' 

. Enclosures 1, 5 and 6 to this Letter Contain Proprietary Information 

Withhold Enclosures 1, 5 and 6 from Public Disclosure in Accordance with 1 O CFR 2.390 

United States Nuclear Regulatory Commission 

Attn.: Document Control Desk 

Washington, D.C. 20555-0001 

Seabrook Station 

License Amendment Request 16-03 

August 1 ,2016 

10 CFR 50.90 

Docket No. 50-443 

SBK-L-16071 

Revise Current Licensing Basis to Adopt a Methodology for the Analysis of Seismic Category I 

Structures with Concrete Affected by Alkali-Silica Reaction 

In accordance with 10 CFR 50.90, Application for amendment of/icense, construction permit, or 

early site permit, NextEra Energy Seabrook, LLC (NextEra) requests an amendment to the 

license for Seabrook Station. Specifically, the proposed change revises the Seabrook Updated 

Final Safety Analysis Report (UFSAR) to include methods for analyzing seismic Category I 

structures with concrete affected by an alkali-silica reaction (ASR). NRC approval of this LAR 

will allow NextEra Energy Seabrook, LLC (NextEra) to proceed in an optimum, safe and 

effective manner toward a long-term solution for ASR degradation at Seabrook Station. The 

proposed methodology changes are necessary to reconcile the design basis of the containment 

building and other seismic Category I structures that are affected by ASR. 

Enclosure 1 to this letter is proprietary, provides a description and assessment of the proposed 

change and provides the existing UFSAR pages (Attachment 1) marked up to show the 

proposed changes. To facilitate the staff's review of the proposed change, several additional 

references are enclosed to provide supporting detail. Enclosure 2 provides the non-proprietary 

version of MPR-4288, "Seabrook Station: Impact of Alkali-Silica Reaction on Structural Design 

Evaluations." Enclosure 3 provides the non-proprietary version of MPR-4273, "Seabrook 

Station - Implications of Large-Scale Test Program Results on Reinforced Concrete Affected by 

Alkali-Silica Reaction". Attachment 4 provides SG&H 160268-R-01, "Development of ASR Load 

Factors for Seismic Category I Structures (Including Containment) at Seabrook Station, 

Seabrook, NH." Enclosure 5 provides the proprietary version of MPR-4288. Enclosure 6 

provides the proprietary version of MPR-4273. Enclosure 7 provides the non- proprietary 

version of NextEra Energy Seabrook's Evaluation of the Proposed Change. This letter is 

supported by an affidavit provided in Enclosure 8 setting forth the basis on which the information 

NextEra Energy Seabrook, LLC, P.O. Box 300, Lafayette Road, Seabrook, NH 03874 

J 
i . ' 

U.S. Nuclear Regulatory Commission 

SBK-L-16071 /Page 2 

may be withheld from public disclosure by the Commission and addressing considerations listed 

in 10CFR2.390(b)(4). Accordingly, it is respectfully requested that the information which is 

proprietary be withheld from public disclosure in accordance with 10CFR2.390. In accordance 

with 10 CFR 50.91, a copy of this application, with attachments is being provided to the 

designated officials in New Hampshire. This letter contains no new or revised commitments. 

NextEra requests NRC review and approval of the requested amendment by October 1, 2017 

and implementation within 90 days. 

Should you have any questions regarding this letter, please contact Kenneth Browne, Licensing 

Manager at 603-773-7932. 

I declare under penalty of perjury that the foregoing is true and correct. 

Executed on August 1, 2016. 

Sincerely, 

~<iL0.r Ralph A. Dodds Ill · · 

Plant General Manager 

NextEra Energy Seabrook, LLC 

Enclosure 1 NextEra Energy Seabrook's Evaluation of the Proposed Change Including 

Attachment 1 Markup of UFSAR Pages (Proprietary) 

Enclosure 2 MPR-4288, Revision 0, "Seabrook Station: Impact of Alkali-Silica Reaction on 

Structural Design Evaluations," July 2016. (Non-Proprietary) 

Enclosure 3 MPR-4273, Revision 0, "Seabrook Station - Implications of Large-Scale Test 

Program Results on Reinforced Concrete Affected by Alkali-Silica Reaction," July 

2016. (Non-Proprietary) 

Enclosure 4 SG&H Report 160268-R-01 "Development of ASR Load Factors for Seismic 

Category I Structures (Including Containment) at Seabrook Station, Seabrook, 

NH," Revision 0 (Seabrook FP# 101039) 

Enclosure 5 MPR-4288, Revision 0, "Seabrook Station: Impact of Alkali-Silica Reaction on the 

Structural Design Evaluations," July 2016. (Seabrook FP# 101020) (Proprietary) 

Enclosure 6 MPR-4273, Revision 0, "Seabrook Station - Implications of Large-Scale Test 

Program Results on Reinforced Concrete Affected by Alkali-Silica Reaction," July 

2016. (Seabrook FP# 101050) (Proprietary) 

Enclosure 7 NextEra Energy Seabrook's Evaluation of the Proposed Change (NonProprietary) 

Enclosure 8 Affidavit in Support of Application for Withholding Proprietary Information from 

Public Disclosure 

NextEra Energy Seabrook, LLC, P.O. Box 300, Lafayette Road, Seabrook, NH 03874 
.. 

U.S. Nuclear Regulatory Commission 

SBK-L-16071 /Page 3 

cc: NRC Region I Administrator 

NRC Project Manager 

NRC Resident Inspector 

Mr. Perry Plummer, Director Homeland Security and Emergency Management 

New Hampshire Department of Safety 

Division of Homeland Security and Emergency Management 

Bureau of Emergency Management 

33 Hazen Drive 

Concord, NH 03305 

Mr. John Giarrusso, Jr., Nuclear Preparedness Manager 

The Commonwealth of Massachusetts 

Emergency Management Agency 

400 Worcester Road 

Framingham, MA 01702-5399 

NextEra Energy Seabrook, LLC, P.O. Box 300, Lafayette Road, Seabrook, NH 03874 
NextEra Energy Seabrook, LLC 

AFFIDAVIT IN SUPPORT OF APPLICATION FOR WITIDIOLDING 

PROPRIETARY INFORMATION FROM PUBLIC DISCLOSURE 

County of Rockingham ) 

) 

State of New Hampshire ) 

I, Ralph A. Dodds III, being duly sworn according to law, depose and state the following: 

(1) I am the Plant General Manager ofNextEra Energy Seabrook, LLC (NextEra Energy 

Seabrook), and have been delegated the function ofreviewing 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 CPR Section 2.390. 

(3) The information sought to be withheld is contained in Enclosures 1, 5, and 6 to this letter, 

"NextEra Energy Seabrook's Evaluation of the Proposed Change" (Proprietary), MPR-4273, 

Revision 0, "Seabrook Station - Implications of Large-Scale Test Program Results on Reinforced 

Concrete Affected by Alkali-Silica Reaction," July 2016 (Seabrook FP# 101050) (Proprietary) 

and MPR-4288, Revision 0, "Seabrook Station: Impact of Alkali-Silica Reaction on the 

Structural Design Evaluations," July 2016 (Seabrook FP# 101020) (Proprietary). The NextEra 

Energy Seabrook proprietary information in Enclosure 1, 5 and 6 is identified by enclosing boxes 

(LJ). 

(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. 

Subscribed and sworn to before me 

this [ ~ day of August, 2016 

'c;:cRvw&. ~mif' Notary Public 

My commission expires 10[11 {Cbll 

~0~C6~t[= Ralph A. Dodds III 

Plant General Manager 

NextEra Energy Seabrook, LLC 

626 Lafayette Road 

Seabrook, New Hampshire 03874 
~, ,( 

SBK-L-16071 

ENCLOSURE 7 

NextEra Energy Seabrook's Evaluation of the Proposed Change 

(Non-Proprietary) 
--Non-Proprietary Version--

Enclosure 1 

NextEra Energy Seabrook's Evaluation of the Proposed Change 

Subject: License Amendment Request 16-03, Revise Current Licensing Basis to Adopt a 

Methodology for the Analysis of Seismic Category I Structures With Concrete 

Affected by Alkali-Silica Reaction Portions to be redacted are contained within 

red boxes. 

1.0 

2.0 

3.0 

SUMMARY DESCRIPTION 

DETAILED DESCRIPTION 

2.1 Background on ASR at Seabrook Station 

2.2. Proposed Changes to UFSAR 

TECHNICAL EVALUATION 

3.1. Seabrook Station Design Requirements 

3.2. Impact of ASR on Seabrook Structures 

3.3. Building Deformation Assessment 

The information to be redacted includes 

details of test programs that MPR conducted 

and results from the test programs. Release 

of this information would concede intellectual 

property. Release of this information would 

also constitute a loss of competitive 

advantage relative to others engaged in 

similar test programs or engaged in 

assessment of structural impacts of alkalisilica reaction . 

