ML24079A300
| ML24079A300 | |
| Person / Time | |
|---|---|
| Site: | 99902056 |
| Issue date: | 03/19/2024 |
| From: | NRC |
| To: | NRC/NRR/DNRL |
| References | |
| Download: ML24079A300 (10) | |
Text
From:
Greg Cranston Sent:
Tuesday, March 19, 2024 3:20 PM To:
Schiele, Raymond Joseph; Klein, Spencer Paul; jmontague@tva.gov Cc:
Allen Fetter; Michelle Hayes; Sean Gallagher; ClinchRiver-CPSafDocsPEm Resource; Joseph Ashcraft; Dinesh Taneja; Luissette Candelario-Quintana; Shao Lai; Brian Wittick; Gordon Curran; Fanta Sacko; Ian Tseng
Subject:
Readiness Assessment Observations on draft PSAR Chapter/Sections 3.3, 3.4, 3.5, and 7, Instrumentation and Controls (Phase 2) - draft Clinch River CP application Attachments:
Initial Observations PSAR 7 Readiness Assessment Phase 2.pdf; Initial Observations PSAR 3.3 3.4 3.5_Readiness Assessment_Phase 2.pdf Good Afternoon, Attached are initial NRC staff observations on draft PSAR Chapter/Sections 3.3, Wind and Tornado Loadings; 3.4, Water Level (Flood) Design, 3.5, Missile protection; and Chapter 7, Instrumentation and Controls, that staff viewed in TVAs electronic reading room as part of Phase 2 of the Readiness Assessment of the draft Clinch River CP application.
After all six phases of the Readiness Assessment are completed, NRC will transmit, via letter, a compilation of all final Readiness Observations on the Clinch River CP PSAR chapters and sections. The nomenclature initial is being used to account for potential TVA updates to the PSAR before the end of the Readiness Assessment.
If TVA makes any future updates to the draft PSAR chapters and sections for follow up observations by NRC staff, please contact me, Allen Fetter or Sean Gallagher.
- Thanks, Greg
Hearing Identifier:
ClinchRiver_CPSafDocs_Public Email Number:
14 Mail Envelope Properties (DM6PR09MB527100A4845EBA25AD6E6FB2902C2)
Subject:
Readiness Assessment Observations on draft PSAR ChapterSections 3.3, 3.4, 3.5, and 7, Instrumentation and Controls (Phase 2) - draft Clinch River CP application Sent Date:
3/19/2024 3:20:16 PM Received Date:
3/19/2024 3:20:22 PM From:
Greg Cranston Created By:
Gregory.Cranston@nrc.gov Recipients:
"Allen Fetter" <Allen.Fetter@nrc.gov>
Tracking Status: None "Michelle Hayes" <Michelle.Hayes@nrc.gov>
Tracking Status: None "Sean Gallagher" <Sean.Gallagher@nrc.gov>
Tracking Status: None "ClinchRiver-CPSafDocsPEm Resource" <ClinchRiver-CPSafDocsPEm.Resource@nrc.gov>
Tracking Status: None "Joseph Ashcraft" <Joseph.Ashcraft@nrc.gov>
Tracking Status: None "Dinesh Taneja" <Dinesh.Taneja@nrc.gov>
Tracking Status: None "Luissette Candelario-Quintana" <luissette.candelario-quintana@nrc.gov>
Tracking Status: None "Shao Lai" <Shaohua.Lai@nrc.gov>
Tracking Status: None "Brian Wittick" <Brian.Wittick@nrc.gov>
Tracking Status: None "Gordon Curran" <Gordon.Curran@nrc.gov>
Tracking Status: None "Fanta Sacko" <Fanta.Sacko@nrc.gov>
Tracking Status: None "Ian Tseng" <Ian.Tseng@nrc.gov>
Tracking Status: None "Schiele, Raymond Joseph" <rjschiele@tva.gov>
Tracking Status: None "Klein, Spencer Paul" <spklein@tva.gov>
Tracking Status: None "jmontague@tva.gov" <jmontague@tva.gov>
Tracking Status: None Post Office:
DM6PR09MB5271.namprd09.prod.outlook.com Files Size Date & Time MESSAGE 911 3/19/2024 3:20:22 PM Initial Observations PSAR 7 Readiness Assessment Phase 2.pdf 98865 Initial Observations PSAR 3.3 3.4 3.5_Readiness Assessment_Phase 2.pdf 170678 Options Priority:
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Readiness Assessment - Phase 2 Chapter 7, Instrumentation and Controlsi Clinch River CP application January 10, 2024 Revision 2/15/24 Chapter/Section 7.1 - Instrumentation and Controls Section Basis for Observation/Comment Readiness Assessment Observations/Comments Section 7.1 -
Instrumentation and Controls 10 CFR Part 50, Appendix A, General Design Criteria Note that the acceptability of the Instrumentation and Control (I&C) systems for BWRX-300 is contingent upon acceptability of NEDC-33934P BWRX-300 Safety Strategy Topical Report currently under review by NRC staff.
