ML19295E590

COL Docs - FW: LAR-19-016R1: Files to Support Oct. 24, 2019 Pre-submittal Meeting

ML19295E590
Person / Time
Site:	Vogtle
Issue date:	10/22/2019
From:	NRC
To:	NRC/NRR/DNRL
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Download: ML19295E590 (33)

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Vogtle PEmails From: Rankin, Jennivine Sent: Tuesday, October 22, 2019 8:18 AM To: Vogtle PEmails

Subject:

FW: LAR-19-016R1: Files to Support Oct. 24, 2019 Pre-submittal Meeting Attachments: LAR-19-016R1 - Draft Enclosures.pdf; PAR-19-016 Draft Enclosure.pdf From: Humphrey, Mark Phillips <MPHUMPHR@southernco.com>

Sent: Monday, October 21, 2019 4:29 PM To: Patel, Chandu <Chandu.Patel@nrc.gov>; Rankin, Jennivine <Jennivine.Rankin@nrc.gov>

Cc: Kellenberger, Nicholas <X2NRKELL@SOUTHERNCO.COM>; Hicks, Thomas E. <X2TEHICK@southernco.com>; Prat, Catherine <x2cpereg@southernco.COM>; Chamberlain, Amy Christine <ACCHAMBE@southernco.com>; Roberts, Kelli Anne <KROBERTS@southernco.com>; Wu, Si <wu1s@westinghouse.com>; Chester, Kenneth D.

<X2KDCHES@SOUTHERNCO.COM>

Subject:

[External_Sender] LAR-19-016R1: Files to Support Oct. 24, 2019 Pre-submittal Meeting Hi Jennie and Chandu-As discussed in prior communications, SNC plans to submit a revision to LAR-19-016 (LAR-19-016R1) on Friday October 25, 2019 to address a recently identified vertical reinforcement nonconformance in Unit 4 Wall L. Attached is a draft of the LAR revision enclosures to facilitate discussions during the pre-submittal meeting scheduled on Thursday, October 24, 2019. The revised LAR will provide new Enclosure 3, Revision to Request for License Amendment: Reinforcement Changes for Wall L and Wall 7.3, and new Enclosure 4, Revision to Proposed Changes to Licensing Basis Documents that will replace Enclosures 1 and 2, respectively, provided in the original LAR. Changes between Enclosures 1 and 3 will be shown with revision bars in the Enclosure 3 margin. The originally requested February 23, 2020 approval date for the LAR will not change.

Related to the LAR revision, SNC also plans to submit a second PAR (PAR-19-016-2) on Friday, October 25, 2019. This PAR will allow for the rebar installation and concrete placement for Unit 4 Wall L above elevation 117-6. [Note that SNC has received a No Objection Notice from the staff for the initial PAR (PAR-19-016) regarding Wall L and Wall 7.3.] This second PAR will only address the recently identified nonconformance with the vertical reinforcement in Wall L. SNC will request a no objection finding from the NRC Staff for the second PAR by November 15, 2019. A draft copy the PAR enclosure is attached.

SNC appreciates the opportunity to discuss these attachments and our associated LAR/PAR plans with the Staff during the October 24, 2019 pre-submittal meeting. Please contact me with any questions you may have.

Respectfully, Mark P. Humphrey Licensing Supervisor Nuclear Development Southern Nuclear 3535 Colonnade Parkway Birmingham, AL 35243 O: 205.992.6452 C: 205.215.5152 mphumphr@southernco.com 1

2 Hearing Identifier: Vogtle_COL_Docs_Public Email Number: 491 Mail Envelope Properties (BN6PR09MB1298ACE9907424CEF78CCAF198680)

Subject:

FW: LAR-19-016R1: Files to Support Oct. 24, 2019 Pre-submittal Meeting Sent Date: 10/22/2019 8:18:08 AM Received Date: 10/22/2019 8:18:20 AM From: Rankin, Jennivine Created By: Jennivine.Rankin@nrc.gov Recipients:

"Vogtle PEmails" <Vogtle.PEmails@nrc.gov>

Tracking Status: None Post Office: BN6PR09MB1298.namprd09.prod.outlook.com Files Size Date & Time MESSAGE 2617 10/22/2019 8:18:20 AM image001.gif 2058 LAR-19-016R1 - Draft Enclosures.pdf 2167958 PAR-19-016 Draft Enclosure.pdf 708662 Options Priority: Standard Return Notification: No Reply Requested: No Sensitivity: Normal Expiration Date:

Recipients Received:

Southern Nuclear Operating Company ND-19-XXXX Enclosure 3 Vogtle Electric Generating Plant nt (VEGP) Un Unit 4 T

AF Revision to Request st for License Amendment:

Reinforcement Changes Amend A

nges for Wall L a (LAR-19-016R1)

(LAR-19-0 and Wall 7.3 DR (This Enclosure consists of 20 pages, including this cover page)

ND-19-XXXX Revision to Request for License Amendment: Reinforcement Changes for Wall L and Wall 7.3 (LAR-19-016R1)

Table of Contents

1.

SUMMARY

DESCRIPTION

2. DETAILED DESCRIPTION

3. TECHNICAL EVALUATION

4. REGULATORY EVALUATION 4.1. Applicable Regulatory Requirements/Criteria 4.2. Precedent 4.3. Significant Hazards Consideration 4.4. Conclusions 5.

6.

ENVIRONMENTAL CONSIDERATIONS REFERENCES T

AF DR Page 2 of 20

ND-19-XXXX Revision to Request for License Amendment: Reinforcement Changes for Wall L and Wall 7.3 (LAR-19-016R1)

Pursuant to 10 CFR 52.98(c) and in accordance with 10 CFR 50.90, Southern Nuclear Operating Company (SNC) hereby requests an amendment to Combined License (COL) No. NPF-92 for Vogtle Electric Generating Plant (VEGP) Unit 4.

1.

SUMMARY

DESCRIPTION The proposed change would revise the provided area of horizontal and vertical steel reinforcement for VEGP Unit 4 Wall L from elevation 117-6 to 135-3 ;and revise the provided area of horizontal steel reinforcement for VEGP Unit 4 Wall 7.3 from elevation 117-6 to 135-3.

The proposed change impacts Updated Final Safety Analysis Report (UFSAR) Tier 2* information in UFSAR Tables 3H.5-5 and 3H.5-7, and Figures 3H.5-4 and 3H.5-12.

This enclosure requests approval of the license amendment necessary to implement this change.

2. DETAILED DESCRIPTION As described in COL Appendix C, Section 3.3, the nuclear island isla structures include the str containment and the shield and auxiliary buildings. The containment, containme sshield and auxiliary T

buildings are structurally integrated on a common basemat asemat which is embed plant grade level. The auxiliary building is reinforced orced concrete forced mechanical and electrical equipment located outside embedded below the finished concre and h e the containment co houses the safety-related and shield buildings.

AF The nuclear island structures, including the which lists the interior wall of auxiliary EL.160'-6" and west wall of the Main 153'-0", are seismic Category I and without loss of structural integrity those loads associated with:

e critical critical sections list ary building n Control Room (MCR) in d are designed anda con listed in COL Appendix C Table 3.3-7 uilding (column lineli 7.3), elevation (EL.) 66'-6" to (MCR (column line L)) EL. 117'-6" to EL.

safety-related functions. The design basis loads are rity and the safety-re safety-relat constructed to withstand design basis loads x

x x

D Normal plant operation R

eration (including dead loads, live loads, lateral earth pressure loads, and equipment loads, ads, including hydrodynamic hydrodyn hydrody External eventss (including rain, earthquake) loads, temperature and equipment vibration) rain snow, flood, tornado, tornado generated missiles and ra Internal events (including flood, pipe rupture, equipment failure, and equipment failure generated missiles)

The auxiliary building is a reinforced concrete and structural steel structure with three floors above grade (EL. 100'-0") and two floors below grade. The floor slabs and the structural walls of the auxiliary building are structurally connected to the cylindrical section of the shield building. The figures in UFSAR Section 1.2 show the layout of the auxiliary building and its interface with the other buildings of the nuclear island. UFSAR Figure 3.7.2-12 shows the key structural dimensions of the nuclear island.