3.4 Summary of ASR and Structure Deformation Methodology Changes 

3.5. Monitoring 

4.0 REGULATORY EVALUATION 

4.1 Applicable Regulatory Requirements/Criteria 

4.2 No Significant Hazards Consideration 

5.0 ENVIRONMENTAL CONSIDERATION 

6.0 REFERENCES 

Attachments: 

I. Markup of UFSAR Pages 

1.0 SUMMARY DESCRIPTION 

License Amendment Request (LAR) 16-03 proposes to revise the Seabrook Updated Final Safety 

Analysis Report (UFSAR) to include methods for analyzing seismic Category I structures with 

concrete affected by an alkali-silica reaction (ASR). ASR is a chemical reaction that occurs in 

susceptible concrete that causes the concrete to expand in volume and potentially reduces the 

capacity of concrete structures. ASR has been identified in concrete structures at Seabrook 

Station. In addition to ASR's potential effects on the capacity of concrete structures, the 

expansion effects from ASR have imposed an additional static load that was not accounted for in 

their original design. 
--Non-Proprietary Version--

Seismic Category I structures other than the containment building were designed to the 

requirements of American Concrete Institute (ACI) 318-71 (Reference 1). The containment 

building is a reinforced concrete structure that is designed in accordance with the requirements of 

Section III of the American Society of Mechanical Engineers (ASME) Boiler & Pressure Vessel 

Code (1975 Edition) (Reference 2). ACI 318-71 and the ASME Code do not include provisions 

for the analysis of structures affected by ASR. The proposed amendment incorporates the effects 

of ASR in the design of seismic Category I structures at Seabrook Station. 

NRC approval of this LAR will allow NextEra Energy Seabrook, LLC (NextEra) to proceed in 

an optimum, safe, and effective manner toward a long-term solution for ASR effects at Seabrook 

Station. The proposed methodology changes are necessary to reconcile the design basis of the 

containment building and other seismic Category I structures that are affected by ASR. 

2.0 DETAILED DESCRIPTION 

2.1 Background on ASR at Seabrook Station 

NextEra Energy initially identified pattern cracking typical of ASR in the B Electrical Tunnel in 

2009, and subsequently, several other seismic Category I structures. As a result, multiple 

campaigns were completed to remove concrete cores from the walls in several plant structures to 

confirm the presence of ASR. Petrographic examination of the cores concluded the concrete had 

ASR. ASR is a reaction that occurs over time in concrete between alkalis iq the cement and 

reactive non-crystalline silica, which is found in many common aggregates. The presence of 

water promotes ASR. The reaction produces an alkali-silicate gel that expands as it absorbs 

moisture. The expansion exerts a stress on the surrounding concrete and results in cracking. 

A root cause investigation into the ASR at Seabrook concluded that the original concrete mix 

designs used a coarse aggregate that was susceptible to ASR. The concrete used at Seabrook 

Station was not expected to be susceptible to ASR due to the combination of measures taken to 

prevent it: (1) the coarse aggregate is igneous rock that passed the ASR reactivity testing used 

during construction; (2) low-alkali cement (<0.6% total alkali) was used; and (3) the aggregate 

passed petrographic examination per ASTM C295-65. The American Society for Testing and 

Materials (ASTM) standard test procedure ASTM C289-71 was used to assess aggregate 

reactivity during construction (Reference 3). ASTM C289-71 was an appropriate test at the time 

of construction, but it is now known that the test may not accurately predict the reactivity of 

slow-reacting aggregates, such as the aggregate used at Seabrook Station. 1 A combination of 

aggregate being more susceptible to ASR than originally thought and groundwater intrusion 

during plant life appears to have resulted in the observed ASR in several structures. 

The expansion of concrete and cracking from ASR can potentially impact both the capacity (i.e., 

material properties) of a concrete structure and the demand (i.e., loads) on a structure. 

1 The ASTM testing standard has since been revised to caution that the specified aggregate test is not effective in 

identifying slow-reacting aggregate, and other ASTM testing standards have been issued to more reliably identify 

concrete mixtures to minimize the susceptibility to ASR. 
--Non-Proprietary Version--

• ASR may affect the material properties of concrete (compressive strength, elastic modulus, 

tensile strength). The property most notably affected is the elastic modulus (Reference 4). 

However, the change in material properties does not necessarily result in a corresponding 

decrease in capacity of a reinforced concrete structure. ASR-induced expansion in reinforced 

concrete has a prestressing effect that mitigates the loss of structural capacity that would be 

assumed based on the change in material properties. 

• ASR expansion can lead to deformation of a structure, and can cause stresses where the 

expansion is resisted internally by reinforcement or externally by supports, other structures, 

or adjoining parts of the same structure that are outside the ASR-affected region. The 

deformation is important from the perspective of the increase in load or demand on the 

structure and on the consequences of the deformation in relation to seismic isolation of 

structures and the impact on equipment and components. 

2.1. 1 Evaluation of ASR at Seabrook 

An interim structural assessment was completed in 2012 which evaluated the structural adequacy 

of reinforced concrete structures at Seabrook Station affected by ASR and system/component 

anchorages in ASR-affected concrete (Reference 4). The evaluation concluded that the 

reinforced structures at Seabrook Station remain suitable for continued service for an interim 

period given the extent of ASR identified at that time. The evaluation noted that additional 

testing was required to verify that some structures satisfy ACI 318-71 code requirements for 

shear and reinforcement anchorage. The test programs would produce the data necessary to fully 

assess design compliance for the concrete structures at Seabrook Station. NextEra has since 

completed large-scale test programs (see Reference 25) and used the test results and literature to 

define guidance for evaluating ASR-affected reinforced concrete structures at Seabrook Station 

(see Reference 24). The conclusions from the testing and guidance for structural evaluations 

establish a method for analyzing ASR in reinforced concrete structures at Seabrook Station. 

In 2014, a walkdown of a water leak in the Mechanical Penetration area of the West Pipe Chase 

noted that a vertical seismic gap seal between the Containment Enclosure Building (CEB) and 

the containment building was torn. NextEra concluded that the condition of the seal and other 

local evidence indicated that the damage to the seal appeared to be caused by relative building 

movement and not seal degradation, such as shrinkage or material deterioration. A subsequent 

evaluation of the condition determined that the seal damage was caused by radial deformation of 

the CEB. The CEB deformation was caused primarily by the expansion of concrete in the CEB 

and the backfill concrete that abuts the CEB structure below grade. 

NextEra Energy has assessed ASR-affected concrete on Seabrook structures to determine impact 

on operability of system, structures, and components. Prompt Operability Determinations have 

been performed on affected structures which concluded that the structures and concrete anchors 

are operable but degraded, and structures, systems and components housed within the structures 

are operable. NextEra is currently evaluating all seismic Category I structures at Seabrook with 

indications of ASR to verify that structures continue to satisfy the ACI 318-71 and ASME Code 

acceptance criteria, as appropriate, with the additional demand from ASR concrete expansion. 

The proposed amendment will adopt a method to incorporate the material effects and loads of 
--Non-Proprietary Version--

ASR into the Seabrook design basis to demonstrate that structures with ASR continue to meet 

the design codes for original construction. 

2.2 Proposed Changes to UFSAR 

ACI 318-71 and the ASME Boiler and Pressure Vessel Code Section III, Division 2, Subsection 

CC are the codes used to design seismic Category I structures and the containment structure, 

respectively, at Seabrook Station. These codes do not include methods to address the effects of 

ASR on the structural properties used in the design of concrete structures. NextEra evaluated 

ASR material effects and concluded that no adjustments to structural properties are necessary 

when the extent of ASR is less than the limits from NextEra's large-scale test program. The 

analyses and testing to assess ASR material effects established a method to incorporate ASR into 

the Seabrook design basis that is not described in either ACI 318-71 or the ASME Code. 

Incorporating the loads into the UFSAR and evaluating structures using the appropriate 

properties for ASR affected structural members is a change in methodology that requires NRC 

review and approval. Details of the analysis and tests to evaluate the impact of ASR on 

structural properties are included in Section 3.2. 

As indicated above, ACI 318-71 and the ASME Code do not specify how loads that arise from 

ASR expansion and structure deformation are evaluated. For structures designed to these codes, 

load factors are proposed to combine these loads with other design basis loads. The approach 

used to establish ASR load factors was consistent with the methods used to determine structural 

load factors for other loads described in ACI 318-71 and the ASME Code. The proposed method 

to evaluate ASR loads includes calculating the loads currently imposed on the structure and 

adding margin for future deformation. A description of the process for defining load factors and 

the proposed method to evaluate ASR loads in structures is included in Section 3.3. 

UFSAR Section 3.8 includes the requirements for the design of Category I structures at 

Seabrook. Section 3.8.1 applies to the concrete containment building, and Section 3.8.4 applies 

to other seismic Category I structures. Changes are proposed to each of these subsections to 

incorporate the changes related to ASR material effects and loads. Additional changes to other 

subsections of the UFSAR are necessary for limits on anchors in concrete walls and slabs 

affected by ASR, a change to the method for combining seismic loads using an alternate 

approach recommended by the NRC in Regulatory Guide 1.92, Revision 3, and a change to 

allow the use of ANSYS computer software. The proposed changes to the specific subsections 

of the Seabrook UFSAR are described below and presented in Attachment 1. 

Proposed Changes to Section 3.8.1 Concrete Containment 

• Section 3.8.1.3 of the UFSAR includes the loads and load combinations that were considered 

in the design of containment. The section is revised to define the load associated with ASR 

as Normal Startup, Operational, and Shutdown Loads. 

• Section 3.8.1.4.e identifies transient and localized loads in the containment design procedure. 

This section is revised to define the load from ASR as a localized load. 
--Non-Proprietary Version--

• Section 3.8.1.4.i is revised to state that a tensile strain is imposed on reinforcement in areas 

affected by ASR. Also, analyses of ASR-affected concrete use the structural properties and 

code equations from the original design analyses when ASR expansion levels are below the 

limits defined in Section 3.8.4.7. 

• Table 3.8-1 is revised to include the specific load combinations and load factors for analyses 

of ASR loads. 

Proposed Changes to Section 3.8.3 Containment Internals Concrete 

• Section 3.8.3.3 of the UFSAR identifies the design loads and load combinations that were 

considered in the design of containment internals. The section is revised to define the load 

associated with ASR as Normal Startup, Operational, and Shutdown Loads 

• Section 3.8.3.6 is revised to describe the effects of ASR and the relationship between the 

expansion of concrete from ASR and the deformation of structures. 