Chapter/Section 7.3.1.2 - Instrumentation and Controls - System Design and Associated Safety Functions Section Basis for Observation/Comment Readiness Assessment Observations/Comments Section 7.3.1.2 -
Instrumentation and Controls - System Design and Associated Safety Functions IEEE Standard 603-2018, Standard Criteria for Safety Systems for Nuclear Power Generating Stations, Clause 6.8 IEEE 603-2018 requires that for all devices that setpoints shall be determined using a documented methodology. A setpoint methodology was not provided nor mentioned in the CP. When will this document be provided to the NRC staff for review?
Section 7.3.1.2 -
Instrumentation and Controls - System Design and Associated Safety Functions 10 CFR 50.36, Technical Specifications 10 CFR 50.36(c)(1)(ii)(A) states that limiting safety system settings are settings for automatic protective devices related to those variables having significant safety functions. This clause requires that where a limiting safety system setting (LSSS) is specified for a variable on which a safety limit has been placed, the setting must be chosen so that automatic protective action will correct the abnormal situation before a safety limit is exceeded.
Clause 6.8 of IEEE 603 requires a setpoint methodology. Typically, this methodology complies with RG 1.105 r/4, which endorses ANSI/ISA 67.04.01 - 2018. The starting point for this calculation requires an analytic limit (AL), which is provided in the safety analysis of the application to protect the safety limits (SL). Typically, tables are provided in Chapter 7 that document all
Readiness Assessment - Phase 2 safety functions protecting SLs, thus requiring a setpoint calculation. This table includes sensor range, nominal setpoint (SP), and AL. Some of this information may not be available in the CPA until the design is complete.
i Input provided by NRR/DEX/EICB
Readiness Assessment - Phase 2 Initial Readiness Assessment Observationsi on draft PSAR Sections 3.3, Wind and Tornado Loadings, Section 3.4, Water Level (Flood) Design and 3.5, Missile Protection Clinch River CP application January 12, 2024 Revision 3/6/24 Section 3.3, Wind and Tornado Loadings Chapter/
Section Basis for Observation/Comment Readiness Assessment Observations Section 3.3, Wind and Tornado Loadings 10 CFR Part 50, Appendix A, General Design Criteria 2, Design Bases for Protection Against Natural Phenomena CPA Section 3.3 referenced other Chapter 3 subsections that have information required in Section 3.3. To be able to confirm that the extent of information required for Section 3.3 is complete, the staff will review the referenced CPA subsections per their respective phase schedules.
Currently, they are not in the TVA CPA eRR.
These include Subsection 3.8.4.4, Seismic II and Non-Seismic Category structures that have augmented requirements for tornado wind and missiles, which will be reviewed as part of the Phase 3 review, and Subsection 3.2.2, Assignment of Safety Class to Structures, Systems and Components, which will be reviewed as part of Phase 6.
Section 3.3, Wind and Tornado Loadings 10 CFR Part 50 Appendix A General Design Criteria 2, Design Bases for Protection Against Natural Phenomena Section 3.3.1.2 states that the BWRX-300 design uses ASCE 7-16. However, section 3.3.2.2 compares the BC-TOP-3-A criteria to ASCE 7-05.
Provide justification for not following the same code edition.
Section 3.3, Wind and Tornado Loadings 10 CFR Part 50, Appendix A, General Design Criteria 2, Design Bases for Protection Against Natural Phenomena and Standard Review Plan 3.3,2, Tornado Loadings.
SRP Section 3.3.2, in part E of the acceptance criteria, describes how to calculate combined tornado effects. CPA Section 3.3 does not seem to include information about the combined tornado effects.
Section 3.3, Wind and Tornado Loadings 10 CFR Part 50 Appendix A General Design Criteria 2, Design Bases for Protection Against Natural Phenomena Section 3.3.2.1 refers to subsection 3.8.4.4 for Seismic II and Non-Seismic Category structures.
Subsection 3.8.4.4 is for the control building (CB) and states that the CB is category II structure design per IBC. 3.8.4.4 further states that the CB
Readiness Assessment - Phase 2 is also evaluated for seismic and wind interaction with the RB.
Clarify whether all the Seismic II and Non-Seismic Category structures share the same augmented requirements described for the CB in section 3.8.4.4.
Section 3.3, Wind and Tornado Loadings 10 CFR Part 50, Appendix A, General Design Criteria 2, Design Bases for Protection Against Natural Phenomena CPA Section 3.3.2.2 states that "the RB is an enclosed (unvented) structure and that the exposed exterior roof and walls are designed for the full pressure drop". However, additional information should be provided on how the pressure differences created between the interior and the exterior of the structure were considered.
