ML17308A019

2016/06/14 Seabrook La - (External_Sender) NextEra ASR LAR Presentation to NRC - June 15, 2016

ML17308A019
Person / Time
Site:	Seabrook
Issue date:	06/14/2016
From:	- No Known Affiliation
To:	Division of Operating Reactor Licensing
References
17-953-02-LA-BD01
Download: ML17308A019 (32)

Text

1 SeabrookLANPEm Resource From: Ossing, Michael <Michael.Ossing@nexteraenergy.com>

Sent: Tuesday, June 14, 2016 4:29 PM To: Poole, Justin Cc:Ossing, Michael; Browne, Kenneth; Brown, Brian; 'Simons, John' (jsimons@mpr.com);

Hamrick, Steven; Nicholson, Larry

Subject:

[External_Sender] NextEra ASR LAR Presentation to NRC - June 15, 2016 Attachments:

ASR LAR presentation 6-14-16 JWS.pptx Justin Attached is the NextEra presentation that will be discussed at the June 15, 2016 ASR LAR pre-submittal public meeting.

NextEra will bring 20 copies.

Hearing Identifier: Seabrook_LA_NonPublic Email Number: 232 Mail Envelope Properties (A1E9B801E0F7AE4AB658C34C690F3D3255103BA9)

Subject:

[External_Sender] NextEra ASR LAR Presentation to NRC - June 15, 2016 Sent Date: 6/14/2016 4:29:14 PM Received Date: 6/14/2016 4:29:27 PM From: Ossing, Michael Created By: Michael.Ossing@nexteraenergy.com Recipients: "Ossing, Michael" <Michael.Ossing@nexteraenergy.com>

Tracking Status: None "Browne, Kenneth" <Kenneth.J.Browne@nexteraenergy.com>

Tracking Status: None "Brown, Brian" <Brian.Brown@nexteraenergy.com> Tracking Status: None

"'Simons, John' (jsimons@mpr.com)" <jsimons@mpr.com> Tracking Status: None "Hamrick, Steven" <Steven.Hamrick@fpl.com>

Tracking Status: None "Nicholson, Larry" <Larry.Nicholson@fpl.com> Tracking Status: None "Poole, Justin" <Justin.Poole@nrc.gov> Tracking Status: None

Post Office: goxsa3144.fplu.fpl.com Files Size Date & Time MESSAGE 163 6/14/2016 4:29:27 PM ASR LAR presentation 6-14-16 JWS.pptx 2166999

Options Priority: Standard Return Notification: No Reply Requested: No Sensitivity: Normal Expiration Date: Recipients Received:

License Amendment Request:Methodology for the Analysis of Concrete Seismic Category I Structures with Concrete Affected by Alkali Silica

Reaction Seabrook StationJune 15, 2016 2*$17B Consolidated Revenues (1)*44,900 MW in operation (1, 2)*13,800 employees

• One of the largest U.S. electric utilities

• 4.8 MM customer accounts

• 25,100 MW in operationNextEra Energy (NYSE: NEE) is comprised of two strong businesses supported by a common platform

• U.S. leader in renewable generation

• Assets primarily in 25 states and Canada

• 19,800 MW in operation (1, 2)Among Fortune Aûs 2015 list of AúWorld Aûs Most Admired Companies Aûand among top 10 companies in the world in both the categories of innovativeness and community responsibilityWorld Aûs largest generator of renewable energy from the wind and sunNamed to 2015 World Aûs Most Ethical Company list (Ethisphere Institute)(1)As of Dec. 31, 2014 from 10-k(2)Includes NEE's ownership share of NextEra Energy Partners' portfolio 3The foundation for everything we do are the Values and Core Principles of our Nuclear Excellence Model 4 Seabrook Attendees

• Ken BrowneNEE Seabrook ASR Project Manager

• Mike OssingNEE Seabrook Licensing Manager

• Brian BrownNEE Seabrook Principal Engineer

• Larry NicholsonNEE Fleet Licensing Director

• John SimonsMPR Gen Manager Power Projects

• Dr. Said BolourchiSG&H Senior Principal Engineer

• Jim MoroneyMPR ASR Test Program PM

• Phil RushMPR Engineering Associate 5 Presentation Outline*Alkali-Silica Reaction*Overview of License Amendment Request (LAR)

• Structural Capacity Testing of ASR-Affected Specimens

• Evaluation of Structural Deformation

• Monitoring of ASR Expansion and Structure Deformation

• Summary of LAR changes

• Closing Remarks-Presentation describes Next Era current intent regarding License Am endment Application 6 Alkali-Silica Reaction 7 Alkali-Silica Reaction*ASR (alkali-silica reaction) is a chemical reaction between silica from the aggregate (gravel and/or sand) and alkali constituents in the cement*Reaction produces a gel that expands as it absorbs moisture and exerts a tensile stress from within the concreteformsalkali cement + reactive aggregateexpansive gel K+Na+cracking of the aggregate and paste

