ML11159A211

License Amendment Request to Incorporate Use of Fiber-Reinforced Polymer System to Strengthen Existing Auxiliary Building Masonry Brick Walls for Tornado Loadings - Response to Request for Additional Information.

ML11159A211
Person / Time
Site:	Oconee
Issue date:	06/06/2011
From:	Gillespie T Duke Energy Carolinas
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
Download: ML11159A211 (14)

Text

"duke T. PRESTON GILLESPIE, JR.

Vice President ergy, Oconee Nuclear Station Duke Energy ONO1 VP / 7800 Rochester Hwy.

Seneca, SC 29672 June 6, 2011 864-873-4478 864-873-4208 fax Document Control Desk T.Gillespie@duke-energy.con?

U.S. Nuclear Regulatory Commission Washington, DC 20555-0001

Subject:

Duke Energy Carolinas, LLC Oconee Nuclear Station, Units 1, 2, and 3 Docket Numbers 50-269, 50-270, and 50-287, Renewed Operating Licenses DPR-38, DPR-47, and DPR-55 "License Amendment Request to Incorporate Use of Fiber-Reinforced Polymer System to Strengthen Existing Auxiliary Building Masonry Brick Walls for Tornado Loadings - Response to Request for Additional Information."

References:

1. Letter from Dave Baxter, Site Vice President, Oconee Nuclear Station, Duke Energy Carolinas, LLC, to the U. S. Nuclear Regulatory Commission, "License Amendment Request to Incorporate Use of Fiber-Reinforced Polymer System to Strengthen Existing Auxiliary Building Masonry Brick Walls for Tornado Loadings" - License Amendment Request No. 2009-05" dated June 29, 2009.

2. Letter from Dave Baxter, Site Vice President, Oconee Nuclear Station, Duke Energy Carolinas, LLC, to the U. S. Nuclear Regulatory Commission, "Tornado Mitigation License Amendment Request - Response to Request for Additional Information," dated June 24, 2010.

3. Letter from T. Preston Gillespie, Jr., Site Vice President, Oconee Nuclear Station, Duke Energy Carolinas, LLC, to the U. S. Nuclear Regulatory Commission, "Tornado Mitigation License Amendment Request - Response to Request for Additional Information," dated February 15, 2011.

On June 29, 2009, Duke Energy Carolinas, LLC (Duke Energy) submitted a License Amendment Request (LAR) to incorporate the use of a Fiber Reinforced Polymer (FRP) system to strengthen existing masonry brick walls for uniform pressure loads resulting from a tornado event. The masonry walls to be strengthened are part of the Units 1, 2, and 3 Auxiliary Buildings (ABs) walls.

Duke Energy has received and responded to several FRP-related Requests for Additional Information (RAI) with the latest dated June 24, 2010 [Ref. 2], and February 15, 2011,

[Ref. 3]. Following the Staff's review of these submittals, additional follow-up conference calls were held in order for the Staff to request: (1) additional information and/or (2) that Duke Energy clarify statements made in the earlier submittals. The attachment to this letter contains this information and supplements the previous submittals.

If you have any questions in regard to this submittal, please contact Stephen C. Newman, )

Oconee Regulatory Compliance Group, at 864-873-4388. 2b www. duke-energy.con?

U. S. Nuclear Regulatory Commission June 6, 2011 Page 2 I declare under penalty of perjury that the foregoing is true and correct. Executed on June 6, 2011.

Sincerely, TPreston Gillespie, Jr.,

Site Vice President, Oconee Nuclear Station Attachment

U. S. Nuclear Regulatory Commission June 6, 2011 Page 3 cc: (w/attachment)

Mr. J. F. Stang, Project Manager Office of Nuclear Reactor Regulation U. S. Nuclear Regulatory Commission Mail Stop 8 G9A Washington, D. C. 20555 Mr. Victor McCree, Regional Administrator U. S. Nuclear Regulatory Commission - Region II Marquis One Tower 245 Peachtree Center Ave., NE, Suite 1200 Atlanta, GA 30303-1257 Mr. Andy Sabisch NRC Senior Resident Inspector Oconee Nuclear Station S. E. Jenkins, Manager Infectious and Radioactive Waste Management Section 2600 Bull Street Columbia, SC 29201

Attachment FRP RAI Supplemental Information

U. S. Nuclear Regulatory Commission Attachment - FRP RAI Supplemental Information

'June 6, 2011 Page 1 NOTE: The following request for additional information (RAI) responses contain NRC requested "additional" or "clarification" information from discussions held with the Staff after Duke Energy's initial submittal of these specific RAI responses. Unless otherwise noted, this information supplements the prior RAI responses contained in References 2 and 3.

