Enclosure 3 to SBK-L-15107

MPR-4153

Seabrook Station

Approach for Estimating Through-Thickness Expansion from Alkali-Silica Reaction

MPR Associates, Inc., Alexandria, VA, 2015

(Non-Proprietary)
W MPR

MPR-4153

Revision 1

(Seabrook FP # 100918)

June 2015

Seabrook Station - Approach for

Determining Through- Thickness

Expansion from Alkali-Silica Reaction

QUALITY ASSURANCE DOCUMENT

This document has been prepared, reviewed, and approved in accordance with the Quality Assurance

requirements of 10CFR50 Appendix B and/or ASME NQA-1, as specified in the MPR Nuclear Quality

Assurance Program.

Prepared for

NextEra Energy Seabrook, LLC

P.O. Box 300, Lafayette Rd., Seabrook, NH 03874

Page 1 of 88
*MPR

Seabrook Station - Approach for

Determining Through- Thickness

Expansion from Alkali-Silica Reaction

NPR-4153

Revision 1

(Seabrook FP # 100918)

June 2015

QUALITY ASSURANCE DOCUMENT

This document has been prepared, reviewed, and approved in accordance with the Quality Assurance

requirements of 1 OCFR50 Appendix B and/or ASME NQA-1, as specified in the MPR Nuclear Quality

Assurance Program.

Prepared by: C.WL. B

C. W. Baglef'

Reviewed by: 2 U1&w2

J6hn W. Simons

Approved by: Ja!Z- -oney

Additional Contributors

K. Mulvaney

D. Bergquist

A. Card

M. Saitta

R. Vayda

Prepared for

NextEra Energy Seabrook, LLC

P.O. Box 300, Lafayette Rd., Seabrook, NH 03874

320 KING STREET ALEXANDRIA, VA 22314-3230 703-519-0200 FAX: 703-519-0224 www.mpr.com

Page 2 of 88
RECORD OF REVISIONS

Revision Affected Pages Description

0

1

All

Body of Report,

Appendix A

Initial Issue

Included corrected data for expansion of FSEL test specimens

in the through-thickness direction. Also made minor editorial

changes throughout the body of the report.

MPR-4153

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Executive Summary

This report recommends a methodology for determining the extent of through-thickness

expansion of reinforced concrete structural members at Seabrook Station. Quantifying

through-thickness expansion will enable NextEra Energy to apply the results of the ongoing

structural testing programs to Seabrook Station based on the condition of existing plant

structures.

Data from the structural testing programs have shown that expansion in the in-plane direction

plateaus at low expansion levels, while expansion in the through-thickness direction continues to

increase. Accordingly, the test programs will provide results correlating structural performance

to expansion in the through-thickness direction.

NextEra plans to install instruments in concrete structures at Seabrook Station to measure

expansion in the through-thickness direction (i.e., extensometers). This approach will enable

measuring expansion for a given concrete structural member from the time the extensometer is

installed. To calculate total expansion, NextEra will need to determine expansion from original

construction until the time the extensometer is installed.

MPR recommends the following approach for determining total ASR-induced through-thickness

expansion at each instrumented location at Seabrook Station. The recommended method

determines the pre-instrument expansion based on the reduction in modulus of elasticity.

1. Determine the current elastic modulus of the concrete by material property testing of cores

removed from the structure. Elastic modulus testing requires companion compressive

strength testing, so MPR recommends obtaining a minimum of four test specimens at each

proposed monitoring location. Two test specimens are for compressive strength testing

and two test specimens are for subsequent elastic modulus testing.

2. Establish the original elastic modulus of the concrete by either (1) using the ACI 318-71

correlation to calculate elastic modulus from 28-day compressive strength records or

(2) obtaining cores from representative ASR-free locations and testing for elastic modulus.

3. Calculate the reduction in elastic modulus by taking the ratio of the test result from the

ASR-affected area to the original elastic modulus.

4. Determine through-thickness expansion from original construction to the time the

extensometer is installed using the correlation developed in this report. The correlation

relates reduction in elastic modulus with measured expansion from beam specimens used

during the large-scale ASR structural testing programs.

5. Calculate total expansion levels by adding the extensometer measurements to the

expansion at the time of instrument installation.

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Contents

Title Page .......................................................................................................................................... i

Signature Page ................................................................................................................................. ii

Record of Revisions ........................................................................................................................ iii

Executive Summ ary ........................................................................................................................ iv

Contents ........................................................................................................................................... v

Figures ............................................................................................................................................ vi

1 Introduction ..................................................................................................... 1-1

1.1 Purpose ..................................................................................................................... 1-1

1.2 Background ............................................................................................................... 1-1

2 Expansion Behavior in Test Specimens .................................................... 2-1

2.1 Overview of Test Specim ens .................................................................................... 2-1

2.2 Expansion in Reinforced Concrete ........................................................................... 2-3

2.3 Implications for M onitoring A SR at Seabrook ......................................................... 2-5

3 Determining Pre-instrument Expansion from Elastic Modulus ................. 3-1

3.1 M aterial Properties of Test Specim ens ..................................................................... 3-1

3.2 Development of Correlation between Modulus and Expansion ............................... 3-3

3.3 Establishing Original Elastic M odulus at Seabrook ................................................. 3-5

4 Recom m ended Approach ............................................................................. 4-1

4.1 Overview of Approach ............................................................................................. 4-1

4.2 Uncertainty ............................................................................................................... 4-1

5 References .......................................................... ............................................... 5-1

A Correlation Between Expansion and Elastic Modulus .............................. A-1

B Evaluation of ACI Equation for Elastic Modulus ......................................... B-1

C Compressive Strength of Concrete at Seabrook Station ........................... C-1

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Figures

Figure 1-1. A SR Expansion M echanism .................................................................................... 1-1

Figure 2-1. Example Reinforcement Pattern in Shear Test Specimen (Reference 7.3) ...... 2-1

Figure 2-2. Plan View of Embedded Rods (Reference 7.6)

(Embedded Reinforcement with Terminators also Shown) ...................................... 2-2

Figure 2-3. Elevation View of Embedded Expansion Rods (Reference 7.6)

(Embedded Reinforcement with Terminators also Shown) ...................................... 2-2

Figure 2-4. Expansion Trends in Example Test Specimen ......................................................... 2-3

Figure 2-5. Crack in Through-Thickness Direction of Example Test Specimen ........................ 2-4

Figure 3-1. Material Properties as a Function of Expansion from Test Data (Reference 13) ..... 3-2

Figure 3-2. Splitting Tensile Strength as a Function of Expansion from Test Data

(R eference 13) ........................................................................................................ 3-3

Figure 3-3. Elastic Modulus as a Function of Expansion from Test Data (Reference 13) .......... 3-4

Figure 3-4. Comparison of Derived Relationship with Literature Data (Reference 13) ............. 3-5

Figure 3-5. Comparison of Test Data to ACT Equation (Reference 18) ...................................... 3-6

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1

Introduction

1.1 PURPOSE

This report recommends a methodology for determining the extent of through-thickness

expansion of reinforced concrete structural members that are affected by alkali-silica reaction

(ASR) at Seabrook Station. Quantifying through-thickness expansion of existing plant structures

is necessary to relate the extent of ASR in a given structure to the results of the structural testing

programs at Ferguson Structural Engineering Laboratory (FSEL).

1.2 BACKGROUND

1.2.1 Overview of Alkali-Silica Reaction

ASR occurs in concrete when reactive silica in the aggregate combines with alkali ions (Na+, K+)

in the pore solution. The reaction produces a gel that expands as it absorbs moisture, exerting

tensile stress on the surrounding concrete and resulting in cracking. Typical cracking caused by

ASR is described as "pattern" or "map" cracking and is usually accompanied by dark staining

adjacent to the cracks. Figure 1-1 provides an illustration of this process.

alkali cement + expansive gel cracking of the

reactive aggregate aggregate and paste

Figure 1-1. ASR Expansion Mechanism

Several publications indicate that the cracking may degrade the material properties of the

concrete (References 1, 2, and 3). The concrete properties most rapidly and severely affected are

the elastic modulus and tensile strength. Compressive strength is also affected, but less rapidly

and less severely.

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While development of ASR causes a reduction in material properties, there is not necessarily a

corresponding decrease in structural performance. As discussed in previous MPR reports on

ASR at Seabrook Station and the approach for the FSEL test program (References 4 and 5),

cores removed from a reinforced ASR-affected structure are no longer confined by the

reinforcement and do not represent the structural context of the in-situ condition. Therefore,

material properties obtained from cores have limited applicability for evaluating the capacity of a

structure.

1.2.2 ASR at Seabrook Station

NextEra Energy has identified ASR in multiple safety-related, reinforced concrete structures at

Seabrook Station (Reference 6). To evaluate this condition, MPR performed a structural

assessment (Reference 4) of selected ASR-affected structures. Based on the low level of

observed cracking and the apparent slow rate of change, MPR concluded that these structures are

suitable for continued service for at least an interim period (i.e., at least several years).

A follow-up evaluation will assess the long-term adequacy of the concrete structures at Seabrook

Station. This evaluation will incorporate the results of large-scale test programs currently being

performed at FSEL using test specimens that were specifically designed and fabricated to

represent reinforced concrete at Seabrook Station.

1.2.3 Test Programs at FSEL

MPR is sponsoring four test programs at FSEL to support NextEra's efforts to resolve the ASR

issue at Seabrook Station. Three of the test programs focus on the structural performance data

necessary to complete the final structural assessment of ASR-affected structures. The fourth test

program evaluates instruments for monitoring expansion of Seabrook Station. A brief overview

of each program is provided below.

* Anchor Test Program-This program evaluates the impact of ASR on performance of

anchors installed in the concrete. Tests will be performed at multiple levels of ASR

degradation.

" Shear Test Program-This program evaluates the impact of ASR on shear performance of

reinforced concrete beams. The test scope includes tests at multiple levels of ASR

degradation and, if necessary, tests of retrofits for restoring the shear capacity.

" Reinforcement Anchorage Test Program--This program evaluates the impact of ASR on

reinforcement anchorage using beams that have reinforcement lap splices. The test scope

includes tests at multiple levels of ASR degradation and, if necessary, tests of retrofits.

" Instrumentation Test Program-This program evaluates instruments for the measurement

of through-thickness expansion. Insights gained from this program will be used to select

which instrument to use at Seabrook Station and refine installation procedures.

As part of the test programs, FSEL monitors development of ASR. For the shear, reinforcement

anchorage, and instrumentation test programs, FSEL both measures expansion of the test

specimens and determines the effect on material properties of concrete, which are related to ASR

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development. Using this information, this report recommends a methodology for determining

the extent of ASR-induced expansion at Seabrook Station. (Similar data were not obtained as

part of the Anchor Test Program, so this report does not utilize expansion data from the Anchor

Test Program.) Quantifying the extent of ASR development will enable comparison of the test

data to the condition of existing structures at Seabrook Station.

