AP1000 Shield Building RC to SC Connections

Walk Through and Discussion

SNC LARs 13-014 & 13-018 Meeting with the NRC

August 29, 2013

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AgendaIntro and Meeting ObjectivesReview of LAR-13-018 CA03 changesAddress Licensing Questions (LAR-13-014)

1. Approval of changes to Tier 2 and Tier 2* 2. Significant Hazards Consideration Discussion for Tier 2

Address Licensing Basis Comments (LAR-13-014)3a. Walk through of licensing basis changes

• Figure 3H.5-7• Figure 3H.5-16

3b. Information removed from figures7. Plate thickness and Tie Bar Spacing Changes

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Agenda Continued3a. Changes to GLR-602

Technical Questions (LAR-13-014)4. Assumptions for the design roof connection5. Global Seismic Response6. Shield Building Design Adjacent to Penetrations.

Actions on RC to SC LAR-13-014Wrap-up

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CA03 Changes LAR-13-0181) What corrosion mitigation strategies are in place to address galvanic

corrosion concerns?>No dissimilar metals in corrosive environment.

2) How does the licensee plan to address contamination of the duplex stainless steel IRWST plate during fabrication?>Contamination addressed by general notes on design drawings.

3) What weld filler material will be used for the dissimilar metal welding, and how is it addressed in the corrosion test plan?> filler material requirements per weld spec, per AWS D 1.1 & 1.6

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Licensing Questions LAR-13-0141. Address Tier 2 and Tier 2* reference inconsistencies in 4.1

Associated T2 material requires approval only because T2* information is involved. As necessary, Section 4.1 can be revised to address appropriately address both T2 and T2* information changes and change requirements

2. Address Tier 2 and Tier 2* reference inconsistencies in 4.3Associated T2 material requires approval only because T2* information is involved. As necessary, Section 4.3 can be revised to address appropriately address both T2 and T2* information changes and change requirements

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Licensing Basis Comments3a. NRC staff requests a page-by-page walk thru of the relevant

licensing basis changes 1. Revision of APP-GW-GLR-602 reference

• APP-GW-GLR-602 is referenced by the UFSAR to include Westinghouse proprietary information in the licensing basis.

• The revision of APP-GW-GLR-602 is changed in 2 places in UFSAR Table 1.8-1 to Rev. 2.

• The references in USFAR Subsection 3.8.7 and 3H.5.8 to GLR-602 are changed to Rev. 2.

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Licensing Basis Changes2. UFSAR Subsection 3H.5.6 includes the following changes

• Correction of the description of Figure 3H.5-16. The original figure and the revised figure show the location of the RC to SC connection. Neither version shows dimensions of the connections. Neither version shows information about the surface plates.

• Addition of the note that the column line and auxiliary building roof information in Figure 3H.5-16 is shown for reference and is not Tier 2* information.

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Licensing Basis Changes3. Changes for allowance for thicker faceplates.

• Change to UFSAR Subsection 3H.5.7.1 to identify that the faceplates are thicker in localized areas to address loads from connections and attachments.

• Change the note on plate thickness in UFSAR Table 3H.5-14 to note that it is “design minimum”.

• Since the thicker plates are for fabrication reasons the design of the studs and tie bars are not altered unless the tie bars are changed to act as backup structure.

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Licensing Basis Changes4. Changes to Aux Building Roof to Shield Building Wall Module

connection. Change to UFSAR Figure 3H.5-7 to show• Redesign of the shear lug • Addition of a connection plate for connection of roof reinforcement to

structural modules• The design of the connector plate allows for removal of the radial

reinforcement connected to the faceplate. • Addition of an overlay or backing plate welded to the module

faceplate• The extension of roof reinforcement into the wall is removed. • Tie bars in the wall module are added and designated as internal wall

reinforcement to develop roof reinforcement and provide backup structure for the roof girder connection.

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Licensing Basis Changes5. Changes to location of RC to SC connection in UFSAR

Figure 3H.5-16 to show• Shifted slightly the vertical connection between RC and SC near

wall N• Remove an offset in the vertical connection near the bottom of the

connection. The offset was in place to avoid concrete blocks used to shield the fuel transfer canal.

• Extend a portion of the vertical connection to move to the right of the main steam and main feedwater penetrations. In the original location the penetrations would interfere with reinforcement bars extending into the reinforced concrete.

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Changes to Figure 3H.5-16Location of Connection

The following figures show the differences in the RC to SC connections shown on Figure 3H.5-16.

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Changes to Figure 3H.5-16Location of Connection

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Changes to Figure 3H.5-16Location of Connection

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Removed Information3b. In particular, clarify why specific information on Tier 2* figures

(e.g., 3H.5-7, 3H.5-16 sheets 1&2, etc.) is being deleted and describe whether similar information with equivalent regulatory control is provided in the FSAR.

1. Removal of roof information from Figure 3H.5-7• Appendix 3H is included to define and describe the critical sections. • The critical section shown in Figure 3H.5-7 is the connection of the auxiliary

building roof of the shield building and the adjacent portion of the roof. • The information for the remainder of the roof is not needed to describe the

critical section. • Information removed includes dimensions of the roof and walls, most column

lines, distance between column lines, roof elevations, and center lines.• The scale is removed from the roof plan. • The N direction indicator is removed from the upper right portion of the figure.

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Removed Information2. Removal of the Reinforcement Floor Detail in Region “A” and Region “B”

• Region “A” is not part of the critical section. • The information in Region “B” is duplicated in Section A.

