ND-18-1305, Request for License Amendment: Column Line 1 Wall Reinforcement Area Change (LAR-18-026)

Request for License Amendment: Column Line 1 Wall Reinforcement Area Change (LAR-18-026)

ML18292A660
Person / Time
Site:	Vogtle
Issue date:	10/19/2018
From:	Whitley B Southern Nuclear Operating Co
To:	Document Control Desk, Office of New Reactors
References
LAR-18-026, ND-18-1305
Download: ML18292A660 (21)

Text

B. H. Whitley Southern Nuclear Director Operating Company, Inc.

Regulatory Affairs 3535 Colonnade Parkway Birmingham, AL 35243 Tel 205.992.7079 October 19, 2018 Docket No.:52-025 ND-18-1305 10 CFR 50.90 10 CFR 52.63 U.S. Nuclear Regulatory Commission Document Control Desk Washington, DC 20555-0001 Southern Nuclear Operating Company Vogtle Electric Generating Plant Unit 3 Request for License Amendment:

Column Line 1 Wall Reinforcement Area Change (LAR-18-026)

Ladies and Gentlemen:

Pursuant to 10 CFR 52.98 (c) and in accordance with 10 CFR 50.90, Southern Nuclear Operating Company (SNC), the licensee for Vogtle Electric Generating Plant (VEGP) Units 3 and 4, hereby requests an amendment to the Combined License (COL) for VEGP Unit 3 (License Number NPF-91). This amendment request proposes to depart from certified AP1000 Design Control Document (DCD) Tier 2* material that has been incorporated into the Updated Final Safety Analysis Report (UFSAR).

The proposed departure consists of changes to Tier 2* information in the UFSAR (which includes the plant-specific DCD information) to change the vertical reinforcement information provided in the VEGP Unit 3 column line 1 wall from elevation 135'-3" to 137'-0". contains the detailed description, technical evaluation, regulatory evaluation (including the Significant Hazards Consideration Determination), and environmental considerations for the proposed changes in the License Amendment Request (LAR). provides markups depicting the requested changes to the licensing basis documents.

SNC requests staff approval of the license amendment by April 19, 2019, to support the construction schedule for VEGP Unit 3. SNC expects to implement the proposed amendment through incorporation into the licensing basis documents within 30 days of approval of the requested changes.

SNC also expects to submit a Preliminary Amendment Request (PAR) along with this LAR submittal to allow for the rebar installation and concrete placement for the VEGP Unit 3 column line 1 wall above elevation 135'-3". This PAR is expected to request a "no objection" finding from the NRC Staff by November 16, 2018.

In accordance with 10 CFR 50.91, SNC is notifying the State of Georgia of this LAR by transmitting a copy of this letter and enclosures to the designated State Official.

U.S. Nuclear Regulatory Commission ND-18-1305 Page 2 of 4 This letter contains no regulatory commitments. This letter has been reviewed and determined not to contain security-related information.

Should you have any questions, please contact Ms. Paige Ridgway at (205) 992-7516.

I declare under penalty of perjury that the foregoing is true and correct. Executed on the 19th of October 2018.

Respectfully submitted, SOUTHERN NUCLEAR OPERATING COMPANY Brian H. Whitley Director, Regulatory Affairs Southern Nuclear Operating Company Enclosures 1) Vogtle Electric Generating Plant (VEGP) Unit 3- License Amendment Request: Column Line 1 Wall Reinforcement Area Change (LAR-18-026)

2) Vogtle Electric Generating Plant (VEGP) Unit 3- Proposed Changes to the Licensing Basis Documents (LAR-18-026)

U.S. Nuclear Regulatory Commission ND-18-1305 Page 3 of 4 cc:

Southern Nuclear Operating Company / Georgia Power Company Mr. S. E. Kuczynski (w/o enclosures)

Mr. D. G. Bost (w/o enclosures)

Mr. M. D. Meier (w/o enclosures)

Mr. D. H. Jones (w/o enclosures)

Mr. J. B. Klecha Mr. G. Chick Mr. D. L. McKinney (w/o enclosures)

Mr. T. W. Yelverton (w/o enclosures)

Mr. B. H. Whitley Ms. C. A. Gayheart Mr. C. R. Pierce Ms. A. G. Aughtman Mr. D. L. Fulton Mr. M. J. Yox Mr. C. T. Defnall Mr. J. Tupik Mr. W. A. Sparkman Ms. A. C. Chamberlain Ms. A. L. Pugh Ms. P. Reister Ms. K. Roberts Document Services RTYPE: VND.LI.L00 File AR.01.02.06 Nuclear Regulatory Commission Mr. W. Jones (w/o enclosures)