• Section 3.8.3.7 is revised to include a discussion on the Structural Monitoring Program 

requirements for inspection of ASR affected structures . 

. • Table 3.8-14 is revised to include the specific load combinations and load factors for 

analyses of ASR loads. 

Proposed Changes to Section 3.8.4 Other Seismic Category I Structures 

• Section 3.8.4.3 of the UFSAR specifies the design loads that were evaluated in the design of 

Category I structures other than containment. Subsection 3.8.4.3a.l(a) is revised to identify 

creep, shrinkage and swelling as dead loads on structures when ASR loads are evaluated. 

Subsection 3.8.4.3a. l(e) is added to define ASR reaction loads as passive loads that occur in 

conjunction with other Normal Startup, Operational, and Shutdown Loads. 

• Section 3.8.4.3.c defines the other load considerations for seismic Category I structures other 

than containment. Subsection 3.8.4.3.c.1 is revised to indicate that creep is included in the 

analysis of structures with ASR. Subsection 3.8.4.3.c.3 is added to define self-straining loads 

as those associated with ASR expansion, creep, shrinkage and swelling. 

• Section 3.8.4.4 includes the design and analysis procedures for Category I structures. 

Section 3.8.4.4.a is revised to describe the analysis procedure for evaluating the self-straining 

loads associated with ASR expansion, creep, shrinkage and swelling. Section 3.8.4.4.b is 

revised to specify the use of material properties in their normal range of values for structures 

withASR. 

• Section 3.8.4.6 is revised to describe the effects of ASR and the relationship between the 

expansion of concrete from ASR and the deformation of structures. 
--Non-Proprietary Version--

• Section 3.8.4.7 is revised to define limits for ASR expansion to ensure structural properties 

of reinforced structures with ASR are consistent with properties and code equations used in 

the original design of structures. Limits for structure deformation are classified and included 

in the Structural Monitoring Program. 

• Table 3.8-16 is revised to specify the load factors and load combinations used in analyzing 

the effects of ASR. 

• Table 3 .8-17 is revised to identify the structures that have undergone a detailed analysis of 

ASR deformation which used ANSYS as the computer code for the analysis. 

• Table 3.8-18 is added to establish limits for concrete expansion in areas affected by ASR. 

Other Proposed Changes to the UFSAR 

• Sections 1.8 and 3.7(B).2.1 are revised to indicate that seismic analysis results may be 

combined using the 100-40-40 procedure from Regulatory Guide 1.92, Revision 3 for 

analyses of ASR expansion loads. 

• Section 3.9(B).3.4 is revised to include the limit on the allowable ASR expansion for 

concrete with embedded plates, anchors, and inserts that are used for component supports. 

3.0 TECHNICAL EVALUATION 

3.1 Seabrook Station Design Requirements 

3.1.1 Seismic Category I Structures Other Than Containment 

Safety-related structures other than containment were designed and constructed to comply with 

the 1971 edition of ACI 318, Building Code Requirements for Reinforced Concrete 

(Reference 1) per the Seabrook Station UFSAR Section 3.8.4. The loads determined in 

accordance with ACI 318 include normal loads (startup, operation and shutdown), environmental 

loads (severe and extreme), abnormal loads, and site-related (i.e., site-specific) loads. The load 

combinations in UFSAR Table 3.8-16 define the required strength during normal and unusual 

loading conditions. The load combinations are determined in accordance with ACI 318. While 

ACI 318-71 contains provisions for Working Strength Design (WSD) and Ultimate Strength 

Design (USD), the Seabrook design methodology for safety-related structures other than 

containment is USD. 

The selection of material properties for design of concrete structures at Seabrook Station is based 

on the standard concrete mix specification (including Containment and other safety-related 

structures) from original plant construction. ACI 318-71 recognizes the concrete mix 

specification as the primary location to specify the design concrete compressive strength. Other 

material properties for concrete design (i.e., elastic modulus) are calculated based on the 

specified concrete compressive strength. The specified compressive strength of concrete used in 

design is a value below the actual compressive strength, which is established by the concrete 

mix. The margin between the specified compressive strength value and the value expected from 
--Non-Proprietary Version--

the concrete mix ensures there is a low probability of measuring a compressive strength value 

after construction below the specified strength value. 

3.1.2 Containment Structure 

The containment structure was designed and constructed to the 1975 edition of the ASME Boiler 

and Pressure Vessel Code Section III, Division 2, Subsection CC (Reference 2) as described in 

the Seabrook Station UFSAR Section 3.8.1. The applicable loads determined in accordance with 

Article CC-3000 of the ASME Code include test pressure loads, normal loads (startup, operation 

and shutdown), environmental loads (severe and extreme), and abnormal loads. Several 

site-related loads were considered in the design, but none had a significant effect on containment 

design. The applicable load combinations define the required strength of containment at various 

locations. The load combinations are listed in UFSAR Table 3.8-1 and were determined per 

ASME Code Section III, Article CC-3000. The load combinations reflect a combination of 

working strength WSD and USD methodology. Using WSD, stresses are computed based on the 

assumption of an elastic strain profile. In USD, a non-linear strain profile can be used, which 

models the behavior of concrete much more accurately. Using either WSD or USD, the 

containment structure must behave elastically to the specified load combinations when thermal 

effects are not included and satisfy the acceptance criteria in UFSAR Section 3.8.1.5. These 

criteria were developed to comply with the requirements in Article CC-3000 of the ASME Code, 

Section III. 

A secondary stress is defined as a normal or shear stress developed by the constraint of adjacent 

material or by self-constraint of the structure. Expansion from ASR produces a secondary stress 

in the affected structure that is relieved by cracking. The ASME Code allows for higher stresses 

for peak, localized and secondary stresses. Local yielding, minor distortions, and concrete 

cracking are permitted for these self-limiting conditions, per Reference 2, Article CC-3136.4. 

The ASME code limits the average tensile stress in steel reinforcing bars to 50% of the yield 

stress in WSD for service loads (normal) and 90% of the yield stress in USD for factored loads 

(severe and abnormal load conditions). The design acceptance criteria for reinforcement are 

enforced on an average basis and are not applicable to peak or localized stresses. These limits 

are also not applicable to secondary stresses. Specifically, local yielding, minor distortions, and 

concrete cracking are permitted in self-limiting conditions per Article CC-3136.4 of Section III 

of the ASME Code. 

3.1.3 Concrete Anchors 

Seabrook Station uses cast-in-place anchorages and post-installed anchors. The strength of the 

concrete in which an anchor is embedded must be sufficient to ensure the anchor is capable of 

sustaining loads equal to the ultimate loads specified by the anchor manufacturer. Cast in place 

anchors (e.g., Nelson studs or embedded unistrut-type channels) are designed with embedment 

depths such that the limiting failure mode is ductile failure of the anchor steel. Post-installed 

anchors are designed in accordance with the requirements ofNRC IE Bulletin 79-02 

(Reference 5). This includes using a safety factor of four on the mean failure load for the design 

of post-installed anchors for pipe supports. 
--Non-Prop_rietary Version--

3.2 Impact of ASR on Seabrook Structures 

NextEra evaluated the effects of ASR on the load carrying capability of structural members and 

its impact on other design considerations. The limit states correspond to the capacity associated 

with a specific mode of loading for structural members. The design considerations are related to 

other requirements that are specified in the design codes. Table 1 identifies each of the limit 

states and design considerations that were evaluated for ASR. 

Table 1. Potential Structural Consequences of ASR 

Structural Limit States Design Considerations 

Flexure & reinforcement anchorage Reinforcement steel strain 

development Reinforcement fracture 

Shear Seismic response 

Compression Applicability of design basis 

Anchor bolts and structural material properties 

attachments to concrete Effect of structural deformation 

Each of the items in Table 1 were evaluated using data from structural testing of ASR-affected 

specimens. The evaluation considered data from large-scale test programs conducted 

specifically for Seabrook Station by MPR Associates in collaboration with the Ferguson 

Structural Engineering Laboratory (FSEL) at The University of Texas at Austin. In addition, the 

MPRIFSEL structural test data were supplemented with publicly available literature in the 

evaluation. 

The large-scale test program and evaluation of available literature to assess the effects of ASR is 

consistent with methods recommended in ACI 318-71. ACI 318-71 is a Construction Code 

written in the context of new design and construction. Chapter 20 of the code, "Strength 

Evaluation of Existing Structures," includes an approach to address strength deficiencies from 

construction. Chapter 20 is not part of the licensing basis of Seabrook structures and was not 

used during original construction. Also, this LAR does not propose to incorporate Chapter 20 of 

ACI 318-71 into the Seabrook licensing basis. However, Chapter 20 provides some guidance for 

structural assessments performed to address concerns regarding the safety of a structure. 

Paragraph 20.1 of ACI 318-71 states that "a structural strength investigation by analysis or by 

means ofload tests or by a combination of these methods" may be used ifthe strength of a 

structure is unclear. Load testing of the as-built structures is impractical for the Seabrook Station 

ASR issue. Therefore, an analysis is the best available means of evaluating the impact of ASR 

on strength. The objective of a strength evaluation by analysis is to demonstrate that the building 

will have strength close to or in excess of that envisaged in the original design or as required by 

the code. 
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The shear and reinforcement anchorage testing at FSEL2 used methods that are consistent with 

those used for the original ACI code testing. Also, the specimens that were used in testing were 

structurally representative of concrete used in constructing Seabrook structures. The testing at 

FSEL, evaluation of the test results along with other published literature on ASR, and the 

analysis method discussed in Section 3.3 are intended to satisfy the objective stated in 

ACI 318-71 to demonstrate that Seabrook structures with ASR have a strength in excess of code 

requirements. 

