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| | number = ML15240A134 | | | number = ML15240A134 |
| | issue date = 09/03/2015 | | | issue date = 09/03/2015 |
| | title = Sequoyah Nuclear Plant Units 1 & 2- Interim Staff Response to Reevaluated Flood Hazards Submitted in Response to 10 CFR50.54 Information Request - Flood Causing Mechanism Reevaluation | | | title = Interim Staff Response to Reevaluated Flood Hazards Submitted in Response to 10 CFR50.54 Information Request - Flood Causing Mechanism Reevaluation |
| | author name = Uribe J F | | | author name = Uribe J |
| | author affiliation = NRC/NRR/JLD | | | author affiliation = NRC/NRR/JLD |
| | addressee name = Shea J W | | | addressee name = Shea J |
| | addressee affiliation = Tennessee Valley Authority | | | addressee affiliation = Tennessee Valley Authority |
| | docket = 05000327, 05000328 | | | docket = 05000327, 05000328 |
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| | page count = 8 | | | page count = 8 |
| | project = TAC:MF6032, TAC:MF6033 | | | project = TAC:MF6032, TAC:MF6033 |
| | | stage = Other |
| }} | | }} |
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| {{#Wiki_filter:QFFICIAL. USli ONbY SECURITY RELATED INFORMATION UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 Mr. Joseph W. Shea Vice President, Nuclear Licensing Tennessee Valley Authority 1101 Market Street, LP 3R-C Chattanooga, TN 37 402-2801 September 3, 2015 SUBJECT: SEQUOYAH NUCLEAR PLANT, UNITS 1AND2 -INTERIM STAFF RESPONSE TO REEVALUATED FLOOD HAZARDS SUBMITTED IN RESPONSE TO 10 CFR 50.54(f) INFORMATION REQUEST -CAUSING MECHANISM REEVALUATION (TAC NOS. MF6032 AND MF6033) Dear Mr. Shea: The purpose of this letter is to provide a summary of the U.S. Nuclear Regulatory Commission (NRC) staff's assessment of the re-evaluated flood-causing mechanisms described in the March 12, 2015 (Agencywide Document Access and Management System (ADAMS) Accession No. ML 15071A462), flood hazard reevaluation report (FHRR) submitted by Tennessee Valley Authority (TVA.the licensee) for Sequoyah Nuclear Plant, Units 1 and 2 (Sequoyah), as well as supplemental information resulting from requests for additional information and audits. By letter dated March 12, 2012, the NRC issued a request for information pursuant to Title 1 O of the Code of Federal Regulations, Section 50.54(f) (hereafter referred to as the 50.54(f) letter) (ADAMS Accession No. ML 12053A340). The request was issued as part of implementing lessons-learned from the accident at the Fukushima Dai-ichi nuclear power plant. Enclosure 2 to the 50.54(f) letter requested licensees to re-evaluate flood-causing mechanisms using present-day methodologies and guidance. Concurrently, with the reevaluation of flooding hazards, licensees were required to develop and implement mitigating strategies in accordance with NRC Order EA-12-049, "Requirements for Mitigation Strategies for Beyond-Design-Basis External Events" (ADAMS Accession No. ML 12054A735). On March 30, 2015, the Commission provided Staff Requirements Memoranda (SRM) (ADAMS Accession No. ML 15089A236) to COMSECY-14-0037, "Integration of Mitigating Strategies for Beyond-Design-Basis External Events and the Reevaluation of Flooding Hazards," dated November 21, 2014 (ADAMS Accession No. ML 14309A256), affirming that licensees need to address the reevaluated flooding hazards within their mitigating strategies for beyond-design-basis external events. The NRC staff has reviewed the information submitted by the licensee and has summarized the results of the review in the tables provided as Enclosure 1 to this letter. Table 1 provides the current design-basis flood hazard mechanisms. Enclosure 2 transmitted herewith contains Security-Related Information. When separated from the Enclosure, this document is decontrolled. 'OFFICIAL USE ONLYŽ SECURITY RELATED INFORMATION OFFICIAL' 'SE ONLY SECURITY RELAiTEO INFORMAiTION J. Shea -2 -Table 2 provides reevaluated flood hazard mechanisms; however, reevaluated hazard mechanisms bounded by the current design-basis (Table 1) are not included. Because Table 2 includes security-related information, Enclosure 1 contains the redacted version of Table 2. Enclosure 2 is withheld from public disclosure and restores the security-related information to Table 2. The NRC staff has concluded that the licensee's reevaluated flood hazards information, as summarized in the Enclosure, is suitable for the assessment of mitigating strategies developed in response to Order EA-12-049 (i.e., defines the mitigating strategies flood hazard information described in guidance documents currently being finalized by the industry and NRC staff) for Sequoyah. Further, the NRC staff has concluded that the licensee's reevaluated flood hazard information is a suitable input for other assessments associated with Near-Term Task Force Recommendation 2.1 "Flooding". The NRC staff plans