Ms. J. Dixon-Herrity Mr. C. Patel Ms. J. M. Heisserer Mr. B. Kemker Mr. G. Khouri Ms. S. Temple Mr. F. Brown Mr. C. J. Even Mr. A. Lerch Mr. S. Walker State of Georgia Mr. R. Dunn

U.S. Nuclear Regulatory Commission ND-18-1305 Page 4 of 4 Oglethorpe Power Corporation Mr. M. W. Price Ms. A. Whaley Municipal Electric Authority of Georgia Mr. J. E. Fuller Mr. S. M. Jackson Dalton Utilities Mr. T. Bundros Westinghouse Electric Company, LLC Mr. L. Oriani (w/o enclosures)

Mr. C. Churchman (w/o enclosures)

Mr. M. Corletti Mr. M. L. Clyde Ms. L. Iller Mr. D. Hawkins Mr. J. Coward Other Mr. S. W. Kline, Bechtel Power Corporation Ms. L. A. Matis, Tetra Tech NUS, Inc.

Dr. W. R. Jacobs, Jr., Ph.D., GDS Associates, Inc.

Mr. S. Roetger, Georgia Public Service Commission Ms. S. W. Kernizan, Georgia Public Service Commission Mr. K. C. Greene, Troutman Sanders Mr. S. Blanton, Balch Bingham NDDocumentinBox@duke-energy.com, Duke Energy Mr. S. Franzone, Florida Power & Light

Southern Nuclear Operating Company ND-18-1305 Enclosure 1 Vogtle Electric Generating Plant (VEGP) Unit 3 License Amendment Request:

Column Line 1 Wall Reinforcement Area Change (LAR-18-026)

(This Enclosure consists of 14 pages, including this cover page.)

ND-18-1305 License Amendment Request: Column Line 1 Wall Reinforcement Area Change (LAR-18-026)

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 Determination 4.4 Conclusions

5. ENVIRONMENTAL CONSIDERATIONS

6. REFERENCES Page 2 of 14

ND-18-1305 License Amendment Request: Column Line 1 Wall Reinforcement Area Change (LAR-18-026)

Pursuant to 10 CFR 52.98(c) and in accordance with 10 CFR 50.90, Southern Nuclear Operating Company (SNC, or the Licensee) hereby requests an amendment to Combined License (COL)

No. NPF-91 for Vogtle Electric Generating Plant (VEGP) Unit 3.

1.

SUMMARY

DESCRIPTION The proposed change would revise the area of steel vertical reinforcement for the Vogtle Unit 3 auxiliary building wall on column line 1 from elevation (EL.) 135'-3" to 137'-0". The proposed change impacts Updated Final Safety Analysis Report (UFSAR) Tier 2*

information in UFSAR Table 3H.5-3 and UFSAR Figure 3H.5-3.

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

2. DETAILED DESCRIPTION As stated in Combined License (COL) Appendix C, Section 3.3, the nuclear island structures include the containment and the shield and auxiliary buildings. The containment, shield and auxiliary buildings are structurally integrated on a common basemat which is embedded below the finished plant grade level. The auxiliary building is reinforced concrete and houses the safety-related mechanical and electrical equipment located outside the containment and shield buildings.

The nuclear island structures, including the critical sections listed in COL Appendix C Table 3.3-7 which lists the auxiliary building south wall (column line 1), are seismic Category I (C-I) and are designed and constructed to withstand design basis loads without loss of structural integrity and the safety-related functions. The design bases loads are those loads associated with:

• Normal plant operation (including dead loads, live loads, lateral earth pressure loads, and equipment loads, including hydrodynamic loads, temperature and equipment vibration);

• External events (including rain, snow, flood, tornado, tornado generated missiles and earthquake); and

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

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ND-18-1305 License Amendment Request: Column Line 1 Wall Reinforcement Area Change (LAR-18-026)

The safety-related systems and components needed to bring the plant to safe shutdown are located inside the auxiliary building which has thick structural concrete exterior walls that provide protection from missiles generated in other portions of the plant. Protection from external missiles, including those generated by natural phenomena, is provided by the external walls and roof of the Seismic C-I nuclear island structures. The external walls and roofs are reinforced concrete.

