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| {{#Wiki_filter:NRR BriefingTitle: Oconee Flood Protection (NRR/DRA) | | {{#Wiki_filter:NRR Briefing Title: Oconee Flood Protection (NRR/DRA)Category: |
| Category: | | Status |
| Status | |
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| ==Background:== | | ==Background:== |
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| Adequacy of Flood Protection for Standby Shutdown Facility (SSF) Given Failure of theJocassee DamDue to its configuration on Lake Keowee, the Oconee three-unit site relies entirely on accident mitigation from the Standby Shutdown Facility (SSF) to provide RCP seal cooling, inventory | | Adequacy of Flood Protection for Standby Shutdown Facility (SSF) Given Failure of the Jocassee Dam Due to its configuration on Lake Keowee, the Oconee three-unit site relies entirely on accident mitigation from the Standby Shutdown Facility (SSF) to provide RCP seal cooling, inventory control, and secondary side heat removal under several conditions including a site flood from rupture of the upstream Jocassee Pumped Storage Dam. In 2006, the staff using the Significance Determination Process (SDP) evaluated a performance deficiency of an unanalyzed opening made in the SSF rendering it vulnerable to external flood. The licensee appealed the finding twice. During a re-evaluation on the second appeal, the staff discovered that the licensee had erroneously computed a random Jocassee Dam rupture frequency that was significantly lower than what should have been based on actual data.In the 1980s, the licensee had performed a flooding analysis which predicted a resultant flood height of 4.71 feet given Jocassee Dam rupture. This study was used to justify constructing a seismically qualified 5-foot flood protection wall around the entrance to the SSF and was incorporated into the FSAR becoming part of their-licensing basis. ff-the eany 1990,, due to a nationai response plan, the Federal Energy KegdMliory Commission (FERC) with the licensee oerformed a flood analysi o.- cte3 flood height of between 12 and 16 feet. In 1992, the licensee removed the 5-ft wall and Jocassee rupture flood ptcection their iibensing basis using a potentially inappropriate argument. |
| : control, and secondary side heat removal under several conditions including a site flood from rupture of the upstream JocasseePumped Storage Dam. In 2006, the staff using the Significance Determination Process (SDP) evaluated a performance deficiency of an unanalyzed opening made in the SSF rendering it vulnerable to externalflood. The licensee appealed the finding twice. During a re-evaluation on the second appeal, the staffdiscovered that the licensee had erroneously computed a random Jocassee Dam rupture frequency thatwas significantly lower than what should have been based on actual data.In the 1980s, the licensee had performed a flooding analysis which predicted a resultant flood height of4.71 feet given Jocassee Dam rupture.
| | The earlier flooding study which predicted a 4.71-foot flood height is not available. |
| This study was used to justify constructing a seismically qualified 5-foot flood protection wall around the entrance to the SSF and was incorporated into the FSARbecoming part of their-licensing basis. ff-the eany 1990,, due to a nationai response plan, the FederalEnergy KegdMliory Commission (FERC) with the licensee oerformed a flood analysi o.- cte3flood height of between 12 and 16 feet. In 1992, the licensee removed the 5-ft wall and Jocassee ruptureflood ptcection their iibensing basis using a potentially inappropriate argument. | | Only the latter FERC flood analysis is available which clearly demonstrates that the current wall does not provide adequate flood protection. |
| Theearlier flooding study which predicted a 4.71-foot flood height is not available.
| | Another discrepancy relates to the lower Jocassee Dam rupture frequency which is referenced in several documents including the Oconee Individual Plant Examination of External Events (IPEEE) and license renewal Severe Accident Mitigation Alternatives (SAMA) submittals. |
| Only the latter FERC floodanalysis is available which clearly demonstrates that the current wall does not provide adequate floodprotection. | | Moreover, other licensees with similar dam rupture vulnerabilities might have adopted this rupture frequency and used it to justify screening out consideration of external flood damage at their sites. Since the extent and impact at the individual sites of this underestimate is unknown, the staff will communicate concerns of potential deficiencies with licensees. |
| Another discrepancy relates to the lower Jocassee Dam rupture frequency which is referenced in severaldocuments including the Oconee Individual Plant Examination of External Events (IPEEE) and licenserenewal Severe Accident Mitigation Alternatives (SAMA) submittals. | | Licensees may be required to re-visit flooding calculations to ensure validity.SuccesseslAccomplishments: |
| : Moreover, other licensees withsimilar dam rupture vulnerabilities might have adopted this rupture frequency and used it to justifyscreening out consideration of external flood damage at their sites. Since the extent and impact at theindividual sites of this underestimate is unknown, the staff will communicate concerns of potential deficiencies with licensees.
