Letter Sequence Response to RAI |
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Initiation
- Request, Request, Request, Request, Request, Request, Request, Request, Request, Request, Request
- Acceptance
Results
Other: ML110872079, ML11145A064, ML11256A057, ML11256A058, ML12086A081, ML12264A642, ML13029A497, ML13063A071, ML13198A056, ML13253A163, ML16118A311, NOC-AE-12002780, Clarification of Information in Support of the Review of the License Renewal Application, NOC-AE-13002945, Update to License Renewal Application - Environmental Permits
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MONTHYEARML1030102572010-10-25025 October 2010 Project, Units 1 & 2, Transmittal of License Renewal Application Project stage: Request ML1108720792011-04-0505 April 2011 Project Manager Change for the License Renewal of South Texas Project, Units 1 and 2 Project stage: Other ML11145A0642011-06-21021 June 2011 Plan for the Environmental Related Regulatory Audit Regarding the South Texas Project, Units 1 and 2, License Renewal Application Review (TAC Nos. ME4938 and ME4939) Project stage: Other NOC-AE-11002687, Response to Request for Additional Information for the South Texas Project License Renewal Application2011-07-0505 July 2011 Response to Request for Additional Information for the South Texas Project License Renewal Application Project stage: Response to RAI NOC-AE-11002691, Response to Request for Additional Information for the Review of the License Renewal Application2011-07-0505 July 2011 Response to Request for Additional Information for the Review of the License Renewal Application Project stage: Response to RAI ML11154A0132011-07-0606 July 2011 Summary of Telephone Conference Call Held on May 23, 2011, Between the NRC and STPNOC, Concerning Requests for Additional Information Pertaining to the South Texas Project, LRA-Future Consideration of Operating Experience Project stage: RAI ML11201A0622011-08-0404 August 2011 Request for Additional Information for the Review of the South Texas Project, License Renewal Application (TAC Nos. ME4938 and ME5122) Project stage: RAI ML11214A2072011-08-18018 August 2011 RAI for the Review of the STP, License Renewal Application (TAC No. ME4938 and ME512) Project stage: RAI ML1123000162011-08-18018 August 2011 License Renewal - Errata in AMP RAI Package Project stage: RAI NOC-AE-11002711, Response to Request for Additional Information for License Renewal Application2011-08-23023 August 2011 Response to Request for Additional Information for License Renewal Application Project stage: Response to RAI ML11256A0572011-08-31031 August 2011 Documents to Support Review of the South Texas Project License Renewal Application, List of Transmitted Documents Including Copy of Each Document, Enclosure to NOC-AE-11002720 Project stage: Other ML11256A0582011-08-31031 August 2011 Documents to Support Review of the South Texas Project License Renewal Application, WR-5, Tceq Id No. 1610103/1610051 (Operation of Public Potable Water System) Project stage: Other ML11256A0562011-08-31031 August 2011 Project, Units 1 and 2 - Transmittal of Documents to Support Review of the South Texas Project License Renewal Application Project stage: Request ML1123601142011-09-0101 September 2011 Request for Additional Information for the Review of the South Texas Project License Renewal Application Project stage: RAI NOC-AE-11002719, Response to Request for Additional Information for the License Renewal Application2011-09-0606 September 2011 Response to Request for Additional Information for the License Renewal Application Project stage: Response to RAI NOC-AE-11002734, Transmittal of Document to Support Review of the License Renewal Application2011-09-12012 September 2011 Transmittal of Document to Support Review of the License Renewal Application Project stage: Request NOC-AE-11002723, Response to Requests for Additional Information for the License Renewal Application2011-09-12012 September 2011 Response to Requests for Additional Information for the License Renewal Application Project stage: Response to RAI ML11270A0602011-09-22022 September 