The design and analysis procedures for the seismic C-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.

UFSAR Subsection 3.8.4.4.1 also states that provisions of ACI 318-11, Building Code Requirements for Structural Concrete, Section 12.6, for headed and mechanically anchored deformed bars apply, to development of headed reinforcement as an alternative to the provisions in ACI 349-01 Appendix B. The specific application of ACI 318-11 Section 12.6 is used for development of the headed reinforcement to provide ductile behavior. 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 terminating at the edges of structural walls or at openings is detailed in accordance with Subsection 21.6.6.5 of ACI 349-01. The concrete structures are designed according to the strength design methods of ACI 349-01, using the load combinations specified in UFSAR Table 3.8.4-2.

The wall at column line 1 (Wall 1) is the exterior wall at the south end of the nuclear island, adjacent to the radwaste building. The reinforced concrete wall extends from the top of the basemat at EL. 66'-6" to the roof at EL. 180'-0". The wall is designed for the applicable loads including dead load, live load, hydrostatic load, static and dynamic lateral soil pressure loads, seismic loads, and thermal loads. For various segments of this wall, UFSAR Table 3H.5-2 provides the listing and magnitude of the various design loads and UFSAR Table 3H.5-3 presents the details of the wall reinforcement. The sections where the required reinforcement is calculated are shown in UFSAR Figure 3H.5-2 (Sheet 1). Typical wall reinforcement for Wall 1 is shown on UFSAR Figure 3H.5-3.

UFSAR Table 3H.5-3 details the required and provided auxiliary building wall reinforcements for Wall 1 according to elevation with depictions of the locations of wall sections in UFSAR Figure 3H.5-2.

UFSAR Figure 3H.5-3 depicts the typical wall reinforcement in the upper-section view of Wall 1 and details the #8@12" vertical rebar reinforcements, including the vertical development length below and up to EL. 135'-3".

Per UFSAR Subsection 3H.5.1.1, the design of the auxiliary building Wall 1 from EL. 117'-6" to EL. 135'-3" requires outer layer reinforcing bar (rebar) curtains (north & south face) consisting of #11@6" vertical bars with #11@6" horizontal bars. A second layer of #8@12" vertical bars is required to begin development length below EL. 135'-3" and extending splice length above EL. 135'-3"; on the south face only.

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ND-18-1305 License Amendment Request: Column Line 1 Wall Reinforcement Area Change (LAR-18-026)

USFAR Figure 3H.5-3 shows the original rebar configuration in this area. An excerpt from UFSAR Figure 3H.5-3, provided as Figure 1, is shown below.

Figure 1: Excerpt from UFSAR Figure 3H.5-3 At Vogtle Unit 3, there were no second layer #8@12" vertical bars installed in the south face for the entire length of Wall 1 around EL. 135'-3" prior to concrete placement of Wall 1 from EL. 117'-6" to EL. 135'-3". This condition results in a reinforcement area and configuration that deviates from the Tier 2* information contained in UFSAR Table 3H.5-3 and Figure 3H.5-

3. The impacted area is a subsection of wall Section 6 as shown on UFSAR Figure 3H.5-2.

All other sections shown on UFSAR Figure 3H.5-2 remain unaffected by this change. Per COL Appendix C Table 3.3-1 and UFSAR Subsection 3H.5.1.1, the thickness of Wall 1 at this location is 2'-3". The thickness of the wall remains unaffected by this change.

The proposed changes involve the #8@12" vertical rebar being installed around EL. 135'-3" with a mechanically headed reinforcement (T-head), providing full development of the bars at and above EL.137'-0", in accordance with ACI 318-11. As a result of this change, through the development length of the rebar, the provided minimum amount of reinforcement area is less than the existing UFSAR Table 3H.5-3 provided minimum value of 3.91 in2/ft between EL. 135'-3" to EL. 137'-0"; the actual provided value is 3.12 in2/ft, as only the #11@6" bars are developed and can be credited in this elevation range. This is acceptable as the required reinforcement area for the subsection from EL. 135'-3" to EL. 137'-0" is less than the required area for the entire length of the section from EL. 135'-3" to EL. 180'-0" of 3.48 in2/ft as stated in UFSAR Table 3H.5-3. UFSAR Figure 3H.5-3 is also impacted because it shows the

1. 8@12" vertical rebar with the full development length below EL. 135'-3". The #11@6" vertical and horizontal reinforcement on the north and south face remain unchanged. The configuration of the Vogtle Unit 4 Wall 1 remains unchanged.