RAI 2-9 As stated in the June 29, 2009, LAR, the fiber reinforced polymer (FRP) system will be applied to the exterior surface of the masonry brick walls. Page 5 of Enclosure 1 of the LAR states that the proposed FRP system will be exposed to ambient temperature and humidity conditions associated with the local climate. Considering that the temperature and humidity in the confined space between the metal siding and the brick walls are not controlled and will rise during summer months, please provide further information to justify the acceptance of the proposed FRP system.

Duke Energy Response The ASHRAE 50-year maximum air temperature of 106.30 F for Anderson, SC was compared to, and found to be consistent with, the National Oceanic and Atmospheric Administration's (NOAA) National Weather Service all-time maximum air temperature data for Greer, SC (Greenville-Spartanburg Airport), where it was determined that the maximum air temperature since readings began in the Autumn of 1917 was 105 0 F recorded on August 10, 2007. Anderson, SC lies approximately 25 miles south-southeast of the Oconee Nuclear Station, and Greenville, SC lies approximately 30 miles east of the Oconee Nuclear Station, and all three locations experience similar climatic conditions present in the upstate region of South Carolina. These recorded values expand the time frame for maximum temperature evaluation from 50 years to 93 years.

Duke considers the analysis provided in our initial response to remain valid, based on the following: a) there exists almost 100 years of temperature data to support our evaluation that the expected maximum temperature to which the installed FRP material will be exposed is 121.3 0 F, b) there is an almost 60°F margin between the expected maximum exposure temperature and the FRP glass transition temperature, Tg, of 180 0 F, and c) an Environmental Reduction Factor, CE = 0.65, per Chapter 8 of ACI 440.2R-02, is used in the analytical methodology for designing the FRP strengthening system, thus providing for strength reduction of more than one-third as a result of an aggressive environment (e.g., prolonged exposure to high humidity, freeze-thaw cycles, salt water, or alkalinity).

For additional weather information, reference:

http:/Iwww.erh.noaa.*qov/er/qsp/localdat/cases/2007/AuqustHeatWave/2007HeatWave.h tml RAI 2-11 Page 4 of Enclosure 1 of the June 29, 2009, LAR states that the installation of the FRP system will not adversely affect the current structural qualification of the brick walls by significantly increasing the stiffness. Contrary to this statement, based on a review of out-of-plane displacement test results for control wall C3-1.2 (Figure 47) and FRP modified wall S5-1.2-SR (Figure 111), there is an appreciable increase in the

U. S. Nuclear Regulatory Commission Attachment - FRP RAI Supplemental Information

-June 6, 2011 Page 2 out-of-plane stiffness of the FRP modified wall which, in turn, will change the frequency content of the brick wall. Please address the effects of the installation of the FRP system on the in-plane and out-of-plane stiffness of the brick walls. Also, discuss your plan and subsequent actions to evaluate the effects on the seismic analyses performed in response to the NRC Bulletin 80-11 (IEB 80-11), Masonry Wall Design.

Duke Energy Response Duke Energy has considered the effects of the installation of an FRP system on existing Auxiliary Building masonry walls and has ensured that the use of an FRP system on these walls has no adverse effect on the analyses and/or modifications performed in response to IE Bulletin 80-11.

RAI 2-12 Page 3 of Enclosure 1 of the June 29, 2009, LAR states that the existing brick walls will be analyzed in accordance with the Standard Review Plan, Section 3.8.4. Appendix A to the Standard Review Plan, Section 3.8.4, states that the analysis should consider both in-plane and out-of-plane loads, and interstory drift effects. The LAR and the experimental testing program only address the effects of the out-of-plane loading on the FRP modified walls. During a design basis tornado event, these in-fill brick walls will also be subjected to the in-plane forces due to the tornado wind acting on the auxiliary building structural framing system. Please discuss the effects of the in-plane forces concurrent with the out-of-plane forces acting on the FRP modified walls.