On several occasions during testing, NRC inspectors from Region I and representatives from 

NRR have audited the activities at FSEL related to the large-scale test programs for ASR. The 

inspectors witnessed testing, verified compliance with procedures, evaluated adherence to quality 

assurance/control requirements and examined the newly fabricated instrument beam and 

associated monitoring devices. These activities were performed in support of the NRC staffs 

ongoing review of the Seabrook license renewal application and in anticipation ofNextEra 

submitting a license amendment request to address an ASR-related non-conforming condition 

with the current licensing basis (i.e., this LAR). References 7 - 14 include the NRC observations 

and findings from inspections and audits of the large-scale test programs at FSEL. 

3.2.1 Structural Limit States 

The need for Seabrook-specific testing was driven by limitations in the publicly available test 

data related to ASR effects on structures. Most research on ASR has focused on the science and 

kinetics of ASR, rather than engineering research on structural implications. Although structural 

testing of ASR-affected test specimens has been performed, the application of the conclusions to 

a specific structure can be challenged by lack ofrepresentativeness in the data (e.g., small-scale 

specimens; poor test methods; different reinforcement configuration). The large-scale test 

programs undertaken by N extEra provided data on the limit states that were essential for 

evaluating seismic Category I structures at Seabrook Station. The data produced from these 

programs were a significant improvement from the data in published literature sources, because 

test data across the range of ASR levels were obtained using a common methodology and 

identical test specimens. The results were used to assess the structural limit states and to inform 

the assessment of design considerations. 

The large-scale test programs included testing of specimens that reflected the characteristics of 

ASR-affected structures at Seabrook Station. Tests were completed at various levels of ASR 

cracking to assess the impact on selected limit states. The extent of ASR cracking in the test 

specimens was quantified by measuring the expansion in the in-plane and through-thickness 

specimen dimensions. The in-plane dimension refers to measurements taken in a plane parallel 

to the underlying reinforcement bars. There was no reinforcement in the test specimen 

through-thickness direction (perpendicular to the in-plane direction). ASR expansion 

measurements were monitored throughout testing. The test programs assessed all relevant limit 

states except compression (i.e., flexure and reinforcement anchorage, shear, and anchor bolts and 

structural attachments to concrete). The results of the test program demonstrated that none of 

the assessed limit states are reduced by ASR when ASR expansion levels in plant structures are 

below those evaluated in the large-scale test programs. 

2 Anchor testing was performed consistent with the methods used to demonstrate anchor strength per NRC IE 

Bulletin 79-02 (Reference 5), which is consistent with the Seabrook licensing basis. 
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The effect of ASR on compressive strength was not assessed in the large-scale test program. 

Reference 24 includes an evaluation of compression using existing data from published literature 

sources. The evaluation concluded that ASR expansion in reinforced concrete results in 

compressive load that should be combined with other loads in design calculations. However, 

ASR does not reduce the structural capacity of compression elements. 

The specimens used in the large-scale test programs experienced levels of ASR that bound ASR 

levels currently found in Seabrook structures (i.e., are more severe than at Seabrook), but the 

number of available test specimens and nature of the testing prohibited testing out to ASR levels 

where there was a clear change in limit state capacity. Because there is no testing data for these 

more advanced levels of ASR, periodic monitoring of ASR at Seabrook is necessary to ensure 

that the conclusions of the large-scale test program remain valid and that the level of ASR does 

not exceed that considered under the test programs. Proposed UFSAR Table 3 .8-18 includes 

limits to maintain the validity of the test program results for Seabrook structures. 

The overall conclusion from analyses of structural limit states is that limit state capacity is not 

degraded when small amounts of ASR expansion are present in structures. Presently, the ASR 

expansion levels in Seabrook structures are below the levels at which limit state capacities are 

reduced. Reference 25 documents the results of the large-scale test program and includes 

additional details on the assessment of structural limit states. 

One of the objectives of the test program was to identify effective methods for monitoring ASR. 

The program concluded that monitoring the in-plane and through-thickness expansion is 

effective for characterizing the significance of ASR in structures. A Combined Cracking Index 

(CCI) methodology based on crack width summation was shown to be effective for in-plane 

expansion monitoring. Snap ring borehole extensometers (SRBEs) provided accurate and 

reliable measurements for monitoring through-thickness expansion. Section 3.5 provides 

additional discussion of ASR monitoring and includes the quantitative limits for applying the 

conclusions from the test programs to Seabrook structures. 

3.2.2 Design Considerations 

The evaluation of design considerations in Reference 24 concluded that Seabrook structures 

affected by ASR should be evaluated for reinforcement strain and deformation. The effects of 

ASR on other design considerations listed in Table 1 (i.e., reinforcement fracture, seismic 

response, and design properties) were not significant for Seabrook structures (see Reference 24). 

The following summarizes the impact of ASR on design considerations. 

Reinforcement Steel Strain 

The expansion of concrete from ASR-induced cracking imposes a tensile strain on steel 

reinforcement within the affected material. For structures designed to ACI 318-71, the design 

code allows for reinforcement strains beyond the yield point of the steel bars for flexural 

elements to prevent brittle compression failure of the concrete in bending. The added strain to 

the reinforcement should be evaluated in conjunction with the strains imposed by other loads on 

the structure. 

For the containment structure, the stresses and strains introduced into the reinforcement by ASR 

should be evaluated using provisions in the ASME Code for reinforcement yielding due to 
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secondary stresses as well as those for local yielding. The original design code for the Seabrook 

containment building includes these provisions. 

Reinforcement Fracture 

The reinforcement steel at Seabrook Station is not susceptible to brittle fracture because design 

codes do not permit rebar bending to the extent that would be required for susceptibility to rebar 

fracture. The additional strain introduced from the expansion effects of ASR is insufficient to 

strain reinforcement to the extent that fracture could occur. 

Seismic Response 

The seismic response is a function of the natural frequency of the structure and the seismic 

demands acting upon the structure. The seismic demand for safety-related structures is the 

ground motion response spectra provided in UFSAR Section 2.5. The natural frequency of the 

structure is a function of the structural stiffness and mass. ASR does not change the mass of the 

structure, but changes in stiffness can affect a structure's natural frequency. 

In general, the response of a structure to a seismic event is affected by the stiffness of structural 

members in flexure and shear, and their stiffness in response to axial loads. Flexural stiffness is 

the most sensitive to cracking. Modern design codes such as the 2011 version of ACI 318 allow 

the flexural stiffness of cracked beams and walls to be represented as a fraction of the nominal 

flexural rigidity in a linear analysis. Also, this version of ACI 318 does not specify any 

reduction factor for axial rigidity or any reduction factor for shear rigidity if the shear loads are 

less than the shear capacity. Therefore, the effects of ASR on the seismic performance of 

Category I structures were evaluated based on the effects of ASR on flexural stiffness alone. 

The cracking caused by ASR reduces the stiffness properties of structural members relative to 

uncracked concrete sections. Large-scale testing performed by MPR and FSEL (see Reference 

25) to investigate the impact of ASR on the stiffness of reinforced concrete members concluded 

that there is a slight reduction in flexural stiffness at low load levels but at higher loads up to the 

onset of flexural cracking the stiffness is increased. The increase in flexural stiffuess of 

structural members caused by ASR is small compared to other uncertainties in the seismic 

analysis and is covered by peak broadening of the seismic spectrum in the UFSAR. The 

potential change in stiffness is small and bounded by the current seismic analysis. Therefore, the 

seismic analysis results for Seabrook structures are unaffected by the small stiffuess changes 

from ASR. 

Applicability of Design Basis Material Properties 

Although ASR changes the compressive strength, elastic modulus, and tensile strength of 

unreinforced concrete, the MPR/FSEL large-scale test program results showed that the change in 

material properties does not have an adverse effect on structural performance when throughthickness expansion levels are low, as is the case at Seabrook. The results demonstrated that the 

performance of reinforced concrete structures should not be evaluated for ASR simply by 

adjusting the concrete material properties. Analyses of ASR-affected structures should use the 

structural properties from the original design analyses of Seabrook structures. 

Effect of Structural Deformation 

Loads can be generated when ASR expansion occurs in a structural element with free expansion 

of the structure restrained. The loads must be addressed on a case-by-case basis because they are 
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dependent on the geometry of the structure, the location(s) where expansion is restrained, and the 

extent of ASR in the affected structure. The approach for evaluating structure deformation using 

the provisions of the original design codes is described in Section 3.3. 

3.2.3 Summary of ASR Implications for Seabrook Structures 

The design codes used for Seabrook seismic Category I structures include methodologies to 

calculate structural capacities for the various limit states and loading conditions. The evaluation 

of each relevant limit state using published literature and the results of MPR/FSEL test programs 

concluded that structural capacity adjustments are unnecessary when ASR expansion levels are 

below the limits established in the assessment (see Reference 24). The effects of ASR on 

Seabrook Station structures can be evaluated by incorporating the load associated with ASR 

concrete expansion and analyzing structures using the properties specified in the original design 

with the equations of the construction code. 