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ND-18-1305 License Amendment Request: Column Line 1 Wall Reinforcement Area Change (LAR-18-026)

An example sketch of how the mechanically headed reinforcement will be placed at EL.

135'-3" is shown in Figure 2 below:

Figure 2: Sketch of Proposed Wall 1 Mechanically Headed #8@12" Vertical Reinforcement Licensing Basis Change Descriptions:

A new note, Note 4, is added to UFSAR Table 3H.5-3 which describes the reduction in reinforcement area for the wall between EL. 135'-3" and EL. 137'-0" for Vogtle Unit 3 and the acceptability of this change, including the calculated required area of reinforcement for the area from EL. 135'-3" to EL. 137'-0". Note 4 is also placed beside the required and provided (minimum) vertical reinforcement area for the outside face of Wall 1 from elevation 135'-3" to 180'-0". A new note, Note 2, is added to UFSAR Figure 3H.5-3 which describes that the

1. 8@12" will be developed below 137'-0", rather than 135'-3" as shown in the figure, for Vogtle Unit 3.

3. TECHNICAL EVALUATION Wall Design Evaluation The design change specifies the installation of the #8@12" vertical reinforcement considering headed reinforcement and requires the #8@12" vertical reinforcement to be fully developed at EL. 137'-0", instead of EL. 135'-3". Since the #8@12" vertical bars are not fully developed below EL. 137'-0" as part of this change, the bars are not considered to be credited as a portion of the provided steel area below EL. 137'-0".

The development length (Ldt) of a #8 headed reinforcement in tension is Ldt=16", consistent with ACI 349-01 and ACI 318-11, Section 12.6. Given the existing construction joint at EL.

135'-3", the available height of wall to develop the bars prior to EL. 137'-0" is 21". Therefore, the installation of these bars using a headed reinforcement ensures that the bars will be fully Page 6 of 14

ND-18-1305 License Amendment Request: Column Line 1 Wall Reinforcement Area Change (LAR-18-026) developed at EL. 137'-0" and above, consistent with provisions of ACI 318-11 and as evaluated herein.

The design of Wall 1 above EL. 137'-0" remains unchanged, and the area between EL. 135'-

3" and EL. 137'-0" was re-evaluated and remains in compliance with the requirements of ACI 349-01 and ACI 318-11. The required reinforcement to satisfy ACI 349-01 and ACI 318-11 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.

The demand in the wall between EL. 135'-3" and EL. 137'-0" remains less than the capacity of the wall. 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.

A conservative refinement of the reported FEA results was performed. For the impacted region of Wall 1 (EL. 135'-3" to EL. 137'-0"), the provided area of reinforcement considered is 3.12in2/ft (#11@6"). The evaluation determined a maximum required area of steel, along the entire evaluated length of wall between EL. 135'-3" and EL. 137'-0", of 2.801 in2/ft, for load combinations which do not consider simultaneous thermal and safe shutdown earthquake (SSE) loads, consistent with UFSAR Table 3H.5-3 reported values. The resulting interaction ratio of the conservative refinement for the impacted region is IR= 0.898 (2.801 in2/ft / 3.12 in2/ft). For consistency with significant figures in UFSAR Table 3H.5-3, a required area value of 2.81 in2/ft is included in the proposed markups, which conservatively bounds the actual required area of 2.801 in2/ft.

Note that for load combinations which consider simultaneous thermal and SSE loads, the required area of steel is 3.085in2/ft, with a corresponding interaction ratio for the impacted region of IR=0.989 (3.085in2/ft / 3.12in2/ft). Since the interaction ratio is less than 1.0, this change is acceptable and continues to satisfy the acceptance criteria of ACI 349-01 and applicable design criteria.

Tornado Missile Evaluation The change does not adversely affect the design function, regarding the capability of Wall 1 to withstand tornado missile impacts for postulated missiles. Since an impact due to a tornado missile can only occur on the exterior face of the wall, the reduction in reinforcement occurs on the compression face of the wall under tornado loading and the reduction in compression side reinforcing area (south face of Wall 1) has no adverse impact on design function of Wall 1 to withstand tornado missile impacts for postulated missiles. There are no credible postulated internally generated missiles in this area; therefore, there is no adverse impact on the design function of Wall 1 to withstand tornado missile impacts.