Testing is being conducted under FSEL's project-specific quality system manual with quality

assurance oversight from MPR. MPR is commercially dedicating the testing services performed

by FSEL. Commercial grade dedication of services from the test program relevant for this report

is documented in References 22, 23, and 24.

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2

Expansion Behavior in Test Specimens

This section discusses expansion behavior observed in the test specimens thus far in the test

program and the implications for monitoring ASR development in structures at Seabrook Station.

An overview of test specimen design is included to provide context for understanding the

observed expansion behavior.

2.1 OVERVIEW OF TEST SPECIMENS

2.1.1 Reinforcement Pattern

-The-test program specimens are large, reinforced-concrete beams. -Most test specimens are

* feetj inches long,fl inches wide, andfS inches thick (References 7.1 and 7.2). The test

specimens were designed to represent the configuration of reinforced concrete structural

members at Seabrook Station. In particular, the test area of each specimen includes

two-dimensional reinforcement mats on two opposite faces, which is the same reinforcement

detailing used for most reinforced concrete buildings at Seabrook Station (e.g., walls that have

reinforcement mats on the interior and exterior faces). Figure 2-1 provides a schematic of the

reinforcement pattern in an example shear test specimen (Reference 7.3). The reinforcement

anchorage and instrumentation test specimens have some design differences (e.g.,

but

all test specimens contain two-dimensional reinforcement mats consistent with the example in

Figure 2-1 (References 7.4 and 7.5).

Figure 2-1. Example Reinforcement Pattern in Shear Test Specimen (Reference 7.3)

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2.1.2 Embedded Rods

FSEL tracks the progression of ASR by measuring the distance between rods that were

embedded in the concrete during specimen fabrication. Each specimen contains ýrods

perpendicular to the reinforcement mats and ýrods parallel to the reinforcement mats.

As ASR occurs, the concrete between a given set of rods expands, which increases the distance

between the rods.

FSEL measures the distance between each set of expansion rods shortly after fabrication to

provide an initial value. The cumulative expansion at a given point in time is the difference

between the initial value and the measurement at a given time (Reference 8). Figure 2-2 and

Figure 2-3 show the configuration of the embedded rods.

Figure 2-2. Plan View of Embedded Rods (Reference 7.6)

(Embedded Reinforcement also Shown)

Figure 2-3. Elevation View of Embedded Expansion Rods (Reference 7.6)

(Embedded Reinforcement also Shown)

The instrumentation specimen has ý rods perpendicular to the reinforcement mats, but

does not have rods parallel to the reinforcement mats. For this specimen, through-thickness

expansion is monitored using a depth gage inserted into small bore holes that go completely

through the specimen.

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2.2 EXPANSION IN REINFORCED CONCRETE

2.2.1 Test Specimens

Expansion of the test specimens is significantly more pronounced in the through-thickness

direction (i.e., perpendicular to the reinforcement mats) than the in-plane direction (i.e., on the

faces of the specimens parallel to the reinforcement mats). Expansion in the in-plane direction

plateaus at low levels, while expansion in the through-thickness direction continues to increase.

This behavior can be seen in Figure 2-4, which is a plot of expansion for Specimen f based on

monitoring the distance between the embedded rods1. Expansion behavior in this test specimen

is representative of other test specimens.

Figure 2-4. Expansion Trends in Example Test Specimen

The difference between in-plane expansion and through-thickness expansion is due to the

reinforcement detailing and the resulting difference in confinement between the in-plane and

through-thickness directions. The reinforcement mats confine expansion in the in-plane

direction. Through-thickness expansion, on the other hand, is not confined because there is no

'Figure 2-4 is for illustrative purposes only. Periodic monitoring of expansion is considered for information only,

whereas the measurements at the time of testing are formal test measurements.

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reinforcement in that direction. Therefore, expansion occurs preferentially in the

through-thickness direction.

For specimens with higher ASR levels, a large crack on the concrete surface formed on each

specimen face that is between the reinforcement mats, as shown in Figure 2-5. This crack was

also between the embedded pins used to measure through-thickness expansion. 2

m-gure z-b. uracK in I nrougn- I niCKness uirection OT exampie I est 6pecimen

Once the large crack forms, expansion measured using the embedded rods is governed by the

increase in crack width. Expansion in the regions outside of the embedded rods remains

relatively unchanged. Therefore, expansion must be calculated based on the total width of the

beam, rather than the distance between the embedded rods, to appropriately characterize

expansion of the specimen. FSEL provided a correlation to relate expansion measurements from

the embedded rods to through-thickness expansion over the total beam width. (Reference 21)

2.2.2 Literature Review

The observed preferential expansion in the through-thickness direction is consistent with

literature on expansion caused by ASR (References 2, 9, and 10). Literature suggests that when

reinforcement is present to restrain the tensile force exerted by ASR expansion, an equivalent

compressive force develops in the concrete, which creates a prestressing effect. If tensile loads

2 Concentration of expansion in the large crack is believed to be an edge effect of the test specimens that is not

representative of Seabrook Station, where the concrete is in its full structural context. There is no evidence of this

type of cracking at Seabrook Station at this time.

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are applied to the structure, the compressive stresses in the concrete from prestressing must be

overcome before there is a net tensile stress. Cracking in confined concrete would not occur

until a net tensile stress is applied.

2.3 IMPLICATIONS FOR MONITORING ASR AT SEABROOK

Based on the expansion behavior observed in the test specimens, expansion in the

through-thickness direction is the best indicator of ASR development in the test specimens and at

Seabrook Station. In-plane expansion is a readily available parameter that can be used to assist

with diagnosis of ASR-affected reinforced concrete. However, the test data suggest that

through-thickness measurement is a more sensitive parameter for characterizing ASR-induced

expansion at Seabrook Station in the long term. Accordingly, the results of the structural testing

program will be correlated to expansion in the through-thickness direction.

NextEra is expanding its ASR monitoring efforts to include through-thickness expansion.

Specifically, NextEra plans to install instruments (i.e., extensometers) in concrete structures at

Seabrook Station to monitor expansion in the through-thickness direction. The current plan

includes installing instruments in ASR-affected areas and some areas unaffected by ASR. The

instruments in areas unaffected by ASR will provide a reference measurement to gauge effects,

such as thermal expansion, that could influence the ASR expansion measurements.

The instruments measure through-thickness expansion that occurs after the instrument is

installed. To determine the cumulative expansion since original construction, this expansion

measurement must be added to the expansion up to the time the instrument is installed. The

subsequent sections of this report provide a methodology for determining the pre-instrument

expansion.

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3

Determining Pre-Instrument Expansion from

Elastic Modulus

This section describes the technical basis and methodology for using the reduction in elastic

modulus to determine the total ASR-induced expansion in the through-thickness direction prior

to instrument installation. The methodology depends on determining the elastic modulus at the

time of instrument installation from cores and establishing the original elastic modulus to

provide a point of reference. The original elastic modulus may be determined by testing

reference cores from concrete without symptoms of ASR or by using original construction data

with an ACI correlation that relates compressive strength to elastic modulus.

Specific topics discussed in this section include:

* Evaluation of changes in material properties to indicate ASR-induced expansion,

* Development of the correlation between expansion and elastic modulus based on test data

from the large-scale ASR testing programs, and

* Determination of the original elastic modulus at Seabrook Station, which is used as the

point of reference for determining reduction in elastic modulus.

The discussion in this section relies on test results obtained to date from the ongoing large-scale

ASR testing programs at FSEL. After all test data are available, MPR will revisit this evaluation

and provide updates, as appropriate.

3.1 MATERIAL PROPERTIES OF TEST SPECIMENS

As part of the large-scale structural testing programs, FSEL has been obtaining material property

data on the beam specimens at different levels of ASR expansion. The difference between the

28-day material property result and the material property result at the time of testing may be used

to quantify development of ASRk.

3.1.1 Material Property Testing during FSEL Structural Testing Programs

During fabrication of the beam specimens, FSEL prepares cylinders (approximately 8 inches in

height and 4 inches in diameter) using the same batch of concrete as the specimens

(Reference 11). A subset of these cylinders are tested 28 days after fabrication to provide initial

values for the material properties of the specimen, including compressive strength, elastic

' The FSEL test results on elastic modulus are material tests of removed cores that no longer exhibit the structural

context of the beam specimen. Load test results of beam specimens show that the reduction in elastic modulus of

the cores does not correlate to a corresponding reduction in stiffness of the beam from which the cores were taken.

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modulus, and splitting tensile strength (Reference 12). At the time of load testing a shear or

reinforcement anchorage specimen, FSEL obtains cores from the specimen and performs testing

for material properties. For the instrumentation specimen, FSEL obtains cores and performs

material property testing at selected expansion levels.

3.1.2 Compressive Strength and Elastic Modulus

Figure 3-1 is a plot showing the normalized values for compressive strength and elastic modulus

as a function of expansion (Reference 13). A normalized material property is the ratio of the

property at the time FSEL obtained the expansion measurement divided by the material property

obtained from testing a cylinder 28 days after fabrication.

Figure 3-1. Material Properties as a Function of Expansion from Test Data (Reference 13)

Key observations from Figure 3-1 include the following:

* Normalized elastic modulus follows a trend where elastic modulus decreases sharply at

expansion levels less than aboutf%. The trend indicates a more gradual decrease at

higher expansion levels.

* Normalized compressive strength shows a general decreasing trend with increasing

expansion levels; however, compared to elastic modulus, there is lower sensitivity with

expansion (i.e., the slope is shallower) and there is more data scatter.

Literature data indicate that trends for normalized material properties are consistent with the

material property results from the test programs (References 1 and 2). In particular, the literature

concludes that reduction in elastic modulus is more sensitive to ASR development than

compressive strength.

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3.1.3 Splitting Tensile Strength

Figure 3-2 is a plot showing the splitting tensile strength values as a function of expansion.

Normalized splitting tensile strength results (which require a 28-day value) are not currently

available because the test program did not start obtaining these results until after FSEL had

fabricated many of the specimens.

Figure 3-2. Splitting Tensile Strength as a Function of Expansion from Test Data

(Reference 13)

Data from higher expansion levels have approximately the same splitting tensile strength values

as data from low expansion levels. Even if normalized data were available, sensitivity with

expansion would be low (i.e., shallow slope). Accordingly, MPR concludes that a correlation to

expansion using normalized tensile strength is unlikely to be more sensitive than a correlation

using normalized elastic modulus.