Reference 25 contains a detailed discussion of the test programs and the literature review that 

supported development of the test approach. Reference 24 incorporates the results oftest 

programs and other studies to assess the effects of ASR on the structural design basis of affected 

concrete structures at Seabrook Station. These two reports provide the basis for the conclusions 

regarding the impact of ASR on structural limit states and design considerations for Seabrook 

structures. Table 2 and Table 3 summarize the results of these assessments. The limits for 

monitoring structures to ensure that the conclusions remain valid are discussed in Section 3.5 
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Table 2. Effect of ASR on Structural Limit States 

Structural Design Conclusion Basis Recommendation Issue 

Flexure & There is no adverse impact on flexural Results from MPR/FSEL testing of Periodically verify that ASR expansion 

reinforcement capacity and reinforcement anchorage specimens indicate no loss of flexural levels in the through-thickness direction are 

anchorage performance for through-thickness capacity. There was also no observed less than.%. 

expansion levels up to.%. reduction in reinforcement anchorage for 

the levels of ASR in the MPR/FSEL test 

specimens. 

Shear Shear capacity is not affected by ASR, Results from the MPR/FSEL tests showed Periodically verify that ASR expansion 

provided that through-thickness expansion no loss in shear capacity due to the levels in the through-thickness direction are 

from ASR is at or below.% and presence of ASR. The test specimens were less than.%. 

expansion behavior is comparable to the more representative of Seabrook Station 

test specimens (i.e., in-plane expansion has than published literature because of 

plateaued at a low level and through- specimen scale effects in published data. 

thickness expansion dominates). 

Compression Structural evaluations must account for the The expansion of concrete from ASR Calculate the loads imposed on the 

compression loading caused by ASR (i.e., increases the compressive stress in the structure from ASR concrete expansion and 

"chemical pre-stressing") and combine this concrete. The additional compressive analyze the loads with other applied loads 

load with other external loads to assess stresses reduce the capacity of to the structure. 

compressive load capacity. This effect compression elements to react to external 

applies only to loads applied in reinforced loads. 

directions. The compression zones of 

structural members in flexure also should 

be considered. 

Anchor bolts and There is no adverse effect to Testing by MPR/FSEL to determine the Periodically verify that ASR expansion of 

structural attachments anchor/embedment capacity when in-plane tensile capacity of anchors in ASR-affected concrete with anchors is less than.% in 

expansion (i.e., in reinforcement plane) concrete showed no loss of tensile the in-plane directions. 

from ASR is at or below. 0

/o. performance for anchors in concrete with up 

to.% in-plane expansion. 
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Table 3. Structural Design Considerations for ASR Effects 

Structural Design Conclusion Basis Recommendation 

Issue 

Reinforcement steel Reinforcement strain from the effects of The expansion of concrete caused by ASR The tensile strain should be calculated and 

strain ASR expansion should be evaluated in cracking results in tensile strain of the evaluated with other applied loads to the 

accordance with the applicable design embedded steel reinforcement, while structure. 

codes. placing the concrete in compression. 

Reinforcement fracture The reinforcement steel at Seabrook Station Seabrook Station was designed in Monitoring and evaluation of reinforcement 

is not susceptible to brittle fracture due to accordance with codes that do not permit fracture is not necessary. 

ASR-induced expansion. rebar bending to the extent that would be 

required for susceptibility to rebar fracture. 

Additionally, quality requirements in effect 

during original construction at Seabrook 

would have prevented the poor construction 

practices that resulted in the observed rebar 

fractures elsewhere. 

Seismic response ASR affects the flexural stiffness of The seismic response of a structure is Periodically verify that ASR expansion 

structural members, but the impact on affected by the stiffness of structural levels are less than.% to ensure 

Seabrook structures is bounded by the members in flexure and shear, and their conclusions on flexure properties are 

current seismic analysis. The current stiffness in response to axial loads. The satisfied. 

seismic analysis results for Seabrook flexural stiffness is most sensitive to 

cracking. Large-scale testing demonstrated structures are unaffected by the small that the change in flexural stiffness of 

stiffness changes from ASR. structural members affected by ASR 

cracking is small and does not affect the 

out-of-plane seismic response of structures. 

The structures at Seabrook Station primarily 

resist lateral loads using shear walls. The 

change in shear stfffness caused by ASR 

cracking is small relative to the impact of 

ASR on flexural properties. 
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Table 3. Structural Design Considerations for ASR Effects 

Structural Design Conclusion Basis Recommendation Issue 

Material properties Using the material properties that were The MPR/FSEL test programs confirmed Periodically verify that ASR expansion 

used in the original design of Seabrook that the elastic modulus and strength of levels are less than.% to ensure 

structures is appropriate and conservative. unreinforced concrete cores with ASR is structural limit state conclusions are valid. 

reduced, but the strength of test specimens 

with ASR is consistent with that calculated 

using the original measured concrete 

compressive strength rather than the 

reduced strength measured from extracted 

cores with ASR. Hence, limited amounts of 

ASR did not have an adverse effect on the 

capacity of reinforced structural members. 

Structural deformation Loads caused by ASR expansion require Structure deformation results in an Quantify loads imposed by deformation of 

evaluation on a case-by-case basis. additional load when the expansion of ASR- structures from ASR and evaluate with 

affected concrete is resisted by another other applied loads to the structure. 

structure or structural member or is 

restrained by concrete outside the ASRaffected region of a structure. Deformation 

loads should be included with other loads 

used in the design of a structure to verify 

that acceptance criteria are satisfied. 

Section 3.3 discusses the methods for 

analysis of structure deformation loads. 
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3.3 Building Deformation Assessment 

The evaluation of design considerations concluded that external loads can be imposed on 

structures when ASR expansion is restrained. Unlike the evaluation of the structural limit states 

and several of the design considerations given in Table 1, structure deformation loads must be 

analyzed on a case-by-case basis. Once the deformation is quantified and the loads calculated, 

the methods in the original design codes are used to evaluate whether acceptance criteria are 

satisfied. This section discusses the approach of evaluating structure deformation loads that arise 

from ASR expansion. 

The original design calculations for Seabrook structures consider the factored load combinations 

listed in UFSAR Table 3.8-1 (containment) and Table 3.8-16 (other seismic Category I 

structures). These load combinations do not include self-straining loads. ASR expansion is one 

of the so-called "self7straining" behaviors that affect concrete; others are swelling, creep, and 

shrinkage. Inspections of structures at Seabrook have noted relative building movements, 

equipment misalignments, and concrete cracking which indicate the presence of self-straining 

mechanisms such as ASR. A Root Cause Evaluation of deformation measured for the 

Containment Enclosure Building (CEB) has concluded that ASR is the cause oflocalized 

structural deformations (Reference 6). 

ASR expansion can lead to movement or deformation of a structure such as that observed for the 

CEB and affects the width of seismic gaps. In reinforced concrete sections, the concrete 

expansion is resisted by tension in the steel reinforcing bars, which leads to compression in 

concrete. A load arises when the expansion of ASR-affected concrete is resisted by another 

structure or the deformation is restrained by concrete outside the ASR-affected region of a 

structure. Building deformation caused by ASR results in additional stresses on the structure that 

were not considered in the original design analyses. The self-straining loads caused by ASR 

expansion are added to the other loads that are considered in the design of Seabrook structures. 

The concrete fill at Seabrook is unreinforced and similarly susceptible to ASR as concrete 

structures at the site. Expansion of the concrete fill is resisted only by its boundary (i.e., bedrock 

and the adjacent structures). ASR expansion of concrete fill can potentially apply an external 

load on an adjacent structure. ASR expansion of the fill may cause the fill to come into contact 

with structure which imposes a pressure on the rigid buried structural walls. When the concrete 

fill is not confined by another structure vertically, the maximum pressure is limited by the 

overburden pressure on the concrete fill. 

Swelling of concrete that is in contact with water for a long period of time results in a stress 

behavior in reinforced concrete similar to that for ASR expansion. Shrinkage and creep could 

decrease the tension of the reinforcement bars which could relieve some of the demands due to 

other design loads. Creep is a time-dependent strain in hardened concrete under sustained load. 

The mechanism occurs relatively early in the structure's life and does not change significantly 

over time. Shrinkage is caused by a reduction in concrete volume as water not consumed by 

cement hydration leaves the system. Analyses of ASR and these other effects (creep, shrinkage, 

and swelling) indicate that ASR expansion is the largest contributor of the self-straining 
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behaviors active at Seabrook Station. However, all of these self-straining mechanisms can 

contribute to the observed deformations, so it is necessary to evaluate all simultaneously in the 

evaluation process. Self-straining behaviors were not included in the original design analyses 

either because they were deemed insignificant or because they were not known during the design 

process (i.e., ASR). Demands (forces and moments) caused by creep and shrinkage are 

conservatively neglected in cases where they reduce the overall demand from ASR. However, 

deformations due to creep and shrinkage are included in order to make comparisons with field 

measurements of deformation. 

The deformation of structures changes the clearances between structures and equipment 

contained within the structure. Clearances in penetrations through structural members are also 

affected. Supports attached to a structure may also move with the structure and alter the loads on 

components. NextEra has completed walkdowns local to the Containment Enclosure Building to 

verify that structure-to-structure (Reference 6) and structure-to-component (Reference 16) 

clearances are adequate to ensure seismic isolation is achieved. The effects of structure 

deformation on plant equipment and seismic gaps will be managed through the Corrective 

Action Program based on input from the Structural Monitoring Program. The Structural 

Monitoring Program is discussed below. 

The Corrective Action Program will require that changes in component clearances caused by 

deformation be evaluated for the impact on the equipment. Adverse effects caused by reduced 

clearances or the movement of supports and equipment will be corrected or evaluated to ensure 

the additional load on components is acceptable. 

3.3.1 Design Material Properties 

The structure deformation analyses will use the structural properties that were used in the 

original design analysis of the structures based on the results in Section 3.2 above. 