Construction Joint Evaluation for Wall 1 at EL. 135'-3" The change does not impact the amount of provided rebar considered transverse to the horizontal construction joint in Wall 1 at EL. 135-3", as only the #11@6" reinforcement located on the northern and southern face of the wall were considered. Therefore, changing the

1. 8@12" reinforcement has no impact to the existing qualification of the construction joint located within Wall 1 at EL. 135'-3".

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ND-18-1305 License Amendment Request: Column Line 1 Wall Reinforcement Area Change (LAR-18-026)

Aircraft Impact Assessment (AIA) Consideration The change to Wall 1 results in a smaller vertical reinforcement ratio in the region between EL. 135'-3" and EL. 137'-0". An assessment of this change to Wall 1 with respect to AIA was performed and concluded that because a specific vertical reinforcement ratio is not credited in the AIA, and because the wall thickness and other design standards and features of Wall 1 are not changing, there is no effect on the AIA due to the change to Wall 1. There is no change to the design of key design features described in UFSAR Appendix 19F.

Impact on Adjacent Walls and Slabs The slabs are not impacted by the change in Wall 1 vertical reinforcement. The proposed change has no effect on the analysis or capacity of the concrete walls intersecting Wall 1.

Horizontal bars of the intersecting walls, which terminate in Wall 1, remain in conformance with ACI 349-01 requirements.

Impact from Adjacent Building Wall 1 is located adjacent to the non-seismic radwaste building. During a seismic event, it is possible that the radwaste building could collapse and strike Wall 1. If the radwaste building were to impact the nuclear island or collapse in the SSE, it would not impair the integrity of the reinforced concrete nuclear island. Wall 1 has been evaluated to show that it can resist the impact from the radwaste building. Adjustment of the location of development of the vertical #8 bars does not affect the ability of Wall 1 to resist the impact from a collapse of the radwaste building.

Technical Justification Summary Per UFSAR Subsection 3.8.4.5.3, deviations from the design due to as-procured or as-built conditions are acceptable based on an evaluation consistent with the methods and procedures of UFSAR Sections 3.7 and 3.8 provided the following acceptance criteria are met:

• The structural design meets the acceptance criteria specified in UFSAR Section 3.8

• The seismic floor response spectra meet the acceptance criteria specified in UFSAR Subsection 3.7.5.4 Considering the applicable loading scenarios and acceptance criteria required by the current licensing basis, as discussed above, the demands in Wall 1 remain below the capacity of Wall 1. The change to the reinforcement area between EL. 135'-3" and EL. 137'-0" is in accordance with and continues to satisfy the acceptance criteria of ACI 349-01 and ACI 318-11.

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, and the design remains in accordance with RG 1.29. The seismic C-I structure continues to comply with the quality assurance requirements of 10 CFR 50, Appendix B.

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.

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ND-18-1305 License Amendment Request: Column Line 1 Wall Reinforcement Area Change (LAR-18-026)

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 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 wall 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 and other seismic Category I structures are not changed. The design and material selection of the concrete floor beneath the reactor vessel is not altered. The response of the containment to a postulated reactor vessel failure, including direct containment heating, ex-vessel steam explosions, and core concrete interactions is not altered by the vertical reinforcement in Wall

1. The design of the reactor vessel and the response of the reactor vessel to a postulated severe accident are not altered by the change.

The proposed change does not affect the containment, control, channeling, monitoring, processing or releasing of radioactive and non-radioactive materials. The types and quantities of expected effluents are not changed, and no effluent release path is affected by the proposed changes. Therefore, radioactive and non-radioactive material effluents are not affected by the proposed change.

Plant radiation zones (as described in UFSAR Section 12.3), controls under 10 CFR 20, and expected amounts and types of radioactive materials are not affected by the proposed change. The change to the reinforcement was also examined with respect to the walls effectiveness in providing radiation shielding, and no adverse impacts were identified.

Therefore, individual and cumulative radiation exposures do not change.

These changes do not impact the emergency plans or the physical security evaluation since there are no changes to the configuration of walls, doors, or access to the nuclear island.

The proposed changes do not involve, nor interface 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.