3.2 DEVELOPMENT OF CORRELATION BETWEEN MODULUS AND EXPANSION

3.2.1 Data from Test Program

Figure 3-3 includes a plot of the test data for reduction in modulus of elasticity and the

corresponding expansion measurements (Reference 13; Appendix A). The plot uses a

normalized modulus value that is the ratio of the elastic modulus at the time the expansion

measurement was obtained (Et) divided by the 28-day elastic modulus (Eo).

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Figure 3-3. Elastic Modulus as a Function of Expansion from Test Data (Reference 13)

Results of calculations using the data from Figure 3-3 include the following:

* The correlation shown in Figure 3-3 has the following equation determined by

least-squares regression (Reference 13):

W [Equation 1]

* The correlation fits well with the data and therefore supports use of a= formulation.

The coefficient of determination (R2) is M (Reference 13). MPR performed scoping

evaluations of several different forms of the equation for the correlation and determined

that a= formulatior * provided the best fit.

3.2.2 Data from Literature

As part of the Reference 13 calculation, MPR compared the relationship developed from the

FSEL test data against data available in literature (References 14, 15, and 16). The literature

data reflect small specimens that were cast and cured as unconfined concrete.

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Figure 3-4. Comparison of Derived Relationship with Literature Data (Reference 13)

Overall, the trend from the literature data compares favorably with the correlation generated

from the FSEL data. Accordingly, the comparison to literature data corroborates application of

the experimentally-determined correlation at Seabrook Station.

3.2.3 Applicability of Correlation to Seabrook Station

The correlation developed from the FSEL data relating expansion to reduction in elastic modulus

is applicable to reinforced concrete structures at Seabrook Station. The test data used to generate

the correlation were obtained from test specimens that were designed to be as representative as

practical of the concrete at Seabrook Station, including the reinforcement detailing.

Additionally, comparison against literature data shows that the correlation follows a trend that is

consistent with other published studies which cover a range of concrete mixtures.

3.3 ESTABLISHING ORIGINAL ELASTIC MODULUS AT SEABROOK

The correlation shown in Figure 3-3 and provided in Equation 1 uses the 28-day elastic modulus

as an input for determining expansion. However, consistent with typical construction practices,

material property testing of concrete used at Seabrook Station verified only the 28-day

compressive strength; the elastic modulus was not measured. This section describes two

approaches for establishing the 28-day elastic modulus for concrete at Seabrook Station.

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3.3.1 Approach 1: Code Equation Based on Compressive Strength

ACI 318-71 (Reference 17) provides the following equation for the elastic modulus of concrete

(Eo) calculated based on compressive strength (f,') and the density of concrete in lb/ft3 (W,):

E, = 33 x w,1.5 X A(f 0 ') [Equation 2]

The equation presented in ACI 318-71 is based on fitting a curve to publicly available

information on compressive strength and elastic modulus of various concrete specimens. The

data used cover a range of concrete mixtures from lightweight concrete to normal weight

concrete.

Confirmation of Code Equation for FSEL-Generated Data

Using data from the test program for 28-day compressive strength and elastic modulus for a

concrete mix design that represented Seabrook Station, MPR confirmed that the ACI equation is

applicable (Reference 18; Appendix B). ACI 318-71 states that the actual elastic modulus is

expected to be within ±20% of the calculated value. As shown in Figure 3-4, flofs data

points a%) obtained from the test program met this criterion.

Figure 3-5. Comparison of Test Data to ACI Equation (Reference 18)

MPR concludes that the ACI 318-71 equation is applicable for concrete at Seabrook Station for

the following reasons:

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* The FSEL data are consistent with the equation from ACI 318-71 and the stated variance

of ±20%.

* The concrete test specimens fabricated by FSEL are designed to be representative of the

concrete used at Seabrook Station and therefore better represent the concrete at Seabrook

than the range of mixtures used to generate the code equation.

Original Compressive Strength

Using original construction records for compressive strength tests and the ACI 318-71

correlation, NextEra could establish the 28-day elastic modulus.

NextEra has retrieved records for concrete fabrication from original construction for selected

buildings. For convenience, MPR Calculation 0326-0062-CLC-02 (Reference 19; Appendix C)

summarizes the currently-available 28-day compressive strength test results and the buildings

associated with those results. For structural assessment of particular concrete members,

application of values from Reference 19 will need to be evaluated on a case-by-case basis to

determine whether the available data are sufficiently representative of the concrete being

evaluated. NextEra may need to retrieve additional original construction records to implement

this approach.

In addition, NextEra has statistical analysis of over 5,000 compressive strength specimens

representing 12 mix classes used during original construction (Reference 20). These data could

be applied if NextEra can identify the mix class used for a particular concrete surface.

3.3.2Approach 2: Reference Cores

An alternative approach for determining the original elastic modulus is to obtain and test

reference cores for elastic modulus from concrete at Seabrook Station that is not affected by

ASR. The elastic modulus determined using the reference cores would then be applied as

equivalent to the 28-day elastic modulus.

NextEra plans to install through-thickness expansion monitoring instrumentation in "control"

locations where ASR has not affected the concrete. NextEra would test the cores obtained

during installation to obtain elastic modulus results.

To implement this approach, NextEra would need to justify that the reference cores were

representative of original construction concrete for the location in question. Petrographic

examination of the cores (potentially after elastic modulus testing) would conclusively determine

that the reference core is not affected by ASR. The original construction data discussed in

Appendix C indicate that there are differences in material properties among the buildings at

Seabrook Station. NextEra should evaluate selection of a representative reference core on a

case-by-case basis.

3.3.3 Selection of an Approach for Determining Original Elastic Modulus

Approach 1 and Approach 2 are both valid approaches. The approach should be selected based

on specific considerations of the area being evaluated. If both approaches are feasible, both

approaches may be used to validate the results using two independent means.

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4

Recommended Approach

4.1 OVERVIEW OF APPROACH

MPR recommends the following approach for determining ASR-induced through-thickness

expansion for instrumented locations at Seabrook Station.

1. Determine the current elastic modulus of the concrete by testing of cores removed from the

structure. Elastic modulus testing requires companion compressive strength testing, so

MPR recommends obtaining a minimum of four specimens. Two test specimens are for

compressive strength testing and two test specimens are for subsequent elastic modulus

testing.

2. Establish the original elastic modulus of the concrete by one of the following methods:

- Using the ACI 318-71 correlation to calculate elastic modulus from 28-day

compressive strength test results.

- Obtaining cores from ASR-free locations and testing for elastic modulus.

3. Calculate the reduction in elastic modulus by finding the ratio of the test result from the

ASR-affected area to the original elastic modulus.

4. Determine through-thickness expansion from original construction to the time the

extensometer is installed using the correlation developed in this report. The correlation

relates reduction in elastic modulus with measured expansion from beam specimens used

during the large-scale ASR structural testing program.

5. Calculate the total expansion by adding the extensometer measurement to the expansion at

the time of instrument installation.

4.2 UNCERTAINTY

The recommended methodology relies on the correlation between through-thickness expansion

and normalized elastic modulus. For normalized elastic modulus greater thanfl, the correlation

indicates a relatively narrow range of expansion values from f% to|%. For normalized elastic

modulus values less than f, the expansion values increase sharply. Uncertain with the

methodology is more impactful for normalized elastic modulus values less thari.

NextEra previously tested cores from ASR-affected areas for elastic modulus as part of the

original diagnosis of ASR at Seabrook Station. Using these test results and Approach 1 for

establishing the original elastic modulus, MPR performed a scoping calculation that concluded

MPR-4153 4-1

Revision 1

Page 22 of 88
that the minimum normalized elastic modulus currently at Seabrook Station is higher than fl.

Uncertainty associated with determining the normalized elastic modulus may result in a potential

value for elastic modulus that is less than f and therefore in the range of high sensitivity for

determining expansion.

MPR will conduct a more specific treatment of uncertainty and the associated consequences for

determining structural performance when all test data are available.

MPR-4153 4-2

Revision 1

Page 23 of 88
5

References

1. Institution of Structural Engineers, Structural Effects ofAlkali-Silica Reaction: Technical

Guidance on the Appraisal of Existing Structures, London, UK, 1992.

2. Bayrak, 0., "Structural Implications of ASR: State of the Art," July 2014.

(Seabrook FP # 100697)

3. Fournier, B. et al, FHWA-HIF-09-004, Report on the Diagnosis, Prognosis, and

Mitigation ofAlkali-Silica Reaction in Transportation Structures, January 2010.

4. MPR-3727, Seabrook Station: Impact ofAlkali-Silica Reaction on Concrete Structures

and Attachments, Rev. 1, May 2012. (Seabrook FP # 100716.)

5. MPR-3 848, Seabrook Station - Approach for Shear and Reinforcement Anchorage Testing

of Concrete Affected by Alkali-Silica Reaction, Rev. 0, April 2013.

(Seabrook FP # 100818)

6. United States Nuclear Regulatory Commission, NRC Information Notice 2011-20,

"Concrete Degradation by Alkali-Silica Reaction," November 18, 2011. (ADAMS

Accession No. ML1 12241029)

7. Test Program Drawings

7.1. FSEL Drawing DWG 0326-0063-0S-G, fl-Inch Shear Specimen Geometry,

Revision 1.

7.2. FSEL Drawing DWG_0326-0063_JA-G, f-Inch Anchorage Specimen Geometry,

Revision 3.

7.3. FSEL Drawing DWG_0326-0063- S-RI, f-Inch Shear Specimen Reinforcement,

Revision 1.

7.4. FSEL Drawing DWG 0326-0063_MA-R1, l-Inch Anchorage Specimen

Reinforcement, Revision 3.

7.5. FSEL Drawing DWG 0326-0063-01-R2, f-Inch Instrumentation Specimen

Reinforcement - Assembly, Revision 0.

7.6 FSEL Drawing DWG 0326-0063-ES-I, N-Inch Shear Specimen Instrumentation,

Revision 1.

8. FSEL Procedure 4-3, Periodic Monitoring of Concrete Expansions, Revision 6.

MPR-4153 5-1

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Page 24 of 88
9. Deschenes, D., Bayrak, 0., and Folliard, K., ASR/DEF-Damaged Bent Caps. Shear Tests

and Field Implications, Technical Report IAC-12-8XXIA006, Center for Transportation

Research, Bureau of Engineering Research, University of Texas at Austin, August 2009.

10. Miyagawa, T. et al, Fracture of Reinforcing Steels in Concrete Structures Damaged by

Alkali-Silica Reaction - Field Survey, Mechanism, and Maintenance, Journal of Advanced

Concrete Technology, Vol. 4 No. 3, October 2006.

11. FSEL Procedure 1-5, Placement and Curing of Materials Testing Samples, Revision 3.

12. MPR Test Specification 0326-0062-05, Revision 9, "Specification for Shear and

Reinforcement Anchorage Testing of ASR-Affected Reinforced Concrete."