to issue a staff assessment documenting the basis for these conclusions at a later time. In addition, NEI 12-06 "Diverse and Flexible Coping Strategies (FLEX) Implementation Guide" is currently being revised. This revision will include a methodology to perform a Mitigating Strategies Assessment (MSA) with respect to the reevaluated flood hazards. Once this methodology is endorsed by the NRC, flood event duration parameters and applicable flood associated effects should be considered as part of the Sequoyah MSA. The NRC staff will evaluate the flood event duration parameters (including warning time and period of inundation) and flood-related associated effects developed by the licensee during the NRC staff's review of the MSA. As stated above, Table 2 of the enclosure to this letter describes the reevaluated flood hazards that exceed the current design-basis. In order to complete its response to the information requested by Enclosure 2 to the 50.54(f) letter, the licensee is expected to submit an integrated assessment or a focused evaluation, as appropriate, to address these reevaluated flood hazards, as described in the NRC letter, "Coordination of Request for Information Regarding Flooding Hazard Reevaluation and Mitigating Strategies for Beyond-Design-Basis External Events" (ADAMS Accession No. ML 15174A257). This letter describes the changes in the NRC's approach to the flood hazard reevaluations that were approved by the Commission in its SRM to COMSECY-15-0019, "Closure Plan forthe Reevaluation of Flooding Hazards for Operating Nuclear Power Plants" (ADAMS Accession No. ML 15209A682). OFFICIAb USI! ONbY SECURITY RELATED INFORMATION Ol=l=ICIAb USE ONbY SECURITY REbATEC INl=Ol'nll4TION J.Shea -3 -If you have any questions, please contact me at (301) 415-3809 or e-mail at Juan.Uribe@nrc.gov. Docket Nos. 50-327 and 50-328 Enclosures: 1) Summary of Results of Flooding Sincer ribe, Project Manager Hazards Management Branch Japan Lessons-Learned Division Office of Nuclear Reactor Regulation Hazard Re-Evaluation Report (Redacted Version) 2) Summary of Results of Flooding Hazard Re-Evaluation Report (Non-Public Version) cc w/encl: Distribution via Listserv OFFICIAb. lislili QHkV SEGPBITY BEi AJFD INFORBUIION ENCLOSURE 1: SUMMARY TABLES OF REEVALUATED FLOOD HAZARD LEVELS-REDACTED VERSION Sequoyah, Units 1 & 2 Table 1. Current Design Basis Flood Hazards for Use in the MSA Mechanism Stillwater Waves/ I Design Basis Reference Elevation Run up Hazard Elevation -----------------------Local Intense Precipitation 705.7 ft msl Minimal 705.7 ft msl FHRR Section 3.4.1 Streams and Rivers Diesel Generator Building 722.0 ft msl 1.2 ft ! 723.2 ft msl FHRR Section 3.4.2 I FHRR Section 3.4.8.1 I i I ERCW Pumping Station 722.0 ft msl 4.2 ft I 726.2 ft msl FHRR Section 3.4.2 FHRR Sec.tion 3.4.8.1 i ' I Failure of Dams and Onsite ! Water Control/Storage I Structures I I 708.6 ft msl Not 708.6 ft msl FHRR Section 3.4.8.2 applicable Storm Surge i Not included Not included Not included FHRR Section 3.4.4 I in DB in DB in DB Seiche I Not included Not included Not included FHRR Section 3.4.4 in DB in DB in DB I Tsunami Not included Not included Not included FHRR Section 3.4.5 in DB in DB in DB Ice-Induced Flooding I Not included Not included Not included FHRR Section 3.4.6 in DB in DB in DB I I Sequoyah, Units 1 & 2 Table 1. Current Design Basis Flood Hazards for Use in the MSA r ------------------------------------------------Mechanism Stillwater Waves/ Design Basis Reference Elevation Run up Hazard Elevation Channel Migrations/Diversions Not included Not included Not included I FHRR Section 3.4.7 in DB in DB in DB Note: Reported values are rounded to the nearest one-tenth of a foot. | | {{#Wiki_filter:QFFICIAL. USli ONbY SECURITY RELATED INFORMATION UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 September 3, 2015 Mr. Joseph W. Shea Vice President, Nuclear Licensing Tennessee Valley Authority 1101 Market Street, LP 3R-C Chattanooga, TN 37402-2801 |
| Sequoyah, Units 1 & 2 Table 2. Reevaluated Flood Hazards for Flood-Causing Mechanisms for Use in the MSA ,-----------------l Mechanism Stillwater Waves/ Reevaluated Reference Elevation Run up Hazard Elevation Local Intense Precipitation I ! I I 706.3 ft msl I 706.3 ft msl Minimal FHRR Table 11-1 i ! I I I I I Streams and Rivers [Redacted] [Redacted] [Redacted] [Redacted] [Redacted] ---------------------------Note 1: The licensee is expected to develop flood event duration parameters and applicable flood associated effects to conduct the MSA. The staff will evaluate the flood event duration parameters (including warning time and period of inundation) and flood associated effects during its review of the MSA. -----, I Note 2: Reevaluated hazard mechanisms bounded by the current design basis (see Table 1) are not included in this table. Note 3: Reported values are rounded to the nearest one-tenth of a foot.
