Letter Sequence RAI |
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EPID:L-2022-LLA-0162, Proposed License Amendment Request Removal of Refueling Water Chemical Addition Tank and Replacement of Containment Sump (Open) |
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MONTHYEARML22307A3172022-11-0303 November 2022 Proposed License Amendment Request Removal of Refueling Water Chemical Addition Tank and Replacement of Containment Sump Project stage: Request ML22342B1472022-12-0808 December 2022 NRR E-mail Capture - Acceptance Review for LAR Re NAPS Post LOCA Buffer Change (L-2022-LLA-0162) Project stage: Acceptance Review ML23059A2282023-02-28028 February 2023 NRR E-mail Capture - Draft RAIs for Containment Buffer Change to Natb (L-2022-LLA-0162) Project stage: Draft RAI ML23075A0232023-03-15015 March 2023 NRR E-mail Capture - RAI - License Amend Req (LAR) to Revise Tech Spec (Ts) 3.6.8 Limiting Condition for Operation to Remove Refueling Water Chemical Addition Tank and Replace the Containment Sump Buffer North Anna, 1 and 2 (L-2022-LLA-0162 Project stage: RAI 2022-12-08
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Category:E-Mail
MONTHYEARML23320A1122024-01-18018 January 2024 NRC to Fws, Concurrence with Endangered Species Act Determinations for North Anna Power Station, Units 1 and 2, Subsequent License Renewal, Issuance of Draft Supplemental Environmental Impact Statement, and Opportunity for Public Comment ML23355A2722023-12-21021 December 2023 NRR E-mail Capture - Schedule Revision for Emergency Preparedness Staff Augmentation Times License Amendment Request ML23318A1172023-11-13013 November 2023 NRR E-mail Capture - Formal Issuance of RAIs for North Anna Technical Support Center (TSC) License Amendment Request (LAR) (L-2023-LLA-0006) ML23257A2092023-09-14014 September 2023 NRR E-mail Capture - Formal Issuance of 2nd Round RAIs for Surry Units 1&2 and North Anna Units 1&2 Emergency Plans LAR ML23243A9862023-08-31031 August 2023 NRR E-mail Capture - Draft RAIs for EP Staff Augmentation Times LAR (L-2022-LLA-0166) ML23219A1602023-08-0707 August 2023 003 Radiation Safety Baseline Inspection Information Request ML23171B0522023-06-20020 June 2023 NRR E-mail Capture - RAI for Review of Appendix F to DOM-NAF-2-P (Redacted) ML23075A0232023-03-15015 March 2023 NRR E-mail Capture - RAI - License Amend Req (LAR) to Revise Tech Spec (Ts) 3.6.8 Limiting Condition for Operation to Remove Refueling Water Chemical Addition Tank and Replace the Containment Sump Buffer North Anna, 1 and 2 (L-2022-LLA-0162 ML23067A2162023-03-0707 March 2023 NRR E-mail Capture - RAI for North Anna, 1 & 2, Surry 1 & 2, Millstone, 2 & 3, Request for Approval of App. F Fleet Report DOM-NAF-2-P, Qual of the Framatome ORFEO-GAIA and ORFEO-NMGRID CHF Correlations in the Dominion VIPRE-D Computer Code ML23060A0932023-03-0101 March 2023 NRR E-mail Capture - Formal Issuance of RAIs for Surry/North Anna Emergency Plans LAR ML23059A2282023-02-28028 February 2023 NRR E-mail Capture - Draft RAIs for Containment Buffer Change to Natb (L-2022-LLA-0162) ML23039A1712023-02-0808 February 2023 NRR E-mail Capture - Acceptance Review for Technical Support Center (TSC) Relocation (L-2023-LLA-0006) ML23018A0352023-01-17017 January 2023 NRR E-mail Capture - Acceptance Review for Fleet Report Re Appendix F of DOM-NAF-2-P (L-2022-LLT-0003) ML22342B1472022-12-0808 December 2022 NRR E-mail Capture - Acceptance Review for LAR Re NAPS Post LOCA Buffer Change (L-2022-LLA-0162) ML22335A4842022-12-0101 December 2022 NRR E-mail Capture - Acceptance Review for LAR North Anna Power Station - Units 1 and 2 and Surry Power Station - Units 1 