2011 Response to Requests for Additional Information for License Renewal Application (TAC Nos. ME4938 and ME5122) Project stage: Response to RAI ML11269A0022011-09-28028 September 2011 Requests for Additional Information for the Review of the South Texas Project License Renewal Application (TAC ME4938 and ME5122) Project stage: RAI ML11298A0852011-10-18018 October 2011 Response to Requests for Additional Information for License Renewal Application (TAC No. ME4938 and ME5122) Project stage: Response to RAI NOC-AE-11002761, Clarification to Response to Request for Additional Information for License Renewal Application (TAC No. ME4938 & ME5122)2011-11-17017 November 2011 Clarification to Response to Request for Additional Information for License Renewal Application (TAC No. ME4938 & ME5122) Project stage: Response to RAI NOC-AE-12002780, Clarification of Information in Support of the Review of the License Renewal Application2012-01-10010 January 2012 Clarification of Information in Support of the Review of the License Renewal Application Project stage: Other NOC-AE-11002773, Supplemental Response to Requests for Additional Information for the South Texas Project License Renewal Application - SAMA2012-01-19019 January 2012 Supplemental Response to Requests for Additional Information for the South Texas Project License Renewal Application - SAMA Project stage: Response to RAI ML12033A1342012-02-14014 February 2012 January 31, 2012, Summary of Telephone Conference Call Held Between the NRC and STP Nuclear Operating Company, Concerning Requests for Additional Information Pertaining to the South Texas Project License Renewal Application Project stage: RAI NOC-AE-12002795, Clarification to Supplemental Response to Request for Additional Information for the South Texas Project License Renewal Application - SAMA2012-02-16016 February 2012 Clarification to Supplemental Response to Request for Additional Information for the South Texas Project License Renewal Application - SAMA Project stage: Response to RAI ML12017A1282012-02-29029 February 2012 RAI for the Review of the STP LRA (TAC Nos. ME4938 and ME5122) Project stage: RAI ML12047A2852012-02-29029 February 2012 January 17, 2012, Summary of Telephone Conference Call Held Between the U.S. Nuclear Regulatory Commission & STP Nuclear Operating Company, Concerning Requests for Additional Information Pertaining to the South Texas Project License Renewal Project stage: RAI NOC-AE-12002818, Response to Requests for Additional Information for the Review of the South Texas Project License Renewal Application2012-03-12012 March 2012 Response to Requests for Additional Information for the Review of the South Texas Project License Renewal Application Project stage: Response to RAI ML11290A2262012-03-19019 March 2012 Revision of Schedule for the Conduct of Environmental Review of the South Texas Project License Renewal Application Project stage: Approval NOC-AE-12002840, Renewal of the Wastewater Discharge Permit2012-04-17017 April 2012 Renewal of the Wastewater Discharge Permit Project stage: Request ML12128A0612012-05-0404 May 2012 NRR E-mail Capture - NEPA Consultation - Waterborne Outbreak Project stage: Request ML12142A0022012-05-18018 May 2012 NRR E-mail Capture - Environmental Permit Updated Status Project stage: Request ML12144A4432012-06-25025 June 2012 Request for Additional Information for the Review of the South Texas Project, Units 1 and 2, License Renewal Application- Aging Management, Set 20 TAC Nos. ME4939 and ME4937) STP-RAIs-Set 20-RAI Project stage: RAI ML12171A4832012-08-10010 August 2012 Revision of Schedule for the Conduct of Environmental Review of the South Texas Project License Renewal Application (TAC Nos. ME5122, ME5123, ME4938, and ME4939) Project stage: Approval ML11153A0822012-11-14014 November 2012 Issuance of Environmental Scoping Summary Report Associated with the Staff'S Review of the Application by STP Nuclear Operating Company for Renewal of the Operating License for South Texas Project, Units 1 and 2 Project stage: Approval ML12086A0812012-11-14014 November 2012 Environmental