| | |
| OFFICIAL USE ONLY SECURITY RELATED INFORMATION J. Shea -3 -If you have any questions, please contact me at (301) 415-3809 or e-mail at Juan.Uribe@nrc.gov. Sincerely, IRA/ Juan F. Uribe, Project Manager Hazards Management Branch Japan Lessons-Learned Division Office of Nuclear Reactor Regulation Docket Nos. 50-327 and 50-328 Enclosures: 1) Summary of Results of Flooding Hazard Re-Evaluation Report (Redacted Version) 2) Summary of Results of Flooding Hazard Re-Evaluation Report (Non-Public Version) cc w/encl: Distribution via Listserv DISTRIBUTION: PUBLIC JUribe, NRR RidsNrrDorlLpl2-2 Resource RidsRgn3MailCenter Resource RidsOpaMail Resource ARivera-Varona, NRO MWillingham, NRO MShams, NRR JLD R/F LQuinn-Willingham, NRO RidsNrrDorl Resource RidsNrrLASLent RidsAcrsAcnw_MailCtr Resource KErwin, NRO RRivera-Lugo, NRO RidsNRRJLD Resource RidsNroDsea Resource RidsNrrPMSequoyah Resource RidsOgcMailCenter Resource CCook, NRO ACampbell, NRO BHarvey, NRO ADAMS Accession Nos.: PKG ML 15240A163; LTR: ML 15240A134; ENCL: ML 15238B656 (PUBLIC) ML 15226A549 (NON-PUBLIC) *via email OFFICE NRR/JLD/JHMB/PM NRR/JLD/LA NRO/DSEA/RHM1/TR* NRO/DSEA/RHM2/BC* NAME JUribe SLent SBreithaupt ARiveraVarona DATE 8 I 28 /15 8 / 28 /15 8 / 17 /15 8 / 17 /15 OFFICE NRR/JLD/JHMB/BC NRR/JLD/JHMB/PM NAME MShams JUribe DATE 8 / 28 /15 9 / 3 /15 OFFICIAL RECORD COPY 10FFICIAL USE ONLYŽ SECURlff-RELATED INFORMATION
| | ==SUBJECT:== |
| }} | | SEQUOYAH NUCLEAR PLANT, UNITS 1AND2 - INTERIM STAFF RESPONSE TO REEVALUATED FLOOD HAZARDS SUBMITTED IN RESPONSE TO 10 CFR 50.54(f) INFORMATION REQUEST - FLOOD-CAUSING MECHANISM REEVALUATION (TAC NOS. MF6032 AND MF6033) |
| | |
| | ==Dear Mr. Shea:== |
| | |
| | The purpose of this letter is to provide a summary of the U.S. Nuclear Regulatory Commission (NRC) staff's assessment of the re-evaluated flood-causing mechanisms described in the March 12, 2015 (Agencywide Document Access and Management System (ADAMS) Accession No. ML15071A462), flood hazard reevaluation report (FHRR) submitted by Tennessee Valley Authority (TVA.the licensee) for Sequoyah Nuclear Plant, Units 1 and 2 (Sequoyah), as well as supplemental information resulting from requests for additional information and audits. |
| | By letter dated March 12, 2012, the NRC issued a request for information pursuant to Title 1O of the Code of Federal Regulations, Section 50.54(f) (hereafter referred to as the 50.54(f) letter) |
| | (ADAMS Accession No. ML12053A340). The request was issued as part of implementing lessons-learned from the accident at the Fukushima Dai-ichi nuclear power plant. Enclosure 2 to the 50.54(f) letter requested licensees to re-evaluate flood-causing mechanisms using present-day methodologies and guidance. Concurrently, with the reevaluation of flooding hazards, licensees were required to develop and implement mitigating strategies in accordance with NRC Order EA-12-049, "Requirements for Mitigation Strategies for Beyond-Design-Basis External Events" (ADAMS Accession No. ML12054A735). On March 30, 2015, the Commission provided Staff Requirements Memoranda (SRM) (ADAMS Accession No. ML15089A236) to COMSECY-14-0037, "Integration of Mitigating Strategies for Beyond-Design-Basis External Events and the Reevaluation of Flooding Hazards," dated November 21, 2014 (ADAMS Accession No. ML14309A256), affirming that licensees need to address the reevaluated flooding hazards within their mitigating strategies for beyond-design-basis external events. |
| | The NRC staff has reviewed the information submitted by the licensee and has summarized the results of the review in the tables provided as Enclosure 1 to this letter. Table 1 provides the current design-basis flood hazard mechanisms. |
| | Enclosure 2 transmitted herewith contains Security-Related Information. When separated from the Enclosure, this document is decontrolled. |
| | 'OFFICIAL USE ONLY' SECURITY RELATED INFORMATION |
| | |
| | OFFICIAL' 'SE ONLY SECURITY RELAiTEO INFORMAiTION J. Shea Table 2 provides reevaluated flood hazard mechanisms; however, reevaluated hazard mechanisms bounded by the current design-basis (Table 1) are not included. Because Table 2 includes security-related information, Enclosure 1 contains the redacted version of Table 2. is withheld from public disclosure and restores the security-related information to Table 2. |
| | The NRC staff has concluded that the licensee's reevaluated flood hazards information, as summarized in the Enclosure, is suitable for the assessment of mitigating strategies developed in response to Order EA-12-049 (i.e., defines the mitigating strategies flood hazard information described in guidance documents currently being finalized by the industry and NRC staff) for Sequoyah. Further, the NRC staff has concluded that the licensee's reevaluated flood hazard information is a suitable input for other assessments associated with Near-Term Task Force Recommendation 2.1 "Flooding". The NRC staff plans to issue a staff assessment documenting the basis for these conclusions at a later time. |
| | In addition, NEI 12-06 "Diverse and Flexible Coping Strategies (FLEX) Implementation Guide" is currently being revised. This revision will include a methodology to perform a Mitigating Strategies Assessment (MSA) with respect to the reevaluated flood hazards. Once this methodology is endorsed by the NRC, flood event duration parameters and applicable flood associated effects should be considered as part of the Sequoyah MSA. The NRC staff will evaluate the flood event duration parameters (including warning time and period of inundation) and flood-related associated effects developed by the licensee during the NRC staff's review of the MSA. |