Duke Energy Response To clarify, Duke Energy's response dated June 24, 2010, to RAI 2-12 (Ref. 2) sought to address the effects of tornado-induced in-plane forces on the Auxiliary Building in-fill masonry walls by comparing the magnitude of these forces to those resulting from the design-basis seismic event and for which the masonry walls were previously qualified. In both cases, in-plane forces acting on the masonry are produced by inter-story drift of the Auxiliary Building structural framing system; however, design-basis tornado wind loads, when applied to the Auxiliary Building frame, produce forces that are less than one half of the seismic inertial forces for which the consequences of inter-story drift (i.e., in-plane forces acting on the unreinforced masonry) have already been evaluated and found to be acceptable. As such, tornado-induced inter-story drift and, hence, in-plane forces acting on the FRP-strengthened in-fill masonry walls of the Auxiliary Building structures are acceptable by comparison without crediting or quantifying the contribution of the FRP strengthening system.

RAI 2-15 Page 4 of Enclosure 2 of the June 29, 2009, LAR states that as part of the long term surveillance program, visual inspections will be performed on selected portions of FRP strengthened brick walls and adjacent test walls. Please provide further clarification relative to the term "selected portions."

U. S. Nuclear Regulatory Commission Attachment - FRP RAI Supplemental Information

-June 6, 2011 Page 3 Duke Energy Response Duke Energy's response dated June 24, 2010, to RAI 2-15 stated that it did not plan to perform in-service surveillance of the FRP system on the FRP-strengthened wall elements. After follow-up discussions with the Staff on this matter, Duke Energy will perform periodic visual inspections on both FRP-strengthened masonry block and brick walls, as well as on designated masonry test walls, in order to assess the FRP's long-term performance and durability. The visual inspection program meets the requirements of, and is more prescriptive than, Chapter 7 of ACI 440.2R-02. The inspection program provides a 95% confidence level that all FRP-strengthened wall element surface areas will be represented by the sampling process. Visual inspections will be performed and controlled using a dedicated visual inspection procedure. A post-installation inspection utilizing digital photographic images and documented "eyes-on" visual observations of all FRP-strengthened wall element areas will be used to establish a baseline to which all future observations in subsequent inspections will be compared.

Inspections will be performed at each unit's outage cycle for the first six years from 2012 through 2017, then, ifjustified based on no observed FRP degradation, transition to every-other outage cycle for the next four years from 2018 through 2021, then, if justified based on continued no observed FRP degradation, transition to every third outage cycle thereafter from 2022 until end of license in July 2034. See Figure RAI 2-15, Sheet 7 (below).

Figure RAI 2-15. FRP Visual Inspection Plan Schedule Sheet 7 Oconee Nuclear Station Units 1, 2, and 3 Schedule for Implementing FRP Inspection Plan (24-month Outage Cycle)

Year: 2011 2012 201 201 20521621 Qtr: 1 23 41 2 341 23 41 23 41 2 3 41 23 41 23 4 Unit 1 NY1 Y2 Y3 Unit 2 NY Y2 Y3 Unit 3 Y1 Y2 Y3 1Per Unit Outage Cycle -- >

Year:

Qtr:

Unit 1 Unit 2 Unit 3 Year:

Qtr:

Unit 1 Unit 2 Unit 3 Year:

Qtr:

Unit 1 Unit 2 Unit 3

U. S. Nuclear Regulatory Commission Attachment - FRP RAI Supplemental Information

'June 6, 2011 Page 4 The FRP will be observed for any damage or deficiencies either by remote digital imaging or by "eyes-on" methods. In addition, adhesion pull-off testing will be performed on designated test panels to assess long-term bond of the FRP to the masonry substrate. The adhesion pull-off testing will be performed and controlled using a dedicated test procedure. The guidance of EDM-410, "Inspection Program for Civil Engineering Structures and Components," will be followed. The severity and extent of any damage or deficiencies will be determined and documented in Duke's corrective action program. For deficiencies designated as either moderate or significant, an engineering evaluation will be performed and any necessary remediation will be initiated.

RAI 2-16 Page 4 of Enclosure 2 of the June 29, 2009, LAR states that the test walls will be more accessible for tension adhesion testing, implying that the test walls are not configured the same as the FRP modified walls (e.g., there is no siding to remove). Considering RAI 2-9 please provide further discussion to justify that the test walls are exposed to the same environmental conditions as the FRP modified walls.

