ML17308A019
| 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:
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Recipients Received:
License Amendment Request:
Methodology for the Analysis of Concrete Seismic Category I Structures with Concrete Affected by Alkali Silica Reaction Seabrook Station June 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 operation NextEra 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 Fortunes 2015 list of Worlds Most Admired Companies and among top 10 companies in the world in both the categories of innovativeness and community responsibility Worlds largest generator of renewable energy from the wind and sun Named to 2015 Worlds Most Ethical Company list (Ethisphere Institute)
(1) As of Dec. 31, 2014 from 10-k (2) Includes NEEs ownership share of NextEra Energy Partners portfolio
3 The foundation for everything we do are the Values and Core Principles of our Nuclear Excellence Model
4 Seabrook Attendees Ken Browne NEE Seabrook ASR Project Manager Mike Ossing NEE Seabrook Licensing Manager Brian Brown NEE Seabrook Principal Engineer Larry Nicholson NEE Fleet Licensing Director John Simons MPR Gen Manager Power Projects Dr. Said Bolourchi SG&H Senior Principal Engineer Jim Moroney MPR ASR Test Program PM Phil Rush MPR 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 Amendment 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 concrete forms alkali cement +
reactive aggregate expansive gel K+
Na+
cracking of the aggregate and paste
+ H2O gel gel SiO2 SiO2 SiO2 OH-OH-
8 Overview of License Amendment Request
9 Overview 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
10 Overview of License Amendment Request Applies to Seismic Cat 1 Structures and Containment Structure Establish ASR expansion limits from testing:
Shear capacity Flexural capacity and reinforcement development length Anchor 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 factors Include the effects of concrete creep, shrinkage and swelling in structure deformation analyses Identify 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 Pages MPR 4288, Rev 0 Seabrook Station: Impact of ASR on Structural Design Structural Design Evaluations MPR 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
11 Structural Capacity Testing of ASR-Affected Specimens
12 Structural 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
13 Structural Capacity Testing of ASR-Affected Specimens Anchor Test Program Anchor Test Program Shear Test Program Reinforcement Anchorage Test Program Instrument Evaluation Program Beam Test Programs
14 Structural Capacity Testing of ASR-Affected Specimens Test Program Results Key Conclusion Anchor 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 expansion No impact on anchors at Seabrook based on expansion levels expected Beam 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 expansion Original design strength and code equations can 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
15 Structural Capacity Testing of ASR-Affected Specimens
- Licensing Implications
- Impact on UFSAR Large-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 conservative No change to the UFSAR-described methodology is necessary for determining capacity provided ASR expansion is within limits from testing
- ASR expansion limits Expansion limits established based on range of expansion covered in testing Limits 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
18 Methodology 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 (Sa)
Stage 1:
Screening Evaluation Field Observations Stage 2:
Analytical Evaluation Original Design Demands &
Capacities Adequate Margin with Sa No Define Threshold for Monitoring Yes Evaluation of Structural Deformation Sa = Load associated with ASR
20 Stage 2: Analytical Evaluation Finite Element Modeling Correlate with Field Observations Sa Inputs Based on Field Measurements and other self straining loads Define Threshold for Monitoring Yes Original Design Demands & Capacities Adequate Margin with Sa Stage 3:
Detailed Evaluation No Calculate Sa Evaluation of Structural Deformation
21 Stage 3: Detailed Evaluation Finite Element Modeling Refined Sa Inputs Based on Additional Field Measurements Original Design Loads Inputs Define Threshold for Monitoring Evaluate Using Total Factored Design Demands Including Sa
- 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
26 Typical 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 Program Tier Structural Monitoring Program Category Recommendation for Individual Concrete Components CRITERIA Combined Cracking Index (CCI) 3 Unacceptable (requires further evaluation)
Structural Evaluation 1.0 mm/m or greater 2
Acceptable with Deficiencies Quantitative 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.
1 Acceptable Routine inspection as prescribed by the Structural Monitoring Program Area has no indications of pattern cracking or water ingress-No visual presence of ASR
28 Review of ASR Expansion and Deformation Monitoring Stage Deformation Evaluation Stage Monitoring Interval 1D Screening 3 years 2D Analytical 18 months 3D Detailed 6 months Inspection requirements for structures with ASR-induced deformation Parameters that are measured are specific to each structure
- Parameters will be defined in the structure deformation evaluation
- Limits established from deformation evaluation
29 Summary 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 31st