and 2 Emergency Plan Staff Augmentation Times (L-2022-LLA-0166) ML22242A0452022-08-23023 August 2022 NRR E-mail Capture - Dominion GL 04-02 Response Draft RAIs (L-2017-LRC-0000) ML22174A3552022-06-23023 June 2022 NRR E-mail Capture - Acceptance Review for Dominion Fleet LAR to Implement TSTF-554 (L-2022-LLA-0078) ML22104A0252022-04-14014 April 2022 NRR E-mail Capture - Dominion Presentation Slides for April 21, 2022 Public Meeting on Emergency Preparedness Submittal for the North Anna Power Station and the Surry Power Station ML22083A2102022-03-24024 March 2022 NRR E-mail Capture - Draft RAI - Relief Request N2-14-LMT-003 Fourth Ten Year Inservice Inspection Interval ML22032A0962022-02-0101 February 2022 002 Radiation Safety Baseline Inspection Information Request ML22018A0272022-01-18018 January 2022 2022 All RFI Responses - Exercise and Program Inspections - Revl ML22007A2672022-01-0707 January 2022 NRR E-mail Capture - North Anna, Unit 2, ASME Section XI Inservice Inspection Program Relief Request N2-14-LMT-003 Fourth Interval Third Period Limited Examinations (L-2021-LLR-0088) ML21335A0812021-12-0101 December 2021 NRR E-mail Capture - Acceptance Review for OMN-28 Request Alternative to ISTC-3700, Position Verification Testing (L-2021-LLR-0086) ML21334A1922021-11-30030 November 2021 NRR E-mail Capture - Audit Plan for Reactor Core Thermal-Hydraulics Using the VIPRE-D Appendix E Review ML21327A3652021-11-23023 November 2021 NRR E-mail Capture - Draft RAI for TSTF-577 LAR ML21326A1502021-11-22022 November 2021 NRR E-mail Capture - Acceptance Review for Relocation of Unit Staff Requirements to the QAPD LAR (L-2021-LLA-0195) ML21322A0962021-11-18018 November 2021 Final Request for Additional Information Set 5 - North Anna SLRA Safety Review (EPID No. L-2020-SLR-0000) - Email ML21312A0082021-11-0404 November 2021 Enclosure 2 - NAPS Draft SER Table A.1-1 Markup ML21312A0112021-11-0404 November 2021 Enclosure 3 - NAPS Draft SER Section 3 Comments ML21312A0012021-11-0404 November 2021 Comments on North Anna Draft SER ML21306A3302021-11-0202 November 2021 NRR E-mail Capture - Acceptance Review for TSTF-569 LAR ML21286A7372021-10-13013 October 2021 Additional Element Included in the Implementation Plan for the Surry Fuel Melt Safety Limit (SL) LAR ML21274A0022021-09-30030 September 2021 NRR E-mail Capture - Acceptance Review for TSTF-577 LAR (L-2021-LLA-0158) ML21312A0022021-09-21021 September 2021 Enclosure 1 - E-mail - NAPS SLR SER Appendix a for Dominion Review ML21312A0072021-09-21021 September 2021 Enclosure 1 - E-mail - Enclosure B - NAPS SER App a - Dominion Comments 9-21-2021 ML21312A0032021-09-21021 September 2021 Enclosure 1 - E-mail - Enclosure a - Dominion Table A4.4-1 Clean Version ML21256A0672021-09-13013 September 2021 Final Request for Confirmation of Information Set 2 - North Anna SLRA Safety Review (EPID No. L-2020-SLR-0000) - Email ML21152A1722021-09-0707 September 2021 NRC to Fws, NRC Issuance of Draft Environmental Impact Statement for North Anna Subsequent License Renewal, Opportunity for Public Comment, and Endangered Species Act Determinations ML21238A0942021-08-25025 August 2021 Draft Request for Additional Information Set Z - North Anna SLRA Safety Review (EPID No. L-2020-SLR-0000) - Email ML21225A5512021-08-13013 August 2021 Discussion Point for Public Meeting Regarding Fire Protection Piping Cyclic Loading - Transmittal E-mail ML21195A2442021-07-13013 July 2021 NRR E-mail Capture - Draft RAI Appendix E to Topical Report DOM-NAF-2 Qualification of the Framatome BWU-I CHF Correlation in the Dominion Energy VIPRE-D Computer Code ML21188A1632021-07-0707 July 2021 Final