As described in UFSAR Subsection 1.2.4.3, the primary function of the auxiliary building is to provide protection and separation for the seismic Category I mechanical and electrical equipment located outside the containment building. The seismic classification methodology used in AP1000 complies with the preceding criteria, as well as with recommendations stated within Regulatory Page 3 of 20

ND-19-XXXX Revision to Request for License Amendment: Reinforcement Changes for Wall L and Wall 7.3 (LAR-19-016R1)

Guide (RG) 1.29. Seismic Category I structures, systems, and components (SSCs) meet the quality assurance requirements of 10 CFR 50, Appendix B.

The design and analysis procedures for the seismic Category I structures, including assumptions on boundary conditions and expected behavior under loads, are in accordance with American Concrete Institute (ACI) 349-01, Code Requirements for Nuclear Safety Related Concrete Structures, as required by UFSAR Subsection 3.8.4.4.1. The criteria of ACI 349-01, Chapter 12, are applied in development and splicing of the reinforcing steel. The ductility criteria of ACI 349-01, Chapter 21, are applied in detailing and anchoring of the reinforcing steel. The application of Chapter 21 detailing is demonstrated in the reinforcement details of critical sections.

Sections 21.2 and 21.6 of ACI 349-01 are applicable to walls serving as parts of the earthquake force-resisting systems. These requirements are considered in the detailing of reinforcement in the walls and floors of the auxiliary building. Transverse reinforcement em terminating at the edges of structural walls or at openings is detailed in accordance with Subsect Subsection 21.6.6.5 of ACI 349-01.

Subse The concrete structures are designed according to the strength ngth d methods of ACI 349-01, design m using the load combinations specified in UFSAR Table 3.8.4-2.8.4-2 8.4-2.

Auxiliary Building Wall L As described in UFSAR Subsection 3H.5.1.3, the the west side of the Main Control Room (MCR).

T e wall at column R). It extends colum line L (Wall L) is a shear wall on xtends from the top of the basemat at 66'-6" AF to the top of the roof. The wall is 2 feet thick.

by the floor slabs on both side of it and the of the MCR boundary is from EL. 117'-6" The auxiliary building design loads designed for the applicable loads.

k. Out-of-plane lateral ck.

he roof at the top. Th

'-6" to EL.

L. 135'-3".

ds are described in UFSAR UF la support is provided to the wall The segment of the wall that is a part Subsection 3H.3.3, and the wall is ads. In addition to tthe dead, live and seismic loads, the wall is designed to withstand a 6.5 pounds unds per square inch pressure load due to a pipe break in the main D

steam isolation valve (MSIV) is also designed to withstand R

pipe rupture and are shown eve though it is a break exclusion area. This wall segment SIV) room even hstand a jet load due The governing load combination an hown in UFSAR du to the pipe break.

associated design loads are those due to the postulated and as UFSA Table 3H.5-6. Table 3H.5-7 and Figure 3H.5-12 present the details of the wall reinforcement.

forcement The sections where the required reinforcement is calculated are shown in UFSAR Figure 3H.5-23H.5 (Sheet 3).

As shown in UFSAR Figure 3H.5-12, the design of the Auxiliary Building Wall L requires horizontal reinforcement bar consisting of #11@6" Each Face (EF) + #10@12"EF in two layers from EL.

117'-6" to EL. 135'-3", and vertical reinforcement bar consisting of #11@6" EF + #10@6" EF in two layers from EL. 117'-6" to EL. 135'-3".

Auxiliary Building Wall 7.3 As described in UFSAR Subsection 3H.5.1.2, the wall at column line 7.3 (Wall 7.3) is a shear wall that connects the shield building and the nuclear island exterior wall at column line I. It extends from the top of the basemat at elevation 66'-6" to the top of the roof. The wall is 3 feet thick below the grade at EL 100'-0" and 2 feet thick above the grade.

The auxiliary building design loads are described in UFSAR Subsection 3H.3.3, and the wall is designed for the applicable loads. For various segments of this wall, the corresponding governing Page 4 of 20

ND-19-XXXX Revision to Request for License Amendment: Reinforcement Changes for Wall L and Wall 7.3 (LAR-19-016R1) load combination and associated design loads are shown in UFSAR Table 3H.5-4. UFSAR Table 3H.5-5 and Figure 3H.5-4 present the details of the wall reinforcement. The sections where the required reinforcement is calculated are shown in UFSAR Figure 3H.5-2 (Sheet 2).

As shown in UFSAR Figure 3H.5-4, the design of the Auxiliary Building Wall 7.3 requires horizontal reinforcement bar consisting of #10@12" EF + #10@12" EF in one layer from EL.

117'-6" to EL. 135'-3.

During construction at VEGP Unit 4, three independent nonconformities at two separate locations (Wall L and Wall 7.3) were identified. At Wall L, the as-built amount of horizontal and vertical reinforcement provided does not meet the specified minimum provided reinforcement in the UFSAR. At Wall 7.3,, the as-built amount of horizontal reinforcement provided does not meet the specified minimum provided reinforcement in the UFSAR.

Wall L Changes In accordance with UFSAR Figure 3H.5-12, the design of the Auxiliary Auxilia Build Building Wall L from EL.

117'-6" to 135'-3" requires horizontal reinforcement bar (rebar) cons consisting of #11@6" EF +

1. 10@12" EF in two layers. As specified on design majority of the width of the wall. At the boundaries reinforcement bar (referred to as dowels) developed T n drawings, straight b ies of the wall, aries evelopeded within w

with the bo bar is utilized to span a ba this straight bar is spliced to bounding walls. The vertical AF construction joint at the face of the Shield Building represents VEGP Unit 4, the Shield Building wall has represen the south boundary for Wall L. At as 35 #11 hook bar dowel Wall L. At VEGP Unit 4, Wall 11 hass 36 #11 hook bar (or U-bar) to 135'-3". This means that for one out EF) to splice to that matches e #11 bar EF there ther is not es the configuration of U

do d outs EF from EL. 117'-6" to 135'-3". The vertical construction jointt at the face of Wall 11 represents the north boundary for dowel outs EF from EL. 117'-6" n a Shield Building wall dowel (35 dowel o Wall 11 (36 dowel out EF).

D One horizontal reinforcement VEGP Unit 4 Wall L (EL.

EF + #10@12 EF between R

required by the design, ment bar #11 (EF) located L. 117'-6" to EL. 13 loca 135'-3").

directly above EL. 117'-6" is omitted from 135'-3" All other horizontal reinforcement bars, #11@6 etween EL. 117'-6" and an EL. 135'-3" remain unchanged and are installed as gn, including one row directly above the omitted row consisting of both a #11 and #10 bar EF. The 36 standard h unchanged and are developed hook bar (or U-Bar) dowels EF installed into Wall 11 remain ho oped within with Wall L as required by the design.

A simplified sketch of the typical i #11 rebar configuration is shown in Figure 1 (#10@12" not shown). A simplified sketch of the proposed change, applicable to the single omitted #11(EF), is shown in Figure 2.

Page 5 of 20

ND-19-XXXX Revision to Request for License Amendment: Reinforcement Changes for Wall L and Wall 7.3 (LAR-19-016R1)

Figure 1: Typical #11 Rebar Configuration for Wall L RAF Figure 2: Proposed Rebar Configuration directly above a EL. 117'-6" for Wall L As clarified by Figure 2, the single #11 (EF) is not developed for the entire width of Wall L.

Therefore, this bar is unable to be credited as provided reinforcement. This results in the as-built provided amount of horizontal reinforcement area being less than the current UFSAR Table 3H.5-7 Wall Section 2 (Elevation 135-3 to 117-6) provided minimum value of 4.39 in2/ft; the actual provided value is 4.36 in2/ft. This condition results in the provided horizontal reinforcement area Page 6 of 20

ND-19-XXXX Revision to Request for License Amendment: Reinforcement Changes for Wall L and Wall 7.3 (LAR-19-016R1) and reinforcement configuration not in compliance with the Tier 2* information contained in UFSAR Table 3H.5-7 and Figure 3H.5-12. The impacted area is a subsection of Wall L Section 2 as shown in UFSAR Figure 3H.5-2 (Sheet 3).