Duke Energy Response Duke Energy stated in its previous response to RAI 2-16 that "no such access points

[i.e., removable portions of siding] will be provided for the FRP-strengthened wall elements." After follow-up discussions with the Staff on this matter, Duke Energy will provide two removable siding panels at each unit's Auxiliary Building (one for the Cask Decontamination Tank Room and one for the West Penetration Room) for the purpose of visually inspecting the FRP-strengthened wall elements. Each of these locations will serve as the control ("eyes-on") samples for the planned long-term visual inspection program for FRP.

RAI 2-19 of the June 29, 2009, LAR states that the structural steel shear restraint system will be installed along the top and sides of the masonry walls since the performance testing program demonstrated that potential shrinkage cracks along the sides or settlement cracks along the top edge of the masonry walls may exist. The design methodology proposed in this LAR uses a simply supported plate on all four sides. The bottom edge of the wall could also be affected by shrinkage cracks and may not provide shear resistance. Considering this uncertainty, relative to the as-built wall boundary condition, to maximize the flexural demand on the FRP system and to maximize the reaction force on the shear restraint system, please provide discussion on the design methodology if the bottom edge of the wall is considered free.

Duke Energy Response Inspection of each masonry wall element subject to FRP-strengthening is performed and documented by the responsible plant civil engineer in accordance with Engineering Directive EDM-410, "Inspection Program for Civil Engineering Structures and Components." (It should be noted that the Oconee Nuclear Station UFSAR Chapter 18 identifies the inspection program for civil engineering structures and components as one of the Aging Management Programs and periodic inspections that are ongoing through

U. S. Nuclear Regulatory Commission Attachment - FRP RAI Supplemental Information

• June 6, 2011 Page 5 the duration of the operating licenses of the Oconee Nuclear Station.) As required by Section 410.4.7 of EDM-410, the individual performing the inspection is a registered Professional Engineer. The responsible plant civil engineer has responsibility for each unit's Auxiliary Building structure, including the masonry walls. As per EDM-410, masonry walls are examined for "cracks in joints, unsealed penetrations, missing or broken blocks, or separation from supports". The acceptance criteria for the condition of a structure are based on examination and assessment by the engineer using the preceding criteria along with applicable codes and standards. From EDM-410 Section 410.4.5, "Acceptable structures or components are those which are capable of performing their intended function, including the protection or support of nuclear safety-related systems or components. Acceptable structures or components are free of deficiencies which could lead to possible failure prior to the next regularly scheduled inspection, or may contain minor deficiencies resulting from normal operation or anticipated service conditions which, if not corrected by routine or preventive maintenance, will not lead to possible failure of the structure or component prior to the next regularly scheduled inspection."

In addition to the inspection performed and documented in accordance with EDM-410, a second inspection of the masonry walls is performed by Duke Energy craft prior to FRP installation in accordance with the FRP installation procedure. The objective of this inspection is to ensure the integrity of the masonry substrate prior to applying the FRP.

Each wall element is inspected for smoothness, flatness, holes, chipped/gouged-out spots, cracks, open mortar joints, cleanliness, coatings, sharp edges, protrusions, and free moisture.

In summary, masonry walls are inspected for any form of degradation on two separate occasions by separate individuals prior to installation of the FRP-strengthening system.

Masonry walls are repaired as required as a result of either inspection's findings.

Long-term integrity of the mortar joints located along the bottom edge of the FRP-strengthened masonry walls is assured through (1) visual inspections of the mortar joint conducted as part of the FRP visual inspection program and (2) periodic inspection of the masonry walls conducted under EDM-410.

RAI 2-21 The experimental testing program was conducted using one FRP ply and a maximum coverage of 100 percent. Considering the fact that the experimental testing program was conducted to support the design methodology for the FRP strengthened brick walls, please provide further discussion if the modifications of the existing Oconee Nuclear Station brick walls require more than one ply of FRP reinforcement, which will be outside the parameters of the tested conditions.

Duke Energy Response The analytical method presented in Enclosure 4 to License Amendment Request No.

2009-05 and used to evaluate double-wythe solid concrete brick walls and design the FRP strengthening system was developed to ensure ample design margin with respect to tornado-induced differential pressure loads. Consequently, the method produces very conservative results in terms of the required amount of FRP strengthening. The design's conservatism is primarily embodied in three (3) aspects of the analytical method:

U. S. Nuclear Regulatory Commission Attachment - FRP RAI Supplemental Information

'June 6, 2011 Page 6 The design method limits allowable stress in the FRP composite system to 13% of the composite's ultimate strength. (Please refer to the discussion of the environmental reduction factor, CE, and the bond-dependent coefficient for flexure, Kin, contained in Enclosure 4 to the LAR and the associated discussions contained in Enclosure 4 (Attachment 4.2) and Enclosure 6 (Part B) to the LAR.)