Impact Statement Scoping Process Summary Report for South Texas Project, Units 1 and 2 Project stage: Other ML12264A6422012-11-14014 November 2012 STP Scoping Report_Paula Cooper Project stage: Other ML12324A0492012-11-30030 November 2012 NUREG-1437 Supp 48 Dfc Generic Environmental Impact Statement for License Renewal of Nuclear Plants: Regarding South Texas Project, Units 1 and 2 (Draft for Comment) Project stage: Draft Other ML12339A2652012-12-0505 December 2012 Notice of Availability of the Draft Plant-Specific Supplement 48 to the GEIS for License Renewal of Nuclear Plants Regarding South Texas Project, Units 1 and 2, (TAC ME5122, ME5123, ME4938, and ME4939) Project stage: Draft Other ML12195A0852012-12-0505 December 2012 Notice of Availability of the Draft Plant-Specific Supplement 48 to the GEIS for License Renewal of Nuclear Plants Regarding South Texas Project, Units 1 and 2, (TAC Nos. ME5122, ME5123, ME4938, and ME4939) Project stage: Draft Other ML13029A4972013-01-15015 January 2013 Slides - Preliminary Site-Specific Results of the Environmental Review for South Texas Project License Renewal Project stage: Other ML13029A7552013-01-15015 January 2013 Transcript of South Texas Project License Renewal Public Meeting: Afternoon Session, January 15, 2013, Pages 1-34 Project stage: Meeting NOC-AE-13002945, Update to License Renewal Application - Environmental Permits2013-01-21021 January 2013 Update to License Renewal Application - Environmental Permits Project stage: Other ML13011A1312013-02-11011 February 2013 Revision of Schedule for the Conduct of Environmental Review of the South Texas Project License Renewal Application (TAC Nos. ME5122, ME5123, ME4938, and ME939) Project stage: Approval ML13023A3342013-02-25025 February 2013 1/15/2013 Summary of Public Meetings Conducted to Discuss Draft Supplemental Environmental Impact Statement Related to Review of South Texas Project, Units 1 & 2, License Renewal Application ML13063A0712013-03-0101 March 2013 Efh Consultation W/ NRC for South Texas Nuclear Plant License Renewal Project stage: Other NOC-AE-13002969, Response to Requests for Additional Information for Review of License Renewal Application Concerning Wildlife Management (TAC Nos. ME5122 and ME5123)2013-03-0606 March 2013 Response to Requests for Additional Information for Review of License Renewal Application Concerning Wildlife Management (TAC Nos. ME5122 and ME5123) Project stage: Response to RAI ML13077A1172013-03-14014 March 2013 NRR E-mail Capture - South Texas NRC Informal Consultation Project stage: Request NOC-AE-13002999, Annual Environmental Operating Report, Chapter 5 Through End2013-04-30030 April 2013 Annual Environmental Operating Report, Chapter 5 Through End Project stage: Request NOC-AE-13003000, Radioactive Effluent Release Report2013-04-30030 April 2013 Radioactive Effluent Release Report Project stage: Request 2012-11-30
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Category:Letter type:NOC
MONTHYEARNOC-AE-230040, Supplement to Proposed Alternate Frequency to Containment Unbonded Post-Tensioning System Inservice Inspection (Relief Request RR-ENG-4-06)2023-12-14014 December 2023 Supplement to Proposed Alternate Frequency to Containment Unbonded Post-Tensioning System Inservice Inspection (Relief Request RR-ENG-4-06) NOC-AE-230039, Docket Nos. Stn 50-498, Stn 50-499 - Reply to a Notice of Violation, NRC Inspection Report 05000498/2023003 and 05000499/20230032023-12-12012 December 2023 Docket Nos. Stn 50-498, Stn 50-499 - Reply to a Notice of Violation, NRC Inspection Report 05000498/2023003 and 05000499/2023003 NOC-AE-230039, Submittal of Update Foreign Ownership, Control or Influence (FOCI)2023-07-11011 July 2023 Submittal of Update Foreign Ownership, Control or Influence (FOCI) NOC-AE-220039, Physical Security Plan, Training and Qualification Plan, Safeguards Contingency Plan, and Independent Spent Fuel Storage Installation Security Program Revision 252023-02-0606 February 2023 Physical Security Plan, Training and Qualification Plan, Safeguards Contingency Plan, and Independent Spent Fuel Storage Installation