Additionally, in accordance with UFSAR Figure 3H.5-12, the design of the Auxiliary Building Wall L from EL. 117'-6" to 135'-3" requires vertical rebar consisting of #11@6" EF + #10@6" EF in two layers, with the #11s on the outside layer and #10s on the inside layer.

When reinforcement placement is defined by a specified effective length of concrete (i.e. length from one face of concrete to another face of concrete) and a recommended spacing, the minimum number of bars shall be calculated as [Effective Length] / [Recommended Spacing]. If this results in a fraction of a bar, an additional bar of the same specified ec bar size shall be provided within the effective length.

The effective length of concrete is calculated considering the length o of Wall L at the exposed face of concrete. The south end of Wall L is defined by y the construction joint at the exterior face the west face and east face of Wall L. T al to this radius, the effective of the Shield wall radius. As Wall L is not orthogonal effe eff length differs for minimum provided)

AF hort (95 bars installed, West face inside layer (#10s): 1 bar short follows fo At VEGP Unit 4, each of the four layers is missing rebar as follows:

ins 96 bars UFSAR specified West face outside layer (#11s): 1 bar short (95 bars installed, 96 bars UFSAR specified minimum provided)

D minimum provided)

R ded) yer er (#10s): 3 bars short East face inside layer tside layer (#11s): 2 bars East face outside minimum provided) vided)

The vertical rebar was installed talled suc of the number of bars in the wall.

shor (95 bars installed, 98 bars UFSAR specified ba short (96 bars installed, 98 bars UFSAR specified such that the spacing of the bars resulted in an overall reduction wal Unlike the omitted horizontal rebar discussed above, the rebar was not omitted in a specific location; rather, the spacing of the rebar is generally uniform throughout the length of the wall. While the design allows for a tolerance of +/- 3" for rebar placement, it also specifies that the minimum number of bars be met. Due to the cumulative stacking of tolerances in this section of Wall L, the total number of vertical bars has been reduced, resulting in a reduction in the provided area of steel.

The vertical rebar in Wall L above EL. 135'-3" will be installed with correct spacing as straight bars below the construction joint at EL. 133'-3" such that they are fully developed by EL. 133'-3";

therefore, the wall above EL. 135'-3" is not impacted. For EL. 117'-6" to EL. 135'-3", the omitted rebar results in an as-built provided vertical reinforcement being less than the existing UFSAR Table 3H.5-7 Wall Section 4 (Elevation 135-3 to 117-6) provided minimum value of 5.66 in2/ft; the actual provided value is 4.95 in2/ft.

Page 7 of 20

ND-19-XXXX Revision to Request for License Amendment: Reinforcement Changes for Wall L and Wall 7.3 (LAR-19-016R1)

This condition results in the provided vertical reinforcement area and reinforcement configuration not in compliance with the Tier 2* information contained in UFSAR Table 3H.5-7 and Figure 3H.5-12. The impacted area is a subsection of Wall L Section 4 as shown in UFSAR Figure 3H.5-2 (Sheet 3).

All other sections shown on UFSAR Figure 3H.5-12 (Sheet 3) remain unaffected by this activity.

Therefore, changes are proposed to UFSAR Table 3H.5-7 to add two notes that explain the configuration changes for VEGP Unit 4.

Additionally, changes are proposed to UFSAR Figure 3H.5-12 because the figure shows #11@6" EF horizontal rebar with the full development length between EL. 117'-6" and EL. 135'-3", and

1. 11@6" EF + #10@6" EF (in two layers) vertical rebar with the full ull d development length between ontal reb EL. 117'-6" and EL. 135'-3". Because a single #11 (EF) horizontal rebar is not developed for the d for the heigh entire width of Wall L, and 7 vertical rebar are not developed height of Wall L between EL.

117'-6" and EL. 135'-3", two notes are added to UFSAR FSAR Figure Figur 3H.3H.5-12 to explain the configuration changes for VEGP Unit 4.

Wall 7.3 Changes T AF In accordance with UFSAR Figure 3H.5-4, the drawings, straight bar is utilized to span e design 117'-6" to EL. 135'-3" require horizontal reinforcing pan a majority n of the th Auxiliary Auxilia Building Wall 7.3 from EL.

einforcing bar (rebar)

1. 10@12" EF in one layer (note that thiss is equivalent to #10@6" (re ajority of the width the wall, this straight bar is spliced to reinforcement w

reinfo ment bar (referred (r

consisting of #10@12" EF +

1. 10@ EF). As specified on design

1. 10 of the wall. At the boundaries of to as dowels) developed within the bounding walls. The vertical construction joint at the face of the Shield Building represents the west boundary for Wall 7.3. At VEGP Unit 4, the Sh Shield Building wall has 35 #10 hook bar dowel Shi D

outs EF from EL. 117'-6" to EL.

represents the east boundary dowel outs EF from EL.

R (36 dowel out EF).

L. 135'-3". The vertical ndary for Wall 7.3.

7 At VEGP L. 117'-6" to EL. 135'-3".

Shield Building wall dowel (35 dowel out E One horizontal reinforcement ent bar #

standard hook bar (EF) in Wall V

v construction joint at the face of Wall I Unit 4, Wall I has 36 #10 hook bar (or U-bar) 135'-3 This means that for one #10 bar EF there is not a 135 EF) to splice to that matches the configuration of Wall I

1. 10 (EF) located directly below EL. 135'-3" is to be spliced to all I and extend to 2'-0" from the Shield Building. The associated #10 (EF) dowel developed into the Shield Building is not installed.

The other 35 horizontal reinforcement bars #10@6 between EL. 117'-6" and EL. 135'-3" remain unchanged and will be fully developed as required by the design. The 36 standard hook bar (or U-bar) dowels installed into Wall I remain unchanged and shall be developed within Wall 7.3 as required by the design.

A simplified sketch of the typical #10 rebar configuration is shown in Figure 3. A simplified sketch of the proposed change for one horizontal reinforcement bar #10 (EF) located directly below EL.

135'-3" is shown in Figure 4.

Page 8 of 20

ND-19-XXXX Revision to Request for License Amendment: Reinforcement Changes for Wall L and Wall 7.3 (LAR-19-016R1)

Figure 3: Typical #10 Rebar Configuration for Wall 7.3 RAF Figure 4: Proposed Rebar Configuration onfiguration ation directly be below EL. 135'-3" for Wall 7.3 As clarified by Figure 4, the single #10 (EF) is not developed for the entire width of Wall 7.3.

Therefore, this bar is unable to be credited as provided reinforcement. This results in the as-built provided amount of horizontal reinforcement area being less than the existing UFSAR Table 3H.5-5 Wall Section 3 (Elevation 117-6 to 135-3 )provided minimum value of 2.54 in2/ft. The actual provided value is 2.50 in2/ft for this segment of Wall 7.3. This condition results in the Page 9 of 20

ND-19-XXXX Revision to Request for License Amendment: Reinforcement Changes for Wall L and Wall 7.3 (LAR-19-016R1) provided reinforcement area and reinforcement configuration not in compliance with the Tier 2*

information contained in UFSAR Table 3H.5-5 and Figure 3H.5-4. The impacted area is a subsection of Wall 7.3 Section 3 as shown in UFSAR Figure 3H.5-2 (Sheet 2). All other sections shown on UFSAR Figure 3H.5-2 (Sheet 2) remain unaffected by this activity. Therefore, changes are proposed to UFSAR Table 3H.5-5 to add a note that explains the configuration change for VEGP Unit 4.

Additionally, changes are proposed to UFSAR Figure 3H.5-4 because the figure shows #10@6" horizontal rebar with the full development length between EL. 117'-6" and 135'-3". Because a single #10 (EF) is not developed for the entire width of Wall 7.3, a note is added to UFSAR Figure 3H.5-4 to explain the configuration change for VEGP Unit 4.