Request for Additional Information Set 4 - North Anna SLRA Safety Review (EPID No. L-2020-SLR-0000) - Email ML21154A0152021-06-0101 June 2021 NRR E-mail Capture - Acceptance Review for Primary Grade Water LAR (L-2021-LLA-0082) ML21140A3682021-05-20020 May 2021 Response to North Anna Hardship (Temporary Staff Guidance Additional Guidance for FOF Inspections During the PHE) ML21140A3712021-05-19019 May 2021 FOF Discussion ML21123A2972021-05-0303 May 2021 Final Request for Additional Information Set 3 - North Anna SLRA Safety Review (EPID No. L-2020-SLR-0000) - E-mail ML21091A0022021-04-0101 April 2021 Final Request for Additional Information Set 2 - North Anna SLRA Safety Review (EPID No. L-2020-SLR-0000) - Email ML21076A4622021-03-17017 March 2021 NRR E-mail Capture - Draft RAI for Versatile Internals and Component Program for Reactors Vipre Code Review (L-2021-LLT-0000) ML21075A0032021-03-12012 March 2021 Emergency Preparedness Exercise Inspection Request for Information for - Brunswick, Catawba, North Anna, Oconee, Vogtle 1 & 2 ML21069A3522021-03-10010 March 2021 NRR E-mail Capture - Acceptance Review for Topical Report DOM-NAF-2 VIPRE-D 2024-01-18
[Table view] Category:Request for Additional Information (RAI)
MONTHYEARML23318A1172023-11-13013 November 2023 NRR E-mail Capture - Formal Issuance of RAIs for North Anna Technical Support Center (TSC) License Amendment Request (LAR) (L-2023-LLA-0006) ML23257A2092023-09-14014 September 2023 NRR E-mail Capture - Formal Issuance of 2nd Round RAIs for Surry Units 1&2 and North Anna Units 1&2 Emergency Plans LAR ML23243A9862023-08-31031 August 2023 NRR E-mail Capture - Draft RAIs for EP Staff Augmentation Times LAR (L-2022-LLA-0166) ML23219A1602023-08-0707 August 2023 003 Radiation Safety Baseline Inspection Information Request ML23171B0522023-06-20020 June 2023 NRR E-mail Capture - RAI for Review of Appendix F to DOM-NAF-2-P (Redacted) ML23081A5282023-04-26026 April 2023 Request for Additional Information - North Anna Subsequent License Renewal Application Environmental Review ML23075A0232023-03-15015 March 2023 NRR E-mail Capture - RAI - License Amend Req (LAR) to Revise Tech Spec (Ts) 3.6.8 Limiting Condition for Operation to Remove Refueling Water Chemical Addition Tank and Replace the Containment Sump Buffer North Anna, 1 and 2 (L-2022-LLA-0162 ML23060A0932023-03-0101 March 2023 NRR E-mail Capture - Formal Issuance of RAIs for Surry/North Anna Emergency Plans LAR ML23059A2282023-02-28028 February 2023 NRR E-mail Capture - Draft RAIs for Containment Buffer Change to Natb (L-2022-LLA-0162) ML22251A1292022-09-0909 September 2022 Request for Additional Information Related to Response to Generic Letter 2004-04 ML22242A0452022-08-23023 August 2022 NRR E-mail Capture - Dominion GL 04-02 Response Draft RAIs (L-2017-LRC-0000) ML22083A2102022-03-24024 March 2022 NRR E-mail Capture - Draft RAI - Relief Request N2-14-LMT-003 Fourth Ten Year Inservice Inspection Interval ML21327A3652021-11-23023 November 2021 NRR E-mail Capture - Draft RAI for TSTF-577 LAR ML21322A0962021-11-18018 November 2021 Final Request for Additional Information Set 5 - North Anna SLRA Safety Review (EPID No. L-2020-SLR-0000) - Email ML21322A0992021-11-18018 November 2021 Final Request for Additional Information Set 5 - North Anna SLRA Safety Review (EPID No. L-2020-SLR-0000) - Enclosure ML21256A0672021-09-13013 September 2021 Final Request for Confirmation of Information Set 2 - North Anna SLRA Safety Review (EPID No. L-2020-SLR-0000) - Email ML21256A0692021-09-13013 September 2021 Final Request for Confirmation of Information Set 2 - North Anna SLRA Safety Review (EPID No. L-2020-SLR-0000) - Request