptance ML0816403252008-06-0303 June 2008 Units 2 & 3 - Technical Specifications Change TS-418 - Extended Power Uprate - Supplemental Response to Round 16 Request for Additional Information - SRXB-88 Project stage: Supplement ML0812607122008-06-0505 June 2008 Summary of Meeting with TVA Steam Dryer Portion of the Extended Power Uprate Review Project stage: Meeting ML0817002942008-06-12012 June 2008 Technical Specifications Changes TS-431 and TS-418 - Extended Power Uprate - Response to ACRS Conclusions and Recommendations Regarding Containment Overpressure Credit Project stage: Other 2008-01-30
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Category:Letter
MONTHYEARML24032A4762024-02-0101 February 2024 Final Report of a Part 21 Evaluation Associated with Starter Contactors for the BFN Unit 1 High Pressure Coolant Injection Suppression Pool Inboard Suction Valve ML24023A2802024-01-23023 January 2024 Final Report of a Deviation or Failure to Comply Associated with a Relay in the Reactor Core Isolation Cooling Condensate Pump CNL-24-017, Tennessee Valley Authority - Central Emergency Control Center Emergency Plan Implementing Procedure and Emergency Preparedness Department Procedure Revisions2024-01-17017 January 2024 Tennessee Valley Authority - Central Emergency Control Center Emergency Plan Implementing Procedure and Emergency Preparedness Department Procedure Revisions ML24016A3042024-01-16016 January 2024 Final Report of a Part 21 Evaluation Associated with Check Valve 0-CKV-023-0565 for D1 Residual Heat Removal Service Water Pump CNL-23-071, Response to Request for Additional Information Regarding Browns Ferry Nuclear Plant, Units 1, 2, and 3, Inservice Inspection and Augmented Program Interval Revised Request for Alternative 0-ISI-472024-01-11011 January 2024 Response to Request for Additional Information Regarding Browns Ferry Nuclear Plant, Units 1, 2, and 3, Inservice Inspection and Augmented Program Interval Revised Request for Alternative 0-ISI-47 ML24022A1732024-01-0303 January 2024 Receipt and Availability of the Subsequent License Renewal Application ML23319A1992024-01-0303 January 2024 Issuance of Amendment Nos. 333, 356, and 316 Regarding the Technical Specification Surveillance Requirements 3.4.3.2 and 3.5.1.11 Regarding Safety Relief Valves ML23355A2062023-12-21021 December 2023 Request for Exemption from Enhanced Weapons, Firearms Background Checks, and Security Event Notifications Implementation ML23348A3942023-12-14014 December 2023 Interim Part 21 Report of a Potential Deviation or Failure to Comply Associated with Starter Contactors for the High Pressure Coolant Injection Suppression Pool Inboard Suction Valve IR 05000259/20230102023-12-11011 December 2023 Commercial Grade Dedication Inspection Report 05000259/2023010 and 05000260/2023010 and 05000296/2023010 ML23335A0722023-12-0101 December 2023 Interim Report of a Deviation or Failure to Comply Associated with a Relay in the Unit 2 Reactor Core Isolation Cooling Condensate Pump ML23334A2492023-11-30030 November 2023 Site Emergency Plan Implementing Procedure Revision CNL-23-070, Submittal of Fifth 10-Year Interval Inservice Testing Program Plan2023-11-29029 November 2023 Submittal of Fifth 10-Year Interval Inservice Testing Program Plan ML23331A2532023-11-27027 November 2023 Summary Report for 10 CFR 50.9 Evaluations, Technical Specifications Bases Changes, Technical Requirement Manual Changes, and NRC Commitment Revisions CNL-23-067, Central Emergency Control Center Emergency Plan Implementing Procedure Revisions2023-11-27027 November 2023 Central Emergency Control Center Emergency Plan Implementing Procedure Revisions ML23325A1102023-11-21021 November 2023 Anchor Darling Double Disc Gate Valve Commitment Revision