Licensing Basis Change Descriptions:

UFSAR Changes:

Tier 2* Impacts:

x for VEGP Unit 4.

T escribe what the provided UFSAR Table 3H.5-5: A note is added to describe ontal ntal wall section will be on the Column Line 7.3 wall, horizontal sec provid reinforcement area fro EL. 135'-3" to 117'-6" 3, from x

x bars (one on each face)

AF UFSAR Table 3H.5-7: Two notes are area will be on the Column Line section 4, from EL. 135'-3" to e added to describe describ what the provided reinforcement horizontal wall section 2 and vertical wall ne L wall, both horizon o 117'-6" for VEGP Unit UFSAR Figure 3H.5-4: A note is added to describe d

ace)) are terminated 2'-0 Uni 4.

des that two #10 horizontal reinforcement 2'-0" from the shield building vertical construction x D joint, directly below bars (one on each w 135'-3" for V for additional detail.

R UFSAR Figure etail.

e 3H.5-12: A note note is added to describe Unit 4. The note references UFSAR Table 3H.5-5 VEGP Un no is added to describe that two #11 horizontal reinforcement ach face) are omitted scribe that are omitted for VEGP o directly above 117'-6" for VEGP Unit 4. A second tha seven vertical reinforcement bars (three #11s and four #10s)

P Unit Un 4. Both notes reference Table 3H.5-7 for additional detail.

3. TECHNICAL EVALUATION Wall L Horizontal Evaluation The proposed change specifies that a portion of one horizontal reinforcement bar #11@6" (EF) located directly above EL. 117'-6" is to be omitted from the VEGP Unit 4 Wall L (EL. 117'-6" to EL. 135'-3"). Since this reinforcement bar is not fully developed for the entire width of the wall, the bar is not considered to be credited as a portion of the provided steel area for Wall L.

The reinforcement necessary to satisfy ACI 349-01 requirements is calculated using Finite Element Analysis (FEA) using the applicable load combinations and design criteria, in accordance with UFSAR Table 3.8.4-2 and ACI 349-01. As shown in UFSAR Table 3H.5-7, the horizontal demand in Wall L between Elevations 117'-6" to 135'-3" (1.36 in2/ft) remains less than the revised capacity of this wall segment (4.36 in2/ft). The proposed change does not impact the seismic Page 10 of 20

ND-19-XXXX Revision to Request for License Amendment: Reinforcement Changes for Wall L and Wall 7.3 (LAR-19-016R1) analysis of the nuclear island because it does not affect the mass or stiffness of the seismic model.

Wall L continues to provide MCR boundary.

The documented design margin for Wall L (EL. 117'-6" to EL. 135'-3") is 66.7% based on the critical element. The elements impacted by the proposed change are not located near the critical elements as shown in Figure 5 and have a revised margin of 73.7% considering the subject reduction in area of provided reinforcement presented in this LAR. Therefore, the proposed change does not reduce the design margin for Wall L.

Figure 5 - Wall L FEA Critical Element and Impacted Elements D

Considering the subject R

ect reduction in area of provided horizontal reinforcement presented in this LAR, the maximum calculated interaction ratio of the local impacted elements is IRLocal=0.26.

Since the IR remains less than 1.0, the the acceptance criteria of ACI 349-0 t proposed change is acceptable and continues to satisfy 349-01 and applicable design criteria. Furthermore, the IRLocal is less than the documented critical e element interaction ratio.

Construction Joint (CJ) Evaluation for Wall L There is no impact to the CJ between Wall L and Wall 11 because a #11 hook (located directly above EL. 117'-6") has been installed and is adequately developed on both sides of the vertical CJ. Therefore, the specified amount of design reinforcement is provided transverse to the CJ as required.

The CJ between Wall L and the Shield Building is impacted by the proposed change. The amount of provided rebar, considered transverse to the CJ, in the design analysis is 8.78 in2/ft. This is equivalent to #11@6" + #10@12" (EF). Since the horizontal #11 bar (EF) is not installed directly above EL. 117'-6" transverse to this CJ, the reduction to the provided horizontal reinforcement for the impact portion of the CJ results in an area of 8.39 in2/ft. The nominal shear strength of the CJ is controlled by concrete strength and geometry in accordance with ACI 349-01, Section 11.7.5.

Therefore, the calculated IR of 0.735 remains unchanged. Since the IR remain less than 1.0, the Page 11 of 20

ND-19-XXXX Revision to Request for License Amendment: Reinforcement Changes for Wall L and Wall 7.3 (LAR-19-016R1) proposed change is acceptable and continues to satisfy the acceptance criteria of ACI 349-01 and applicable design criteria.

Shear Reinforcement for Wall L The design of Wall L includes shear reinforcement (#6@6"x6" crossties) from EL. 117'-6" to EL.

133'-3". Requirements for shear reinforcement for Wall L are provided on UFSAR Figure 3H.5-12 and Table 3H.5-7. The crossties are designed to engage vertical reinforcement. The proposed change regarding horizontal reinforcement does not impact the vertical reinforcement or the ability to install shear reinforcement.

Adjacent Walls and Slabs The proposed change has no impact to adjacent walls and slabs. Adja Adj Adjacent walls and slabs remain in conformance with ACI 349-01 requirements.

Wall L Vertical Evaluation Element Analysis (FEA) using the applicable load accordance with UFSAR Table 3.8.4-2 and ACI T

The reinforcement necessary to satisfy ACI 349-01 requirements is calcu d combinations calcula calculated using Finite combination and des CI 349-01.

design criteria, in

-01. As shown in UFSAR Table 3H.5-7, the AF tween EL. 117'-6" to 13 vertical required reinforcement in Wall L between than the revised provided reinforcement of this or stiffness of the seismic model. Wall L continues to pro ifies Even though the design qualifies b

es Wall L under all applicable ap 135'-3" (2.02 in2/ft) remains less his wall segment (4.95 (4

does not impact the seismic analysis of the nuclear island because in2/ft). The proposed change it does not affect the mass provide MCR boundary.

loads with including combined D

thermal and safe shutdown in UFSAR Table 3H.5-7 R

n earthquake (SSE) loads, 7 does not reflect the d ble. The qualification of per Note 1 on the table.

vertical reinforcementt in Wall L between 2.365 in2/ft and the provided betw ded steel = 5.660 5

2.365 in /ft, which considerss all applicable 2 ap loa the required vertical reinforcement shown demands under combined SSE and thermal loads o Wall L shows that the maximum design ratio for the EL 117'-6" to 135'-3"is 0.418 (the required steel =

in2/ft each face). The design required area of steel is loads including combined SSE and thermal loads, is higher than the required value of 2.02 in /ft as specified in UFSAR Table 3H.5-7 and, therefore, 2

is more conservative. While the proposed change has vertical bars omitted in each of the four layers (East/West, inside/outside), at worst only a single bar in each layer is missing over an effective width of 2 times the thickness. This is a conservative interpretation of the ACI limit as defined in ACI 349-01, Section 14.2.4. The average provided reinforcement in a distance of two times the wall thickness of 2 feet is reduced to 4.95 in2/ft each face.

5.66 4 - 1.56 - 1.27 4.95 4

Page 12 of 20

ND-19-XXXX Revision to Request for License Amendment: Reinforcement Changes for Wall L and Wall 7.3 (LAR-19-016R1)

The design ratio then becomes 0.478, which is less than 1.0.

2.365 0.478 4.952 Therefore, the subject wall (Wall L, Section 4) is still qualified with a design margin of 52.2%.

1 0.478 0.522 Construction Joint The horizontal CJ at EL 117-6 in Wall L has a maximum Demand mand / Capacity Ca ratio of 0.523. The proposed change reduces the shear friction capacity from the he vertical reinforcement to 594.24 vertic rein kip/ft, while the concrete shear capacity is 230.4 kip/ft. As the concrete shear capacity is less, it remains the governing interaction ratio at 0.523.