for Confirmation of Information ML21238A0942021-08-25025 August 2021 Draft Request for Additional Information Set Z - North Anna SLRA Safety Review (EPID No. L-2020-SLR-0000) - Email ML21238A0982021-08-25025 August 2021 Draft Request for Additional Information Set Z - North Anna SLRA Safety Review (EPID No. L-2020-SLR-0000) - Enclosure ML21225A5022021-08-13013 August 2021 Request for Additional Information for North Anna Power Station, Units 1 and 2, Surry Power Station, Units 1 and 2, and Millstone Power Station, Units 2 and 3, Appendix E of Fleet Report Com-Naf-2 (EPID:L02021-LLT-0000) Public Version ML21195A2442021-07-13013 July 2021 NRR E-mail Capture - Draft RAI Appendix E to Topical Report DOM-NAF-2 Qualification of the Framatome BWU-I CHF Correlation in the Dominion Energy VIPRE-D Computer Code ML21188A1632021-07-0707 July 2021 Final Request for Additional Information Set 4 - North Anna SLRA Safety Review (EPID No. L-2020-SLR-0000) - Email ML21188A1652021-07-0707 July 2021 Final Request for Additional Information Set 4 - North Anna SLRA Safety Review (EPID No. L-2020-SLR-0000) - Enclosure ML21174A1952021-06-23023 June 2021 Safety RAIs - Set Y - Draft - Enclosure ML21166A3512021-06-15015 June 2021 Safety RAIs - Set 4 - Draft ML21123A2972021-05-0303 May 2021 Final Request for Additional Information Set 3 - North Anna SLRA Safety Review (EPID No. L-2020-SLR-0000) - E-mail ML21123A2982021-05-0303 May 2021 Final Request for Additional Information Set 3 - North Anna SLRA Safety Review (EPID No. L-2020-SLR-0000) - Enclosure ML21091A0032021-04-0101 April 2021 Final Request for Additional Information Set 2 - North Anna SLRA Safety Review (EPID No. L-2020-SLR-0000) - Enclosure 1 - RAIs ML21091A0042021-04-0101 April 2021 SLRA Safety Review - Withdrawn Requests for Information (EPID No. L-2020-SLR-0000) - Enclosure 2 ML21076A4622021-03-17017 March 2021 NRR E-mail Capture - Draft RAI for Versatile Internals and Component Program for Reactors Vipre Code Review (L-2021-LLT-0000) ML21075A0032021-03-12012 March 2021 Emergency Preparedness Exercise Inspection Request for Information for - Brunswick, Catawba, North Anna, Oconee, Vogtle 1 & 2 ML21063A5602021-03-0404 March 2021 Final Request for Additional Information Set 1 - North Anna SLRA Safety Review (EPID L-2020-SLR-0000) - Enclosure ML21049A0212021-02-17017 February 2021 Notification of an NRC Fire Protection Team Inspection (FPTI) (NRC Inspection Report 05000338/2021012 and 05000339/2021012) and Request for Information (RFI) ML21028A3902021-01-29029 January 2021 Request for Additional Information - North Anna Subsequent License Renewal Application Environmental Review (EPID Number: L-2020-SLE-0000) (Docket: 50-338 and 50-339) ML21028A4352021-01-28028 January 2021 Notification of Target Set Inspection and Request for Information (NRC Inspection Report No. 05000338/2021404 and 05000339/2021404) ML21012A3412021-01-22022 January 2021 Requests for Confirmation of Information for the Environmental Review of the North Anna Power Station, Units 1 and 2, Subsequent License Renewal Application (EPID Number: L-2020-SLE-0000) (Docket: 50-338 and 50-339) ML21019A4512021-01-19019 January 2021 Notification of Inspection and Request for Information ML20316A0422020-11-10010 November 2020 NRR E-mail Capture - FW: Draft RAI for North Anna Unit 2 Steam Generator Tube Inspection Report (ML19179A075) ML20223A3412020-08-10010 August 2020 003 Radiation Safety Baseline Inspection Information Request ML20218A4282020-08-0505 August 2020 Notification of Inspection and Request for Information ML20125A0762020-05-0101 May 2020 NRR E-mail Capture - Draft RAI Related