(Seabrook FP # 100759)

13. MPR Calculation 0326-0062-CLC-03, Correlation Between Through-Thickness Expansion

and Elastic Modulus in Concrete Test Specimens Affected by Alkali-Silica Reaction (ASR),

Revision 1.

14. Clark, L., Critical Review of the Structural Implications of the Alkali Silica Reaction in

Concrete, Transport and Road Research Laboratory Contractor Report 169, July 1989.

15. Smaoui, N. et al, Mechanical Properties of ASR-Affected Concrete Containing Fine or

Coarse Reactive Aggregates, Journal of ASTM International, Vol. 3, No. 3, March 2006.

16. Ahmed, T. et al, The Effect ofAlkali Reactivity on the Mechanical Properties of Concrete,

Construction and Building Materials, 17 (2003) 123-144, January 9, 2002.

17. ACI 318-71, Building Code Requirements for Reinforced Concrete, 1971 Edition, Fourth

Printing.

18. MPR Calculation 0326-0062-CLC-01, Evaluation of ACI Equation for Elastic Modulus,

Revision 0.

19. MPR Calculation 0326-0062-CLC-02, Compressive Strength Values for Concrete at

Seabrook Station, Revision 0.

20. Pittsburgh Testing Laboratory letter dated January 25, 1986, "Seabrook Nuclear Station

Spec. 9763.006-5-1 Statistical Analysis -- Concrete Compression Test Data January 1986."

(Seabrook FP # 100348)

21. Letter from FSEL (Bayrak) to MPR (Simons) dated June 23, 2015, "Measurement of ZDirection Expansion of A- and S-Series Specimens."

22. MPR Commercial Grade Acceptance Record CGAR-0326-0062-43-1, Revision 1.

23. MPR Commercial Grade Acceptance Record CGAR-0326-0062-43-2, Revision 0.

24. MPR Commercial Grade Acceptance Record CGAR-0326-0062-43-3, Revision 0.

MPR-4153 5-2

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A

Correlation Between Expansion and Elastic

Modulus

This appendix includes MPR Calculation 0326-0062-CLC-03, Correlation Between

Through-Thickness Expansion and Elastic Modulus in Concrete Test Specimens Affected by

Alkali-Silica Reaction (ASR), Revision 1.

MPR-4153 A-i

Revision 1

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CALCULATION TITLE PAGE

Client: Page 1 of 12 +

NextEra Energy Seabrook Appendices A-C

(28 pages total)

Project: Task No.

Approach for Estimating Through-Wall Expansion from Alkali-Silica

Reaction at Seabrook Station 0326-1405-0074

Title: Calculation No.

Correlation Between Through-Thickness Expansion and Elastic Modulus in

Concrete Test Specimens Affected by Alkali-Silica Reaction (ASR) 03260062CLC03

Preparer / Date Checker I Date Reviewer & Approver / Date Rev. No.

0

Michael Saitta Vaibhav Bhide John W. Simons

February 2, 2015 February 2, 2015 February 2, 2015

Michael Saitta Kathleen Mulvaney John W. Simons

June 23, 2015 June 23, 2015 June 23, 2015

QUALITY ASSURANCE DOCUMENT

This document has been prepared, checked, and reviewed/approved in accordance with the QA requirements of

1OCFR50 Appendix B and/or ASME NQA-1, as specified in the MPR Nuclear Quality Assurance Program.

MPR-QA Form QA-3.1-1, Rev. 2

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RECORD OF REVISIONS

Calculation No. Prepared By Checked By Page: 2

0326-0062-CLC-03 Ae4'*ý gAboW* tV1l

Revision [ Affected Pages Description

0

1

All

All

Initial Issue

Added correction factor for through-thickness expansion values to account

for influence of mid-plane cracks on the expansion measured using

embedded rods. (See new Section 5.2)

Note: The revision number found on each individual page of the calculation carries the revision

level of the calculation in effect at the time that page was last revised.

MPR QA Form QA-3.1-2, Rev. 0

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Table of Contents

1.0 Purpose .......................................................................................................... 4

2.0 Sum m ary of Results ......................................................................................... 4

3.0 Background ....................................................................................................... 5

4.0 Assum ptions ..................................................................................................... 5

4.1 Assumptions with a Basis ....................................................................................... 5

4.2 Unverified Assumptions ......................................................................................... 5

5.0 Discussion ......................................................................................................... 5

5.1 Test Data ............................................................................................................. 5

5.2 Expansion M easurement Correction Factor .......................................................... 6

5.3 Selection of Elastic M odulus as the Property for the Correlation ........................... 6

5.4 Elastic M odulus Correlation ................................................................................... 8

5.5 Comparison to Published Values ........................................................................... 9

6.0 References ....................................................................................................... 11

A Test Data ...................................................................................................... A-1

B Least Squares Regression ........................................................................... B-1

C Reference 6 .................................................................................................. C-1

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1.0 PURPOSE

This calculation determines a correlation between through-thickness expansion and elastic

modulus of concrete test specimens affectedby Alkali-Silica Reaction (ASR). The correlation is

based on data from test programs that MPR is sponsoring at Ferguson Structural Engineering

Laboratory (FSEL). The correlation is compared to published data.

2.0 SUMMARY OF RESULTS

There is a strong correlation between elastic modulus and through-thickness expansion of

concrete test specimens that are affected by ASR. The data were fit with a least squares

regression using a form. Figure 2-1 below shows the FSEL test data and the least

squares fit. The least squares fit compares favorably with the trend observed in the data. The R2

value of the correlation is .

Figure 2-1 also shows data found in the literature for free expansion of ASR-affected concrete

specimens. These data are consistent with the FSEL data.

Figure 2-1. Strong Correlations Between Elastic Modulus and Expansion

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3.0 BACKGROUND

Published data show that the material properties of ASR-affected concrete change with

increasing levels of ASR expansion. MPR intends to use the relationship between material

properties and ASR expansion to develop a methodology to determine the through-thickness

expansion of concrete structures at Seabrook Station. This relationship will be defined using

data from test programs that MPR is sponsoring at FSEL to investigate ASR in reinforced

concrete elements. The test specimens are consistent with structures at Seabrook Station in

terms of reinforcement details, depth of cover and overall depth. In addition, the concrete used

in the specimens is representative of the concrete used at Seabrook Station, with some deviations

to produce significant ASR expansion in a short timeframe.

4.0 ASSUMPTIONS

4.1 Assumptions with a Basis

There are no assumptions with a basis.

4.2 Unverified Assumptions

There are no unverified assumptions.

5.0 DISCUSSION

5.1 Test Data

The test data used herein are for specimens from the Shear Test Program and the Reinforcement

Anchorage Test Program, as well as the Instrument Beam. Combining data from these programs

is appropriate as the same concrete mix was used in all specimens and specimen configurations

and reinforcement details are similar.

Test data on m concrete specimens are used in this calculation. The baseline material

properties are the 28-day tests performed on cylinders molded at the time of concrete placement.

The material properties at various levels of ASR expansion are based on tests of cores removed

from the specimen. The available data include the following:

* 28 days after concrete placement

o Three compressive strength values

o Three elastic modulus values

o Three splitting tensile strength values (note that this test was only performed form of

the I specimens, a total of I tests)

* After ASR had occurred

o Three compressive strength values

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o Three elastic modulus values

o Three splitting tensile strength values

o Through-thickness expansion at the time the cores were removed

These values are taken from Reference 1 and are summarized in Appendix A.

5.2 Expansion Measurement Correction Factor

The test specimens have developed large cracks on the concrete surface in the through-thickness

direction between the reinforcement mats. The large cracks concentrate though-thickness

expansion between the embedded rods. Therefore, the expansion measurement taken at the rods

was significantly higher than the average expansion of the specimen along its width. FSEL

developed a correlation to correct the expansion measured using the embedded rods, yielding an

estimate of the average through-thickness expansion (Reference 6, See Appendix C; Reference 7

and Reference 8). This correlation is:

Where:

Epin is the expansion measured using the rods, measured in percent, and

E is the corrected expansion, measured in percent.

This correction is applied to all of the expansion data, and the corrected data are used throughout

the remainder of the calculation. The results of the correction are presented in Appendix A.

5.3 Selection of Elastic Modulus as the Property for the Correlation

To allow for more valid comparisons, the material properties of each specimen from the

post-ASR testing were normalized against its average value from the 28-day test. Therefore, a

sample that had seen very little change in a material property would have a normalized value of

approximately 1, whereas one that had experienced a 25% reduction in a material property would

have a normalized value of 0.75.

Figure 5-1 plots the normalized compressive strength and the normalized elastic modulus versus

expansion. From the plot, it appears that there is a strong correlation between modulus and

expansion. There also appears to be a weak correlation between compressive strength and

expansion.

There were insufficient data to normalize the splitting tensile strength. Therefore, the splitting

tensile strength was plotted against expansion in Figure 5-2. There does not appear to be a

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correlation between splitting tensile strength and expansion. Therefore, it is determined that

elastic modulus is the best choice to correlate against expansion.

Figure 5-1. Normalized Strengths/Stiffness vs Expansion

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Figure 5-2. Splitting Tensile Strength vs Expansion

5.4 Elastic Modulus Correlation

Non-linear least squares regression was used to fit a curve for the relationship between

normalized modulus and expansion. Based on scoping analysis of several types of equations, it

was determined that the best-fit curve would take the form of:

Least squares fitting was used to determine the constants A and B. The process of least squares

is described in detail in Appendix B. This resulted in a final correlation of:

Where:

expansion is the relative through-thickness expansion of the concrete specimen (0.02

implies a 2% expansion)

modulus is the normalized modulus of the concrete specimen after ASR

This correlation is shown in Figure 5-3. The least squares fit compares favorably with the

observed data. The R2 value for the correlation is M.

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Figure 5-3. Correlation between Expansion and Normalized Modulus

5.5 Comparison to Published Values

Data on the elastic modulus as a function of ASR expansion are available in the literature. These

data are for free expansion of small concrete specimens. Table 5-1 lists data from the sources

considered in Reference 2.

Table 5-1. Existing Data Showing Expansion (%) and

Corresponding Elastic Modulus

Expansion (%) Normalized Elastic Reference

Modulus

0.05 100 3, Table 2.1

0.10 70 3, Table 2.1

0.25 50 3, Table 2.1

0.50 35 3, Table 2.1

1.00 30 3, Table 2.1

1.50 20 3, Table 2.1

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Table 5-1. Existing Data Showing Expansion (%) and

Corresponding Elastic Modulus

Normalized Elastic

Expansion (%) Modulus Reference

0.002 100 4

0.039 66.0 4

0.114 65.2 4

0.210 54.7 4

0.328 50.2 4

0.392 46.7 4

0.007 100 4

0.020 97.7 4

0.038 91.2 4

0.095 78.3 4

0.128 75.8 4

0.291 86.52 5

1.2531 13.92 5

0.431 70.22 5

1.5731 13.72 5

0.431 39.72 5

1.6561 10.32 5

0.431 32.82 5

1.686' 8.12 5

Note 1: Longitudinal prism expansion was selected as the

most representative

Note 2: Taken as elastic modulus at testing divided by

elastic modulus at 28 days

Figure 5-4 plots these data and compares them to the FSEL data and to the correlation based on

the FSEL data.