T The vertical rebar in Wall L above EL. 135'-3 willll be installed with corre 3" such that bars below the construction joint at EL. 133'-3" hat th correct spacing as straight they are fully fu developed by EL. 133'-3";

Shear Reinforcement 133'-3". Requirements for shear AF therefore, the construction joint at EL 133-3 The design of Wall L includes shear 3 is not impacted.

-3 hear reinforcement (#6@6"x6"

(#6@

ar reinforcement for Wall hear crossties) from EL. 117'-6" to EL.

W L are provided on UFSAR Figure 3H.5-D 12 and Table 3H.5-7. The R bs Adjacent Walls and Slabs The proposed change has no e crossties are designed o impact im designe to engage vertical reinforcement and are able propose change. Therefore, there is no impact on the pro to be correctly installed even with the proposed ch shear reinforcement from this proposed change.

to adjacent walls and slabs. Adjacent walls and slabs remain in conformance with ACI 349-01 requirements.

Wall 7.3 Evaluation The proposed change specifies that one horizontal reinforcement bar #10@6" (EF) located directly below EL. 135'-3" is to be spliced to a standard hook bar (EF) in Wall I and extend to 2'-0" from the Shield Building. Since the reinforcement bar is not fully developed to the Shield Building as part of the proposed change, the bar is unable be credited as provided horizontal reinforcement until the straight bar development is achieved within Wall 7.3.

The reinforcement necessary to satisfy ACI 349-01 requirements is calculated using Finite Element Analysis (FEA) using the applicable load combinations and design criteria, in accordance with UFSAR Table 3.8.4-2 and ACI 349-01. As shown in UFSAR Table 3H.5-5, the horizontal demand in Wall 7.3 between EL. 117'-6" to EL. 135'-3" (2.03 in2/ft) remains less than the revised Page 13 of 20

ND-19-XXXX Revision to Request for License Amendment: Reinforcement Changes for Wall L and Wall 7.3 (LAR-19-016R1) capacity (2.50 in2/ft) of this wall segment. The proposed change does not impact the seismic analysis of the nuclear island because it does not affect the mass or stiffness of the seismic model.

The documented design margin for Wall 7.3 (EL. 117'-6" to EL. 135'-3") is 17.2% based on the critical element. The elements impacted by the proposed change are not located near the critical elements as shown in Figure 6 and have a margin of 17.86% considering the subject reduction in area of provided reinforcement presented in this LAR. Therefore, the proposed change does not reduce the design margin for Wall 7.3.

Figure 6 - Wall 7.3 FEA Critical Element and Impacted Elements DR ect reduction in area of provided horizontal reinforcement presented in this Considering the subject LAR, the calculated interaction ratio of the local impacted elements is IRLocal=0.82. Since the IR remains less than 1.0, the proposed change criteria of ACI 349-01 and ccha nd applicable is acceptable and continues to satisfy the acceptance applicab design criteria. Furthermore, the IRLocal is less than the documented critical elementt interaction intera ratio.

Construction Joint (CJ) Evaluation for Wall 7.3 There is no impact to the CJ between Wall 7.3 and Wall I because a #10 hook (located directly below EL. 135'-3") has been installed and is adequately developed on both sides of the vertical CJ. Therefore, the specified amount of design reinforcement is provided transverse to the CJ as required.

The CJ between Wall 7.3 and the Shield Building is impacted by the proposed change. The amount of provided rebar, considered transverse to the CJ, in the design analysis is 5.08 in2/ft.

This is equivalent to #10@6" (EF). Since the horizontal #10 bar (EF) is not installed directly below EL. 135'-3" into the Shield Building, this results in a reduction to the horizontal provided rebar considered transverse to the CJ. The provided reinforcement for the impacted portion of the CJ is 4.76 in2/ft. The nominal shear strength of the CJ is controlled by concrete strength and geometry in accordance with ACI 349-01, Section 11.7.5. Therefore, the calculated IR of 0.847 remains Page 14 of 20

ND-19-XXXX Revision to Request for License Amendment: Reinforcement Changes for Wall L and Wall 7.3 (LAR-19-016R1) unchanged. Since the IR remains less than 1.0, the proposed change is acceptable and continues to satisfy the acceptance criteria of ACI 349-01 and applicable design criteria.

Openings located in Wall 7.3 The #10 reinforcement bar is developed within Wall 7.3 above penetrations, therefore there is no impact on the design of the wall opening in Wall 7.3.

Adjacent Walls and Slabs The proposed change has no impact to adjacent walls and slabs. Adjacent walls and slabs remain in conformance with ACI 349-01 requirements.

Technical Justification Summary (Applies to Wall L and Wall 7.

7.3 Changes)

Per UFSAR Subsection 3.8.4.5.3, deviations from the designsign d due to as-procured or as-built conditions are acceptable based on an evaluation consistent ent methods and procedures of nt with the metho UFSAR Sections 3.7 and 3.8 provided the following acceptance met:

ceptance criteria are m x

x AF e criteria specified in U The structural design meets the acceptance The seismic floor response spectra meet the acceptance Subsection 3.7.5.4 acc UFSAR Section 3.8 criteria specified in UFSAR T

Considering the applicable loading scenarioss and acceptance licensing basis, as discussed above, respective capacities. The proposed posed changes to the continue to satisfy the acceptance accepta ve, the demands in Wall criteria required by the current W L and Wall 7.3 remain below their t reinforcement r

nce criteria of ACI 349-01.

ance 349 34 are in accordance with and D

The proposed changes do R

Regulatory Guide 1.29.

assurance requirements ents o not impact the of Additional Impact Evaluation 10 CFR ion (Applies (Appli

( pp t seismic

.29. The seismic Category 50, 5 A Cate Cat seism analysis of the Nuclear Island because it does not affect the mass or stiffness of the seismic seis model, and the design remains in accordance with Appendix I structure continues to comply with the quality B.

to Wall L and Wall 7.3 Changes)

The proposed change does not affect aircraft impact assessment or tornado missile evaluations.

The walls affected by the change are interior walls and continue to meet design requirements.

The rebar developed into the Shield Building wall from Wall L and Wall 7.3 are not credited in aircraft impact assessment or tornado missile evaluations.

The impact on the walls effectiveness in providing radiation shielding was examined, and there are no adverse effects because the placement of reinforcement does not impact the walls function as a radiation safety barrier since steel is not calculated as part of the shielding analysis.

There is no adverse impact to the bounding conclusions of the radiation analysis.

The proposed change does not alter the fire loads found in any adjacent fire zones and areas as no equipment is added or removed by the activity. The proposed change does not affect any function or feature used for the prevention and mitigation of accidents or their safety analyses.

The proposed change does not involve nor interface with any SSC accident initiator or initiating sequence of events related to accidents evaluated in the UFSAR. The proposed change does not Page 15 of 20

ND-19-XXXX Revision to Request for License Amendment: Reinforcement Changes for Wall L and Wall 7.3 (LAR-19-016R1) affect the radiological source terms (i.e., amounts and types of radioactive materials released, their release rates and release durations) used in the accident analyses. The walls function as a flood barrier is not impacted. The reinforcement of the walls is also not used as an input to the probabilistic risk assessment (PRA), and therefore, there is no PRA impact as a result of the missing reinforcement.

No system or design function or equipment qualification is affected by the proposed change. The change does not result in a new failure mode, malfunction or sequence of events that could affect a radioactive material barrier or safety-related equipment. The proposed change does not allow for a new fission product release path, result in a new fission product barrier failure mode, or create a new sequence of events that would result in significant fuel cladding failures.

The proposed change has no adverse effect on the ex-vessel severe accident. The overall design, geometry, and strength of the containment internal structures es and an other seismic Category I structures are not changed. The design and material selection on of the concrete co floor beneath the reactor vessel is not altered. The response of the containmentinment to a postulated post reactor vessel failure, including direct containment heating, ex-vessel explosions, and core concrete el steam explo The proposed change does not affect the T

interactions is not altered. The design of the reactor vessel essel and the respon to a postulated severe accident are not altered by the change.

e containment, ainme response of the reactor vessel control, contr channeling, monitoring, proposed change.