3.3.2 Evaluation of Self-Straining Loads and Deformations for Seismic Category I 

Structures other than Containment 

The license amendment proposes a method to evaluate each of the seismic Category I structures 

listed in UFSAR Section 3.8.4.l to assess the impact of self-straining loads on the design of the 

structures other than containment. The original design loads listed in UFSAR Table 3.8-16 will 

be combined with the self-straining loads from ASR expansion, creep, shrinkage, and swelling. 

The impact of self-straining loads on seismic gaps will be evaluated at each stage of analysis. 

A three-stage process would be used for analyzing structures. Each stage of the analysis applies 

more sophisticated methods and uses additional field data to improve the accuracy of the results. 

• Stage One-Screening Evaluation: Each of the seismic Category I structures are screened for 

susceptibility to structural deformation caused by ASR using existing field data and 

conservative calculations. 
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• Stage Two -Analytical Evaluation: An analytical evaluation is performed for structures that 

the Stage One Screening Evaluation identifies as susceptible to deformation but do not 

satisfy ACI 318-71 acceptance criteria. A finite element model of the structure is used to 

estimate structural demands due to self-straining loads, while all other demands are taken 

from existing design calculations. Additional field data are obtained to use in the analysis. 

The evaluation verifies compliance with ACI 318-71 using the same criteria as the original 

design. 

• Stage Three - Detailed Evaluation: A detailed design confirmation calculation is performed 

when the Stage Two Analytical Evaluation concludes that some area of a structure does not 

satisfy ACI 318-71 acceptance criteria or when the structure has sufficient deformation that 

may impact demands computed in the original design. The detailed evaluation uses the Stage 

Two finite element model to compute demands due to self-straining loads as well as all other 

design loads. In the Stage Three evaluation, consideration is given to cracked section 

properties, self-limiting secondary stresses, and the redistribution of structural demands when 

sufficient ductility is available. 

All three stages of the evaluation process use the original design acceptance criteria given in the 

UFSAR including separation of structures by seismic gaps. Each analysis stage will determine 

threshold monitoring limits to define the criteria for re-evaluating structures with deformation. 

The threshold monitoring limits are specific to each structure and will be included in the 

Structural Monitoring Program. Section 3.5 discusses monitoring and acceptance criteria for 

ASR cracking and deformation of structures. 

Stage One: Screening Evaluation 

NextEra has conducted walkdowns of structures and plant equipment to identify items of interest 

and evaluate the items through the Corrective Action Program for their impact on plant 

operations. Inspection data from these walkdowns and other measurements obtained for 

ASR-affected structures will be reviewed to identify potential locations and directions of 

movement or deformation. This existing data includes measurements of relative building 

movements, equipment misalignments, and concrete cracking indexes. ASR monitoring grids, 

which are used to measure the strain in reinforced concrete, were installed throughout the 

facility. The monitoring grids were installed at the most severe locations for ASR cracking, and 

therefore, provide a conservative estimate of the strain in the structure. After reviewing existing 

field data, a walkthrough inspection will be performed in the screening evaluation process to 

verify field conditions and determine if ASR expansion only affected localized regions of the 

structure or whether the structure has experienced global deformation of structural members. 

In the Stage I screening process, conservative estimates of deformations and strains based on the 

field data are used to estimate demands caused by self-straining loads for critical locations in the 

structure. Self-straining loads include four components: ASR, creep, shrinkage, and swelling. 

Based on guidance in ACI 318-71, creep, shrinkage and swelling are included with the dead 

load. The ASR demands (identified as "Sa" herein) are factored as described in Section 3.3.4 and 

then combined with demands due to design loads for the load combinations in UFSAR Table 
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3.8-16. An evaluation is performed using strength acceptance criteria in ACI 318-71 for 

reinforced concrete consistent with UFSAR Section 3.8.4.5. 

For screening evaluations that conclude a structure fully complies with the strength acceptance 

criteria, the critical locations of the structure are re-evaluated for a higher level of ASR demand 

to determine the maximum allowable, factored self-straining loads at which the structure meets 

the design acceptance criteria. A set of monitoring elements (consisting of strain measurements, 

deformation measurements, seismic gap measurements, and/or other quantifiable behaviors) is 

established along with threshold limits for each monitoring element. The threshold limits are 

defined as the maximum measurement for each monitoring element that results in a factored selfstraining load equal to the factored self-straining load at the structural design limit (with factored 

design basis loads included). The threshold limit for the monitoring elements defined in Stage 

One is equal to the set of monitoring element measurements that produce a factored ASR 

demand that is 90% of the factored self-straining load at the acceptance limit. If a structure 

monitoring element measurement obtained from walkdowns and other monitoring activities 

exceeds the monitoring threshold limit, then a Stage Two Analytical Evaluation is required. 

A structure is classified as Stage 1 if the Screening Evaluation concludes that the structure 

satisfies the strength acceptance criteria and the structure monitoring element measurements are 

less than the Stage One threshold limits. The Screening Evaluation for Stage 1 structures is 

summarized in a calculation package that supplements the original design calculation. The 

calculation package also documents the set of monitoring measurements and the threshold limits 

for the monitoring process. The monitoring measurements and the threshold limits are 

incorporated into the Seabrook Structural Monitoring Program to periodically assess the 

condition of structures and verify that the structure meets the design acceptance criteria. 

Stage Two: Analytical Evaluation 

For structures that cannot be shown to meet the ACI 318-71 acceptance criteria using the 

conservative methods of the Screening Evaluation or monitoring measurements indicate high Sa 

demands, an Analytical Evaluation is required. The Analytical Evaluation uses more accurate 

methods to quantify demands due to self-straining loads. Also, additional inspections are 

performed to measure structural strains and deformations at a broader range of critical locations 

on the structure. These measurements would be used to compute the self-straining loads with 

more accuracy than possible using the inputs from the Stage One Screening Evaluation process. 

An ANSYS finite element model (FEM) of the structure is created based on design drawings and 

uncracked design section properties. The model is initially benchmarked to the original design 

analysis of the structure with only the current licensing basis loads. The FEM is then calibrated 

such that the deformations and strains due to unfactored sustained loads and self-straining loads 

are consistent with field measurements. The FEM is used to compute the structural demands due 

to ASR loads (Sa). The self-restraining demands from the finite element analysis are then 

factored as described in Section 3.3.4 and combined with demands due to factored design loads 

from the original design calculations for the load combinations in UFSAR Table 3.8-16. The 

structural demand in critical regions of the structure is evaluated using strength acceptance 
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criteria in ACI 318-71 for reinforced concrete consistent with UFSAR Section 3 .8.4.5. The 

methods used for the Stage Two analysis are unchanged from the original design analyses with 

the exception of accounting for the self-straining loads in the analysis and the use of the AN SYS 

software program for computing the sustained and self-straining loads. 

Structures that satisfy the Analytical Evaluation acceptance criteria are re-evaluated for a higher 

level of Sa to compute the maximum allowable self-straining loads on the structure. The 

maximum allowable loads correspond to the maximum, factored self-straining loads at which the 

structure meets the design acceptance criteria. A set of monitoring measurements are identified 

and threshold limits are set for each measurement based on the maximum allowable selfstraining load. The threshold limits for each monitoring element defined in Stage Two are 

determined by scaling all measurements proportionally such that a factored self-restraining 

demand equal to 95% of the value at the design acceptance limit is achieved. 

A structure is classified as Stage 2 if the Analytical Evaluation concludes that the structure 

satisfies the strength acceptance criteria and the structure monitoring element measurements are 

less than the Stage Two threshold limits. The Analytical Evaluation calculation for Stage 2 

structures supplements the original design calculation. The monitoring measurements, 

measuring locations, and threshold limits for monitoring are also included in the supplement to 

the calculation. The monitoring measurements and the threshold limits are incorporated into the 

Seabrook Structural Monitoring Program to periodically assess the condition of structures and 

verify that the structure continues to satisfy the design acceptance criteria. 

Stage Three: Detailed Evaluation 

Structures that do not meet the acceptance criteria of the Stage Two Analytical Evaluation are 

analyzed by a Detailed Evaluation. In the Detailed Evaluation, Sa demands and the loads from 

creep, shrinkage and swelling are recomputed using the Stage Two FEM. Structural demands 

due to design loads are recomputed by applying design demands (i.e. wind, seismic, hydrostatic 

pressure, etc.) to the FEM. A detailed structural evaluation is performed for all load 

combinations listed in UFSAR Table 3.8-16. The structure is evaluated using strength 

acceptance criteria in ACI 318-71 for reinforced concrete consistent with UFSAR Section 

3.8.4.5. In the Stage Three evaluation, consideration is given to cracked section properties, selflimiting secondary stresses, and the redistribution of structural demands when sufficient ductility 

is available. The 100-40-40 percent rule in NRC Regulatory Guide 1.92, Revision 3, is used as 

an alternative to the SRSS method for combining three directional seismic loading in the analysis 

of structures that are deformed by the effects of ASR. 

Structures that meet the acceptance criteria of the Detailed Evaluation are classified as Stage 3 

and are re-evaluated for a higher level of self-straining load to establish the threshold limits for 

each monitoring element measurement. A similar process is used as described in the Stage Two 

Analytical Evaluation above. The threshold limit for each monitoring element defined in Stage 3 

is equal to the limit for the monitoring element measurement that produces a factored Sa load at 

the design acceptance limit. 
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The Detailed Evaluation is summarized in a design calculation package that will supersede the 

original design calculation. The calculation package documents the set of monitoring 

measurements and the threshold limits of each monitoring measurement. The monitoring 

elements and their threshold limits are included in the Structural monitoring program to 

periodically verify that the structure continues to meet the design acceptance criteria. 