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Figure 5-4. Modulus vs Expansion From Published Literature

As shown in Figure 5-4, the data from published literature follow a trend that is consistent with

the FSEL test data and the correlation determined using these data.

6.0 REFERENCES

1. FSEL Special Test and Inspection Reports (STIRs) as accepted by CGAR-0326-0062-43-1

Revision 1 and CGAR-0326-0062-43-2 Revision 0

a) STIR-24-21, Revision 0 n) STIR-24-64, Revision 0

b) STIR-24-23, Revision 0 o) STIR-24-67, Revision 0

c) STIR-24-24, Revision 0 p) STIR-24-68, Revision 0

d) STIR-24-26, Revision 0 q) STIR-24-69, Revision 0

e) STIR-24-34, Revision 0 r) STIR-24-70, Revision 0

fj STIR-24-35, Revision 0 s) STIR-24-71, Revision 0

g) STIR-24-56, Revision 1 t) STIR-24-72, Revision 0

h) STIR-24-58, Revision 0 u) STIR-24-79, Revision 1

i) STIR-24-59, Revision 0 v) STIR-24-81, Revision 1

j) STIR-24-60, Revision 0 w) STIR-24-86, Revision 0

k) STIR-24-61, Revision 0 x) STIR-24-88, Revision 0

1) STIR-24-62, Revision 0 y) STIR-24-89, Revision 0

m) STIR-24-63, Revision 0 z) STIR-24-103, Revision 0

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aa) STIR-24-104, Revision 0 ii) STIR-24-116, Revision 0

bb) STIR-24-105, Revision 0 jj) STIR-24-120, Revision 0

cc) STIR-24-106, Revision 0 kk) STIR-24-132, Revision 0

dd) STIR-24-107, Revision 0 11) STIR-24-133, Revision 0

ee) STIR-24-108, Revision 0 mm) STIR-24-134, Revision 0

ffj STIR-24-1 10, Revision 0 nn) STIR-24-140, Revision 0

gg) STIR-24-114, Revision 0 oo) STIR-24-147, Revision 0

hh) STIR-24-115, Revision 0

2. Bayrak, Oguzhan, Structural Implications of ASR: State of the Art, July 28, 2014,

transmitted to Seabrook Station in MPR Letter 0326-0058-200, dated July 29, 2014.

3. Clark, L.A., Critical Review of the Structural Implications of the Alkali Silica Reaction in

Concrete, Transport and Road Research Laboratory Contractor Report 169, July 1989.

4. Smaoui, N. et al., Mechanical Properties of ASR-Affected Concrete Containing Fine or

Coarse Reactive Aggregates, Journal of ASTM International, Vol. 3, No. 3, March 2006.

5. Ahmed, T. et al., The effect ofAlkali Reactivity on the Mechanical Properties of Concrete,

Construction and Building Materials, 17 (2003) 123-144, January 9, 2002.

6. Letter from Oguzhan Bayrak (FSEL) to John Simons (MPR), "Measurement of

Z-Direction Expansion of A- and S-Series Specimens", dated June 23, 2015. (Included as

Appendix C)

7. STIR-0326-0062-24-171, Revision 0.

8. CGAR-0326-0062-43-3, Revision 0.

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A

Test Data

This Appendix includes tables of summarized test data originally from FSEL. Table A-I

contains data from tests conducted 28 days after casting. The data are used to normalize the

post-ASR data. Table A-2 contains data from tests that were conducted after ASR had occurred.

Table A-3 contains expansion values measured using the specimen rods and the corrected

expansion determined using the correlation discussed in Section 5.2. Test data are taken from

Reference 1 of the main body of this calculation.

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Table A-I. FSEL 28-Day Compressive Strength, Elastic Modulus, and Splitting Tensile Strength Test Data

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Table A-2. FSEL Average Expansion, Compressive Strength, and Elastic Modulus

Test Data After ASR

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Table A-3. FSEL Expansion Test Data With

Correction Factor

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B

Least Squares Regression

Purpose

This appendix explains the methodology used to perform the Least Squares Regression Analysis.

A brief description of the fit statistic R2 is also given. After the method of Least Squares is

explained, the method is applied to the correlation between the FSEL test data for compressive

strength and corrected through thickness expansion.

Discussion

Least Squares Regression is a commonly accepted method of fitting a curve to a set of scattered

data. This is done by minimizing the sum of squares error term. This is a common statistical

method that is documented in textbooks such as "Applied Data Analysis and Modeling for

Energy Engineers and Scientists" by T.A. Reddy. The sum of squares is given by:

m

Sj= r2

i=1

Where:

S is the error term,

m is the number of known values, and

rm is the residual of the mth value, as given by:

rm = Yi - f(xi, C)

Where:

yj and xi are a known value pair,

f is the regressed or fit function, and

C is the set of constants used to fit the model.

By combining the above equations with a known set of values, S is minimized by varying C. In

some cases, this can be accomplished analytically, but is often accomplished numerically. The

values of C that minimize S are said to be the fitting parameters, and the function f(xi, C) is the

curve of best fit in the least squares sense.

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It is often desirable to determine how well a given curve fits a set of data. A commonly used

statistic to determine this is the coefficient of determination, R2. R2 is defined as:

R 2 = 1 -SS_

sstot

m SSre (y - f(x,, C)) 2 = S

1=1

m

SStot iy (y - 2

1=1

Example

The least squares regression performed in the main body of this calculation is described in detail

below. The set of points is listed in Table B-1 and plotted in Figure B-1.

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Figure B-I. Plot of Known Values

It appears that a power fit is reasonable. Therefore, it can be fit to an equation of form:

Where:

x is the set of values of X as shown in Table B-1.

A and B are a set of constants (C) used to fit the model.

To begin, we will guess at the values of A and B. In this example, our first guess will be that

A = 1 and B = -0.01. Using the model given above, we compute a value for y at each given x.

For each computed value, the residual is also computed. These values are shown in Table B-2.

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Taking the sum of squares of the residuals, we find a value of=. However, this can be

improved on. To do so, we iteratively adjust the values A and B to minimize S.

Values of A = and B = ý result in S being minimal and provide a good estimate

of the solution. The fitted curve is plotted against the data in Figure B-2. The newly computed

values are shown in Table B-3. The regressed equation is:

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Table B-3. Eyamole Values With ComnL Residuals- Undated

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Figure B-2. Regressed Curve

R2 can now be computed using the regressed curve. The sum of squared residuals i

(SSres). The mean of y isM. Therefore, the sum of squared totals is M (SStot). R can

now be computed.

R2 = 1 - SSr/SStot

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*M PR 320 King Street

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0326-0062-CLC-03 ;K 44-2 0- Revision: I

C

Reference 6

This appendix includes a copy of Reference 6: Letter from Oguzhan Bayrak (FSEL) to John

Simons (MPR), "Measurement of Z-Direction Expansion of A- and S-Series Specimens", dated

June 23, 2015.

Note that Reference 6 is accepted by References 7 and 8

(5 pages follow)

MPR QA Form: QA-3.1-3, Rev. 0

Page 49 of 88
PHIL M. FERGUSON STRUCTURAL ENGINEERING LABORATORY

* }THE UNIVERSITY OF TEXAS AT AUSTIN

10100 Burnet Road, Building 177, Austin, Texas 78758-4497 (512) 471-3062 -Fax (512) 471-1944

June 15, 2015; Revised June 23, 2015

Mr. John W. Simons

MPR Associates Inc.

320 King Street

Alexandria, VA 22314-3230

Subject: Measurement of Z-Direction Expansion of A- and S-Series Specimens

Dear Mr. Simons,

Over the past few years, Ferguson Structural Engineering Laboratory (FSEL) has been using

embedded pins to measure expansion in the through-thickness, or Z-direction, of beam specimens in

the MPR-sponsored test programs. A general view of a test specimen and directional definitions are

provided in Figure 1. Measurement pins are located within the structural core of the test specimens, I

in. from the face with Iin. of concrete cover and Iin. from the face with §in. of concrete cover

(Figure 2). This arrangement places the pins Min. apart, and this distance forms the gage length for

any pin-based expansion measurements.

Over time, most specimens have developed large mid-plane cracks. Investigation of past specimens

with such cracks indicates that these mid-plane cracks are localized near the exposed surfaces of the

specimens, and do not traverse the entire perpendicular dimension of Min. These large cracks occur

between the pins mentioned above and cause significant displacement between measurement points.

Thus, expansions measured using these pins are heavily influenced by the width of this crack and may

not be representative of Z-direction expansion of the entire specimen including areas outside the

embedded pins. In an effort to address this edge effect and to examine expansion of the entire

specimen, a new measurement frame has been designed and fabricated by FSEL.

Annotated views of the frame and specimen cross section are shown in Figure 2. The frame contacts

the specimen at three points on formed concrete surfaces and aligns to both ends of both embedded

pins. Once aligned, a total of fmeasurements can be taken at the locations shown in the figure

using a calibrated depth micrometer. These measurements allow thickness of expanded specimens to

be calculated in a repeatable manner and precisely at N locations. However, the initial throughthickness dimensions of the specimens are not known precisely at this time. To enable expansion

calculations, initial through-thickness dimensions of the specimens have been taken equal to the

width of the bottom portion of the steel forms used to cast the specimens. The forms were measured

at five locations (Figure 3) using calibrated calipers and averaged to determine an initial width of

Min. for the specimens. All expansion calculations compare the average width measurement of

the bottom form with subsequent through-thickness measurements taken on the specimens.

Page C-2 Page 50 of 88

MPR Calculation 0326-0062-CLC-03

Revision I
Figure 1 - Direction Definitions for A- and S-Series Specimens

Figure 2 - Schematic View of the Measurement Frame to Measure Expansions in Z-direction

2

Page C-3 Page 51 of 88

MPR Calculation 0326-0062-CLC-03

Revision 1
Figure 3 - Plan View of Steel Form Bottom Panel with Width Measurements

Through-thickness expansions can be determined by using the measurement frame, and these

expansion values can be compared with those determined using the embedded pins. A summary of

those data are plotted in Figure 4. It is important to note that in addition to the average expansions

calculated using lmeasurements per specimen per cycle of measurement, the minimum and the

maximum values are also shown to provide context. The plot also includes a = best-fit line

through the data. Further, this figure includes both the official data and the data collected on an

information-only basis. However, conclusions and recommendations presented in this letter are based

only on the official data.

eIaIIonsnIp DeIween zxpanslon ivieasurements j~aseu on

External Frame

3

Page C-4

MPR Calculation 0326-0062-CLC-03

Revision I

Page 52 of 88
Based on the plotted comparison, an equation for through-thickness expansion based on pin

measurements can be established as:

Equation I

Where: Ez,pin = Z-direction expansion based on embedded pins in percent, and

Ezfrare = Z-direction expansion based on the measurement frame in

percent.