Security Program Revision 25 NOC-AE-220038, Independent Spent Fuel Storage Installation Registration of Dry Spent Fuel Storage Cask2022-06-23023 June 2022 Independent Spent Fuel Storage Installation Registration of Dry Spent Fuel Storage Cask NOC-AE-210038, Submittal of Operations Quality Assurance Plan Changes QA-089, QA-091, and Revision 252022-01-0404 January 2022 Submittal of Operations Quality Assurance Plan Changes QA-089, QA-091, and Revision 25 NOC-AE-21003858, 10 CFR 50.46 Thirty-Day Report of Significant ECCS Model Changes2021-12-0606 December 2021 10 CFR 50.46 Thirty-Day Report of Significant ECCS Model Changes NOC-AE-21003853, Revised Response to End of Enforcement Discretion and Request for Approval of Alternate Disposal Procedures for Very Low-Level Radioactive Material2021-12-0303 December 2021 Revised Response to End of Enforcement Discretion and Request for Approval of Alternate Disposal Procedures for Very Low-Level Radioactive Material NOC-AE-21003848, Unit 1 Cycle 24 Core Operating Limits Report2021-11-18018 November 2021 Unit 1 Cycle 24 Core Operating Limits Report NOC-AE-21003846, Response to End of Enforcement Discretion and Request for Approval of Alternate Disposal Procedures for Very Low-Level Radioactive Material2021-11-0404 November 2021 Response to End of Enforcement Discretion and Request for Approval of Alternate Disposal Procedures for Very Low-Level Radioactive Material NOC-AE-21003842, 10 CFR 50.59 Summary Report2021-09-23023 September 2021 10 CFR 50.59 Summary Report NOC-AE-21003841, Request for Relief from ASME Section Xl Code Requirements for Weld Examinations (Relief Request RR-ENG-3-25)2021-09-23023 September 2021 Request for Relief from ASME Section Xl Code Requirements for Weld Examinations (Relief Request RR-ENG-3-25) NOC-AE-21003832, Supplement to License Amendment Request to Adopt TSTF-577, Revised Frequencies for Steam Generator Tube Inspections2021-09-0909 September 2021 Supplement to License Amendment Request to Adopt TSTF-577, Revised Frequencies for Steam Generator Tube Inspections NOC-AE-21003812, Application to Revise Technical Specifications to Adopt TSTF-577, Revised Frequencies for Steam Generator Tube Inspections2021-08-10010 August 2021 Application to Revise Technical Specifications to Adopt TSTF-577, Revised Frequencies for Steam Generator Tube Inspections NOC-AE-21003825, Update of Foreign Ownership, Control, or Influence Information (FOCI)2021-08-0505 August 2021 Update of Foreign Ownership, Control, or Influence Information (FOCI) NOC-AE-21003824, Update Foreign Ownership, Control, or Influence (FOCI)2021-07-29029 July 2021 Update Foreign Ownership, Control, or Influence (FOCI) NOC-AE-21003823, Update Foreign Ownership Control or Influence (FOCI)2021-07-28028 July 2021 Update Foreign Ownership Control or Influence (FOCI) NOC-AE-21003820, Nuclear Insurance Protection2021-07-20020 July 2021 Nuclear Insurance Protection NOC-AE-21003819, Inservice Inspection Summary Report - 2RE212021-07-15015 July 2021 Inservice Inspection Summary Report - 2RE21 NOC-AE-21003816, Commitment Change Summary Report2021-06-30030 June 2021 Commitment Change Summary Report NOC-AE-21003814, Technical Specification Bases Control Program2021-06-24024 June 2021 Technical Specification Bases Control Program NOC-AE-21003810, Update Foreign Ownership, Control, or Influence (FOCI)- CPS Energy2021-06-17017 June 2021 Update Foreign Ownership, Control, or Influence (FOCI)- CPS Energy NOC-AE-21003811, Update Foreign Ownership, Control, or Influence (FOCI)- Nrg Energy2021-06-17017 June 2021 Update Foreign Ownership, Control, or Influence (FOCI)- Nrg Energy NOC-AE-21003806, Inservice Inspection Program Plan and Inservice Testing Program Snubber Inservice Test Plan for the Fourth Ten-Year Interval2021-05-20020 May 2021 Inservice Inspection Program Plan and Inservice Testing Program Snubber Inservice Test Plan for the Fourth Ten-Year Interval NOC-AE-21003801, Annual Dose Report for 20202021-04-26026 April 2021 Annual Dose Report for 2020 NOC-AE-21003802, 2020 South Texas Project Electric Generating Station Annual Environmental