AF processing or releasing of radioactive and non-radioactive materials.

expected effluents are not changed, and Plant radiation zones (as described expected amounts and types cribed in UFSAR Section Sect Se es of radioactive materials mater materia The types and quantities of m

o effluent release path is affected by the proposed nd no changes. Therefore, radioactive and non-radioactive dioactive material mater mate effluents are not affected by the 12.3), controls under 10 CFR 20, and are not affected by the proposed change.

D The change to the reinforcement rcement was also examined providing radiation shielding, R

elding, and no adverse These changes do not impact em eme are no changes to the configuration adv cumulative radiation exposures do not change.

cha mpact the emergency exa with respect to the walls effectiveness in impacts were identified. Therefore, individual and plans or the physical security evaluation since there nfiguration of walls, doors, or access to the nuclear island. The proposed changes do not involve, nor interface inter with, any structure, system or component accident initiator or initiating sequence of events, and thus, the probabilities of the accidents evaluated in the UFSAR are not affected.

4. REGULATORY EVALUATION 4.1 Applicable Regulatory Requirements/Criteria 10 CFR Part 52, Appendix D, VIII.B.6 requires prior NRC approval for the departure from Tier 2* information. This change, which includes a change to the provided area of horizontal and vertical reinforcement for the VEGP Unit 4 Wall L from elevation 117 6 to 135-3 and horizontal reinforcement for VEGP Unit 4 Wall 7.3 from elevation 117 6 to 135-3, includes a Tier 2* departure that does not meet the Tier 2* departure exemption Page 16 of 20

ND-19-XXXX Revision to Request for License Amendment: Reinforcement Changes for Wall L and Wall 7.3 (LAR-19-016R1) criteria of License Condition 2.D.(13) of the VEGP Unit 4 COL, and thus requires NRC approval. Therefore, a license amendment request (LAR) (as supplied herein) is required.

10 CFR 50, Appendix A, General Design Criteria for Nuclear Power Plants, General Design Criterion (GDC) 1, Quality standards and records, requires that structures, systems, and components important to safety shall be designed, fabricated, erected, and tested to quality standards commensurate with the importance of the safety functions to be performed. By continuing to follow the guidelines of the NRC Regulatory Guides and industry standards, the requirements of GDC 1 have been maintained.

10 CFR 50, Appendix A, GDC 2, Design bases for protection against natural phenomena, requires that structures, systems, and components important to safety shall be designed to withstand the effects of natural phenomena such as earthquakes, tornadoes, hurricanes, floods, tsunami, and seiches without loss off capability capab cap to perform their safety functions. There is no change to the expected responses natural phenomena, and Wall ses tto natur L and Wall 7.3, even with the change to the reinforcement, cement, continue co to be able to respond to the same design basis earthquake; therefore, there are no changes ch to the conformance with GDC 2.

10 CFR 50, Appendix A, GDC 4, EnvironmentalT ironmental onmental and requires that structures, systems, and components dynamic effects design bases, an dynam nents important to safety shall be designed because the same design AF to accommodate the effects of and associated with normal operation, including loss-of-coolant accidents.

changes to the conformance ormance d to be compatible with the environmental conditions ion, maintenance, testing, conditio ance with GDC 4.

be te tes associated as gn criteria are used before and postulated accidents, dents. The changes to the reinforcement do not alter the walls response to environmental nmental conditions with normal operation, and and after the changes, the auxiliary building continues to be able to withstand similar conditions; therefore, there are no 4.2 4.3 DR Precedent ent No precedentt is identified.

Significant nt Hazards Consideration The requested amendment m proposes changes to information in the Updated Final Safety Analysis Report (UFSAR) related to the provided area of horizontal and vertical reinforcement for Vogtle Electric Generating Plant (VEGP) Unit 4 Wall L from elevation 117-6 to 135-3 and horizontal reinforcement for VEGP Unit 4 Wall 7.3 from elevation 117-6 to 135-3.

An evaluation to determine whether or not a significant hazards consideration is involved with the proposed amendment was completed by focusing on the three standards set forth in 10 CFR 50.92, Issuance of amendment, as discussed below:

4.3.1 Does the proposed amendment involve a significant increase in the probability or consequences of an accident previously evaluated?

Response: No.

Page 17 of 20

ND-19-XXXX Revision to Request for License Amendment: Reinforcement Changes for Wall L and Wall 7.3 (LAR-19-016R1)

As described in UFSAR Subsections 3H.5.1.2 and 3H.5.1.3, interior Wall 7.3 and Wall L are located in the auxiliary building. UFSAR, Section 3H.5 classifies Interior Wall on Column Line 7.3, from elevation (EL) 66-6 to 160-6 as a Critical Section. UFSAR, Section 3H.5 classifies Interior Wall on Column Line L, from EL 117-6 to 153-0 as a Critical Section. Deviations were identified in the constructed walls from the design requirements. The proposed changes modify the provided area of steel reinforcement for VEGP Unit 4 Wall L and Wall 7.3 from elevation 117-6 to 135-3". These changes maintain conformance to American Concrete Institute (ACI) 349-01 and have no adverse impact on the seismic response of Wall L and Wall 7.3. Wall L and Wall 7.3 continue to withstand the design basis loads without loss of structural integrity or the safety-related functions.

The proposed changes do not affect the operation of any system or equipment that initiates an analyzed accident or alter any structures, ure systems, and component (SSC) accident initiator or initiating sequence off eve events.

This change does not adversely affect the design function fun of o VEGP Unit 4 Wall L and Wall 7.3, or the SSCs contained within building.

hin the auxiliary buildin b This change does T

not involve any accident initiating components or events, probabilities of an accident unaltered.

ed.

even eve thus leaving the AF Therefore, the proposed amendment Does the proposed Response: No.

ndment does not n involve a significant increase in the probability or consequencess of an accident previously 4.3.2 previou pre evaluated.

dment create tthe possibility of a new or different d amendment kind of accidentt from any accident accid previously evaluated?

p DR The proposed evaluated.

sed ed change modifies the Unit 4 Wall L and Wall 7.

the continued design structu ed. The proposed th provided area of steel reinforcement for VEGP 7.3 from elevation 117-6 to 135-3". As demonstrated by ontinued conformance to the applicable codes and standards governing the n of the structures, the walls withstand the same effects as previously propose change does not affect the operation of any systems or propo equipment that may initiate a new or different kind of accident or alter any SSC such that a new ew accident a initiator or initiating sequence of events is created. The proposed change does not adversely affect the design function of auxiliary building Wall L and Wall 7.3, or any other SSC design functions or methods of operation in a manner that results in a new failure mode, malfunction, or sequence of events that affect safety-related or non-safety-related equipment. This change does not allow for a new fission product release path, result in a new fission product barrier failure mode, or create a new sequence of events that result in significant fuel cladding failures.

Therefore, the proposed amendment does not create the possibility of a new or different kind of accident from any accident previously evaluated.

4.3.3 Does the proposed amendment involve a significant reduction in a margin of safety?

Response: No.

Page 18 of 20

ND-19-XXXX Revision to Request for License Amendment: Reinforcement Changes for Wall L and Wall 7.3 (LAR-19-016R1)

The proposed change modifies the provided area of steel reinforcement for VEGP Unit 4 Wall L and Wall 7.3 from elevation 117-6 to 135-3". This change maintains conformance to ACI 349-01. The changes to Wall L and Wall 7.3 reinforcement from elevation 117-6 to 135-3 do not change the performance of the affected portion of the auxiliary building for postulated loads. The criteria and requirements of ACI 349-01 provide a margin of safety to structural failure. The design of the auxiliary building structure conforms to criteria and requirements in ACI 349-01 and therefore, maintains the margin of safety. The change does not alter any design function, design analysis, or safety analysis input or result, and sufficient margin exists to justify departure from the Tier 2* requirements for the walls. As such, because the system continues to respond to design basis accidents in the same manner as before without any changes to the expected response of the structure, no safety analysis or design basiss acceptance a limit/criterion is challenged or exceeded by the proposed changes. anges. Accordingly, anges A no significant safety margin is reduced by the change.