| | As stated above, Table 2 of the enclosure to this letter describes the reevaluated flood hazards that exceed the current design-basis. In order to complete its response to the information requested by Enclosure 2 to the 50.54(f) letter, the licensee is expected to submit an integrated assessment or a focused evaluation, as appropriate, to address these reevaluated flood hazards, as described in the NRC letter, "Coordination of Request for Information Regarding Flooding Hazard Reevaluation and Mitigating Strategies for Beyond-Design-Basis External Events" (ADAMS Accession No. ML15174A257). This letter describes the changes in the NRC's approach to the flood hazard reevaluations that were approved by the Commission in its SRM to COMSECY-15-0019, "Closure Plan forthe Reevaluation of Flooding Hazards for Operating Nuclear Power Plants" (ADAMS Accession No. ML15209A682). |
| | OFFICIAb USI! ONbY SECURITY RELATED INFORMATION |
| | |
| | Ol=l=ICIAb USE ONbY SECURITY REbATEC INl=Ol'nll 4 TION J.Shea If you have any questions, please contact me at (301) 415-3809 or e-mail at Juan.Uribe@nrc.gov. |
| | Sincer ribe, Project Manager Hazards Management Branch Japan Lessons-Learned Division Office of Nuclear Reactor Regulation Docket Nos. 50-327 and 50-328 |
| | |
| | ==Enclosures:== |
| | : 1) Summary of Results of Flooding Hazard Re-Evaluation Report (Redacted Version) |
| | : 2) Summary of Results of Flooding Hazard Re-Evaluation Report (Non-Public Version) cc w/encl: Distribution via Listserv OFFICIAb. lislili QHkV SEGPBITY BEi AJFD INFORBUIION |
| | |
| | ENCLOSURE 1: |
| | |
| | ==SUMMARY== |
| | TABLES OF REEVALUATED FLOOD HAZARD LEVELS-REDACTED VERSION |
| | |
| | Sequoyah, Units 1 & 2 Table 1. Current Design Basis Flood Hazards for Use in the MSA Mechanism Stillwater Elevation Waves/ |
| | Run up IDesign Basis Hazard Reference Elevation -- --------- |
| | Local Intense Precipitation 705.7 ft msl Minimal 705.7 ft msl FHRR Section 3.4.1 Streams and Rivers Diesel Generator Building 722.0 ft msl 1.2 ft ! 723.2 ft msl FHRR Section 3.4.2 I FHRR Section 3.4.8.1 I |
| | i I |
| | ERCW Pumping Station 722.0 ft msl 4.2 ft I 726.2 ft msl FHRR Section 3.4.2 FHRR Sec.tion 3.4.8.1 i |
| | Failure of Dams and Onsite ! |
| | I Water Control/Storage I Structures I I 708.6 ft msl Not 708.6 ft msl FHRR Section 3.4.8.2 applicable Storm Surge i Not included Not included Not included FHRR Section 3.4.4 in DB in DB in DB I Seiche Not included Not included Not included FHRR Section 3.4.4 in DB in DB in DB I |
| | I Tsunami Not included Not included Not included FHRR Section 3.4.5 in DB in DB in DB Ice-Induced Flooding I Not included Not included Not included FHRR Section 3.4.6 in DB in DB in DB I |
| | I |
| | |
| | Sequoyah, Units 1 & 2 Table 1. Current Design Basis Flood Hazards for Use in the MSA r - |
| | Mechanism Stillwater Waves/ Design Basis Reference Elevation Run up Hazard Elevation Channel Migrations/Diversions Not included Not included Not included I FHRR Section 3.4.7 in DB in DB in DB Note: Reported values are rounded to the nearest one-tenth of a foot. |
| | |
| | Sequoyah, Units 1 & 2 Table 2. Reevaluated Flood Hazards for Flood-Causing Mechanisms for Use in the MSA Mechanism Stillwater Elevation Waves/ |
| | Reevaluated Reference -- ---, |
| | Run up Hazard Elevation I |
| | Local Intense Precipitation ! |
| | I I |
| | 706.3 ft msl Minimal 706.3 ft msl I FHRR Table 11-1 i I |
| | ! I I I I I Streams and Rivers |
| | [Redacted] [Redacted] [Redacted] [Redacted] [Redacted] |
| | l - -- - - - ---------- - - ---- -- --- |
| | Note 1: The licensee is expected to develop flood event duration parameters and applicable flood associated effects to conduct the MSA. The staff will evaluate the flood event duration parameters (including warning time and period of inundation) and flood associated effects during its review of the MSA. |
| | Note 2: Reevaluated hazard mechanisms bounded by the current design basis (see Table 1) are not included in this table. |
| | Note 3: Reported values are rounded to the nearest one-tenth of a foot. |
| | |
| | PKG ML15240A163; LTR: ML15240A134; ENCL: ML15238B656 (PUBLIC) |
| | ML15226A549 (NON-PUBLIC) *via email OFFICE NRR/JLD/JHMB/PM NRR/JLD/LA NRO/DSEA/RHM1/TR* NRO/DSEA/RHM2/BC* |
| | NAME JUribe SLent SBreithaupt ARiveraVarona DATE 8 I 28 /15 8 / 28 /15 8 / 17 /15 8 / 17 /15 OFFICE NRR/JLD/JHMB/BC NRR/JLD/JHMB/PM NAME MShams JUribe DATE 8 / 28 /15 9 / 3 /15}} |
Letter Sequence Other |