ML23320A2542023-11-16016 November 2023 Interim Part 21 Report of a Deviation or Failure to Comply Associated with Check Valve 0-CKV-023-0565 for D1 Residual Heat Removal Service Water Pump IR 05000259/20230032023-11-13013 November 2023 Integrated Inspection Report 05000259/2023003, 05000260/2023003 and 05000296/2023003 IR 05000259/20230402023-11-0202 November 2023 Supplemental Inspection Supplemental Report 05000259 2023040 and Follow-Up Assessment Letter ML23292A2532023-10-18018 October 2023 BFN 2024-301, Corporate Notification Letter (210-day Ltr) ML23282A0022023-10-0606 October 2023 Interim Part 21 Report of a Deviation or Failure to Comply Associated with Check Valve 0-CKV-023-0565 for D1 Residual Heat Removal Service Water Pump ML23278A0122023-10-0505 October 2023 Updated Final Safety Analysis Report, Amendment 30 ML23271A1702023-09-28028 September 2023 Site Emergency Plan Implementing Procedure Revision ML23270A0702023-09-26026 September 2023 SLRA Pre-Application Meeting Summary 09-13-2023 ML23257A1232023-09-22022 September 2023 Administrative Changes to Technical Specification Pages Issued for License Amendment Nos. 332, 355, and 315 CNL-23-061, Tennessee Valley Authority - Central Emergency Control Center Emergency Plan Implementing Procedure Revision2023-09-20020 September 2023 Tennessee Valley Authority - Central Emergency Control Center Emergency Plan Implementing Procedure Revision ML23263B1042023-09-20020 September 2023 Special Report 260/2023-001 for Inoperable Post Accident Monitoring (PAM) Instrumentation ML23205A2132023-09-0808 September 2023 Issuance of Amendment Nos. 332, 355, and 315 Regarding the Revision of Technical Specifications to Adopt TSTF-566-A and TSTF-580-A, Rev. 1 CNL-23-057, Central Emergency Control Center Emergency Plan Implementing Procedure Revisions. Includes CECC-EPIP-1, Revision 76 and CECC-EPIP-9, Revision 642023-09-0505 September 2023 Central Emergency Control Center Emergency Plan Implementing Procedure Revisions. Includes CECC-EPIP-1, Revision 76 and CECC-EPIP-9, Revision 64 IR 05000259/20230052023-08-29029 August 2023 Updated Inspection Plan for Browns Ferry Nuclear Plant, Units 1, 2 and 3 - Report 05000259/2023005, 05000260/2023005 and 05000296/2023005 ML23233A0432023-08-18018 August 2023 Enforcement Action EA-22-122 Inspection Readiness Notification ML23219A1542023-08-17017 August 2023 Request to Use Later Edition of ASME Code for Operation and Maintenance and Alternative Requests BFN-IST-01 Through 05 for the Fifth 10-Year Interval Inservice Testing Program ML23228A1642023-08-16016 August 2023 Site Emergency Plan Implementing Procedure Revision ML23228A0202023-08-15015 August 2023 (BFN) Unit 1 - Special Report 259/2023-001 for Inoperable Post Accident Monitoring (PAM) Instrumentation IR 05000259/20230022023-08-10010 August 2023 Integrated Inspection Report 05000259/2023002, 05000260/2023002, 05000296/2023002 and 07200052/2023001 ML23192A4472023-07-31031 July 2023 Staff Assessment of Updated Seismic Hazards at TVA Sites Following the NRC Process for the Ongoing Assessment of Natural Hazards Information CNL-23-055, Tennessee Valley Authority - Emergency Preparedness Department Procedure Revision. Includes EPDP-3, Revision 3, Emergency Plan Exercises and Preparedness Drills2023-07-25025 July 2023 Tennessee Valley Authority - Emergency Preparedness Department Procedure Revision. Includes EPDP-3, Revision 3, Emergency Plan Exercises and Preparedness Drills ML23171A8862023-07-24024 July 2023 Issuance of Amend. Nos. 331, 354, and 314; 365 and 359 Regarding Adoption of TSTF-541-A, Add Exceptions to Surveillance Requirements for Valves and Dampers Locked in the Actuated Position ML23201A2182023-07-20020 July 2023 Registration of Use of Cask to Store Spent