• The design method credits only the outer wythe of brick (i.e., the FRP strengthened wythe) when computing the masonry wall's flexural and shear capacities, thereby neglecting the semi-composite action produced by the inter-connected double-wythe construction. (Please refer to the related discussion by the independent reviewer contained in Enclosure 6 (Part B) to the LAR.)

• The design method ignores the masonry's increased resistance to out-of-plane loads produced by compressive membrane action (i.e., arching action) of the in-fill panel that is confined on all four (4) sides by the Auxiliary Building structural framing system. (Please refer to the related discussion by the independent reviewer contained in Enclosure 6 (Part B) to the LAR.)

Evidence of the magnitude of the design's conservatism is reflected in the test results for specimens $5-1.2-SR, S6-1.2-SR, $7-1.2-SR, S1-1.6-SR, and S2-1.6-SR (shear-restrained, no-fill collar joint, FRP coverage ranging from 50/50 to 100/100%). All of these specimens "reached an applied pressure of 3.9 psi with no visible signs of damage" while demonstrating an elastic load-deflection behavior. Moreover, specimen

$7-1.2-SR, which was tested to failure (ultimate applied pressure = 7.5 psi),

demonstrated an elastic load-deflection behavior up to an applied pressure of 5.7 psi.

(Reference Enclosure 6 (Part A, Sections 3.13.1 and 3.16) to the LAR and related discussion by the independent reviewer contained in Enclosure 6 (Part B) to the LAR.)

When evaluated in accordance with Duke's analytical method (using the spreadsheet contained in Enclosure 4 (Attachment 4.3) to the LAR), these specimens and associated test conditions reveal demand-capacity ratios ranging from 1.04 : 1.00 to 3.32 : 1.00, with all except one ratio exceeding 1.55 : 1.00. (It should be noted that the tests were terminated at an applied pressure of 3.9 psi for all specimens except S7-1.2-SR (as described above) and that this restriction prevents the determination of the upper limit to the demand-capacity ratio (i.e., design margin) for each specimen.)

Of the thirty-one (31)1 double-wythe solid concrete brick walls to which the FRP strengthening system will be applied, eight (8) were analytically determined to require an FRP coverage (150%) that exceeds the performance test walls' maximum coverage of 100%. Duke concludes that, based on the conservatism contained in the analytical method (as validated by the test results for the shear-restrained specimens), this amount of FRP amply exceeds that which is actually required to resist design-basis tornado-induced differential pressure loads.

1 Although FRP strengthening has been applied to the Unit 2 Auxiliary Building masonry wall spanning from elevation 809 + 3 to 838 + 0 and located along column line 'X' between column

'78a' and the Unit 2 Reactor Building, this wall is not credited for FRP in the Licensing Basis.

U. S. Nuclear Regulatory Commission Attachment - FRP RAI Supplemental Information

'June 6, 2011 Page 7 RAI 2-24 The installation of shear restraints is the primary parameter required for the validity of the methodology and boundary conditions used in the analysis of the existing brick walls.

Please discuss why the list of regulatory commitments in Attachment 2.2 of Enclosure 2 of the June 29, 2009, LAR and the flow chart shown in Attachment 4.1 of Enclosure 4 of the LAR do not include the installation of shear restraints.

Duke Energy Response Duke commits that, as part of the Natural Phenomenon System Barrier Project modifications, shear restraints will be added to the FRP-strengthened wall elements to remediate potentially limiting conditions of construction as follows:

• Mechanical shear restraints will be installed along the top and side edges of the brick masonry wall perimeters.

" Mechanical shear restraints will be installed along the top edge of block masonry wall perimeters.

RAI 2-26 .1 of Enclosure 2 of the June 29, 2009, LAR includes the UFSAR mark-ups. Please discuss the differences between the UFSAR mark-ups in this LAR and the previous LAR approved by the NRC staff and documented in SEs dated February 21, 2008 and March 26, 2008.

Duke Energy Response Duke agrees that the statement within the first sentence of the second paragraph (in red text) in UFSAR Chapter 3, Section 3.8.4.7.2 Loads and Load Combinations, on page 1 of Attachment 2.1, should be changed from:

"...tornado-induced loadings is contained in Reference 39."

to:

"...tornado-induced loadings is contained in Section 3.3.2.1."