to Revised Reactor Vessel Material Surveillance Capsule Withdrawal Schedule Dominion Energy Virginia North Anna Power Station Units 1 and 2 (L-2020-LLL-0038) ML20113A5792020-04-21021 April 2020 NRR E-mail Capture - Draft RAI North Anna Fifth 10-year Interval Relief Request (L-2020-LLR-0023) ML19354B6142019-12-20020 December 2019 NRR E-mail Capture - Draft RAI for North Anna Relief Request P-9 ML19317F1042019-11-0707 November 2019 NRR E-mail Capture - Draft RAIs for SB LOCA LAR (Non Prop) ML19191A2512019-07-10010 July 2019 NRR E-mail Capture - Request for Additional Information Open Phase Condition LAR ML19169A0962019-06-17017 June 2019 NRR E-mail Capture - Request for Additional Information Emergency Action Level Scheme Change for Millstone Power Station - Units 1, 2, and 3, North Anna Power Station - Units 1 and 2, and Surry Power Station - Units 1 and 2 ML19162A0052019-06-10010 June 2019 NRR E-mail Capture - Draft RAIs for Dominion EAL Scheme Change ML19108A1902019-04-18018 April 2019 Emergency Preparedness Program Inspection Request for Information ML19060A2432019-03-0101 March 2019 Related to License Amendment Request to Address Open Phase Conditions ML18337A1312018-11-29029 November 2018 NRR E-mail Capture - North Anna SPRA (Fukushima 50.54f) Audit Follow-Up Clarification Question on Plant Modifications 2023-09-14
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From: Ed Miller Sent: Wednesday, March 15, 2023 1:09 PM To: Shayan.Sinha@dominionenergy.com
Subject:
RAI for North Anna NaTB LAR Attachments: North Anna NaTB LAR RAI.docx
- Shayan, By letter dated November 3, 2022 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML22307A317) Viginia Electric and Power Company submitted to the U.S. Nuclear Regulatory Commission (NRC) a request for review and approval of an amendment to the license for North Anna Power Station, Units 1 and 2. The proposed change would allow replacement of the current containment LOCA Ph buffer (NaOH) with a new one (NaTB).
The NRC staff has reviewed the information submitted and needs additional information to complete its review and approval of the licensees submittal. These requests for additional (RAIs) are attached to this email and are released formally with a 30-day response period (April 14, 2023) requested.
Ed Miller (301) 415-2481
Hearing Identifier: NRR_DRMA Email Number: 2000 Mail Envelope Properties (SA1PR09MB7487DD69DC96EC20A1907075E9BF9)
Subject:
RAI for North Anna NaTB LAR Sent Date: 3/15/2023 1:09:16 PM Received Date: 3/15/2023 1:09:00 PM From: Ed Miller Created By: Ed.Miller@nrc.gov Recipients:
"Shayan.Sinha@dominionenergy.com" <Shayan.Sinha@dominionenergy.com>
Tracking Status: None Post Office: SA1PR09MB7487.namprd09.prod.outlook.com Files Size Date & Time MESSAGE 789 3/15/2023 1:09:00 PM North Anna NaTB LAR RAI.docx 36985 Options Priority: Normal Return Notification: No Reply Requested: No Sensitivity: Normal Expiration Date:
REQUEST FOR ADDITIONAL INFORMATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION LICENSE AMENDMENT REQUEST (LAR) TO REVISE TECHNICAL SPECIFICATION (TS) 3.6.8 LIMITING CONDITION FOR OPERATION TO REMOVE THE REFUELING WATER CHEMICAL ADDITION TANK AND REPLACETHE CONTAINMENT SUMP BUFFER NORTH ANNA POWER STATION, UNITS 1 AND 2 NRC DOCKET NOS. 50-338 and 50-339 (L-2022-LLA-0162)
By Letter dated November 3, 2022 (Agencywide Documents Access Management System (ADAMS) Accession No. ML22307A317), Virginia Electric and Power Company (Dominion Energy Virginia, the licensee) requested amendments to North Anna Power Station (NAPS),
Units 1 and 2, Renewed Facility Operating License Numbers NPF-4 and NPF-7, respectively.