Equation 1 is based on a combination of physical parameters related to the specimens and

measurements alongside additional parameters developed based on a statistical best-fit linear

regression. A detailed explanation for the derivation of Equation 1 is provided below.

4

Page C-5

MPR Calculation 0326-0062-CLC-03

Revision 1

Page 53 of 88
Equation 1 represents a combination of terms based on both engineering mechanics and statistical

regression analysis. Over upcoming months, additional data will be taken for expansion

measurements using both the embedded pins and the external frame. Since specimens continue to

expand with time, additional data will be plotted, primarily populating the right-hand side of Figure 4.

Within the existing test programs, no new data will be available to place points within the lower left

portion of the figure. When additional data are available, the coefficients within Equation 1 may

evolve, though significant changes are not expected due to the basis of the equation in structural

mechanics. If changes should be warranted, the form of the equation and the methodology used for

its development should remain unchanged.

Please contact me if you have any questions or comments.

Regards,

Oguzhan Bayrak, Ph.D., P.E.

Director, Phil M. Ferguson Structural Engineering Laboratory

Professor, Civil, Architectural and Environmental Engineering

Charles Elmer Rowe Fellow, Cockrell School of Engineering

The University of Texas at Austin

5

Page C-6

MPR Calculation 0326-0062-CLC-03

Revision 1

Page 54 of 88
B

Evaluation of ACI Equation for Elastic Modulus

This appendix includes MPR Calculation 0326-0062-CLC-01, Evaluation ofACI Equation for

Elastic Modulus, Revision 0.

MPR-4153 B-i

Revision I

Page 55 of 88
MPR Associates, Inc.

UM PR 320 King Street

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CALCULATION TITLE PAGE

Client:

NextEra Energy Seabrook, LLC Page 1 of 12+

Appendix A and B

Project: Task No.

Approach for Estimating Through-Wall Expansion from Alkali-Silica

Reaction at Seabrook Station 0326-1405-0074

Title: Calculation No.

Evaluation of ACI Equation for Elastic Modulus 0326-0062-CLC-0 1

Preparer / Date Checker / Date Reviewer & Approver I Date Rev. No.

Amanda Card David H. Bergquist John W. Simons

0A/29A 215 01/2/201 W0&/2 0

01/29/2015 01/29/2015 01/29/2015 0

QUALITY ASSURANCE DOCUMENT

This document has been prepared, checked, and reviewed/approved in accordance with the QA requirements of

1 OCFR50 Appendix B and/or ASME NQA- 1, as specified in the MPR Nuclear Quality Assurance Program.

MPR-QA Form QA-3.1-1, Rev. 2

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RECORD OF REVISIONS

Calculation No.

0326-0062-CLC-01

Revision Affected Pages

0 All Initial Issue

Note: The revision number found on each individual page of the calculation carries the revision

level of the calculation in effect at the time that page was last revised.

MPR QA Form QA-3.1-2, Rev. 0

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Table of Contents

1.0 Introduction ....................................................................................................... 4

1.1 P u rp o se ......................................................................................................................... 4

1.2 Background ............................................................................................................. 4

2.0 Sum m ary of Results and Conclusions ........................................................... 4

3.0 Approach ........................................................................................................ 4

4.0 Inputs ..................................................................................................................... 5

5.0 Calculation ......................................................................................................... 6

5.1 Concrete Density Verification ................................................................................ 6

5.2 Elastic M odulus Determination ............................................................................. 7

6.0 Results and Conclusions ................................................................................ 7

7.0 References ...................................................................................................... 11

A Sam ple Concrete Density Calculation ........................................................ A-1

B Test Data and Calculations ......................................................................... B-1

MPR QA Form: QA-3.1-3, Rev. 0

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1.0 INTRODUCTION

1.1 Purpose

This calculation evaluates the applicability of the elastic modulus equation provided in

Section 8.5.1 of ACI 318-71 (Reference 2) to the concrete mix used in the Beam Test Programs

that MPR is sponsoring at Ferguson Structural Engineering Laboratory (FSEL).

1.2 Background

MPR is developing a methodology to determine the through-thickness expansion of concrete

structures at Seabrook Station due to Alkali-Silica Reaction (ASR). The through-thickness

expansion results in a reduction in the elastic modulus. One approach for estimating the original

elastic modulus (i.e., the elastic modulus before ASR expansion occurs) is to calculate it using

the 28-day compressive strength of the concrete and the equation provided in ACT 318-71.

2.0 SUMMARY OF RESULTS AND CONCLUSIONS

Based on the results of this calculation, the relationship between the measured 28-day

compressive strength and the elastic modulus for the test specimens within the Beam Test

Programs at FSEL is consistent with the ACI equation. The measured data and calculated results

show a similar trend. Measured and calculated elastic modulus values for all but three data sets

were within the variability range stated in Reference 2, 20%.

3.0 APPROACH

Section 8.5.1 of ACI 318-71 (Reference 2) states that the 28-day elastic modulus (E,) of concrete

can be calculated based on the density of concrete in lb/ft3 (w.) and the 28-day compressive

strength of concrete (fV'). This relationship is expressed using Equation 1.

E, = 33wc'S'V ]c (1)

Section R8.5.1 of ACT 318 (Reference 2) also states that measured values for elastic modulus

range from 80% to 120% of the calculated value.

Reference 3 provides the basis for Equation 1 and supports Reference 2. Equation 1 is based on

light weight and normal weight concrete test data from various published articles and

unpublished reports from the Expanded Shale, Clay, and Slate Institute.

The elastic modulus for normal weight concrete (approximate density of 144 ) can be

calculated using Equation 2, a simplified version of Equation 1. (Reference 2)

MPR QA Form: QA-3.1-3, Rev. 0

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EC = 57,0O olT-, (2)

As part of the Shear and Reinforcement Anchorage Test Programs and Instrumentation

Specimen Testing, FSEL has determined the 28-day concrete elastic modulus and compressive

strength for each beam specimen fabricated to date. These tests use cylinders molded at the time

of concrete placement. In addition to the 28-day data, data are also available from cores

removed from the test specimens used for control tests (i.e., tests performed shortly after

28 days, before the onset of deleterious ASR expansion). The results of the FSEL elastic

modulus and compressive strength tests are compared to Equation 2 (and therefore Equation 1)

in this calculation to confirm that the ACI equation is applicable to the concrete mix used in the

Beam Test Programs.

4.0 INPUTS

As stated in Section 3.0, the 28-day elastic modulus and the 28-day compressive strength of

twenty beams, collected by FSEL, were used to confirm the applicability of Equations 1 and 2.

A total of ddata sets were evaluated.

The data were taken from the Special Test and Inspection Records (STIRs) listed in Table 1.

(Reference 5 through Reference 40)

Table 1. References for Test Data

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Table 1. References for Test Data

5.0 CALCULATION

5.1 Concrete Density Verification

It is important to note that the density of concrete varies slightly among the beams that were

tested. However, all test beams are composed of normal weight concrete (144b).

The simplified equation for normal weight concrete, Equation 2, is therefore applicable and was

used to calculate the elastic moduli reported in this calculation.

The relevance of Equation 2 was verified by calculating the density of a beam and comparing it

to the density of normal weight concrete. The two values agreed.

A sample density calculation is provided in Appendix A.

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5.2 Elastic Modulus Determination

The average 28-day compressive nths and Equation 2 were used to calculate the 28-day

elastic modulus for each of the - data sets listed in Table 1. The percent error is

calculated between the measured and calculated elastic modulus values.

The calculation is provided in Appendix B.

6.0 RESULTS AND CONCLUSIONS

The measured elastic modulus values for the • data sets collected at FSEL align well

with the calculated elastic modulus values (from Equation 2). All but Wof the measured

elastic modulus values are within 80% to 120% of the calculated value.

Figure 1 compares the FSEL data to the trendline for Equation 2.

Figure 2 and Figure 3 illustrate that nearly all of the FSEL data falls within 80% and 120% of the

calculated elastic modulus value, which is consistent with the statement in Section R8.5.1 of ACI

318 (Reference 2) regarding the accuracy of the equation.

It is important to note that the measured elastic modulus is plotted and compared to the trendline

associated with Equation 2 in Figure 1 and Figure 2. The percent difference between measured

elastic modulus and calculated elastic modulus (per Equation 2) is plotted in Figure 3. All three

figures support the conclusion that Equation 2 (and therefore Equation 1) applies to the FSEL

data.

The calculations required to generate Figure 1, Figure 2, and Figure 3 are also provided in

Appendix B. Cylinders are depicted in blue. Cores are depicted in green.

Based on the results of this calculation, the elastic modulus equation, provided in Section 8.5.1

of ACI 318-71, is validated.

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Figure 1. Comparison of FSEL Elastic Modulus Test Data with Equation 2

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Figure 2. Range of FSEL Elastic Modulus Test Data

MPR QA Form: QA-3.1-3, Rev. 0

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10

0

Figure 3. Percent Error: FSEL Elastic Modulus Test Data vs. Equation 2 Elastic Modulus

MPR QA Form: QA-3.1-3, Rev. 0

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7.0 REFERENCES

1. Seabrook Foreign Print No. 100629, "Concrete Test Report," Revision 5.

2. ACI 318-71, "Building Code Requirements for Structural Concrete and Commentary,"

American Concrete Institute, 1971.

3. Pauw, A., "Static Modulus of Elasticity of Concrete as Affected by Density," Journal of the

American Concrete Institute, Vol. 32, No. 6, December 1960, pg. 679-687.

4. United Engineers Calculation No. CD-20, "Design of Mats at El. 20' 0" and 0' 0" and Walls

Below Grade for Electrical Tunnels and Control Building," Revision 2.