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MONTHYEARML15071A2622015-03-12012 March 2015 Flood Hazard Reevaluation Report for Watts Bar Nuclear Plant, Response to NRC Request for Information Pursuant to Title 10 of the Code of Federal Regulations 50.54(f) Regarding Recommendations 2.1, 2.3 and 9.3 of the Near-Term Task Force Re Project stage: Response to RAI CNL-15-042, Flood Hazard Reevaluation Report for Response to NRC Request for Information Pursuant to Title 10 of the Code of Federal Regulations 50.54(f) Regarding Recommendations 2.1, 2.3 and 9.3 of the Near-Term Task Force Review.2015-03-12012 March 2015 Flood Hazard Reevaluation Report for Response to NRC Request for Information Pursuant to Title 10 of the Code of Federal Regulations 50.54(f) Regarding Recommendations 2.1, 2.3 and 9.3 of the Near-Term Task Force Review. Project stage: Response to RAI ML15106A6322015-04-17017 April 2015 Tennessee Valley Authority FHRR Audit Plan-4-22-2015 Project stage: Other ML15240A1832015-09-0303 September 2015 Interim Staff Response to Reevaluated Flood Hazards Submitted in Response to 10 CFR 50.54(f) Information Request - Flood-Causing Mechanism Reevaluation Project stage: Other ML15240A1342015-09-0303 September 2015 Interim Staff Response to Reevaluated Flood Hazards Submitted in Response to 10 CFR50.54 Information Request - Flood Causing Mechanism Reevaluation Project stage: Other ML15238B6562015-09-0303 September 2015 Public Table Project stage: Other ML15294A2032015-10-30030 October 2015 NRC Report for the Audit of Tennessee Valley Authority'S Flood Hazard Reevaluation Report Submittals Relating to the Near-Term Task Force Recommendation 2.1-Flooding for Browns Ferry, Units 1,2 & 3, Sequoyah, Units 1 & 2, and Watts Bar, Uni Project stage: Other 2015-03-12
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Category:Graphics incl Charts and Tables
MONTHYEARML24011A3162024-01-11011 January 2024 Submittal of Discharge Monitoring Report (Dmr), August 2023 ML24011A3172024-01-11011 January 2024 Submittal of Discharge Monitoring Report (Dmr), September 2023 ML24011A3182024-01-11011 January 2024 Submittal of Discharge Monitoring Report (Dmr), October 2023 ML24011A3192024-01-11011 January 2024 Submittal of Discharge Monitoring Report (Dmr), November 2023 ML24011A3202024-01-11011 January 2024 Submittal of Discharge Monitoring Report (Dmr), December 2023 ML22327A1412022-11-22022 November 2022 10 CFR 50.46 Annual and 30-Day Report of Changes in Peak Cladding Temperatures (PCT) ML20322A1462020-11-25025 November 2020 Documentation of the Completion of Required Actions Taken in Response to the Lessons Learned from the Fukushima Dai Ichi Accident CNL-20-076, Response to Request for Additional Information Re Application to Revise Sequoyah Nuclear Plant (SQN) Unit 1 Technical Specifications for Steam Generator Tube Inspection Frequency (SQN-TS-20-01)2020-09-23023 September 2020 Response to Request for Additional Information Re Application to Revise Sequoyah Nuclear Plant (SQN) Unit 1 Technical Specifications for Steam Generator Tube Inspection Frequency (SQN-TS-20-01) ML20164A1442020-06-0303 June 2020 Memorandum from David Lochbaum 2.206 Petition - Review of TVA Employee Concerns Program CNL-17-141, Tennessee Valley Authority - Anchor Darling Double Disc Gate Valve Information and Status2017-12-28028 December 2017 Tennessee Valley Authority - Anchor Darling Double Disc Gate Valve Information and Status ML16056A1392016-03-11011 March 2016 Correction to the U.S. Nuclear Regulatory Commission Analysis of Licensees' Decommissioning Funding Status Reports ML15240A1342015-09-0303 September 2015 Interim Staff Response to Reevaluated Flood Hazards Submitted in Response to 10 CFR50.54 Information Request - Flood Causing Mechanism Reevaluation ML15238B6562015-09-0303 September 2015 Public Table ML15254A5092015-08-11011 August 2015 Revised ITS Conversion Change Tables ML14307B7072014-12-10010 December 2014 Supplemental Information Related to Development of Seismic Risk Evaluations for Information Request Pursuant to Title 10 of the Code of Federal Regulations 50.54(f) Regarding Seismic Hazard Reevaluations for Recommendation 2.1 of the Near-T CNL-13-105, Response to NRC Request for Additional Information Regarding Review of the License Renewal Application, Sets 10 (3.0.3-1, Requests 3, 4, 6), 12 (B.1.6-1b, B.1.6-2b), 16 (4.3.1-8a)2013-11-0404 November 2013 Response to NRC Request for Additional Information Regarding Review of the License Renewal Application, Sets 10 (3.0.3-1, Requests 3, 4, 6), 12 (B.1.6-1b, B.1.6-2b), 16 (4.3.1-8a) ML13289A1262013-09-20020 September 2013 Enclosuflows & Stage 2011 ML13298A0302013-09-20020 September 2013 SQN List of Potential Sources of Ghg Emissions Due to Refrigerant Leaks Submitted on Cd Attached to Letter from TVA, Dated Sep 20, 2013, in Response to RAI 6.a.i.3 ML13289A1362013-09-20020 September 2013 Enclosuchart on Missing Record from 2000 Through 2003 ML13289A1332013-09-20020 September 2013 Enclosutemps 2013 ML13289A1322013-09-20020 September 2013 Enclosutemps 2012 ML13289A1302013-09-20020 September 2013 Enclosutemps 2008 ML13289A1292013-09-20020 September 2013 Enclosutemps 2007 ML13289A1282013-09-20020 September 2013 Enclosuflows & Stage 2013 ML13289A0962013-09-20020 September 2013 Enclosuriver Temperature, 2007-2013 - Daily Max TUS_Comp_24-hr ML13289A1012013-09-20020 September 2013 Enclosure 1: Chart on Temperature 2007 ML13289A1112013-09-20020 September 2013 Enclosure 1: Chart on Temperature 2008 ML13289A1122013-09-20020 September 2013 Enclosure 1: Chart on Temperature 2009 ML13289A1132013-09-20020 September 2013 Enclosuchart on Temperature 2010 ML13289A1142013-09-20020 September 2013 Enclosure 1: Chart on Temperature 2011 ML13289A1152013-09-20020 September 2013 Enclosure 1: Chart on Temperature 2012 ML13289A1162013-09-20020 September 2013 Enclosure 1: Chart on Temperture 2013 ML13289A1172013-09-20020 September 2013 Enclosugraphics and Charts on Years 2007 Through 2013 ML13289A1182013-09-20020 September 2013 Enclosugraphics and Charts on Diffuser Discharge Temperature for Years 2007 Through 2012 ML13289A1192013-09-20020 September 2013 Enclosuflows & Stage 2007 ML13289A1202013-09-20020 September 