+ H 2 O gel gel SiO 2 SiO 2 SiO 2 OH-OH-8Overview of License Amendment Request 9Overview of License Amendment Request*Next Era proposes a change in the UFSAR methodology to address ASR concrete degradation at Seabrook Station*ACI 318-71 and the ASME Code do not include provisions for addressing ASR and its effects-Incorporate loads imposed by ASR into the design basis*Evaluate structures affected by ASR to demonstrate that they satisfy the acceptance criteria of the original construction code-ACI 318-71 for all seismic Category I structures other than containment-ASME Boiler & Pressure Vessel Code,Section III for containment 10Overview of License Amendment Request-Applies to Seismic Cat 1 Structures and Containment Structure-Establish ASR expansion limits from testing:

Shear capacityFlexural capacity and reinforcement development lengthAnchor bolts embedded in concrete with ASR-3 Stage Analysis process for Building Deformation Assessment:Specify how ASR loads are combined with other design basis loads for analyzing structures including defining load factorsInclude the effects of concrete creep, shrinkage and swelling in structure deformation analysesIdentify ANSYS as the computer code used for ASR building deformation analyses Permit use of the 100-40-40 procedure from Regulatory Guide 1.92, Revision 3 for detailed evaluations

("Stage Three") analyses of ASR-affected structures.Use of cracked section properties and redistribution of self-limiting loads for ASR-affected structures-Attachments:UFSAR Markup and 'Clean' PagesMPR 4288, Rev 0 Seabrook Station: Impact of ASR on Structural Desi gn Structural Design EvaluationsMPR 4273, Rev 0 Seabrook Station: Implications of Large Scale Test Program Results on Reinforced Concrete Affected by ASR SGH (#TBD) Computation of Load Factors for ASR Demands .

11Structural Capacity Testing of ASR-Affected Specimens 12Structural Capacity Testing of ASR-Affected Specimens*MPR conducted large-scale test programs to investigate structural impact of ASR on reinforced concrete-Improve current understanding of ASR and its effects on reinforced concrete structures-Evaluate instruments for monitoring (measuring) the through-thickness (out-of-plane) expansion of concrete from ASR 13Structural Capacity Testing of ASR-Affected SpecimensAnchor Test ProgramAnchor Test ProgramShear Test Program Reinforcement Anchorage Test Program Instrument Evaluation ProgramBeam Test Programs 14Structural Capacity Testing of ASR-Affected SpecimensTest ProgramResultsKey ConclusionAnchor Test Program*Anchor performance*insensitive to through-thickness expansion*reduces at high levels of in-plane cracking*No difference between performance of anchors installed before and after ASR expansionNo impact on anchors at Seabrook based on expansion levels expectedBeam Test Programs*Control specimens showed consistency with ACI 318 equations for shear capacity, flexural

capacity and lap splice length*ASR-affected specimens showed: *No adverse impact of ASR on shear capacity, flexural capacity, reinforcement anchorage and lap splice performance*Behavior indicative of pre-stressing due to ASR expansionOriginal design strength and code equationscan be used for ASR-affected reinforced concrete

structures *Shear capacity*Flexural capacity

• Reinforcement development length Instrumentation Evaluation

Program Snap ring borehole extensometers were accurate and reliable throughout duration of program Snap ring borehole extensometers selected for use at

Seabrook Station 15Structural Capacity Testing of ASR-Affected Specimens*Licensing Implications-Impact on UFSARLarge-scale testing or reinforced-concrete beams showed-No adverse impact of ASR on shear capacity, flexural capacity or reinforcement development length-Use of Code equations and design compressive strength to determine capacity is conservativeNo change to the UFSAR-described methodology is necessary for determining capacity provided ASR expansion is within limits from testing-ASR expansion limitsExpansion limits established based on range of expansion covered in testingLimits to be controlled within Structural Monitoring Program 16 Evaluation of Structural Deformation 17 Evaluation of Structural Deformation

• Inspections of Seabrook structures have identified deformation due to ASR expansion effects-ASR-related expansion may impose an additional, internal load on reinforced concrete adjacent to ASR-affected areas-ASR-related expansion of concrete backfill can impose an external load on adjacent structures -Seismic gap widths and close clearances between structures and plant components may be reduced 18Methodology for Analysis of Structural Deformation

• LAR describes progressive approach for evaluating structures with deformation-Stage One -Screening Evaluation-Stage Two -Analytical Evaluation

-Stage Three -Detailed Evaluation

• Structures require an analysis of all load combinations with ASR loads included 19 Evaluate Responses due to ASR loads (S a)Stage 1: Screening Evaluation Field Observations Stage 2: Analytical Evaluation Original Design Demands &