5. MPR Special Test and Inspection Record No. STIR-0326-0062-24-9, Revision 0.

6. MPR Special Test and Inspection Record No. STIR-0326-0062-24-17, Revision 0.

7. MPR Special Test and Inspection Record No. STIR-0326-0062-24-21, Revision 0.

8. MPR Special Test and Inspection Record No. STIR-0326-0062-24-24, Revision 0.

9. MPR Special Test and Inspection Record No. STIR-0326-0062-24-30, Revision 0.

10. MPR Special Test and Inspection Record No. STIR-0326-0062-24-34, Revision 0.

11. MPR Special Test and Inspection Record No. STIR-0326-0062-24-50, Revision 0.

12. MPR Special Test and Inspection Record No. STIR-0326-0062-24-45, Revision 0.

13. MPR Special Test and Inspection Record No. STIR-0326-0062-24-93, Revision 0.

14. MPR Special Test and Inspection Record No. STIR-0326-0062-24-1 10, Revision 0.

15. MPR Special Test and Inspection Record No. STIR-0326-0062-24-86, Revision 0.

16. MPR Special Test and Inspection Record No. STIR-0326-0062-24-96, Revision 0.

17. MPR Special Test and Inspection Record No. STIR-0326-0062-24-13, Revision 0.

18. MPR Special Test and Inspection Record No. STIR-0326-0062-24-19, Revision 0.

19. MPR Special Test and Inspection Record No. STIR-0326-0062-24-23, Revision 0.

20. MPR Special Test and Inspection Record No. STIR-0326-0062-24-26, Revision 0.

MPR QA Form: QA-3.1-3, Rev. 0

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21. MPR Special Test and Inspection Record No. STIR-0326-0062-24-3 1, Revision 0.

22. MPR Special Test and Inspection Record No. STIR-0326-0062-24-35, Revision 0.

23. MPR Special Test and Inspection Record No. STIR-0326-0062-24-84, Revision 0.

24. MPR Special Test and Inspection Record No. STIR-0326-0062-24-106, Revision 0.

25. MPR Special Test and Inspection Record No. STIR-0326-0062-24-1 17, Revision 0.

26. MPR Special Test and Inspection Record No. STIR-0326-0062-24-1 1, Revision 0.

27. MPR Special Test and Inspection Record No. STIR-0326-0062-24-47, Revision 0.

28. MPR Special Test and Inspection Record No. STIR-0326-0062-24-95, Revision 0.

29. MPR Special Test and Inspection Record No. STIR-0326-0062-24-1 11, Revision 0.

30. MPR Special Test and Inspection Record No. STIR-0326-0062-24-89, Revision 0.

31. MPR Special Test and Inspection Record No. STIR-0326-0062-24-98, Revision 0.

32. MPR Special Test and Inspection Record No. STIR-0326-0062-24-87, Revision 0.

33. MPR Special Test and Inspection Record No. STIR-0326-0062-24-107, Revision 0.

34. MPR Special Test and Inspection Record No. STIR-0326-0062-24-90, Revision 0.

35. MPR Special Test and Inspection Record No. STIR-0326-0062-24-123, Revision 0.

36. MPR Special Test and Inspection Record No. STIR-0326-0062-24-124, Revision 0.

37. MPR Special Test and Inspection Record No. STIR-0326-0062-24-127, Revision 0.

38. MPR Special Test and Inspection Record No. STIR-0326-0062-24-128, Revision 0.

39. MPR Special Test and Inspection Record No. STIR-0326-0062-24-135, Revision 0.

40. MPR Special Test and Inspection Record No. STIR-0326-0062-24-136, Revision 0.

MPR QA Form: QA-3.1-3, Rev. 0

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Calculation No.

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A

Sample Concrete Density Calculation

The density of S8 was calculated using data provided in STIR-24-90. (Reference 34)

The relevant data and density calculation are provided in Table A-1.

Table A-1. Concrete Density Calculation

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B

Test Data and Calculations

The information used to perform this calculation and to generate the graphs included herein is

provided in Table B-1 and Table B-2.

Table B-1. Compressive Strength and Calculated Elastic Modulus

MPR QA Form: QA-3.1-3, Rev. 0

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Table B-1. Compressive Strength and Calculated Elastic Modulus

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Table B-1. Compressive StrencQth and Calculated Elastic Modulus

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i and Calculated Elastic Modulus

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Table B-2. Elastic Modulus

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Table B-2. Elastic Modulus

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Table B-2. Elastic Modulus

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C

Compressive Strength of Concrete at Seabrook

Station

This appendix includes MPR Calculation 0326-0062-CLC-02, Compressive Strength Values for

Concrete at Seabrook Station, Revision 0.

MPR-4153 C-1

Revision I

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CALCULATION TITLE PAGE

Client:

NextEra Energy Seabrook, LLC Page 1 of 8 plus

Appendix A

Project: Task No.

Approach for Estimating Through-Wall Expansion from Alkali-Silica

Reaction at Seabrook Station 0326-1405-0074

Title: Calculation No.

Compressive Strength Values for Concrete at Seabrook Station 0326-0074-CLC-02

Preparer / Date Checker / Date Reviewer & Approver / Date Rev. No.

David H. Bergquist Christina Hamm John W. Simons

January 28, 2015 January 28, 2015 January 28, 2015 0

QUALITY ASSURANCE DOCUMENT

This document has been prepared, checked, and reviewed/approved in accordance with the QA requirements of

10CFR50 Appendix B and/or ASME NQA-1, as specified in the MPR Nuclear Quality Assurance Program.

MPR-QA Form QA-3.1-1, Rev. 2

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RECORD OF REVISIONS

Calculation No. Prepared By Checked By Page: 2

0326-0074-CLC-02

Revision t Affected Pages Description

0 All Initial Issue

Note: The revision number found on each individual page of the calculation carries the revision

level of the calculation in effect at the time that page was last revised.

MPR QA Form QA-3.1-2, Rev. 0

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Table of Contents

1.0

2.0

3.0

4.0

5.0

6.0

A

Purpose .......................................................................................................... 4

Sum m ary of Results ......................................................................................... 4

Background ........................................................................................................ 5

Methodology ..................................................................................................... 6

Results ........................................................................................................... 6

References ....................................................................................................... 8

Compressive Strength Data .......................................................................... A-1

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1.0 PURPOSE

This calculation evaluates available 28-day compressive strength values determined from

concrete cylinders during the original construction of Seabrook Station. These values are then

displayed on a histogram to show the data distribution, mean, and standard deviation.

Additionally, the data are separated by location and by the strength class of the concrete (i.e.

specified compressive strength).

2.0 SUMMARY OF RESULTS

All available 28-day compressive strength data points were compiled to form the histogram

given in Figure 1. The average 28-day compressive strength is 5456 psi and the standard

deviation is 568 psi. Seventy-five percent of the data fall within one standard deviation of the

mean and ninety-four percent of the data fall within two standard deviations of the mean.

60

Standard Deviation (a) = 568 psi

50

40

30

20

10

12 11

0 0 D

3184 3752 4320 4888 5456 6023 6591 7159 7727

-4o -30 -20 -lo Mean 410 +2o +3o 44o

28-Day Compressive Strength (psi)

Figure 1. 28-Day Compressive Strength Values for Concrete Cylinders at Seabrook Station

MPR QA Form: QA-3.1-3, Rev. 0

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Table I shows the data presented in Figure 1 along with the data categorized by room at

Seabrook and by concrete strength class.

Table 1. 28-Day Compressive Strength Data for Seabrook Station

Mean Standard No. Of Data Min Max wthnIa % of data % ihn2 of data

Deviation (a) Points within I o within 2 o

All Data 5456 568 121 4240 7360 75% 94%

3000 PSI

Strength Class 5621 691 50 4270 7360 74% 96%

4000 PSI

Strength Class 5339 430 71 4240 6150 70% 99%

(Note 1)

Containment

Enclosure 5426 380 24 4880 6080 67% 100%

Building

RHR

Equipment 5503 491 35 4240 6150 63% 97%

Vault

EFW Pump

House 5390 269 12 4950 5870 67% 100%

Stairway A

RCA Walkway 4891 404 12 4270 5450 50% 100%

B EDG

Building Buidg 5197 371 21 4600 5840 62% 100%

B Electrical 6163 705 17 5220 7360 65% 100%

Tunnel

Note 1: The strength class of 9 samples from the RHR Equipment Room cannot be identified with certainty due to poor

resolution of the reference document. These samples are most likely 4000 psi strength class samples based on their

proximity to other 4000 psi strength class samples. See Appendix A for more details.

3.0 BACKGROUND

MPR is developing a methodology to determine the through-thickness expansion of concrete

structures at Seabrook Station due to the Alkali-Silica Reaction (ASR). The through-thickness

expansion is related to the reduction in elastic modulus of the concrete over time. One approach

for estimating the original elastic modulus is to calculate it from the 28-day compressive strength

of the concrete using an equation from ACI 318 (Reference 1).

MPR QA Form: QA-3.1-3, Rev. 0

Page 81 of 88
MPR Associates, Inc.

320 King Street

Alexandria, VA 22314

Calculation No. Prepared By Checked By Page: 6

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4.0 METHODOLOGY

Seabrook Foreign Print No. 100629 and United Engineers Calculation No. CD-20 (References 2

and 3) include 28-day compressive strength results for concrete used in original construction for

the following buildings at Seabrook Station:

* Containment Enclosure Building

* RHR Equipment Vault

" EFW Pump House Stairway A

* RCA Walkway

" B Diesel Generator Building

* B Electrical Tunnel

These references provide the 121 data points used in this calculation. These 28-day compressive

strength data points are included in Appendix A.

5.0 RESULTS

The average 28-day compressive strength of all data points is 5456 psi and the standard deviation

is 568 psi. Seventy-five percent of the data fall within one standard deviation of the mean and

ninety-four percent of the data fall within two standard deviations of the mean. Therefore, the

mean is a representative value for the 28-day compressive strength of all concrete used at

Seabrook. See Section 2.0 for a histogram of all data points as well as a table of the compressive

strength data by room and concrete strength class. Figures 2 and 3 display the data for the

3000 psi and 4000 psi strength class concrete cores, respectively.

MPR QA Form: QA-3.1-3, Rev. 0

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MPR Associates, Inc.

320 King Street

Alexandria, VA 22314

Calculation No. Prepared By Checked By Page: 7

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25

22 Standard Deviation (o) = 691 psi

20

15

10

5

15

5

4930 5621 6312

28-Day Compressive Strength

0

0-

3547

0

4239 7004 7695

Figure 2. 28-Day Compressive Strength Values for 3000 psi Strength Class Concrete Cores

30 Standard Deviation (o) = 430 psi

25 25

25

20

15

12

10

5-

: 1

0 47

4479

8

4909 5339

28-Day Compressive Strength

5769 6199

Figure 3. 28-Day Compressive Strength Values for 4000 psi Strength Class Concrete Cores

MPR QA Form: QA-3.1-3, Rev. 0

Page 83 of 88
MPR Associates, Inc.

320 King Street

Alexandria, VA 22314

Calculation No. Prepared By Checked By Page: 8

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6.0 REFERENCES

1. ACI 318-71, "Building Code Requirements for Structural Concrete," American Concrete

Institute, 1971.