3. Removal of shield building information from Figure 3H.5-7• The shield building wall radius and thickness and centerline information are

described in Section 3.8.4.1.1 and Figure 3.7.2-12 Sheet 5. • This information is not needed to define the roof to shield building critical

sections. 4. Removal of the Partial Plan at EL. 170'·0 from Figure 3H.5-7

• The connection between auxiliary building Wall 4 and the shield building wall is not part of the critical section.

• This information is in included in Figure 3.7.2-12 Sheet 6 and APP-GW-GLR-602 Figure 5.

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Removed Information5. Removal of the Lower Section in Section A from Figure 3H.5-7

• The shield building wall away from the roof connection is not part of this critical section

• This portion of the shield building is described as part of another critical section in APP-GW-GLR-602 Section 4 and Figures 1-4, and 3H.5.7.2

6. Removal of information from UFSAR Figure 3H.5-16 Sheets 1 and 2 • Figure 3H.5-16 is included to show the location of the connections between

RC and SC in the shield building. • The details of the connection design are included in APP-GW-GLR-602.• Information removed includes background for walls and other structural

elements in the auxiliary building adjacent to or intersecting the shield building wall.

• The information removed is not needed to define the location or design of the RC to SC connection.

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FSAR Changes at Localized Locations7. Discuss the specific FSAR changes to achieve

flexibility for the shield building plate thickness and the tie bar size/spacing at localized locations.• Add the following sentence to UFSAR Subsection 3H.5.7.1:

The faceplates are thicker, as necessary, in localized areas to address loads from connections and attachments.

• Revise Figure 6 of APP-GW-GLR-602 to add a note to state“Tie Bars density and size may be increased to accommodate local attachments.”

• Change the note on plate thickness in UFSAR Table 3H.5-14 to note that it is “design minimum.”

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Changes to APP-GW-GLR-602APP-GW-GLR-602 is a Westinghouse proprietary document that is incorporated by reference into the licensing basis. The following changes, in addition to editorial changes, have been incorporated into Revision 2.

1. Table 1 of APP-GW-GLR-602 (material) is revised to add additional elements of the connection hardware.

2. Text is changed to be consistent with the change in the location of the vertical RC to SC connections

3. Text is changed to note that couplers rather than hoop bars are welded to the end plate.

4. Text is changed to clarify stud and tie bar spacing differences for Type 1 modules.

5. Text is changed to note use of AISC N690 for steel and weld stress evaluation.

6. Notes in Figure 1 of APP-GW-GLR-602 are revised to change the start and stop azimuth for the connection.

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Changes to APP-GW-GLR-6027. In Figure 1 the width of the support plate is revised. 8. In Figure 1 the designation of Design Minimum is added to the support

plate dimensions. 9. In Figure 6 the vertical connection between RC and SC is shifted

slightly from Azimuth 177° to Azimuth 183°on the right side of the figure.

10. In Figure 6 the offset at the bottom of the vertical connection between RC and SC is eliminated.

11. In Figure 6 a portion of the vertical connection is moved to the right of the main steam and main feedwater penetrations.

12. In Figure 6 a note is added to state “Tie Bars density and size may be increased to accommodate local attachments.”

13. In Figure 7 two layers of reinforcement bars radial to the faceplate extending into the concrete roof and two layers of reinforcement perpendicular to these radial bars are removed.

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Changes to APP-GW-GLR-60214. In Figure 7 a connection plate to connect reinforcement bars in the roof

to the wall module faceplate is added. 15. In Figure 7 the shear lug design is revised. 16. In Figure 7 a backing plate welded to the surface of the wall module

faceplate is added. 17. In Figure 7 a stiffener plate is added between the connection plates18. In Figure 7 reinforcements inside the wall module are replaced with

additional wall module tie bars. 19. Note 1 of Figure 7 is revised to remove the specific size and spacing of

reinforcement inside the wall and add the requirement to fully develop reinforcement in the roof.

20. Note 2 of Figure 7 is revised to include discussion of load path through connection plates and tie bars.

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APP-GW-GLR-602

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Technical Changes4. Explain the assumptions for the design of the Aux.

building/Shield building roof connection (Enclosure 4, page 6), including shear design and consideration of ACI 349 Chapter 21 provisions pertaining to design of mechanical connections.

• Code boundaries– The Auxiliary Building roof is designed to ACI 349-01– The Auxiliary Building roof reinforcement is connected to the Shield Building with

mechanical connection– The reinforced concrete in the connection region is designed to ACI 349-01 (i.e.

reinforcing bar distribution is maintained)– The mechanical connection is designed to develop 125% of the specified yield

strength of the reinforcement per ACI 349-01 Paragraph 12.14.3– The mechanical connection structure is designed to AISC N690-1994, including

members and connections

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Technical Changes5. Explain the analysis performed to assess the significance of the

changes in SC-RC connection location (e.g., azimuth changes) on AP1000 global seismic response.

• Location of RC/SC connection near Wall N moved from Azimuth 177° to 183°

• An assessment of the impact of the azimuth change to the NI05 model was performed

– The stiffness and the equivalent thickness of elements in the NI05 model were modified to match with the revised configuration

– SC/RC connection zones are treated as SC section; only the Shield Building wall between Wall L-2 & N are modified

– Static analyses were performed– Initial assessment made by reviewing the difference in member forces

at impacted local area

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Technical Changes6. Provide exterior elevation views showing the change in SB wall

design adjacent to the main steam and main feedwater penetrations. Also, explain the analysis performed to assess the significance of the change on the standard design seismic model(s).

• MS/FW penetration redesigned as a weldment• Designed in accordance with AISC N690• Concrete capacity neglected in the revised design• Reinforcement mechanically anchored to the weldment IAW ACI 349

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Additional Proprietary Info

Provided in Closed Session

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