2013 Enclosuflows & Stage 2008 ML13289A1212013-09-20020 September 2013 Enclosutemps 2009 ML13289A1222013-09-20020 September 2013 Enclosutemps 2010 ML13289A1232013-09-20020 September 2013 Enclosutemps 2011 ML13289A1242013-09-20020 September 2013 Enclosuflows & Stage 2009 ML13289A1252013-09-20020 September 2013 Enclosuflows & Stage 2010 ML13289A1272013-09-20020 September 2013 Enclosuflows & Stage 2012 ML11339A0782011-12-13013 December 2011 G20110262/EDATS: OEDO-2011-0269 - Acknowledgment Letter Regarding 2.206 Petition of April 13, 2011 from Paul Gunter to Immediately Suspend OLs of GE BWR Mark I Units ML0919404632009-09-0404 September 2009 Enclosure 1 Summary of Conference Calls with Tennessee Valley Authority Regarding Decommission Funding Assurance ML0728203072007-10-11011 October 2007 Electronic Distribtion Initiative Letter, Licensee List, Electronic Distribution Input Information, Division Plant Mailing Lists 2024-01-11
[Table view] Category:Letter
MONTHYEARIR 05000327/20240022024-07-31031 July 2024 Integrated Inspection Report 05000327/2024002 and 05000328/2024002 ML24211A0572024-07-29029 July 2024 Submittal of Emergency Plan Implementing Procedure Revision ML24211A0542024-07-29029 July 2024 Operator License Examination Report ML24211A0412024-07-26026 July 2024 Unit 1 Cycle 26 Refueling Outage - 90-Day Inservice Inspection Summary Report ML24199A0012024-07-22022 July 2024 Clarification and Correction to Exemption from Requirement of 10 CFR 37.11(c)(2) ML24172A1342024-07-15015 July 2024 Exemptions from 10 CFR 37.11(C)(2) (EPID L-2023-LLE-0024) - Letter ML24191A4652024-07-0909 July 2024 Response to NRC Regulatory Issue Summary 2024-01, Preparation and Scheduling of Operator Licensing Examinations ML24177A0282024-06-25025 June 2024 Emergency Plan Implementing Procedure Revisions ML24145A0852024-05-30030 May 2024 1B-B Diesel Generator Failure - Final Significance Determination Letter ML24145A1052024-05-29029 May 2024 301 Exam Approval Letter ML24134A1762024-05-13013 May 2024 Submittal of 2023 Annual Radiological Environmental Operating Report CNL-24-040, Tennessee Valley Authority - Central Emergency Control Center Emergency Plan Implementing Procedure Revisions2024-05-0808 May 2024 Tennessee Valley Authority - Central Emergency Control Center Emergency Plan Implementing Procedure Revisions ML24128A0352024-05-0707 May 2024 Providing Supplemental Information to Apparent Violation ML24120A0582024-04-26026 April 2024 10 CFR 50.46 Annual Report for Sequoyah Nuclear Plant Units 1 and 2 ML24116A2612024-04-25025 April 2024 Interim Report of a Deviation or Failure to Comply - Transducer Model 8005N ML24114A0482024-04-23023 April 2024 Annual Radioactive Effluent Release Report for 2023 Monitoring Period CNL-24-037, Clinch River, Sequoyah, Units 1 and 2, Watts Bar, Unit 1 and 2, Nuclear Quality Assurance Plan, TVA-NQA-PLN89-A, Revision 422024-04-22022 April 2024 Clinch River, Sequoyah, Units 1 and 2, Watts Bar, Unit 1 and 2, Nuclear Quality Assurance Plan, TVA-NQA-PLN89-A, Revision 42 ML24144A2322024-04-20020 April 2024 Tennessee Multi-Sector Permit (Tmsp), 2024 Annual Discharge Monitoring Report for Outfalls SW-3, SW-3, and SW-9 ML24144A2362024-04-20020 April 2024 Discharge Monitoring Report (Dmr), March 2024 CNL-24-024, Hydrologic Engineering Center River Analysis System Project Milestone Status Update2024-04-17017 April 2024 Hydrologic Engineering Center River Analysis System Project Milestone Status Update CNL-24-033, Central Emergency Control Center Emergency Plan Implementing Procedure Revisions2024-04-17017 April 2024 Central Emergency Control Center Emergency Plan Implementing Procedure Revisions ML24109A0272024-04-16016 April 2024 Cycle 27 Core Operating Limits Report Revision 0 ML24032A0202024-01-31031 January 2024 NPDES Biocide/Corrosion Treatment Plan Annual Report, Cy 2023 ML23319A2452024-01-29029 January 2024 Issuance of Amendment Nos. 366 and 360; 164 and 71 Regarding the Adoption of TSTF-567, Revision 1, Add Containment Sump TS to Address GSI-191 Issues 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 ML24018A0142024-01-17017 January 2024 Engine Systems, Inc., Report No. 10CFR21-0137, Rev. 1, 56913-EN 56913 ML24011A3202024-01-11011 January 2024 Submittal of Discharge Monitoring Report (Dmr), December 2023 IR 05000327/20234422024-01-11011 January 2024 95001 Supplemental Inspection Report 05000327/2023442 and 05000328/2023442 and Follow-Up Assessment Letter ML24011A3162024-01-11011 January 2024 Submittal of Discharge Monitoring Report (Dmr), August 2023 ML24011A3192024-01-11011 January 2024 Submittal of Discharge Monitoring Report (Dmr), November 2023 ML24011A3172024-01-11011 January 2024 Submittal of Discharge Monitoring Report (Dmr), September 2023 ML24011A3182024-01-11011 January 2024 Submittal of Discharge Monitoring Report (Dmr), October 2023 ML24010A2132024-01-10010 January 2024 CFR 21.21 Final Report Regarding Siemens Medium Voltage Circuit Breakers ML24018A0952024-01-0404 January 2024 Engine Systems, Inc., 10CFR21 Reporting of Defects and Non-Compliance Report No. 10CFR21-0137, Rev. 0 ML24004A0332024-01-0303 January 2024 Interim Report of a Deviation or Failure to Comply Crompton Instruments Type 077 Ammeter ML24004A0402024-01-0303 January 2024 Response to NRCs November 8, 2023, Request for Additional Information - Related to Independent Spent Fuel Storage Installation CNL-23-068, Request for Exemption from Enhanced Weapons, Firearms Background Checks, and