Fuel (MPC-298 and -299) ML23159A2552023-07-20020 July 2023 Proposed Alternative to the Requirements of the ASME Code Regarding Volumetric Inspection of Standby Liquid Control Nozzles ML23199A3072023-07-18018 July 2023 Site Emergency Plan Implementing Procedure Revision CNL-23-053, Tennessee Valley Authority - Radiological Emergency Plan Revisions2023-07-18018 July 2023 Tennessee Valley Authority - Radiological Emergency Plan Revisions IR 05000259/20233012023-07-18018 July 2023 NRC Operator License Examination Report Nos. 05000259/2023301, 05000260/2023301, and 05000296/2023301 2024-02-01
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Text
- Tennessee Valley Authority, Post Office Box 2000, Decatur, Adabama 35609-2000 May 07, 2009 TVA-BFN-TS-418 TVA-BFN-TS-431 10 CFR 50.90 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Mail Stop OWFN, P1-35 Washington, D. C. 20555-0001 In the Matter of ) Docket Nos. 50-259 Tennessee Valley Authority ) 50-260 50-296 BROWNS FERRY NUCLEAR PLANT (BFN) - UNITS 1, 2, AND 3 - TECHNICAL SPECIFICATIONS (TS) CHANGES TS-431 AND TS-418 - EXTENDED POWER UPRATE (EPU) - RESULTS OF REVISED CONTAINMENT OVERPRESSURE (COP) ANALYSES FOR APPENDIX R - DRYWELL COOLERS OPERATING (TAC NOS. MD5262, MD5263, AND MD5264)
By letters dated June 28, 2004 and June 25, 2004 (ADAMS Accession Nos. ML041840109 and ML041840301), TVA submitted license amendment requests to the NRC for the EPU operation of BFN Unit 1 and BFN Units 2 and 3, respectively. The proposed amendments would change the operating licenses to increase the maximum authorized core thermal power level of each -reactor by approximately 14 percent to 3952 megawatts. In the EPU license applications, additional COP credit was requested for the Appendix R special event.
In a submittal dated March 12, 2009, TVA provided the results of a revision to the net positive suction head (NPSH)/COP calculations for the licensing basis Appendix R event.
In that revised Appendix R calculation, the required NPSH (NPSHr) for the Residual Heat Removal (RHR) pump used in the Appendix R analysis was changed to a fixed 3% head loss value, which resulted in a substantial reduction in the magnitude and duration of required COP credit. That Appendix R licensing basis analysis also takes credit for operator action to terminate drywell cooling within two hours of the event initiation.
Terminating drywell air space cooling increases drywell and wetwell pressure, which provides additional COP margin.
This submittal presents the results of an additional Appendix R licensing basis calculation during which drywell cooling remains in service throughout the event. The revised analysis shows that with drywell cooling in service, the minimum containment pressure exceeds that 7bc,3c
U.S. Nuclear Regulatory Commission Page 2 May 07, 2009 required to support NPSHr for RHR pump operation. But since termination of drywell cooling provides additional COP margin, TVA plans to continue to secure drywell cooling in the BFN Appendix R safe shutdown procedures. provides a discussion of the revised calculation and a summary of the results.
A copy of the full TVA calculation is in Enclosure 2. TVA has determined that the additional information provided by this letter does not affect the no significant hazards considerations associated with the proposed TS changes. The proposed TS changes still qualify for a categorical exclusion from environmental review pursuant to the provisions of 10 CFR 51.22(c)(9).
No new regulatory commitments are made in this submittal. If you have any questions regarding this letter, please contact J. D. Wolcott at (256)729-2495.
I declare under penalty of perjury that the foregoing is true and correct. Executed on this 7th day of May, 2009.