U. S. Nuclear Regulatory Commission Attachment - FRP RAI Supplemental Information

'June 6, 2011 Page 8 The following commitment table identifies those actions committed to by Duke Energy Carolinas, LLC (Duke Energy) in support of License Amendment Request (LAR) 2009-005 and subsequent RAI responses. Other actions discussed in the submittal represent intended or planned actions by Duke Energy. They are described to the Nuclear Regulatory Commission (NRC) for the NRC's information and are not regulatory commitments.

Commitment Completion Date

1. Duke Energy will perform qualification testing and reporting in Complete accordance with ICC AC125 [Approved 10/2006, Effective 1/1/2007] for the selected FRP System.

2. Duke Energy will perform and document a technical evaluation Complete of the FRP system (fibers and polymeric resin) in accordance with Duke Energy's Supply Chain Directive SCD230

[Reference 7 of Enclosure 2] to demonstrate that:

• The item qualifies as a commercial grade item.

• The supplier is capable of supplying a quality product.

• The quality of the item can be reasonably assured.

3. Duke Energy will utilize technical procedures to control testing Complete of concrete substrate and installation and inspection of the FRP system in accordance with ICC AC125 [Approved 10/2006, Effective 1/1/2007], ACI 440.2R-02 [Effective 7/1/2002], and ICC AC178 [Approved 6/2003, Effective 7/1/2003, editorially revised 6/2008].

U. S. Nuclear Regulatory Commission Attachment - FRP RAI Supplemental Information

'June 6, 2011 Page 9 Commitment Completion Date

4. Duke Energy will implement a long-term inspection By the Unit 3 Spring program of the FRP system that will be described in 2012 refueling UFSAR Section 18.3.13 and EDM-410, and meeting the outage.

requirements of ICC AC125 [Approved 10/2006, Effective 1/1/2007], ACI 440.2R-02 [Effective 7/1/2002], and ICC AC178 [Approved 6/2003, Effective 7/1/2003, editorially revised 6/2008], on the following schedule: at each unit's outage cycle for the first six years from 2012 through 2017, then, ifjustified based on no observed FRP degradation, transition to every-other outage cycle for the next four years from 2018 through 2021, then, ifjustified based on continued no observed FRP degradation, transition to every third outage cycle thereafter from 2022 until end of license in July 2034. Inspections of the installed FRP system will include:

• visual inspections of test walls and portions (both random and controlled locations) of WPR in-service walls for changes in color, debonding, peeling, blistering, cracking, crazing, deflections and other anomalies;

• tension adhesion testing of cored samples taken from designated test walls using methods specified in ASTM D7234; and,

• visual inspections of mortar joints located along the bottom edge of FRP-strengthened masonry walls.

For each inspection interval, the portions of FRP-strengthened masonry walls to be inspected will be chosen in accordance with a sampling plan developed from guidance provided by a) Draft Regulatory Guide DG-1070, "Sampling Plans Used for Dedicating Simple Metallic Commercial Grade Items for use in Nuclear Power Plants",

and b) EPRI NP-7218 document "Guidelines for the Utilization of Sampling Plans for Commercial Grade Item Acceptance" (NCIG-19), as implemented at ONS by Supply Chain Directive SCD-290 [(new) Reference 21 of Enclosure 2].

Note: This response replaces the five (5) year inspection commitment made in FRP LAR (No. 2009-05) dated June 29, 2009, and will apply to the FRP application for both block and brick.

U. S. Nuclear Regulatory Commission Attachment - FRP RAI Supplemental Information

'June 6, 2011 Page 10 Commitment Completion Date

5. Duke Energy will install mechanical shear restraints along Per commitment 5T the brick masonry wall perimeter (top and sides only) and [Ref. Duke Energy's block masonry wall perimeter (top only) to remediate May 18, 2010 potentially limiting conditions of construction. commitment letter].

6. Duke Energy will incorporate the FRP testing and By the Unit 3 Spring inspection program into Oconee Nuclear Station's Aging 2012 refueling Management Program. outage.

7. As discussed with the Staff, Fyfe Company, LLC, the Complete manufacturer of the FRP products, will provide Duke Energy with a Certificate of Compliance certifying that both the FRP product and its installation meet all applicable requirements.