| | A draft action plan has been prepared, is partially underway, and stakeholders have been identified. |
| Licensees may be required to re-visit flooding calculations to ensure validity. | | A team was assembled initially with personnel from DRA, DE, DORL, and DPR to consider several options on how to proceed. Staff and management meet regularly and provide progress to the ADES. A preliminary averted cost estimate for use in a regulatory analysis has been performed. |
| SuccesseslAccomplishments: | | A draft Information Notice has been written. Potential stakeholders have been briefed through various presentations made to the ET/LT, inter-office Risk Management Team (RMT), DRA staff, and NSIR.Plans and Schedules: |
| A draft action plan has been prepared, is partially | | One option is to address the removal of SSF flood protection references from the licensing basis and require the licensee to re-instate the wall in the licensing basis. The second option considered compliance using the backfit rule, 10 CFR 109. The staff is investigating whether a backfit regulatory analysis needs to be done. In either case, the licensee only has the current FERC study. In order to comply with the requirements of adequate flood protection, compensatory measures need to be taken by the licensee to protect the SSF beyond the 5-foot level. A third option was to simultaneously use the first two options with a heavier emphasis on the backfit aspect. The team will also assess issuing an order following the guidance of LIC-504, "Integrated Risk-Informed Decision-Making Process for Emergent Issues".Contacts: |
| : underway, and stakeholders have been identified.
| |
| Ateam was assembled initially with personnel from DRA, DE, DORL, and DPR to consider several optionson how to proceed.
| |
| Staff and management meet regularly and provide progress to the ADES. Apreliminary averted cost estimate for use in a regulatory analysis has been performed. | |
| A draftInformation Notice has been written. | |
| Potential stakeholders have been briefed through variouspresentations made to the ET/LT, inter-office Risk Management Team (RMT), DRA staff, and NSIR.Plans and Schedules: | |
| One option is to address the removal of SSF flood protection references from the licensing basis andrequire the licensee to re-instate the wall in the licensing basis. The second option considered compliance using the backfit rule, 10 CFR 109. The staff is investigating whether a backfit regulatory analysis needs to be done. In either case, the licensee only has the current FERC study. In order tocomply with the requirements of adequate flood protection, compensatory measures need to be taken bythe licensee to protect the SSF beyond the 5-foot level. A third option was to simultaneously use the firsttwo options with a heavier emphasis on the backfit aspect. The team will also assess issuing an orderfollowing the guidance of LIC-504, "Integrated Risk-Informed Decision-Making Process for EmergentIssues".Contacts: | |
| Mike Franovich 415-1185 or Jeff Circle 415-1152.}} | | Mike Franovich 415-1185 or Jeff Circle 415-1152.}} |
|
|---|
Category:Meeting Briefing Package/Handouts
MONTHYEARML24100A8062024-04-0909 April 2024
Duke Energy Sites Annual Assessment Meeting Presentation Slides April 23, 2024
ML22251A2352022-09-14014 September 2022
Presentation Slides for September 14, 2022, Observation Public Meeting
ML22130A0102022-04-28028 April 2022
Duke Presentation for April 28, 2022 Public Meeting - Containment Liner
ML22130A0092022-04-28028 April 2022
Duke Presentation for April 28, 2022 Public Meeting - Bolting Integrity
ML22067A1992022-03-0303 March 2022
Annual Assessment Meeting Presentation
ML22063A1142022-01-17017 January 2022
Duke Presentation for Public Meeting on February 17, 2022
ML21235A0452021-08-25025 August 2021
August 25, 2021, Oconee Nuclear Station, Units 1, 2, and 3 Subsequent License Renewal Application Public Environmental Scoping Meeting Presentation
ML21102A0632021-04-14014 April 2021
ONS Slides for Pre-Application Meeting to Discuss Proposed Relief Request Related to Code Case N-853
ML21089A1732021-03-30030 March 2021
EOC Slides Final
ML21081A1242021-03-22022 March 2021
EOC Slides Final
ML20300A0902020-10-27027 October 2020
Subsequent License Renewal Environmental Pre-Application Meeting - NRC Presentation
ML20300A0872020-10-27027 October 2020
Subsequent License Renewal Application NRC Environmental Pre-Application Meeting - Duke Energy Presentation
ML19318F2912019-11-18018 November 2019
Duke Energy Presentation for the Pre-submittal Meeting on November 18, 2019, Regarding the RPV Stud Examination Relief Request
ML19302E0512019-11-0606 November 2019
High Energy Line Break License Amendment Public Meeting
ML19214A0562019-08-0707 August 2019