3.3.3 Evaluation of Self-Straining Loads and Deformations for Containment Building 

The conditions and structural configuration of the containment building are unique relative to the 

other seismic Category I structures at Seabrook Station, and make it less susceptible to 

deleterious effects of ASR. Evaluation of Self Straining Loads and Deformation for 

Containment will be performed using the three stage process discussed in Section 3.3.2. The 

containment building will be evaluated at critical locations using the acceptance criteria in the 

ASME Boiler and Pressure Vessel Code as specified in UFSAR Section 3.8.1.5. Because of the 

unique design and for the reasons discussed below it is expected Containment will be screened as 

at a Stage 1 evaluation. 

The containment building is located within the Containment Enclosure Building that protects the 

structure from loads due to outside weather (such as wind, snow, and rain), but also from 

potential loads due to ASR expansion of concrete fill on the containment cylinder. The 

containment structure consists of a mat and a cylinder that is topped by a spherical dome similar 

to the enclosure building. The containment building has two access hatchways and a number of 

piping penetrations; however, these penetrations are strengthened with robust reinforced concrete 

detailing. Finally, the reinforcement detailing for the containment building (heavily reinforced; 

regions with tri-axial reinforcement) limit ASR expansion and the structural implications of 

ASR. 

Creep, shrinkage, and swelling have a negligible impact on the containment building, which is 

consistent with original design calculations. This is based on the robust reinforced concrete 

detailing used in the containment building that also has a continuous foundation and is protected 

from exterior weather. In addition, the containment building does not have large openings at the 

base, as is the case with the CEB, which would enhance the susceptibility to these timedependent deformation mechanisms. 

There are limited localized ASR locations on the exterior surface of the containment building 

cylinder with closely spaced pattern cracking and some regions of widely-spaced pattern cracks 

indicative of lower levels of ASR based on available field inspections and crack indexing 

measurements. A confirmatory visual walk-down inspection of the building exterior wall will be 

performed to further characterize the extent of ASR degradation. The inspection will be 

followed by a calculation to conservatively analyze the force and moment demands in the 

containment building wall due to the localized strain measurements from available expansion 

measurements. The force and moment demands due to ASR are added to the corresponding 

demands in the original design calculation for critical load combinations to estimate total 

demands. 
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The containment building will then be re-evaluated for a higher level of ASR strain to establish a 

threshold at which the structure still meets the design acceptance criteria. A set of monitoring 

measurement locations will be established along with threshold limits for each monitoring 

element. The monitoring requirements will be included in the Structural Monitoring Program to 

periodically verify that the containment building expansion behavior responses are within the 

limits of the ASR evaluation. 

3.3.4 Factored Self-Straining Loads 

The factored load combinations listed in UFSAR Table 3 .8-16 are used for the design of seismic 

Category I structures at Seabrook other than the concrete containment building. The 

self-straining loads consist of four load types; shrinkage, creep, swelling, and ASR (Sa) which 

are not used in the original design calculations. The factored self-straining loads are combined 

with the original design load combination for the screening and analytical evaluations discussed 

above. The load factors for dead load are used for the shrinkage, creep, and swelling loads in 

accordance to ACI 318-71 Section 9.3.7. As discussed in Reference 23, the load factors applied 

to ASR loads (Sa) are developed to yield reliability index values similar to load factors specified 

in ACI 318-71 (Reference 17). The ASR load factors account for the uncertainty in ASR 

expansion by considering the variability in crack index measurements from all ASR monitoring 

grids in Seabrook Station structures. For unusual load combinations, such as SSE and tornado 

wind combinations, all load factors are taken as 1.0, including the factor for ASR loads, which is 

consistent with the method presently used in the UFSAR. 

Reliability index is a parameter that accounts for uncertainties in demands and resistance. Load 

combinations in design codes generally use target reliability indices of 3.0, 2.5, and 1.75 for 

static, wind, and seismic (OBE) combinations, respectively (Reference 18). 

The variability of ASR-related demands at Seabrook Station is based on 216 crack index 

measurements associated with the two axes of 108 plant-wide ASR monitoring grids. Expansion 

measurements from the large-scale test programs have shown that crack index provides a 

reasonable and conservative approximation of true engineering strain for reinforced concrete 

members undergoing ASR expansion. The dataset of the 216 crack index measurements is fit to 

probabilistic distributions for calculating ASR load factors. 

3.3.5 Evaluation of Containment Enclosure Building 

Analyses of Seabrook Station structures for ASR deformation are ongoing. The CEB was 

evaluated for deformation using the process described in Section 3.3.2 (reference 26). This 

evaluation is described as an example of a Stage 3 implementation of the methodology described 

above. The deformed shape of the CEB model, when subjected to sustained loads and selfstraining loads, simulates field measurements of deformations. The CEB meets evaluation 

criteria of ACI 318-71 for all factored load combinations and analysis cases analyzed when ASR 

loads are amplified by a threshold factor of 1.2 to account for future ASR expansion. The asdeformed condition does not significantly impact the dynamic properties of the structure, and 
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therefore the maximum seismic acceleration profiles for OBE and SSE excitation used in 

original design of the CEB remain valid. 

3.4 Summary of ASR and Structure Deformation Methodology Changes 

The analyses, evaluations, and acceptance criteria used in the screening and analyses of structure 

deformation are consistent with the methods described in the UFSAR except for the following: 

• The effects of ASR can be evaluated by incorporating the load associated with ASR concrete 

expansion and analyzing structures using the properties specified in the original design with 

the equations of the construction code when ASR expansion is less than the limits established 

in Reference 24. 

• ASR expansion loads were not considered in the UFSAR. The load factors associated with 

ASR loads for different load combinations are developed for the current evaluations. 

Incorporating the load from ASR expansion adds to the current design loads and reduces the 

original calculated design margin of each structure while meeting the intent of the codes of 

record. 

• Creep, shrinkage, and swelling loads are considered to be insignificant in the UFSAR. These 

loads are considered in the evaluations of structures other than containment. Including these 

loads is necessary to accurately estimate the total load due to deformation based on the 

existing deformed shape of each structure. 

• ANSYS Mechanical APDL Version 15.0 is used for the Analytical and Detailed Evaluations 

of seismic Category I structures with deformation. Although a different version of ANSYS 

was used in the dynamic and static analyses of seismic Category I code and non-code items, 

this computer software was not used in the original design calculations for Seabrook 

structures. ANSYS has been used for design analyses of seismic structures at other nuclear 

plants (e.g., Vogtle 3 and 4 and VC Summer 2 and 3). 

• Detailed Evaluations of the loads caused by ASR may combine the orthogonal spatial 

components of seismic loads using the 100-40-40 procedure in accordance to Regulatory 

Guide 1.92 Revision 3. The current UFSAR specifies that only the square-root-of sum-of 

squares (SRSS) procedure is used to combine spatial components. 

3.5 Monitoring 

All seismic Category I structures at Seabrook Station are monitored under the Structural 

Monitoring Program (SMP). The SMP provides guidance for meeting the requirements of 

I OCFR50.65, the Maintenance Rule. The program provides a systematic approach for evaluating 

plant structures to provide assurance that structures are capable of fulfilling their intended 

function. NextEra has implemented a number of enhancements to the SMP to monitor the 

progression of ASR. The monitoring actions incorporated into the SMP are consistent with 

currently available industry practices (Reference 8). The SMP currently includes provisions for 
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detection and monitoring of ASR degradation in plant structures. Monitoring of ASR is 

performed through periodic measurement of ASR expansion and periodic inspections of ASRaffected structures to identify and trend building deformation. 

3.5.1 ASR Expansion 

Expansion monitoring includes determination and trending of in-plane expansion and throughthickness (i.e., out-of-plane) expansion. These data track the progression of ASR in plant 

structures. Monitoring of building deformation includes measurement of seismic gaps and other 

key dimensions to identify and trend building deformation, and inspections to identify the impact 

of building deformation on plant components. The monitoring elements for deformation and the 

acceptance criteria are determined from the building deformation analyses described in 

Section 3 .3 above and are specific to each structure. The structure-specific deformation criteria 

ensure code acceptance criteria are satisfied. 

Although ASR-induced expansion can occur in all directions, expansion may not be equal in all 

directions depending on the confinement provided by steel reinforcement, loads (e.g., 

deadweight), and building configuration. NextEra has monitored in-plane expansion of 

ASR-affected structures using the Combined Cracking Index (CCI). CCI is measured by 

overlaying a grid onto areas with ASR and measuring the crack widths that intersect the 

horizontal and vertical lines of a grid. CCI is equal to the sum of the all crack widths divided by 

the cumulative length of the grid lines (millimeters/meter). CCI has been successfully used as an 

indicator of relative area expansions on Seabrook structures for several years. There are other 

methods for measuring in-plane expansion caused by ASR cracking, but CCI is method that 

provides the total in-plane expansion that has occurred since ASR cracking initiated. Viable 

alternate methods that were evaluated are relative in that they rely on calculating differences 

between repeated measurements. 

NextEra is installing extensometers for measuring through-thickness expansion of plant 

structures. The extensometer is installed in a borehole that is perpendicular to the face of the 

wall (or slab). The instrument consists of two anchors and a rod. The rod is attached to the 

anchor installed deep in the borehole and slides through a hole in the anchor installed near the 

surface. Expansion is monitored by measuring the distance between the end of rod and the 

reference surface on the anchor near the surface. The extensometer being installed is a snap-ring 

borehole extensometer. It was selected because it was shown to be accurate and reliable in the 

MPR/FSEL testing. 