Capacities Adequate Margin with "S a"No Define Threshold for MonitoringYes Evaluation of Structural Deformation"Sa" = Load associated with ASR 20 Stage 2: Analytical Evaluation Finite Element Modeling Correlate with Field Observations "S a" Inputs Based on Field Measurements andother self straining loadsDefine Threshold for MonitoringYes Original Design Demands & Capacities Adequate Margin with "S a"Stage 3: Detailed Evaluation No Calculate S a Evaluation of Structural Deformation 21 Stage 3: Detailed Evaluation Finite Element Modeling Refined "S a" Inputs Based on Additional Field Measurements Original Design Loads InputsDefine Threshold for MonitoringEvaluate Using Total Factored Design Demands Including "S a"*Cracked section*Redistribution of Self-limiting load*100-40-40 Combination of

seismic components Evaluation of Stage 3 Structural Deformation 22 Evaluation of Structural Deformation

• Including ASR loads with other design basis loads requires definition of load factors for each loading combination-ACI 318-71 and 1975 Edition of ASME B&PV Section III Division 2 does not include load factors for ASR-SGH developed load factors consistent with ACI 318-71 and ASME 1975 Edition load factor development -Load factors for ASR will be used in the analysis of Seabrook structures and included in Tables 3.8-1 and 3.8-16 of the UFSAR

• Structures evaluated to demonstrate that additional ASR expansion is permissible-Margin is included in the acceptance criteria for each stage to ensure that additional deformation does not challenge design limits-A higher level of deformation is analyzed relative to current measurements to set the threshold for monitoring 23 Evaluation of Structural Deformation

• Stage 2 or Stage 3 evaluation will use an ANSYS finite element model-Alternate computer codes were used in the original analyses of Seabrook structures-ANSYS has been used for analyzing safety-related structures in other plant designs (e.g., AP1000, ESBWR)-NRC has previously accepted the use of ANSYS for structural analysis at other facilities

• Effects of creep, shrinkage, and swelling of concrete must be accounted for in the structure deformation analyses -Creep, shrinkage and swelling loads are discussed in the Seabrook UFSAR but they were considered negligible in the original design analyses-ACI 318-71 includes load factors for loads caused by creep, shrinkage and swelling 24 Review of ASR Expansion and Structure Deformation Monitoring 25 Review of ASR Expansion and Structure Deformation Monitoring

• Continued monitoring of ASR and its effects is necessary-Expansion caused by ASR must be measured and remain bounded by limits established from the large-scale test program-Periodic measurements of structure deformation are necessary to ensure limits from deformation analyses are satisfied

• Separate monitoring requirements will be included in the Structural Monitoring Program (SMP) for ASR expansion and structure

deformation

• SMP uses a three-tiered approach to classify the results of inspections-ASR expansion levels and structure deformation measurements will be evaluated using classification levels-Increased monitoring and analysis are necessary for progressively higher levels of ASR expansion and structure deformation 26Typical methods used to measure ASR expansion at Seabrook Review of ASR Expansion and Structure Deformation Monitoring 27 Tiers for classifying ASR cracking Review of ASR Expansion and Structures Monitoring*Limits established in the large-scale test program will be included in the Structural Monitoring ProgramTier Structural Monitoring Program Category Recommendation for Individual Concrete Components CRITERIA Combined Cracking Index (CCI)3Unacceptable (requires further evaluation)Structural Evaluation1

.0 mm/m or greater2Acceptable with DeficienciesQuantitative Monitoring and Trending 0.5 mm/m or greater Qualitative Monitoring Any area with visual presence of ASR (as defined in FHWA-HIF-12-022) accompanied an estimated summation of crack widths not supporting a 0.5 mm/m CI in the vertical or horizontal direction.1Acceptable Routine inspection as prescribed by the Structural Monitoring

ProgramArea has no indications of pattern cracking or water ingress-No visual presence of ASR 28 Review of ASR Expansion and Deformation MonitoringStageDeformation Evaluation StageMonitoring Interval1DScreening3 years2DAnalytical18 months 3DDetailed6 months*Inspection requirements for structures with ASR-induced deformation*Parameters that are measured ar e specific to each structure -Parameters will be defined in the structure deformation evaluation-Limits established from deformation evaluation 29Summary of LAR Changes

• NextEra will submit the following changes to the Seabrook UFSAR:-ASR expansion loads are taken into account for seismic Category I structures-Load factors for ASR loads are included in the design load combinations

-Creep, shrinkage and swelling effects are evaluated in the process of analyzing structures with ASR-related deformation-ANSYS is used for deformation evaluations

-Stage Three deformation evaluations may use 100-40-40 method from NRC Regulatory Guide 1.92, Revision 3, for combining seismic loads

instead of the SRSS method in Revision 1 of this regulatory guide.

30 Closing Remarks*License Amendment Request Represents multiple years of research and learning about ASR*Third Party Reviews in progress

• Submit to NRC by July 31 st