Security Event Notifications Implementation2023-12-21021 December 2023 Request for Exemption from Enhanced Weapons, Firearms Background Checks, and Security Event Notifications Implementation CNL-23-036, Application to Revise Function 5 of Technical Specification Table 3.3.2-1, Engineered Safety Feature Actuation System Instrumentation, for the Sequoyah Nuclear Plant and Watts Bar Nuclear Plant (SQN-TS-23-02 and WBN-TS-23-08)2023-12-18018 December 2023 Application to Revise Function 5 of Technical Specification Table 3.3.2-1, Engineered Safety Feature Actuation System Instrumentation, for the Sequoyah Nuclear Plant and Watts Bar Nuclear Plant (SQN-TS-23-02 and WBN-TS-23-08) ML23346A1222023-12-12012 December 2023 Annual Non-Radiological Environmental Operating Report - 2023 IR 05000327/20234202023-11-28028 November 2023 Security Baseline Inspection Report 05000327/2023420 and 05000328/2023420 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 ML23324A4362023-11-0909 November 2023 Exam Corporate Notification Letter Aka 210-day Letter ML23307A0822023-11-0808 November 2023 Request for Additional Information August 4, 2022, Exemption Request for Deviating from the Conditions of Certificate of Compliance No. 1032, Amendment No. 3, Related to Sequoyah Nuclear Plant Independent Spent Fuel Storage Installation IR 05000327/20230032023-11-0303 November 2023 Integrated Inspection Report 05000327/2023003 and 05000328/2023003 ML23306A1592023-11-0202 November 2023 Enforcement Action EA-22-129 Inspection Readiness Notification ML23292A0792023-10-19019 October 2023 Tennessee Valley Authority - Emergency Plan Implementing Procedure Revision, Includes EPIP-5, Revision 58, General Emergency IR 05000327/20230112023-10-16016 October 2023 Triennial Fire Protection Inspection Report 05000327/2023011 and 05000328/2023011 ML23285A0882023-10-12012 October 2023 Submittal of Sequoyah Nuclear Plant, Units 1 and 2, Submittal of Updated Final Safety Analysis Report Amendment 31 ML23284A4252023-10-11011 October 2023 10 CFR 50.59 and 10 CFR 72.48 Changes, Tests, and Experiments Summary Report; Commitment Summary Report; and Update to the Fire Protection Report ML23283A2792023-10-10010 October 2023 Revisions to the Sequoyah Nuclear Plant Units 1 and 2 Technical Requirements Manual 2024-07-09
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QFFICIAL. USli ONbY SECURITY RELATED INFORMATION UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 September 3, 2015 Mr. Joseph W. Shea Vice President, Nuclear Licensing Tennessee Valley Authority 1101 Market Street, LP 3R-C Chattanooga, TN 37402-2801
SUBJECT:
SEQUOYAH NUCLEAR PLANT, UNITS 1AND2 - INTERIM STAFF RESPONSE TO REEVALUATED FLOOD HAZARDS SUBMITTED IN RESPONSE TO 10 CFR 50.54(f) INFORMATION REQUEST - FLOOD-CAUSING MECHANISM REEVALUATION (TAC NOS. MF6032 AND MF6033)
Dear Mr. Shea:
The purpose of this letter is to provide a summary of the U.S. Nuclear Regulatory Commission (NRC) staff's assessment of the re-evaluated flood-causing mechanisms described in the March 12, 2015 (Agencywide Document Access and Management System (ADAMS) Accession No. ML15071A462), flood hazard reevaluation report (FHRR) submitted by Tennessee Valley Authority (TVA.the licensee) for Sequoyah Nuclear Plant, Units 1 and 2 (Sequoyah), as well as supplemental information resulting from requests for additional information and audits.
By letter dated March 12, 2012, the NRC issued a request for information pursuant to Title 1O of the Code of Federal Regulations, Section 50.54(f) (hereafter referred to as the 50.54(f) letter)
(ADAMS Accession No. ML12053A340). The request was issued as part of implementing lessons-learned from the accident at the Fukushima Dai-ichi nuclear power plant. Enclosure 2 to the 50.54(f) letter requested licensees to re-evaluate flood-causing mechanisms using present-day methodologies and guidance. Concurrently, with the reevaluation of flooding hazards, licensees were required to develop and implement mitigating strategies in accordance with NRC Order EA-12-049, "Requirements for Mitigation Strategies for Beyond-Design-Basis External Events" (ADAMS Accession No. ML12054A735). On March 30, 2015, the Commission provided Staff Requirements Memoranda (SRM) (ADAMS Accession No. ML15089A236) to COMSECY-14-0037, "Integration of Mitigating Strategies for Beyond-Design-Basis External Events and the Reevaluation of Flooding Hazards," dated November 21, 2014 (ADAMS Accession No. ML14309A256), affirming that licensees need to address the reevaluated flooding hazards within their mitigating strategies for beyond-design-basis external events.
The NRC staff has reviewed the information submitted by the licensee and has summarized the results of the review in the tables provided as Enclosure 1 to this letter. Table 1 provides the current design-basis flood hazard mechanisms.
Enclosure 2 transmitted herewith contains Security-Related Information. When separated from the Enclosure, this document is decontrolled.
'OFFICIAL USE ONLY' SECURITY RELATED INFORMATION
OFFICIAL' 'SE ONLY SECURITY RELAiTEO INFORMAiTION J. Shea Table 2 provides reevaluated flood hazard mechanisms; however, reevaluated hazard mechanisms bounded by the current design-basis (Table 1) are not included. Because Table 2 includes security-related information, Enclosure 1 contains the redacted version of Table 2. is withheld from public disclosure and restores the security-related information to Table 2.