Summary The proposed change modifies the vertical reinforcement information provided in the VEGP Unit 3 Wall 1 from elevation 135'-3" to 137'-0". The proposed change impacts information in UFSAR Table 3H.5-3 and UFSAR Figure 3H.5-3. This change maintains conformance to the ACI 318-11 and ACI 349-01 codes and has no adverse impact on the seismic response of Wall 1. The change does not significantly impact the approved design and Wall 1 will continue Page 9 of 14

ND-18-1305 License Amendment Request: Column Line 1 Wall Reinforcement Area Change (LAR-18-026) to withstand the design basis loads without loss of structural integrity or the safety-related functions.

Therefore, the above proposed changes would not adversely affect any safety-related equipment or function, design function, radioactive material barrier, or safety analysis.

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 vertical reinforcement for the Vogtle Unit 3 column line 1 wall (Wall 1), includes a Tier 2* departure 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 of capability to perform their safety functions. There is no change to the expected responses to natural phenomena, and the Wall 1, even with the change to the reinforcement, continues to be able to respond to the same design basis earthquake; therefore, there are no changes to the conformance with GDC 2.

10 CFR 50, Appendix A, GDC 4, Environmental and dynamic effects design bases, requires that structures, systems, and components important to safety shall be designed to accommodate the effects of and to be compatible with the environmental conditions associated with normal operation, maintenance, testing, and postulated accidents, including loss-of-coolant accidents. The change to the reinforcement does not alter the walls response to environmental conditions associated with normal operation, and because the same design criteria are used before and after the change, the auxiliary building continues to be able to withstand similar conditions; therefore, there are no changes to the conformance with GDC 4.

4.2 Precedent No precedent is identified.

4.3 Significant Hazards Consideration Determination The requested amendment proposes changes to information in the Updated Final Safety Analysis Report (UFSAR) related to the vertical reinforcement for the Vogtle Page 10 of 14

ND-18-1305 License Amendment Request: Column Line 1 Wall Reinforcement Area Change (LAR-18-026)

Unit 3 auxiliary building wall on column line 1 (Wall 1) from elevation 135'-3" to 137'-0".

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 As described in UFSAR Subsection 3H.5.1.1, the exterior wall at column line 1 (Wall 1) is located at the south end of the auxiliary building. It is a reinforced concrete wall extending from the basemat at elevation 66'-6" to the roof at elevation 180'-0". Deviations were identified in the constructed wall from the design requirements. The proposed change modifies the vertical reinforcement information provided in the VEGP Unit 3 Wall 1 from elevation 135'-3" to 137'-

0". This change maintains conformance to the ACI 318-11 and ACI 349-01 codes and has no adverse impact on the seismic response of Wall 1. Wall 1 continues to withstand the design basis loads without loss of structural integrity or the safety-related functions. The proposed change does not affect the operation of any system or equipment that initiates an analyzed accident or alter any SSC accident initiator or initiating sequence of events.

This change does not adversely affect the design function of the VEGP Unit 3 Wall 1 or the SSCs contained within the auxiliary building. This change does not involve any accident initiating components or events, thus leaving the probabilities of an accident unaltered.

Therefore, the proposed amendment does not involve a significant increase in the probability or consequences of an accident previously evaluated.

4.3.2 Does the proposed amendment create the possibility of a new or different kind of accident from any accident previously evaluated?

Response: No The proposed change modifies the vertical reinforcement information provided in the VEGP Unit 3 Wall 1 from elevation 135'-3" to 137'-0". As demonstrated by the continued conformance to the applicable codes and standards governing the design of the structures, the wall withstands the same effects as previously evaluated. The proposed change does not affect the operation of any systems or equipment that may initiate a new or different kind of accident, or alter any SSC such that a new accident initiator or initiating sequence of events is created. The proposed change does not adversely affect the design function of the auxiliary building Wall 1 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.

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ND-18-1305 License Amendment Request: Column Line 1 Wall Reinforcement Area Change (LAR-18-026)

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 The proposed change modifies the vertical reinforcement information provided in the VEGP Unit 3 Wall 1 from elevation 135'-3" to 137'-0". This change maintains conformance to the ACI 318-11 and ACI 349-01 codes. The change to the vertical reinforcement elevation 135'-3" to 137'-0" does 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 wall. 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 basis acceptance limit/criterion is challenged or exceeded by the proposed changes. Accordingly, no significant safety margin is reduced by the change.

Therefore, the proposed change does not involve a significant reduction in a margin of safety.

Based on the above, it is concluded that the proposed 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.