Therefore, the proposed amendment does oes not involve a significant signi reduction in a margin of safety.

Based on the above, it is concluded that T

at the he proposed propos amendment amen does not involve a 4.4 Conclusions AF significant hazards consideration under er the standards accordingly, a finding of no significant In conclusion, based on the considerations assurance that the health the proposed manner, standa consideration discussed dis lth and safety of the public alth pu set forth fo in 10 CFR 50.92(c), and, ant hazards consideration cant considera consid is justified.

above, (1) there is reasonable will not be endangered by operation in ner, (2) such activities will be conducted in compliance with the 5.

D Commissions regulations, the common defense R

10 CFR 50.92, ulations, and (3) the issuance gulations, 2, the requested change Consideration.

n ENVIRONMENTAL AL CONSIDERATIONS CONSI CONSID c

is of the amendment will not be inimical to efense and security or to the health and safety of the public. Pursuant to does not involve a Significant Hazards The details of the proposed changes are provided in Section 2 and 3 of Enclosure 3 of this license amendment request.

The requested amendment proposes changes to information in the Updated Final Safety Analysis Report (UFSAR) related to the provided area of steel reinforcement for VEGP Unit 4 Wall L and Wall 7.3 from elevation 117-6 to 135-3.

A review has determined the proposed change requires an amendment to the COL. However, a review of the anticipated construction and operational effects of the requested amendment has determined the requested amendment meets the eligibility criteria for categorical exclusion set forth in 10 CFR 51.22(c)(9), in that:

(i) There is no significant hazards consideration.

As documented in Section 4.3, Significant Hazards Consideration Determination, of Enclosure 3 of this license amendment request, an evaluation was completed to determine Page 19 of 20

ND-19-XXXX Revision to Request for License Amendment: Reinforcement Changes for Wall L and Wall 7.3 (LAR-19-016R1) whether or not a significant hazards consideration is involved by focusing on the three standards set forth in 10 CFR 50.92, Issuance of amendment. The Significant Hazards Consideration determined that (1) the requested amendment does not involve a significant increase in the probability or consequences of an accident previously evaluated; (2) the requested amendment does not create the possibility of a new or different kind of accident from any accident previously evaluated; and (3) the requested amendment does not involve a significant reduction in a margin of safety.

Therefore, it is concluded that the requested amendment does not involve a significant hazards consideration under the standards set forth in 10 CFR 50.92(c), and accordingly, a finding of no significant hazards consideration is justified.

(ii) There is no significant change in the types or significant increase in the amounts of any effluents that may be released offsite.

The proposed change modifies the provided area of steel reinforcement reinforce re for VEGP Unit 4 Wall L and Wall 7.3 from elevation 117-6 to 135-3.

5 -3

-3. The e proposed prop change is unrelated Furthermore, the proposed change does T

to any aspect of plant construction or operationn that would introduce introduc a types (e.g., effluents containing chemicals orr biocides, sanitary syst effluents), or affect any plant radiological al or nonradiological nonradio oes not affect any effluent efflu any change to effluent system effluents, and other effluent release quantities.

e release path or diminish AF the functionality of any design or operational Therefore, it is concluded that erational features that are release of effluents during plant operation.

ration.

hat the requested ame change in the types or a significant increase released offsite.

a credited with controlling the amendment does not involve a significant increas in the t amounts of any effluents that may be (iii)

D There is no significant exposure.

R The proposed cant ant increase in individu d change modifies the Wall L and Wallll 7.3 from elevation UFSAR Section 12.3) are n with respect to the walls elevat elev individual or cumulative occupational radiation th provided area of steel reinforcement for VEGP Unit 4 117-6 to 135-3. Plant radiation zones (addressed in not affected, and controls under 10 CFR Part 20 preclude a significant increase in occupational occ radiation exposure. The change was also examined l effectiveness in providing radiation shielding, and no adverse impacts were identified.

Based on the above review of the requested amendment, it has been determined that anticipated construction and operational effects of the requested amendment do not involve (i) a significant hazards consideration, (ii) a significant change in the types or significant increase in the amounts of any effluents that may be released offsite, or (iii) a significant increase in the individual or cumulative occupational radiation exposure. Accordingly, the requested amendment meets the eligibility criteria for categorical exclusion set forth in 10 CFR 51.22(c)(9). Therefore, pursuant to 10 CFR 51.22(b), an environmental impact statement or environmental assessment of the proposed exemption is not required.

6. REFERENCES None.

Page 20 of 20

Southern Nuclear Operating Company ND-19-XXXX Enclosure 4 T

Vogtle Electric Generating Plant (VEGP) Unit 4 AF Revision to Proposed Changes Reinforcement s to the Licensing hanges Licens Wall L and Wall 7.3 ment Changes ffor Wa (LAR-19-016R1)

(LAR-19-01 Basis Documents DR Added ttext is shown as Blue Underline Deleted Text is shown as Red Strikethrough Omitted itt text is shown as three asterisks (***)

(This Enclosure consists of 5 pages, including this cover page)

ND-19-XXXX Revision to Proposed Changes to Licensing Basis Documents - (LAR-19-016R1)

Revise UFSAR Table 3H.5-5 Interior Wall on Column Line 7.3 Details of Wall Reinforcement as shown below:

WallSegment ReinforcementonEachFace(in2/ft)

(SeedetailinSubsection

3H.5.1.2) Location WallSection Required (1) [Provided (Min.)]*

Elevation 135-3 to 117-6 Horizontal 3 2.03 2.54(4)

Vertical 9 2.63 3.12 Notes:

DR vertical construction joint (CJ). These bars, ment

[4 For Vogtle Unit 4, two horizontal reinforcement nt bars are terminate ars, one terminated 2'-0" from the shield building e #10 on each face fac of the wall, are located directly AF below elevation 135'-3". This effectively ely reduces the the minimum provided area of steel in this wall segment to 2.50 in2/ft. The provideded minimum reinfo reinforcemen reinforcement is reduced from the shield building CJ through the development length h of the bars. However, However it does not change the performance of the existing structure under postulated ulated ated loads and does notno cause any excessive stress locally along the development length of the bar.]*

T Page 2 of 5

ND-19-XXXX Revision to Proposed Changes to Licensing Basis Documents - (LAR-19-016R1)

Revise UFSAR Table 3H.5-7 Interior Wall on Column Line L Details of Wall Reinforcement as shown below:

WallSegment ReinforcementonEachFace(in2/ft2)

(SeedetailinSubsection

3H.5.1.3) Location WallSection Required (1) [Provided (Min.)]*

Elevation 135-3 to 117-6 Horizontal 2 1.36 4.39(3)

Vertical 4 2.02 5.66(4)]*

Notes:

DR elevation 117'-6" for the entire width of the orcement ementt bars (one

[3. For Vogtle Unit 4, two #11 horizontal reinforcement he wall.

ll. Th T

This

( on eaeach face) are omitted directly above is effectively rreduces the minimum provided area of AF steel in this wall segment to 4.36 in2/ft.

ft. The provided minimum reinforcement is reduced for the entire width of the wall segment. However, er, it does not chan change the performance of the existing structure under postulated loads and does es not cause any excessive excessiv stress locally.]*

exce

[4. For Vogtle Unit 4, three #11 11 and four #10 verticall reinforcement re bars are omitted from elevation 117'-

6" to elevation 135'-3". This effectively reduces re the t minimum provided area of steel in this wall T

segment to 4.95 in2/ft.

ft. The provided minim minimum reinforcement is reduced for the entire width of the wall segment. However,, it does not change the performance of the existing structure under postulated loads and does not cause any excessive excess stress locally.]*

Page 3 of 5

ND-19-XXXX Revision to Proposed Changes to Licensing Basis Documents - (LAR-19-016R1)

Revise UFSAR Figure 3H.5-4, Typical Reinforcement in Wall 7.3 as shown below:

Note 2 T

AF R

NOTE 2:

FOR VOGTLE UNIT 4, TWO HORIZONTAL REINFORCEMENT BARS ARE TERMINATED 2'-0" FROM THE SHIELD BUILDING VERTICAL CONSTRUCTION JOINT. THESE BARS, ONE #10 ON EACH FACE OF THE WALL, ARE LOCATED DIRECTLY BELOW ELEVATION 135'-3". SEE TABLE 3H.5-5 FOR ADDITIONAL DETAILS.