The NRC staff has concluded that the licensee's reevaluated flood hazards information, as summarized in the Enclosure, is suitable for the assessment of mitigating strategies developed in response to Order EA-12-049 (i.e., defines the mitigating strategies flood hazard information described in guidance documents currently being finalized by the industry and NRC staff) for Sequoyah. Further, the NRC staff has concluded that the licensee's reevaluated flood hazard information is a suitable input for other assessments associated with Near-Term Task Force Recommendation 2.1 "Flooding". The NRC staff plans to issue a staff assessment documenting the basis for these conclusions at a later time.
In addition, NEI 12-06 "Diverse and Flexible Coping Strategies (FLEX) Implementation Guide" is currently being revised. This revision will include a methodology to perform a Mitigating Strategies Assessment (MSA) with respect to the reevaluated flood hazards. Once this methodology is endorsed by the NRC, flood event duration parameters and applicable flood associated effects should be considered as part of the Sequoyah MSA. The NRC staff will evaluate the flood event duration parameters (including warning time and period of inundation) and flood-related associated effects developed by the licensee during the NRC staff's review of the MSA.
As stated above, Table 2 of the enclosure to this letter describes the reevaluated flood hazards that exceed the current design-basis. In order to complete its response to the information requested by Enclosure 2 to the 50.54(f) letter, the licensee is expected to submit an integrated assessment or a focused evaluation, as appropriate, to address these reevaluated flood hazards, as described in the NRC letter, "Coordination of Request for Information Regarding Flooding Hazard Reevaluation and Mitigating Strategies for Beyond-Design-Basis External Events" (ADAMS Accession No. ML15174A257). This letter describes the changes in the NRC's approach to the flood hazard reevaluations that were approved by the Commission in its SRM to COMSECY-15-0019, "Closure Plan forthe Reevaluation of Flooding Hazards for Operating Nuclear Power Plants" (ADAMS Accession No. ML15209A682).
OFFICIAb USI! ONbY SECURITY RELATED INFORMATION
Ol=l=ICIAb USE ONbY SECURITY REbATEC INl=Ol'nll 4 TION J.Shea If you have any questions, please contact me at (301) 415-3809 or e-mail at Juan.Uribe@nrc.gov.
Sincer ribe, Project Manager Hazards Management Branch Japan Lessons-Learned Division Office of Nuclear Reactor Regulation Docket Nos. 50-327 and 50-328
Enclosures:
- 1) Summary of Results of Flooding Hazard Re-Evaluation Report (Redacted Version)
- 2) Summary of Results of Flooding Hazard Re-Evaluation Report (Non-Public Version) cc w/encl: Distribution via Listserv OFFICIAb. lislili QHkV SEGPBITY BEi AJFD INFORBUIION
ENCLOSURE 1:
SUMMARY
TABLES OF REEVALUATED FLOOD HAZARD LEVELS-REDACTED VERSION
Sequoyah, Units 1 & 2 Table 1. Current Design Basis Flood Hazards for Use in the MSA Mechanism Stillwater Elevation Waves/
Run up IDesign Basis Hazard Reference Elevation -- ---------
Local Intense Precipitation 705.7 ft msl Minimal 705.7 ft msl FHRR Section 3.4.1 Streams and Rivers Diesel Generator Building 722.0 ft msl 1.2 ft ! 723.2 ft msl FHRR Section 3.4.2 I FHRR Section 3.4.8.1 I
i I
ERCW Pumping Station 722.0 ft msl 4.2 ft I 726.2 ft msl FHRR Section 3.4.2 FHRR Sec.tion 3.4.8.1 i
Failure of Dams and Onsite !
I Water Control/Storage I Structures I I 708.6 ft msl Not 708.6 ft msl FHRR Section 3.4.8.2 applicable Storm Surge i Not included Not included Not included FHRR Section 3.4.4 in DB in DB in DB I Seiche Not included Not included Not included FHRR Section 3.4.4 in DB in DB in DB I
I Tsunami Not included Not included Not included FHRR Section 3.4.5 in DB in DB in DB Ice-Induced Flooding I Not included Not included Not included FHRR Section 3.4.6 in DB in DB in DB I
I
Sequoyah, Units 1 & 2 Table 1. Current Design Basis Flood Hazards for Use in the MSA r -
Mechanism Stillwater Waves/ Design Basis Reference Elevation Run up Hazard Elevation Channel Migrations/Diversions Not included Not included Not included I FHRR Section 3.4.7 in DB in DB in DB Note: Reported values are rounded to the nearest one-tenth of a foot.
Sequoyah, Units 1 & 2 Table 2. Reevaluated Flood Hazards for Flood-Causing Mechanisms for Use in the MSA Mechanism Stillwater Elevation Waves/
Reevaluated Reference -- ---,
Run up Hazard Elevation I
Local Intense Precipitation !
I I
706.3 ft msl Minimal 706.3 ft msl I FHRR Table 11-1 i I
! I I I I I Streams and Rivers
[Redacted] [Redacted] [Redacted] [Redacted] [Redacted]
l - -- - - - ---------- - - ---- -- ---
Note 1: The licensee is expected to develop flood event duration parameters and applicable flood associated effects to conduct the MSA. The staff will evaluate the flood event duration parameters (including warning time and period of inundation) and flood associated effects during its review of the MSA.
Note 2: Reevaluated hazard mechanisms bounded by the current design basis (see Table 1) are not included in this table.
Note 3: Reported values are rounded to the nearest one-tenth of a foot.
PKG ML15240A163; LTR: ML15240A134; ENCL: ML15238B656 (PUBLIC)
ML15226A549 (NON-PUBLIC) *via email OFFICE NRR/JLD/JHMB/PM NRR/JLD/LA NRO/DSEA/RHM1/TR* NRO/DSEA/RHM2/BC*
NAME JUribe SLent SBreithaupt ARiveraVarona DATE 8 I 28 /15 8 / 28 /15 8 / 17 /15 8 / 17 /15 OFFICE NRR/JLD/JHMB/BC NRR/JLD/JHMB/PM NAME MShams JUribe DATE 8 / 28 /15 9 / 3 /15