Presentation: Duke Energy Presubmittal Meeting - August 7, 2019
ML19207A0172019-07-30030 July 2019
Summary of Meeting with Duke Energy Carolinas, LLC to Discuss Proposed License Amendment Request for Oconee Nuclear Station, Units 1, 2, and 3 Regarding High Energy Line Break Licensing Basis
ML18227B3212018-09-0505 September 2018
Tornado License Amendment Pre-Application Meeting Slides
ML18134A2292018-05-14014 May 2018
Summary of April 26, 2018, Public Teleconference with Duke Energy Carolinas, LLC to Discuss Proposed License Amendment and 3 Regarding Technical Specification 3.8.1
ML17258A0122017-09-26026 September 2017
Presentation Slide Regarding Committee to Review Generic Requirements Meeting on Oconee Nuclear Station Cable Separation TIA
ML15348A2032015-12-14014 December 2015
Duke Energy Presentation in Support of December 15, 2015, Public Meeting with NRC Staff Cable Testing Discussion for Proposed 50.55a Alternative Request
ML15343A1142015-12-0808 December 2015
NRC Questions to Duke Energy Regarding Cable Testing in Support of Public Meeting on 12/15/15
ML15321A1782015-11-17017 November 2015
Presentation Material in Support of November 18, 2015 Pre-Application Meeting Between NRC and Duke 50.55a(z) Alternative to Code and Standards Requirements
ML15286A0762015-10-13013 October 2015
Duke Energy Presentation in Support of October 13, 2015, Public Meeting with NRC Staff Pre-Application Meeting for LAR to Support Khu Stator Replacement. (Revised)
ML15282A0722015-10-0909 October 2015
Duke Energy Presentation in Support of October 13, 2015, Public Meeting with NRC Staff Pre-Application Meeting for LAR to Support Khu Stator Replacement
ML15148A2632015-05-27027 May 2015
Meeting Slides from the May 27, 2015 Oconee Major Projects Between Duke Energy and NRC
ML15113A6262015-04-23023 April 2015
April 14, 2015 Summary of Public Meeting on Oconee Nuclear Station, Units 1, 2 and 3 to Discuss the Annual Assessment
ML14356A0062014-12-0303 December 2014
Presentation at December 3, 2014, Category 1 Public Meeting with Duke Energy Carolinas, LLC to Discuss NTTF Recommendation 2.1, Flooding Response
ML14211A2162014-07-31031 July 2014
NRC Meeting Slides 7-31-14 Reg Conference
ML14211A2132014-07-31031 July 2014
Duke Energy Presentation for 2014-07-31 Meeting
ML14147A3652014-05-27027 May 2014
Annual Assessment Public Meeting Summary Memo
ML14058A0772014-02-0404 February 2014
Slides on Oconee Ssf Flood Barrier Breach SDP Lessons Learned
ML14058A0742014-02-0404 February 2014
Slides on Oconee Ssf Flood Barrier Breach SDP - Lessons Learned
ML14058A0482014-02-0404 February 2014
NRR Briefing on Oconee Flood Protection (Nrr/Dra)
ML13336A5452013-11-13013 November 2013
Presentation Slides from Meeting with Duke Energy Carolinas, LLC, Oconee Nuclear Station Units 1, 2, and 3, Keowee Hydro Unit Generator Field Pole Rewind Project - License Amendment Request
ML13312A9882013-11-0808 November 2013
Summary of Public Meeting with Duke Energy Carolinas, LLC, to Provide Opportunities to Discuss the Planned Fukushima-Related Modifications
ML13308A0072013-11-0101 November 2013
Open Phase Resolution Update Meeting Duke Energy Entitled Open Phase Detection and Protection.
ML13275A2692013-10-0303 October 2013
10/3/13 Presentation Slides from Meeting with Duke Energy Carolinas, LLC, Oconee Nuclear Station Units 1, 2, and 3, Protected Service Water Alternate Cooling
ML13275A2252013-09-24024 September 2013
9/24/13 Meeting Slides from Meeting with Duke Energy Carolinas, LLC, Oconee Nuclear Station Units 1, 2, and 3, Jocassee Dam Seismic Analysis
ML13239A3372013-08-27027 August 2013
NRC Meeting Slides, Oconee Major Project Meeting - August 28, 2013
ML13239A3402013-08-27027 August 2013
Presentation for NRC Projects
ML13099A4472013-04-10010 April 2013
Slides from Meeting with Duke Energy Carolinas, LLC, Oconee Nuclear Station Units 1, 2, and 3, Milestones for Corrective Actions for an Apparent Violation of a License Condition on Fire Protection
ML13095A2132013-04-0909 April 2013
Slides from Meeting with Duke Energy Carolinas, LLC, Oconee Nuclear Station Units 1, 2, and 3, External Flood Reevaluation
ML13123A2042013-03-25025 March 2013
Slides from Meeting with Duke Energy Carolinas, LLC, Oconee Nuclear Station Units 1, 2, and 3, Concerning the Flooding Hazard Reevaluation Report
ML13064A1022013-03-0505 March 2013
Slides from Predecisional Enforcement Conference with Duke Energy Carolinas, LLC, Oconee Nuclear Station Units 1, 2, and 3, Apparent Violation of a License Condition on Fire Protection
ML13056A1042013-02-0606 February 2013
Briefing Slides on the Fliod Scenario Rupture of Jocassee Dam
ML13056A1032013-02-0606 February 2013
Briefing on Draft Information Notice - Potential Nonconservative Screening Value for Dam Failure Frequency in Probabilistic Risk Assessments.