The proposed amendment would revise the NAPS, Units 1 and 2, TS to eliminate the Refueling Water Chemical Addition Tank (CAT) and allow the use of sodium tetraborate decahydrate (NaTB) to replace sodium hydroxide (NaOH) as a chemical additive (buffer) for Containment sump pH control.
The NRC staff has reviewed the LAR. As a result of its review, the NRC staff has determined that the following additional information is needed to complete its review of the LAR.
ELTB RAI - 1 The regulations in 10 CFR 50.49, Environmental qualification of electric equipment important to safety for nuclear power plants, requires, in part, licensees to establish a program for qualifying electric equipment important to safety as defined in 50.49(b). The regulation in 50.49(e) requires that the electric equipment qualification program must include and be based on the following parameters: temperature and pressure, humidity, chemical effects, radiation, aging, submergence, synergistic effects, and margins.
Section 3.1.6, Environmental Qualification (EQ) of Equipment, of the submittal dated November 3, 2022, provides the licensees evaluation of the impact the proposed changes have on the chemical parameters for equipment subject to 10 CFR 50.49. It is not apparent, however, that the licensee discussed the impact of the proposed changes on other environmental parameters that affect EQ of electric equipment such as temperature, pressure, radiation, etc.
Provide a discussion on the impact of the proposed changes on the other environmental parameters specified in 10 CFR 50.49(e).
NCSG RAI - 1 Page 14 of 26 in attachment 1 of the submittal dated November 3, 2022, states that each of the 8 empty baskets weighs 1,465 lbs. The weight of each basket when loaded with sodium tetraborate is stated to be approximately 4,450 lbs. Subtracting the weight of the empty basket from the total loaded weight results in 2,985 lbs of sodium tetraborate per basket. The combined weight of sodium tetraborate for 8 baskets would be 23,880 lbs. This amount exceeds the proposed TS limit for maximum mass of sodium tetraborate which is stated as 22,192 lbs. Explain how the maximum TS value for sodium tetraborate will not be exceeded given the design parameters of a fully loaded basket described above.
SNSB RAI - 1 The following General Design Criteria of Title 10 of Code of Federal Regulations (CFR), Part 50, Appendix A, whose conformity is discussed in Chapter 3 of the North Anna UFSAR, are applicable for containment design:
Criterion 16Containment design. Reactor containment and associated systems shall be provided to establish an essentially leak-tight barrier against the uncontrolled release of radioactivity to the environment and to assure that the containment design conditions important to safety are not exceeded for as long as postulated accident conditions require.
Criterion 38Containment heat removal. A system to remove heat from the reactor containment shall be provided. The system safety function shall be to reduce rapidly, consistent with the functioning of other associated systems, the containment pressure and temperature following any loss-of-coolant accident and maintain them at acceptably low levels.
Criterion 50Containment design basis. The reactor containment structure, including access openings, penetrations, and the containment heat removal system shall be designed so that the containment structure and its internal compartments can accommodate, without exceeding the design leakage rate and with sufficient margin, the calculated pressure and temperature conditions resulting from any loss-of-coolant accident. This margin shall reflect consideration of (1) the effects of potential energy sources which have not been included in the determination of the peak conditions, such as energy in steam generators and as required by § 50.44 energy from metal-water and other chemical reactions that may result from degradation but not total failure of emergency core cooling functioning, (2) the limited experience and experimental data available for defining accident phenomena and containment responses, and (3) the conservatism of the calculational model and input parameters.
In its letter dated November 3, 2022, Attachment 1, Section 4.1, Applicable Regulatory Requirements/Criteria, states that the ability of the quench spray (QS) and recirculation spray (RS) subsystems to cool the reactor core and return the containment to subatmospheric pressure and maintain it at subatmospheric pressure is not affected by the proposed change. It also states that the proposed change will not impact the ability of NAPS to comply with the requirements of Criterion 38. It is not, however, apparent that a technical evaluation of these results is provided in Section 3.0, Technical Evaluation.
Based on the proposed change, the combined effect of parameters given below could impact the loss-of-coolant accident (LOCA) containment response.
- The reduction of containment free volume from the addition of NaTB baskets.
- Removal of NaOH from the refueling water storage tank (RWST) water in the analysis of record (AOR) would affect its density and, therefore, impact the QS pump performance and flow rate.