4.4 Conclusions In conclusion, based on the considerations discussed above, (1) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, (2) such activities will be conducted in compliance with the Commissions regulations, and (3) the issuance of the amendment will not be inimical to the common defense and security or to the health and safety of the public. Pursuant to 10 CFR 50.92, the requested change does not involve a Significant Hazards Consideration.

5. Environmental Considerations The details of the proposed changes are provided in Section 2 and 3 of this license amendment request.

The requested amendment proposes changes to information in the Updated Final Safety Analysis Report (UFSAR) related to the vertical reinforcement for the Vogtle Unit 3 auxiliary building wall on column line 1 (Wall 1) from elevation 135'-3" to 137'-0".

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 Page 12 of 14

ND-18-1305 License Amendment Request: Column Line 1 Wall Reinforcement Area Change (LAR-18-026) 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 this enclosure, an evaluation was completed to determine whether 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 Determination 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 vertical reinforcement information provided in the VEGP Unit 3 Wall 1 from elevation 135'-3" to 137'-0". The proposed change is unrelated to any aspect of plant construction or operation that would introduce any change to effluent types (e.g., effluents containing chemicals or biocides, sanitary system effluents, and other effluents), or affect any plant radiological or non-radiological effluent release quantities. Furthermore, the proposed change does not affect any effluent release path or diminish the functionality of any design or operational features that are credited with controlling the release of effluents during plant operation.

Therefore, it is concluded that the requested amendment does not involve a significant change in the types or a significant increase in the amounts of any effluents that may be released offsite.

(iii) There is no significant increase in individual or cumulative occupational radiation exposure.

The proposed change modifies the vertical reinforcement information provided in the VEGP Unit 3 Wall 1 from elevation 135'-3" to 137'-0". Plant radiation zones (addressed in UFSAR Section 12.3) are not affected, and controls under 10 CFR Part 20 preclude a significant increase in occupational radiation exposure. The change was also examined with respect to the walls effectiveness in providing radiation shielding, and no adverse impacts were identified.

Therefore, the proposed amendment does not involve a significant increase in individual or cumulative occupational radiation exposure.

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 Page 13 of 14

ND-18-1305 License Amendment Request: Column Line 1 Wall Reinforcement Area Change (LAR-18-026) 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 14 of 14

Southern Nuclear Operating Company ND-18-1305 Enclosure 2 Vogtle Electric Generating Plant (VEGP) Unit 3 Proposed Changes to the Licensing Basis Documents (LAR-18-026)

Added text is shown as Blue Underline Deleted Text is shown as Red Strikethrough Omitted text is shown as three asterisks (***)

(This Enclosure consists of 3 pages, including this cover page)

ND-18-1305 Proposed Changes to the Licensing Basis Documents (LAR-18-026)

Revise UFSAR Table 3H.5-3 Exterior Wall on Column Line 1 Details of Wall Reinforcement (in2/ft) as shown below:

Wall Segment Required(2) [Provided (Minimum)]*

(See detail in Subsection 3H.5.1.1.) Location Vertical Horizontal Shear(3) Vertical Horizontal Shear(3)

Wall Section 1, 6 Elevation 180'-0" to 135'-3" NR None Outside Face 3.48(4) 2.65 [3.91(4) 3.12 Inside Face 1.94 1.52 3.12 3.12]*

Notes:

[4. For Vogtle Unit 3, the #8@12" vertical reinforcement bars are fully developed at elevation 137'-0" and above on the outside face with a headed reinforcement bar, effectively reducing the minimum provided area of steel in this wall to 3.12in2/ft for the development length of the bars to elevation 137'-0". This reduction in minimum provided area does not change the performance of the existing structure under postulated loads and does not cause any excessive stress locally along the development length of the bar, as the required area of steel for elevation 135'-3" to 137'-0" is 2.81 in2/ft. The arrangement of bars in the wall for both units is unchanged per Figure 3H.5-3.]*

Page 2 of 3

ND-18-1305 Proposed Changes to the Licensing Basis Documents (LAR-18-026)

Revise the Upper Section view of UFSAR Figure 3H.5-3 Typical Reinforcement in Wall on Column Line 1 as shown below:

NOTE 2:

FOR VOGTLE UNIT 3, THE DEVELOPMENT LENGTH FOR THE #8@12" VERTICAL REINFORCEMENT BARS IS SUCH THAT THE BARS ARE FULLY DEVELOPED AT ELEVATION 137'-0". SEE TABLE 3H.5-3 FOR ADDITIONAL DETAILS.

Page 3 of 3