Operating Report2021-04-26026 April 2021 2020 South Texas Project Electric Generating Station Annual Environmental Operating Report NOC-AE-21003804, Operator Licensing Examination Schedule2021-04-21021 April 2021 Operator Licensing Examination Schedule NOC-AE-21003800, Radioactive Effluent Release Report2021-04-19019 April 2021 Radioactive Effluent Release Report NOC-AE-21003799, Changes to South Texas Project Electric Generating Station (STPEGS) Emergency Plan2021-04-15015 April 2021 Changes to South Texas Project Electric Generating Station (STPEGS) Emergency Plan NOC-AE-21003795, Cycle 22 Core Operating Limits Report2021-04-15015 April 2021 Cycle 22 Core Operating Limits Report NOC-AE-21003796, Update Foreign Ownership, Control, or Influence (FOCI)2021-04-15015 April 2021 Update Foreign Ownership, Control, or Influence (FOCI) NOC-AE-21003791, Financial Assurance for Decommissioning - 2021 Update2021-03-31031 March 2021 Financial Assurance for Decommissioning - 2021 Update NOC-AE-21003790, Response to Apparent Violations in NRC Inspection Report 05000498/2020401 and 05000499/2020401: (EA-20-122) (Letter)2021-03-31031 March 2021 Response to Apparent Violations in NRC Inspection Report 05000498/2020401 and 05000499/2020401: (EA-20-122) (Letter) NOC-AE-210037, STP Fire Hazards Analysis Report, Amendment 26 (Redacted)2021-03-30030 March 2021 STP Fire Hazards Analysis Report, Amendment 26 (Redacted) NOC-AE-21003792, STP Fire Hazards Analysis Report, Amendment 26 (Redacted)2021-03-30030 March 2021 STP Fire Hazards Analysis Report, Amendment 26 (Redacted) NOC-AE-200037, License Amendment Request to Revise Technical Specification 3.6.3 to Append a Note and Remove the Index from Technical Specifications2021-03-11011 March 2021 License Amendment Request to Revise Technical Specification 3.6.3 to Append a Note and Remove the Index from Technical Specifications NOC-AE-21003784, Response to Request for Additional Information Regarding 1RE22 Inspection Summary Report for Steam Generator Tubing2021-03-0808 March 2021 Response to Request for Additional Information Regarding 1RE22 Inspection Summary Report for Steam Generator Tubing NOC-AE-21003786, Annual Fitness for Duty Performance Report for 20202021-03-0101 March 2021 Annual Fitness for Duty Performance Report for 2020 NOC-AE-21003785, Evidence of Financial Protection2021-02-23023 February 2021 Evidence of Financial Protection NOC-AE-21003781, Notice Regarding Withdrawal of Funds from Nuclear Decommissioning Trust Subaccounts2021-01-27027 January 2021 Notice Regarding Withdrawal of Funds from Nuclear Decommissioning Trust Subaccounts NOC-AE-21003780, Submittal of Update Foreign Ownership, Control, or Influence (FOCI)2021-01-0707 January 2021 Submittal of Update Foreign Ownership, Control, or Influence (FOCI) NOC-AE-20003778, Changes to South Texas Project Electric Generating Station Emergency Plan2020-12-17017 December 2020 Changes to South Texas Project Electric Generating Station Emergency Plan NOC-AE-20003777, STPNOC Concerns Regarding the Proposed Change to the Evaluated Force-on-Force Inspection Guidance During the COVID-19 Public Health Emergency2020-12-10010 December 2020 STPNOC Concerns Regarding the Proposed Change to the Evaluated Force-on-Force Inspection Guidance During the COVID-19 Public Health Emergency NOC-AE-20003766, Supplement to Change Implementation Date for License Amendment Request to Revise the STPEGS Emergency Plan2020-12-0202 December 2020 Supplement to Change Implementation Date for License Amendment Request to Revise the STPEGS Emergency Plan NOC-AE-20003767, Request for a One-Time Exemption from 10 CFR 73, Appendix 8, Section VI, Subsection C.3.(1)(1) Regarding Annual Force-on-Force (FOF) Exercises, Due to Covid 19 Pandemic2020-11-16016 November 2020 Request for a One-Time Exemption from 10 CFR 73, Appendix 8, Section VI, Subsection C.3.