- Addition of NaTB and removal of NaOH from the sump water in the AOR would affect its density and, therefore, impact RS pump performance and flow rate during the LOCA recirculation phase.
- Change in the performance of the RS cooler due to change in flow rate and its overall heat transfer coefficient.
- Change in the properties of the QS and RS droplets.
Due to the combined effect of the changes in above parameters and/or any other, provide a discussion of changes and impact on the following:
(a) LOCA containment pressure and temperature response AOR results.
(b) Net positive suction head (NPSH) AOR results for the pumps that draw water from the sump during LOCA recirculation phase.
ESEB RAI 1
Background:
The following General Design Criteria of Title 10 of Code of Federal Regulations (CFR), Part 50, Appendix A, whose conformity is discussed in Chapter 3 of the North Anna UFSAR, are applicable for containment design:
10 CFR 50, Appendix A, General Design Criterion (GDC) 1, Quality standards and records, with respect to ensuring that the structures important to safety other than containment are designed, fabricated, erected, constructed, tested, and inspected to quality standards commensurate with the safety function to be performed.
10 CFR Part 50, Appendix A, GDC 2, Design bases for protection against natural phenomena, as it relates to the design of seismic Category I structures, systems, and components (SSCs),
requires, in part, that the SSCs important to safety shall be designed to withstand the effects of natural phenomena such as earthquakes, tornadoes, hurricanes, floods, tsunami, and seiches without loss of capability to perform their safety functions.
In its letter dated November 3, 2022, (ADAMS Accession No. ML23017A317), the licensee states in Subsection 3.2.1, NaTB Basket Design,:
The baskets are classified as Non-safety Quality (NSQ) based on not being functionally safety-related, but are required to be seismically anchored to prevent damage to nearby safety-related equipment. The baskets are also required to remainfunctional (i.e., some of or all their passive functions must remain intact) during and/or after a Design Basis Event (DBE). Therefore, the baskets are designed to meet Seismic II/I requirements and maintain their structural integrity during a DBE.
The design loads for the baskets are generated by combining the unfactored load effects of dead loading, chemical pressure loading, and seismic loading. The NaTB baskets were evaluated to maintain their structural integrity during an Earthquake DBE concurrent with post-LOCA elevated temperature conditions.
The basket members and connections are analyzed to meet applicable licensing and design basis requirements in the NAPS Updated Final Safety Analysis Report (UFSAR) for Unit 1 and Unit 2 and Dominion Energy Nuclear Engineering Standard (DNES)
DNES-VA-CE-0046, American Institute of Steel Construction (AISC) 9th Edition, "Manual of Steel Construction" [Reference 12].
Issue/Request:
a) Although, the NaTB is placed in granular form in baskets, it is not apparent whether additional forces or moments can result from movement of the NaTB within the baskets during seismic events and/or due to eccentric or non-uniform loading of the NaTB and may affect the walls or anchorage of the baskets. Discuss whether the forces generated from movement and/or eccentric/non-uniform loading of the NaTB within the baskets were considered in the seismic analysis.
b) It is not apparent whether the anchorage patterns of the NaTB baskets can be placed at the sites as qualified in the analytical report(s). Discuss whether the anchorage patterns of the NaTB baskets, as qualified in the analytical report(s), can be placed with acceptable engineering tolerances during the installation process at the sites.
c) It is not apparent whether prying effects on the anchor loads were considered in qualifying the anchors and associated baseplates. Describe whether the anchor loadings include prying effects to qualify the anchors and associated base plates. If not, describe why prying effect on anchors were not considered.
d) It is not apparent whether the material compositions of the NaTB basket and its anchorage system may be vulnerable to or could cause dissimilar-metal corrosion that could degrade the structural integrity of anchorages over the remaining period of the renewed facility operating license. Describe whether dissimilar-material condition exists between the NaTB basket and the anchorage system, and whether there would be a condition of dissimilar-metal corrosion. Describe whether a plant periodic condition monitoring program (new or existing) will be initiated to ensure the structural integrity of basket anchorages during the extended period of operation.
e) The application did not provide engineering/fabrication drawings of the basket and refer to any associated analytical report(s) in the application. Provide engineering/fabrication drawings and analytical report(s) of the NaTB basket(s).