2. Seabrook Foreign Print No. 100629, "Concrete Test Report," Revision 0.

3. United Engineers Calculation No. CD-20, "Design of Mats at El. 20' 0" and 0' 0" and

Walls Below Grade for Electrical Tunnels and Control Building," Revision 4.

M PR QA Form: QA-3.1-3, Rev. 0

Page 84 of 88
MPR Associates, Inc.

*M PR 320 King Street Alexandria, VA 22314

Calculation No. Prepared By Checked By Page: A-1

0326-0074-CLC-02 Revision: 0

A

Compressive Strength Data

Table A-1 contains the 28-day compressive strength data for concrete cores at Seabrook Station.

Table A-1: 28-Day Compressive Strengths for Concrete Cores at Seabrook

Station

Room Sample Compressive Strength Class

No. Strength (psi) (psi)

4405 5130 4000

4406 5200 4000

4407 5620 4000

4405A 6080 4000

4406A 5700 4000

4407A 5410 4000

4641 5200 4000

4642 5060 4000

4643 5410 4000

4641A 5980 4000

4642A 6050 4000

Containment Enclosure 4643A 6010 4000

Building 4648 5020 4000

(Reference 2) 4649 5090 4000

4650 4950 4000

4655 5380 4000

4656 5240 4000

4657 4880 4000

4648A 5020 4000

4649A 5160 4000

4650A 5360 4000

4655A 5780 4000

4656A 5730 4000

4657A 5770 4000

MPR QA Form: QA-3.1-3, Rev. 0

Page 85 of 88
MPR Associates, Inc.

3MPR King Street

Alexandria, VA 22314

Calculation No. Prepared By Checked By Page: A-2

0326-0074-CLC-02 Revision: 0

Table A-1: 28-Day Compressive Strengths for Concrete Cores at Seabrook

Station

Room Sample Compressive Strength Class No. Strength (psi) (psi)

94 6070 3000

RHR Equipment Vault

(Reference 2)

95 5780 3000

96 5710 3000

101 5800 3000

102 5730 3000

103 5700 3000

108 6140 3000

109 5960 3000

110 6030 3000

430 5020 40001

431 4990 40001

432 5060 40001

430A 5450 4000

431A 5480 4000

432A 5380 4000

437 6010 4000

438 5620 4000

439 5980 4000

437A 6010 4000

438A 6150 4000

439A 6120 4000

unknown 4670 4000

unknown 4740 4000

unknown 5660 4000

unknown 5450 4000

unknown 5480 4000

unknown 5620 4000

unknown 5700 4000

unknown 5700 4000

unknown 4600 40001

unknown 5130 40001

unknown 4240 40001

unknown 5270 40001

unknown 5240 40001

Concrete strength class cannot be determined with certainty due to poor resolution of reference document.

MPR QA Form: QA-3.1-3, Rev. 0

Page 86 of 88
MPR Associates, Inc.

U M P R 320 King Street

Alexandria, VA 22314

Calculation No. Prepared By Checked By Page: A-3

0326-0074-CLC-02 Ll-.7A.. Revision: 0

Table A-1: 28-Day Compressive Strengths for Concrete Cores at Seabrook

Station

Room Sample Compressive Strength Class

No. Strength (psi) (psi)

RHR Equipment Vault unknown 4920 40001

590 5700 3000

591 5700 3000

592 5590 3000

590A 4950 3000

591A 5200 3000

EFW Pump House 592A 5240 3000

Stairway A 597A 5290 3000

(Reference 2) 598A 5870 3000

599A 5380 3000

604A 5180 3000

605A 5340 3000

606A 5240 3000

489 5310 3000

490 4440 3000

491 4950 3000

489A 5200 3000

490A 5450 3000

RCA Walkway 491A 4880 3000

(Reference 2) 484 4470 3000

485 4270 3000

486 4370 3000

484A 5040 3000

485A 5090 3000

486A 5220 3000

unknown 4620 4000

unknown 4700 4000

unknown 4600 4000

unknown 5150 4000

B EDG Building unknown 5660 4000

(Reference 2) unknown 5200 4000

315 5520 4000

316 5590 4000

317 5470 4000

315A 5840 4000

MPR QA Form: QA-3.1-3, Rev. 0

Page 87 of 88
MPR Associates, Inc.

FWM PR 320 King Street Alexandria, VA 22314

Calculation No. Prepared By Checked By Page: A-4

0326-0074-CLC-02 L Revision: 0

Table A-1: 28-Day Compressive Strengths for Concrete Cores at Seabrook

Station

Room Sample Compressive Strength Class

No. Strength (psi) (psi)

316A 5110 4000

317A 5640 4000

unknown 4600 4000

unknown 4950 4000

B EDG Building unknown 4950 4000

(Reference 2) unknown 5380 4000

unknown 5310 4000

unknown 5040 4000

unknown 5340 4000

unknown 5040 4000

unknown 5430 4000

427 5410 3000

428 5220 3000

426A 6560 3000

427A 6490 3000

428A 6100 3000

433 5470 3000

434 5550 3000

435 5890 3000

B Electrical Tunnel 433 7000 3000

(Reference 3) 433A 7000 3000

434A 7220 3000

435A 7360 3000

440 5730 3000

441 5480 3000

442 5390 3000

440A 6330 3000

441A 6810 3000

442A 6760 3000

MPR QAk Form: QA-3.1-3, Rev. 0

Page 88 of 88
*MPR

June 25, 2015

DRN 0326-0062-69

Mr. Rick Noble

NextEra Energy Seabrook LLC

P.O. Box 300

Lafayette Road

Seabrook, NH 03874

Subject: Withholding MPR-4153 from Public Disclosure under 10 CFR 2.390

Dear Mr. Noble:

We understand that NextEra Energy Seabrook intends to submit MPR-4153, Seabrook Station -

Approach for Determining Through-Thickness Expansion from Alkali-Silica Reaction,

Revision 1 on the docket to support the NRC's review of the alkali-silica reaction (ASR) issue at

Seabrook Station. Further, we understand that NextEra is requesting that the documents be

withheld from public disclosure under 10 CFR 2.3 90(a)(4). The report is marked proprietary to

NextEra Energy Seabrook and MPR Associates as it contains information which has a

commercial value to both parties. Specifically, the report includes details on the test programs

that MPR is sponsoring on behalf of NextEra, as well as results from the test programs. Public

release of the information would concede intellectual property and a commercial advantage to

others pursuing similar test programs or assessing the structural implications of ASR.

We hereby grant our consent to docket MPR-4153, Revision 1 in support of the NRC's review of

the Seabrook ASR issue provided it is withheld from public disclosure. In support of NextEra

requesting that the information be withheld from public disclosure under 10 CFR 2.390(a)(4), we

are providing the following:

" A notarized affidavit for withholding the report from public disclosure under

10 CFR 2.390.

* Three versions of MPR-4153, Revision 1:

- A version that includes a heading that states "proprietary information - withhold

from public disclosure under 10 CFR 2.390."

- A markup that shows the proposed redactions using red boxes. It includes a

statement on the cover regarding the basis for redacting information.

- A non-proprietary version in which the proprietary information is redacted.

(Headings and statements about it being proprietary have been removed to be

consistent with a non-proprietary designation.)

320 KING STREET ALEXANDRIA, VA 22314-3230 703-519-0200 FAX: 703-519-0224 www.mpr.com
Mr. Rick Noble -2-

Please contact me (703-519-0258) if you have any questions.

June 25, 2015

Sincerely,

John W. Simons

Director, Plant Systems & Components
K LF- eraG; ENERGfY _ SEABROOK

NextEra Energy Seabrook, LLC

AFFIDAVIT IN SUPPORT OF APPLICATION FOR WITHHOLDING

PROPRIETARY INFORMATION FROM PUBLIC DISCLOSURE

County of Rockingham )

)

State of New Hampshire )

I, Dean Curtland, being duly sworn according to law, depose and state the following:

(1) I am the Site Vice President of NextEra Energy Seabrook, LLC (NextEra Energy Seabrook),

and have been delegated the function of reviewing the information described in paragraph (3) which is

sought to be withheld, and have been authorized to apply for its withholding.

(2) I am making this Affidavit in conjunction with NextEra Energy Seabrook's "Application for

Withholding Proprietary Information from Public Disclosure" accompanying this Affidavit and in

conformance with the provisions of 10 CFR Section 2.390.

(3) The information sought to be withheld is contained in Enclosures 4 of NextEra Energy

Seabrook's letter SBK-L-15107, Dean Curtland (NextEra Energy Seabrook) to U.S. Nuclear

Regulatory Commission, entitled "Seabrook Station Response to Requests for Additional Information

for the Review of the Seabrook Station, License Renewal Application- SET 23 (TAC NO. ME4028)

Relating to the Alkali-Silica Reaction (ASR) Monitoring Program," dated June 30, 2015. The NextEra

Energy Seabrook proprietary information in Enclosure 4 of SBK-L- 15107, is identified by enclosing

boxes (").

(4) The information sought to be withheld is considered to be proprietary and confidential

commercial information because alkali-silica reaction (ASR) is a newly-identified phenomenon at

domestic nuclear plants. The information requested to be withheld is the result of several years of

intensive NextEra Energy Seabrook effort and the expenditure of a considerable sum of money. This

information may be marketable in the event nuclear facilities or other regulated facilities identify the
presence of ASR. In order for potential customers to duplicate this information, similar technical

programs would have to be performed and a significant manpower effort, having the requisite talent

and experience, would have to be expended. The extent to which this information is available to

potential customers diminishes NextEra Energy Seabrook's ability to sell products and services

involving the use of the information. Thus, public disclosure of the information sought to be withheld is

likely to cause substantial harm to NextEra Energy Seabrook's competitive position and NextEra

Energy Seabrook has a rational basis for considering this information to be confidential commercial

information.

(5) The information sought to be withheld is being submitted to the NRC in confidence.

(6) The information sought to be withheld has, to the best of my knowledge and belief, consistently

been held in confidence by NextEra Energy Seabrook, has not been disclosed publicly, and not been

made available in public sources.

(7) The information is of a sort customarily held in confidence by NextEra Energy Seabrook, and is

in fact so held.

(8) All disclosures to third parties, including any required transmittals to the NRC, have been or

will be pursuant to regulatory provisions and/or confidentiality agreements that provide for maintaining

the information in confidence.

I declare that the foregoing affidavit and the matters stated therein are true and correct to the best of my

knowledge, information, and belief. Further, the affiant sayeth not.

Dean Curtland

Site Vice President

NextEra Energy Seabrook, LLC

626 Lafayette Road

Seabrook, New Hampshire 03874

Subscribed and sworn to before me

this Zo day of June, 2015.

_____ _____ ____ JAN-'~

Notary Pub/ic

My commission expires 9 ,,"