(1)(1) Regarding Annual Force-on-Force (FOF) Exercises, Due to Covid 19 Pandemic NOC-AE-20003765, Inservice Testing Program Description for the Fourth Ten-Year Interval2020-10-28028 October 2020 Inservice Testing Program Description for the Fourth Ten-Year Interval NOC-AE-20003764, 1 RE22 Inspection Summary Report for Steam Generator Tubing2020-10-0707 October 2020 1 RE22 Inspection Summary Report for Steam Generator Tubing NOC-AE-20003762, Supplement to License Amendment Request to Revise Technical Specifications to Adopt TSTF-374, Revision 0, Revision to TS 5.5.13 and Associated TS Bases for Diesel Fuel Oil Using the Consolidated Line Item Improvemen2020-09-22022 September 2020 Supplement to License Amendment Request to Revise Technical Specifications to Adopt TSTF-374, Revision 0, Revision to TS 5.5.13 and Associated TS Bases for Diesel Fuel Oil Using the Consolidated Line Item Improvemen NOC-AE-20003761, Supplement to Exemption Request from 10 CFR 50 Appendix E Due to COVID-19 Pandemic2020-09-10010 September 2020 Supplement to Exemption Request from 10 CFR 50 Appendix E Due to COVID-19 Pandemic NOC-AE-20003760, Update Foreign Ownership. Control. or Influence(FOCI)- Transmittal2020-09-0808 September 2020 Update Foreign Ownership. Control. or Influence(FOCI)- Transmittal 2023-07-11
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Text
Nuclear Operating Company South Texas Projcd Etectnc GeneratingStation P.. Box 289 Wadsworth, 7exas 77483 A A AA August 23, 2011 NOC-AE-1 1002711 10CFR54 STI: 32910421 File: G25 U. S. Nuclear Regulatory Commission Attention: Document Control Desk One White Flint North 11555 Rockville Pike Rockville, MD 20852-2746 South Texas Project Units 1 and 2 Docket Nos. STN 50-498, STN 50-499 Response to Request for Additional Information for the South Texas Proiect License Renewal Application (TAC No. ME4938)
References:
- 1. STPNOC Letter dated October 25, 2010, from G. T. Powell to NRC Document Control Desk, "License Renewal Application" (NOC-AE-10002607) (ML103010257)
- 2. NRC letter dated May 31, 2011, "Requests for Additional Information for the Review of the South Texas Project, License Renewal Application" (ML11140A015)
- 3. STPNOC letter dated July 5, 2011, from G. T. Powell to NRC Document Control desk, "Response to Request for Additional Information for the South Texas Project License Renewal Application" (NOC-AE-1 1002687) (ML11193A016)
- 4. Teleconference between the South Texas Project and the NRC, "STP SAMA RAI Response Clarifications," on July 28, 2011.
By Reference 1, STP Nuclear Operating Company (STPNOC) submitted a License Renewal Application (LRA) for South Texas Project (STP) Units 1 and 2. By Reference 2, the NRC staff requested additional information for review of the STP LRA. STP provided a response to the requested additional information in Reference 3. During a teleconference with the Nuclear Regulatory Commission staff on July 28, 2011 (Reference 4), STP agreed to clarify some of the responses provided in Reference 3. The clarification is provided in the Enclosure to this letter.
There are no regulatory commitments in this letter.
Should you have any questions regarding this letter, please contact either Arden Aldridge, STP License Renewal Project Lead, at (361) 972-8243 or Ken Taplett, STP License Renewal Project regulatory point-of-contact, at (361) 972-8416.
-44'1
NOC-AE-1 1002711 Page 2 I declare under penalty of perjury that the foregoing is true and correct.
Executed on Date G. T. Powell Vice President, Technical Support & Oversight KJT
Enclosure:
Clarification of STPNOC Response to Request for Additional Information
NOC-AE-1 1002711 Page 3 cc:
(paper copy) (electronic copy)
Regional Administrator, Region IV A. H. Gutterman, Esquire U. S. Nuclear Regulatory Commission Kathryn M. Sutton, Esquire 612 East Lamar Blvd, Suite 400 Morgan, Lewis & Bockius, LLP Arlington, Texas 76011-4125 Balwant K. Singal John Ragan Senior Project Manager Catherine Callaway U.S. Nuclear Regulatory Commission Jim von Suskil One White Flint North (MS 8B1) NRG South Texas LP 11555 Rockville Pike Rockville, MD 20852 Ed Alarcon Senior Resident Inspector Kevin Polio U. S. Nuclear Regulatory Commission Richard Pena P. 0. Box 289, Mail Code: MN1 16 City Public Service Wadsworth, TX 77483 C. M. Canady Peter Nemeth City of Austin Crain Caton & James, P.C.