Section 3.3, Wind and Tornado Loadings 10 CFR Part 50, Appendix A, General Design Criteria 2, Design Bases for Protection Against Natural Phenomena CPA Section 3.3.2.3 states that the SSC that are not designed to withstand the tornado loading are arranged and designed to ensure no gross failure under the controlling wind loading. However, the applicant should include additional information that demonstrate that its failure will not result in structural damage to safety related structures, systems, and components.
Readiness Assessment - Phase 2 Section 3.4, Water Level (Flood) Design & Internal Flood Protection Chapter/Section Basis for Observation/Comment Readiness Assessment Observations Section 3.4, Water Level (Flood)
Design & Internal Flood Protection 10 CFR Part 50, Appendix A, General Design Criteria 2, Design Bases for Protection Against Natural Phenomena CPA Section 3.3 referenced other CPA subsections that have information required in Section 3.3 to be able to confirm that the extent of information required for Section 3.3 is complete. The staff will review the referenced CPA subsections per their respective phase schedules. These include Subsection 3.1.1, overall compliance for BWRX-300 design to 10CFR 50, Appendix A, General Design Criteria 2 and 4 for flood protection, and Subsections 2.4.1 through 2.4.14, evaluation of external flooding from natura phenomena.
These reviews are part of Phase 6. Currently, they are not in the TVA CPA eRR.
Note that two of the COL Action Items for the ESP SER Section 2.4 are related to establishing design basis external flood level and flood protections, which are in turn used in Chapter 3.4. The applicant should provide information on how to address these two COL Action items related to flood hazard evaluation.
Readiness Assessment - Phase 2 10 CFR Part 50, Appendix A, General Design Criteria 2, Design Bases for Protection Against Natural Phenomena.
Standard Review Plan 3.4.1; and Regulatory Guide 1.70, Standard Format and Content of Safety Analysis Reports for Nuclear Power Plants (LWR Edition).
Provide additional details of flood analysis methodology and approach to address items such as:
- 1. Describe limiting flood sources (pipe routing, tank, or other water source)
- 2. Location of SSCs subject to flooding.
- 3. Describe analysis methodology, such as level-by-level and room-by-room details of limiting/bounding source and failure considered.
- 4. Describe protective and mitigation features provided or credited. Design features that will be used to mitigate the effects or spread of internal flooding.
- 5. Describe building elevation flooding evaluated.
- 6. Describe features credited within building and impact on other levels or areas to establish bounding flood levels.
- 7. Considers possible flow paths from non-safety related areas into areas containing safety related SSCs.
Readiness Assessment - Phase 2 Section 3.5, Missile Protection Chapter/Section Basis for Observation/Comment Readiness Assessment Observations Section 3.5, Missile Protection 10 CFR Part 50, Appendix A, General Design Criteria 2, Design Bases for Protection Against Natural Phenomena Standard Review Plan, Sections 3.5.1.1 Internally Generated Missiles (Outside Containment) and 3.5.1.2, Internally Generated Missiles (Inside Containment)
CPA sections 3.5.1.1 and 3.5.1.2 define internal generated missile protection. CPA section 3.5.1.1 states, Potential missiles that could result from failure of pressurized components are characterized as contained fluid energy missiles or stored energy (elastic missiles). These potential missiles are conservatively evaluated against the design criteria. CPA indicates missiles analyzed include rotating equipment, high-pressure system ruptures, and missiles caused by, or as consequence of, gravitational effects (e.g., heavy load drop).
CPA section 3.5.1.1 and 3.5.1.2 should describe design criteria and type of missile sources evaluated, including justification for declaring missile source as credible or non-credible. For potential missiles considered, the method of SSC protection should be defined.
10 CFR Part 50, Appendix A, General Design Criteria 2, Design Bases for Protection Against Natural Phenomena Standard Review Plan (SRP)
Sections: 3.5.1.1, Internally Generated Missiles (Outside Containment); 3.5.1.2, Internally Generated Missiles (Inside Containment); and 3.5.1.3, Turbine Missiles.
CPA Section 3.5.1 indicates that portions of SRP sections 3.5.1.1, 3.5.1.2 and 3.5.1.3 are used to define parameters, but it is unclear which portions are applicable. The document contains statements, as defined in Nuclear Regulatory Reports (NUREG)-0800, Standard Review Plan (SRP) 3.5.1.1 through 3.5.1.3 and applicable portions of new NUREG-0800, SRP 3.5.1.1 through 3.5.1.3. SRP describes potential missiles and contain specific criteria to define statistical significance of an identified missile using probabilistic analysis.
CPA should elaborate on applicable SRP guidance and method for defining statistically significant missiles, such as potential missile occurrence, impact on significant target, and probability of significant damage.
i Input provided by NRR/DEX/ESEB & NRR/DSS/SCPB staff.