Sincerely, Site Vice President
Enclosures:
- 1. Results of Revised Containment Overpressure (COP) Analyses for Appendix R -
Drywell Coolers Operating
- 2. Calculation MDQ099920060011, Rev. 5, "Transient NPSH/Containment Pressure Evaluation of RHR and Core Spray Pumps"
U.S. Nuclear Regulatory Commission Page 3 May 07, 2009
Enclosures:
cc: State Health Officer Alabama Dept. of Public Health RSA Tower - Administration Suite 1552 P.O. Box 303017 Montgomery, AL 36130-3017 Ms. Eva Brown, Project Manager U.S. Nuclear Regulatory Commission (MS 08G9)
One White Flint, North 11555 Rockville Pike Rockville, Maryland 20852-2739 Ms. Heather J. Gepford, Acting Branch Chief U.S. Nuclear Regulatory Commission Region II Sam Nunn Atlanta Federal Center 61 Forsyth Street, SW, Suite 23T85 Atlanta, Georgia 30303-8931 NRC Resident Inspector Browns Ferry Nuclear Plant 10833 Shaw Road Athens, Alabama 35611-6970
ENCLOSURE1 TENNESSEE VALLEY AUTHORITY BROWNS FERRY NUCLEAR PLANT (BFN)
UNITS 1, 2, AND 3 TECHNICAL SPECIFICATIONS (TS) CHANGES TS-431 ANDTS-418 EXTENDED POWER UPRATE (EPU)
RESULTS OF REVISED CONTAINMENT OVERPRESSURE (COP) ANALYSES FOR APPENDIX R - DRYWELL COOLERS OPERATING EPU net positive suction head (NPSH) calculations for the licensing basis Appendix R event have utilized the same required NPSH (NPSHr) criteria as used for the design basis Loss-of-Coolant Accident. The Appendix R analysis also credits operator action to secure drywell cooling within two hours of the fire event beginning to preserve adequate NPSH. This approach is reflected in the NPSH/COP calculations submitted to NRC on August 31, 2006 (ADAMS Accession No. ML062510371). In a submittal dated March 12, 2009, TVA provided the results of a revised analysis for the licensing basis Appendix R event in which the NPSHr for the Residual Heat Removal (RHR) pump was changed from a time dependent value based on 8000 hours0.0926 days <br />2.222 hours <br />0.0132 weeks <br />0.00304 months <br /> of operation to a fixed value corresponding to a 3% head loss. This change resulted in a reduction in the magnitude and duration of required COP credit, and an increase in the margin between minimum containment pressure available and the maximum COP required.
With the increased COP margin, an additional Appendix R analysis has been performed with drywell cooling remaining in service throughout the event. A summary of the revised analysis results is provided below. The revised analysis shows that with drywell cooling operating during the entire event, the minimum containment pressure exceeds that required to support NPSHr for, RHR pump operation.
Effects of Drywell Cooling on COP Initial conditions for the licensing basis Appendix R analysis assume that all drywell coolers are operating and removing heat at rated capacity with a heat removal rate equal to the heat load in the drywell from the primary system piping and equipment. In the Appendix R event, the reactor is depressurized using safety relief valves at 25 minutes, which reduces the heat load in the drywell and causes drywell air temperature and pressure to begin decreasing. Termination of drywell cooling reverses this trend and increases available NPSH (NPSHa). Accordingly, a regulatory commitment was established in a TVA submittal dated August 4, 2006 (ML062220647) to terminate drywell cooling in the Appendix R safe shutdown procedures.
Revisions in the analysis submitted March 12, 2009, yielded an increase in NPSH margin and as a result, an additional licensing basis Appendix R case has been analyzed with the drywell coolers operating throughout the event to determine if termination of drywell cooling was still required. All other analysis inputs and assumptions remained the same.
Table 1 shows the summary results from the new analysis and from the previous Appendix R calculations for comparison. Figure 1 provides a graphical comparison of the two cases with drywell cooling secured at two hours and with drywell cooling continuing to operate after two hours. The magnitude and duration of COP credit is not significantly affected by drywell cooling.
E1-1
Available wetwell pressure and NPSH are decreased with drywell cooling always operating, but the NPSHa still exceeds NPSHr. Since termination of drywell cooling provides additional COP margin and no credit is taken for drywell cooling in an Appendix R event, TVA plans to continue to secure drywell cooling in the BFN Appendix R safe shutdown procedures.
A copy of the TVA calculation, MDQ09992006001 1, Rev. 5, is provided in Enclosure 2. This calculation replaces in entirety the calculation submitted on August 31, 2006.
- pounas per square mcn Figure: 1: Appendix R Coolers On vs. Coolers Off After 2: Hours 240 40 220 35 200 30
.4 180 25 a.
W 60 20:0 140 15 120 10 100
- 0 5 10 15 20 26 30 :35 40. 45 60 .55 60 TIME, HOURS E1-2