Electric Utility Department 721 Barton Springs Road C. Mele Austin, TX 78704 City of Austin John W. Daily Richard A. Ratliff License Renewal Project Manager (Safety) Alice Rogers U.S. Nuclear Regulatory Commission Texas Department of State Health Services One White Flint North (MS 011-Fl)
Washington, DC 20555-0001 Balwant K. Singal Tam Tran John W. Daily License Renewal Project Manager Tam Tran (Environmental) U. S. Nuclear Regulatory Commission U. S. Nuclear Regulatory Commission One White Flint North (MS 011 F01)
Washington, DC 20555-0001
Enclosure NOC-AE-1 1002711 Page 1 of 4 Clarification of STPNOC Response to Request for Additional Information SOUTH TEXAS PROJECT LICENSE RENEWAL APPLICATION REQUEST FOR ADDITIONAL INFORMATION REGARDING THE ANALYSIS OF SEVERE ACCIDENT MITIGATION ALTERNATIVES
References:
- 1. STPNOC letter dated July 5, 2011, from G. T. Powell to NRC Document Control desk, "Response to Request for Additional Information for the South Texas Project License Renewal Application", (NOC-AE-1 1002687)
(ML11193A016)
- 2. Teleconference between the South Texas Project and the NRC, "STP SAMA RAI Response Clarifications," on July 28, 2011.
The STPNOC response to a request for additional information (RAI) for the South Texas Project License Renewal Application is provided in Reference 1. By Reference 2, the Nuclear Regulatory Commission (NRC) staff requested clarification of the STP response to RAI questions designated in Reference 1 as 1 .d, 1.f and 6.b. The RAI questions from Reference 1 are repeated below followed by the additional clarification requested in Reference 2.
NRC Requested Information:
- 1. Provide the following information regarding the Probabilistic Risk Assessment (PRA) used for the Severe Accident Mitigation Alternative (SAMA) analysis:
- d. ER Section F.7.1 states that the CDF of 6.39E-06 per year is a mean value from the RISKMAN Monte Carlo quantification. Confirm that all the CDF and release category frequency values given are also mean values. If so, describe why it appears that the sum of the initiating event contributor's mean values reported in Table F.2-1 equal the mean of the total distribution.
Additional Clarification Requested:
The response to this RAI states that a reduced set of sequences was used for the uncertainty analysis and the results scaled so that the mean of the distribution was scaled to match the mean of the CDF point estimate or 6.39E-06 per year. It is unclear how this scaling of the CDF distribution impacts the 95th percentile multiplier of 1.6 used in the uncertainty analysis.
Provide the mean and 95th percentile CDF from the Monte Carlo distribution and the ratio of this 95th percentile CDF to the point estimate CDF for the reduced set of sequences. If the resulting ratio is greater than 1.6, consider the impact on the SAMA cost benefit analysis provided in the ER and in response to RAIs. Also, confirm that all CDF and release frequency values provided in the ER and in RAI responses are point estimates based on mean basic event values.
Enclosure NOC-AE-1 1002711 Page 2 of 4 STPNOC Response:
The distribution for core damage frequency (CDF) for the reduced set of sequences has a mean of 8.52E-06 per year and a 95th percentile of 1.59E-05 per year. The point estimate CDF for the reduced set of sequences is 5.89E-06 per year. The ratio of the 95th of Monte Carlo CDF distribution to the point estimate is 1.59E-05 divided by 5.89E-06, or 2.70. There are no new cost beneficial SAMAs identified as a result of the revised multiplier. The CDF and release frequency estimates are point estimates based on mean basic event values.