Page 4 of 5

ND-19-XXXX Revision to Proposed Changes to Licensing Basis Documents - (LAR-19-016R1)

Revise UFSAR Figure 3H.5-12, Typical Reinforcement in Wall L as shown below:

T DR Note 3 Note 2 AF NOTE 2:

FOR VOGTLE UNIT 4, TWO #11 HORIZONTAL REINFORCEMENT BARS (ONE ON EACH FACE) ARE OMITTED DIRECTLY ABOVE ELEVATION 117'-6", FOR THE ENTIRE WIDTH OF THE WALL. SEE TABLE 3H.5-7 FOR ADDITIONAL DETAILS.

NOTE 3:

FOR VOGTLE UNIT 4, THREE #11 AND FOUR #10 VERTICAL REINFORCEMENT BARS ARE OMITTED FROM ELEVATION 117'-

6" TO ELEVATION 135'-3". SEE TABLE 3H.5-7 FOR ADDITIONAL DETAILS.

Page 5 of 5

Southern Nuclear Operating Company ND-19-XXXX Enclosure Vogtle Electric Generating Plant nt (VEGP)

(V GP) Unit U 4 T

AF Second Preliminary ry Amendment Reinforcement dme Request:

rcement Changes fo (PAR PA -19 9-016 0

Req for Wall L (PAR-19-016-2)

DR (This Enclosure consists of 4 pages, including this cover page.)

ND-19-XXXX Enclosure Second Preliminary Amendment Request: Reinforcement Changes for Wall L (PAR-19-016-2)

Pursuant to 10 CFR 52.98(c) and in accordance with 10 CFR 50.90, Southern Nuclear Operating Company (SNC) submitted license amendment request (LAR)-19-016R1 to change the Vogtle Electric Generating Plant (VEGP) Unit 4 licensing basis documents associated with Combined License No. NPF-92.

Accordingly, SNC requests the determination of whether the NRC has any objection to SNC proceeding with construction of VEGP Unit 4 Wall L, which is subject to the changes proposed in LAR-19-016R1. Delayed determination regarding this Preliminary Amendment Request (PAR) will result in delay in the construction completion of VEGP Unit 4, as identified in the PAR provided below, to be provided by the date shown below.

PAR Request Number: Station Name: Unit Number(s): PAR Request Date:

SNC PAR-19-016-2 VEGP 3 4 October 25, 2019

1. NRC PAR Notification Requested Date (see Block ock 7 for or bas basis): N November 15, 2019 D

2. License Amendment Request References (as applicable):

R Expected LAR submittal date:

e:

appli LAR submittal date and SNC Correspondence espondence ondence Number:

N LAR-19-016R1 - October 25, 2019 / ND-19-XXXX AF

3. Brief Description of Proposed ed Change:

The proposed change would ould revise licensing licensin basis ba information in the Updated Final Safety Analysis Report (UFSAR) AR) Tier 2*

2* information informatio (plant-specific DCD), to change the provided nforcement for Vogtle area of vertical steel reinforcement Vog Electric Generating Plant (VEGP) Unit 4 Wall L from 117-6 and d 135-3.

135-3 135 -3.

12.

T d change impacts The proposed

4. Reason for License impac UFSAR se Amendment Amend Wall L Changes - Vertical UFS UFSA Tier 2* information in Table 3H.5-7 and Figure 3H.5-Request:

rtic Reinforcement In accordance with UFSAR Figure 3H.5-12, the design of the Auxiliary Building Wall L from EL. 117'-6" to 135'-3" requires vertical rebar consisting of #11@6" EF + #10@6" EF in two layers, with the #11s on the outside layer and #10s on the inside layer. At VEGP Unit 4, each of the four layers is missing rebar as follows:

- West face inside layer: 1 (#10) bar short (95 bars installed, 96 bars UFSAR specified minimum provided)

- West face outside layer: 1 (#11) bar short (95 bars installed, 96 bars UFSAR specified minimum provided)

- East face inside layer: 3 (#10) bars short (95 bars installed, 98 bars UFSAR specified minimum provided)

- East face outside layer: 2 (#11) bars short (96 bars installed, 98 bars UFSAR specified minimum provided)

Page 2 of 4

ND-19-XXXX Enclosure Second Preliminary Amendment Request: Reinforcement Changes for Wall L (PAR-19-016-2)

This condition results in the provided vertical reinforcement area and reinforcement configuration not in compliance with the Tier 2* information contained in UFSAR Table 3H.5-7 and Figure 3H.5-12.

The reinforcement necessary to satisfy ACI 349-01 requirements is calculated using Finite Element Analysis (FEA) using the applicable load combinations and design criteria, in accordance with UFSAR Table 3.8.4-2 and ACI 349-01. As shown in UFSAR Table 3H.5-7, the vertical required reinforcement in Wall L between Elevations 117'-6" to 135'-3" (2.02 in2/ft) remains less than the revised provided reinforcement of this wall segment (4.95 in2/ft).

The proposed change does not impact the seismic analysis of the nuclear island because it does not affect the mass or stiffness of the seismic model. Wall L continues to provide MCR boundary.

For the wall reinforcement changes, the structural design gn meets the acceptance criteria specified in UFSAR Section 3.8. Furthermore, the seismic mic floor f response spectra meet the acceptance criteria specified in UFSAR Subsection n 3.7.5.4.

3.7.5.4. Considering 3.7.5 Co the applicable loading scenarios and acceptance criteria required uired by the current curre licensing basis, as discussed above, the demands in Wall L remainain below their respective rrespec capacities. The acceptance criteria of ACI 349-01. T proposed changes to the reinforcement are in accordance with andan continue to satisfy the D

The proposed change requires a change ange to Tier 2*

2 information informa in UFSAR. Therefore, the proposed change requires NRC approval pproval accordance with 10 CFR 52.98(c).

proval in accordanc R

Additional details are provided ed referenced LAR d in the referenc LA (LAR-19-016R1).

5. Is Exemption Requestt Required? Y Yes No AF

6. Identify Applicable cribe the Reason for tthe Exemption.

If Yes, Briefly Describe No exemption required equired for the PAR.

PAR icable Precedents:

Precedents Precede No precedent identified.

ntified.

ntified

7. Impact of Change on Installation In and Testing Schedules:

A delayed determination regarding this PAR will result in delay of rebar installation and concrete placement for VEGP Unit 4 Wall L , as described below.

As such, this PAR requests a no objection finding related to the changes described in LAR-19-016R1 related to Wall L by the date identified in Block 1 above (or sooner if reasonably achievable) to allow for appropriate notifications and release of further activities dependent on construction of the VEGP Unit 4 Wall L, as noted below.

Specifically, SNC is requesting a no objection finding to allow:

x Rebar installation and concrete placement for VEGP Unit 4 Wall L above elevation 117-6 Construction holds have been issued for these activities.

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ND-19-XXXX Enclosure Second Preliminary Amendment Request: Reinforcement Changes for Wall L (PAR-19-016-2)

A no objection finding for the above activities would allow for VEGP Unit 4 construction activities to proceed.

8. Impact of Change on ITAAC:

No ITAAC are affected by this change, but it will impact the closure of the ITAAC. Final approval of the License Amendment Request will be necessary for closure of the related ITAAC, but a no objection finding is requested for this PAR in order to proceed with construction pursuant to the process outlined in COL Condition 2.D(1), Changes during Construction. This PAR should be considered for any inspections related to ITAAC 3.3.00.02.a.i.d (Item No. 763) of the VEGP Unit 4 COL Appendix C Table 3.3-6.

9. Additional Information:

None AF T

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