ML13052A7822013-02-0606 February 2013
Slides on Oconee Ssf Flood Barrier Breach SDP - Lessons Learned
ML13056A0992013-02-0606 February 2013
Meeting Slides on Oconee Ssf Flood Barrier Breach Sdsp - Lessons Learned
ML13056A1022013-02-0606 February 2013
Meeting Slides on Oconee Flood Issue Jocassee Dam Failure Frequency
ML13035A2332013-01-30030 January 2013
Projects Meeting - Licensee'S Public Meeting Slides
2024-04-09
[Table view] |
Text
NRR Briefing Title: Oconee Flood Protection (NRR/DRA)Category:
Status
Background:
Adequacy of Flood Protection for Standby Shutdown Facility (SSF) Given Failure of the Jocassee Dam Due to its configuration on Lake Keowee, the Oconee three-unit site relies entirely on accident mitigation from the Standby Shutdown Facility (SSF) to provide RCP seal cooling, inventory control, and secondary side heat removal under several conditions including a site flood from rupture of the upstream Jocassee Pumped Storage Dam. In 2006, the staff using the Significance Determination Process (SDP) evaluated a performance deficiency of an unanalyzed opening made in the SSF rendering it vulnerable to external flood. The licensee appealed the finding twice. During a re-evaluation on the second appeal, the staff discovered that the licensee had erroneously computed a random Jocassee Dam rupture frequency that was significantly lower than what should have been based on actual data.In the 1980s, the licensee had performed a flooding analysis which predicted a resultant flood height of 4.71 feet given Jocassee Dam rupture. This study was used to justify constructing a seismically qualified 5-foot flood protection wall around the entrance to the SSF and was incorporated into the FSAR becoming part of their-licensing basis. ff-the eany 1990,, due to a nationai response plan, the Federal Energy KegdMliory Commission (FERC) with the licensee oerformed a flood analysi o.- cte3 flood height of between 12 and 16 feet. In 1992, the licensee removed the 5-ft wall and Jocassee rupture flood ptcection their iibensing basis using a potentially inappropriate argument.
The earlier flooding study which predicted a 4.71-foot flood height is not available.
Only the latter FERC flood analysis is available which clearly demonstrates that the current wall does not provide adequate flood protection.
Another discrepancy relates to the lower Jocassee Dam rupture frequency which is referenced in several documents including the Oconee Individual Plant Examination of External Events (IPEEE) and license renewal Severe Accident Mitigation Alternatives (SAMA) submittals.
Moreover, other licensees with similar dam rupture vulnerabilities might have adopted this rupture frequency and used it to justify screening out consideration of external flood damage at their sites. Since the extent and impact at the individual sites of this underestimate is unknown, the staff will communicate concerns of potential deficiencies with licensees.
Licensees may be required to re-visit flooding calculations to ensure validity.SuccesseslAccomplishments:
A draft action plan has been prepared, is partially underway, and stakeholders have been identified.
A team was assembled initially with personnel from DRA, DE, DORL, and DPR to consider several options on how to proceed. Staff and management meet regularly and provide progress to the ADES. A preliminary averted cost estimate for use in a regulatory analysis has been performed.
A draft Information Notice has been written. Potential stakeholders have been briefed through various presentations made to the ET/LT, inter-office Risk Management Team (RMT), DRA staff, and NSIR.Plans and Schedules:
One option is to address the removal of SSF flood protection references from the licensing basis and require the licensee to re-instate the wall in the licensing basis. The second option considered compliance using the backfit rule, 10 CFR 109. The staff is investigating whether a backfit regulatory analysis needs to be done. In either case, the licensee only has the current FERC study. In order to comply with the requirements of adequate flood protection, compensatory measures need to be taken by the licensee to protect the SSF beyond the 5-foot level. A third option was to simultaneously use the first two options with a heavier emphasis on the backfit aspect. The team will also assess issuing an order following the guidance of LIC-504, "Integrated Risk-Informed Decision-Making Process for Emergent Issues".Contacts:
Mike Franovich 415-1185 or Jeff Circle 415-1152.