NRC Requested Information:
- 1. Provide the following information regarding the Probabilistic Risk Assessment (PRA) used for the Severe Accident Mitigation Alternative (SAMA) analysis:
- f. Provide a brief summary of the history of the STP Level 1 PRA that includes for each revision: the date released, the CDF contribution for internal events and each of the external event hazards [i.e., seismic, fire, tornado, and main cooling reservoir (MCR) breach], and the major changes in the revision that led to the change in the CDF, including identification of major changes or updates to the modeling for various initiator groups such as internal flooding, fire, and seismic. Also, identify the STP PRA revision reviewed in the 2002 Westinghouse Owners Group (WOG) peer review.
Additional Clarification Requested:
The total CDF for STPREV4 is given in Table 1-3 of the RAI response as 1.17E-05 per year. Section F.2 of the ER and page 9 of Attachment 1 to STPNOC's 2/28/07 RMTS submittal give the total as 9.08E-06 per year.
Explain this difference and/or indicate the necessary corrections in the submittals.
STPNOC Response:
The total CDF given in Table 1-3 of the original RAI response is incorrect. The corrected table is provided below.
Table 1-3 STP REV4 CDF Groupings (events/year)
Total CDF Internal Events External Events Contribution Contribution 9.08E-06 6.60E-06 Fires 1.OE-06 Floods 1.40E-08 Flood MCR 2.88E-07 High Winds (i.e. 1.1E-06 tornados)
Seismic 7.26E-08 Total External 2.48E-06
Enclosure NOC-AE-1 1002711 Page 3 of 4 NRC Requested Information:
- 6. Provide the following information with regard to the Phase II cost-benefit evaluations:
- b. ER Section F.6.3, 5th paragraph, explains that the evaluation of SAMA 12 did not consider the condition in which non-condensable gases such as hydrogen are present since this condition is not modeled in the PRA, but that this condition is conservatively treated in the PRA. If this SAMA impacts this condition then the estimated risk reduction is potentially underestimated. Also, this same section of the ER states that SBO sequences were excluded in the modeling of this SAMA because AC power is needed to start a reactor coolant pump (RCP). This also potentially underestimates the risk reduction benefit for this SAMA since it does not appear to include SBO scenarios in which AC power is recovered. Discuss these issues and their impact on the SAMA analysis.
Additional Clarification Requested:
The ER discussion of the modeling of SAMA 12 appears to indicate that the only sequences impacted and credited in the cost benefit analysis are those involving leakage from the primary system. The conservative modeling discussed involves hydrogen generation for non-leakage sequences. The response to the RAI states sequences involving this conservative modeling are included in the assessment of the impact of this SAMA. Describe how these conservatively modeled sequences are included in the SAMA evaluation.
STPNOC Response:
The "non-leakage" scenarios that involve hydrogen generation are similar to that which occurred at TMI-2 when both steam generator cooling and high pressure injection were temporarily lost. For the STP Probabilistic Risk Assessment (PRA) models, temporary losses are conservatively treated as complete losses for later times (i.e., the frequency of such sequences is not divided up into sequences with recovery and others without recovery). Unrecovered losses of steam generator cooling lead to reactor coolant system (RCS) pressure increases and eventual RCS leakage. Subsequent failure of feed-and-bleed would lead to a high pressure core damage sequence with the steam generators boiled dry. This unrecovered sequence is used to assess induced steam generator tube rupture. The frequency of sequences that have either temporary or complete interruptions of both steam generator cooling and high pressure injection (regardless whether they involve recovery or not) are subsumed into one conservative representation of the sequence. The sequence is conservative with respect to calculations of induced steam generator tube ruptures because the RCS is at high pressure and the steam generators are not cooled at later times. Hydrogen generation, whether it occurs or not, would not make the assessment of induced tube ruptures, as analyzed in the PRA, more severe.
The stated concern appears to be that scenarios in which HPI/AFW are recovered after the generation of non-condensable gases could result in conditions where the reactor coolant pumps may be started and cause an induced steam generator tube rupture (ISGTR); however, if HPI and/or AFW are recovered, the conditions of concern are eliminated. Recovery of AFW would allow re-fill of the steam generators, which would
Enclosure NOC-AE-1 1002711 Page 4 of 4 preclude ISGTR. Recovery of HPI would cool the core and also preclude an ISGTR. No additional scenarios have been identified for STP that would increase the averted cost-risk calculated for SAMA 12 in the ER.