Extensometers provide a relative measurement of the expansion because the readings show the 

increase in expansion relative to the time it was installed. The measured expansion needs to be 

combined with the expansion that occurred up to the time of instrument installation to yield the 

total through-thickness expansion to a given time. NextEra will use an empirical correlation 

developed in the large-scale test program to correlate concrete elastic modulus measurements 

with the through-thickness expansion to date (Reference 20). 
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The conclusions from NextEra's evaluation of the effects of ASR on structural limit states and 

other design considerations is predicated on maintaining ASR expansion levels below the limits 

described in Reference 24. The ASR expansion limits for structural limit states are summarized 

in Table 4. Maintaining these limits is assured by periodically measuring through-thickness 

expansion in areas affected by ASR. This LAR proposes to include the limits for ASR 

expansion in the Seabrook UFSAR as Table 3.8-18. UFSAR Section 3.8.4.7 is also revised to 

discuss the limits for ASR expansion and reference the SMP for periodic inspections of ASR and 

limits on structure deformation. Although the eiansion limit for flexure and reinforcement 

anchorage from the large-scale test programs is %, the lower value of.% for shear is 

included in the UFSAR and the SMP for these limit states. 

Table 4. ASR Expansion Limits For Structural Limit States 

Structural Limit State ASR Expansion Limit 

Shear .% through-thickness 

Flexure .% through-thickness 

Reinforcement Anchorage .% through-thickness 

Anchors % in-plane 

ASR expansion limits for seismic design considerations discussed in Section 3.2.2 are 

maintained by satisfying the expansion limits in Table 4. The additional strain in reinforcement 

and axial compression in concrete are evaluated by analyzing ASR expansion loads with other 

design loads on ASR-affected structures. Additional discussion on limits for rebar strain and 

axial compression is included in Section 3.5.2. 

The SMP also includes the monitoring frequencies for inspecting areas with ASR. Regions of 

structures with signs of ASR are classified based on the total ASR expansion to date. Structures 

with higher levels of ASR expansion are inspected more frequently than structures with minimal 

ASR expansion. The criteria for classifying structures based on ASR expansion are included in 

Table 5. The SMP requires installation of extensometers in the ASR affected locations that are 

classified as Tier 3. 
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Table 5. ASR Expansion Acceptance Criteria and Condition Monitoring Frequencies 

Tier Recommendation from In-Plane Expansion Inspection Frequency 

Inspection 

1 Routine inspection in NA* As prescribed in the SMP accordance with SMP 

Areas with pattern cracking 

Qualitative monitoring that cannot be accurately 

2 measured 30 months 

Quantitative monitoring 0.05% and trending 

3 Structural evaluation and 

implement enhanced ASR 0.1% 6 months 

monitoring 

* No indications of pattern cracking or water ingress. 

The testing at FSEL demonstrated that anchor capacity is maintained for relatively high in-plane 

expansion levels that could only exist in structures classified as Tier 3 for ASR cracking. Tier 3 

structures are inspected on a six month frequency which would ensure timely detection of any 

changes in ASR cracking that could potentially challenge anchor performance. 

Current in-plane expansion levels in ASR-affected areas at Seabrook are well below the limits 

where anchor capacity may be reduced (Reference 21 ). Also, the expansion behavior observed 

in reinforced test specimens at FSEL suggests that in-plane expansion is unlikely to achieve 

levels where anchors are affected. Periodic monitoring of in-plane expansion in accordance with 

the frequencies in Table 5 will ensure that NextEra can take appropriate action before expansion 

reaches the ASR expansion criteria in Table 4. 

3.5.2 Structure Deformation 

The SMP also includes the requirements for monitoring Seabrook structures with measureable 

deformation. Structures with ASR are initially screened for deformation using the process 

described in Section 3.3. The process will classify affected structures into one of three 

categories: (1) structures with minimal amounts of deformation that do not affect the structural 

capacity as determined in the original design analysis; (2) structures with elevated levels of 

deformation that are shown to be acceptable using FEA and still meet the original design basis 

requirements when ASR effects are included; and (3) structures with significant deformation that 

are analyzed and shown to meet the requirements of the code ofrecord using the methods 

described herein. 

The deformation evaluation process described in Section 3.3.2 will establish threshold 

monitoring limits for ASR-affected structures. The process identifies the specific set of 

monitoring elements used to quantify deformation for each structure. Monitoring elements will 

include a combination of strain measurements, measurements of the relative deformation 
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betWeen structures, and other quantifiable behaviors. The threshold limits are defined as the 

maximum allowable measurement for each monitoring element that limits the self-straining 

loads to some fraction of the maximum allowable self-straining load. 

The structure deformation evaluation process will classify affected structures into one of three 

categories, Stage 1, Stage 2, or Stage 3, based on the analysis necessary to demonstrate 

compliance with ACI 318-71 (or the ASME Code for containment). This approach is consistent 

with guidance in ACI 349.3R-1996 used to establish the inspection criteria for other degradation 

mechanisms in the SMP. The Stage 1, 2 and 3 deformation categories do not necessarily 

correspond to the criteria used to characterize local ASR expansion that are summarized in 

Table 5. The deformation monitoring frequencies for structures are summarized in Table 6. 

Table 6. Structure Deformation Monitoring Requirements 

Stage Deformation Evaluation Stage Monitoring Interval 

1 Screening Evaluation 3 years 

2 Analytical Evaluation 18 months 

3 Detailed Evaluation 6 months 

Limits for rebar strain and axial compressive stress in concrete are evaluated in the process of 

evaluating structures for deformation. The magnitude of these parameters is directly related to 

the applied loads and the level of expansion that occurs locally in ASR-affected concrete, and 

each is calculated in the structure deformation analysis process. The threshold monitoring limits 

established in the deformation analysis process discussed in Section 3.3.2 and 3.3.3 limit the 

allowable levels of ASR expansion to ensure that rebar strain and axial compressive stresses are 

acceptable per the design codes for original construction. 

There are no published standards that include inspection frequencies for monitoring ASRaffected structures. In addition, ACI 318-71 and the ASME Code, Section III, Division 2, do not 

have guidance for inspecting ASR-affected structures. Reference 22 includes guidance from the 

U.S. Department of Transportation Federal Highway Administration for inspecting 

transportation structures with ASR degradation. The guidance recommends inspections from six 

months to 5 years depending on the age of the damage to the structure and the rate of change in 

degradation. The monitoring frequencies in Table 6 are based on the recommendations in 

Reference 22 and the relative margin to design acceptance criteria from the structure deformation 

assessment process. 

The process for evaluating deformation in ASR-affected structures is progressing in accordance 

with the Seabrook Station corrective action process. The inspection frequencies in Table 6 and 

the monitoring elements specific to each structure will be included in the SMP after all structures 

have been evaluated. 
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4.0 REGULATORY EVALUATION 

4.1 Applicable Regulatory Requirements/Criteria 

4.1.1 10CFR50.59 

10 CFR 50.59( c )(2)(viii) requires a licensee to obtain a license amendment pursuant to 10 CFR 

50.90 prior to implementing a proposed change if the change would "result in a departure from a 

method of evaluation described in the FSAR (as updated) used in establishing the design bases or 

in the safety analyses". 

4.1.2 Design Criterion 

Seabrook Station was licensed for construction on July 7, 1976, and at that time committed to the 

General Design Criteria (GDC) reflected in Section 3 of the UFSAR. The GDC that are 

applicable to the proposed UFSAR changes are Criterion 1, 2, 4, 16, and 50. 

• Appendix A to Part 50-General Design Criteria for Nuclear Power Plants 

GDC Criterion 1 - Quality Standards and Records. Structures, systems, and 

components important to safety shall be designed, fabricated, erected, and tested to 

quality standards commensurate with the importance of the safety functions to be 

performed. Where generally recognized codes and standards are used, they shall be 

identified and evaluated to determine their applicability, adequacy, and sufficiency 

and shall be supplemented or modified as necessary to assure a quality product in 

keeping with th~ required safety function. A quality assurance program shall be 

established and implemented to provide adequate assurance that these structures, 

systems, and components will satisfactorily perform their safety functions. 

Appropriate records of the design, fabrication, erection, and testing of structures, 

systems, and components important to safety shall be maintained by or under the 

control of the nuclear power unit licensee throughout the life of the unit. 

GDC Criterion 2 - Design Bases for Protection Against Natural Phenomena. 

Structures, systems, and components important to safety shall be designed to 

withstand the effects of natural phenomena such as earthquakes, tornadoes, 

hurricanes, floods, tsunami, and seiches without loss of capability to perform their 

safety functions. The design bases for these structures, systems, and components 

shall reflect: (1) appropriate consideration of the most severe of the natural 

phenomena that have been historically reported for the site and surrounding area, 

with sufficient margin for the limited accuracy, quantity, and period of time in which 

the historical data have been accumulated, (2) appropriate combinations of the 

effects of normal and accident conditions with the effects of the natural phenomena 

and (3) the importance of the safety functions to be performed. 
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Criterion 4 - Environmental and Missile Design Bases. Structures, systems, and 

components important to safety shall be designed to accommodate the effects of and 

to be compatible with the environmental conditions associated with normal 

operation, maintenance, testing, and postulated accidents, including loss-of-coolant 

accidents. These structures, systems, and components shall be appropriately 

protected against dynamic effects, including the effects of missiles, pipe whipping, 

and discharging fluids, that may result from equipment failures and from events and 

conditions outside the nuclear power unit. However, dynamic effects associated with 

postulated pipe ruptures in nuclear power units may be excluded from the design 

basis when analyses reviewed and approved by the Commission demonstrate that the 

probability of fluid system piping rupture is extremely low under conditions 

consistent with the design basis for the piping. 

Criterion 16 - Containment Design. Reactor containment and associated systems 

shall be provided to establish an essentially leak-tight barrier against the uncontrolled 

release of radioactivity to the environment and to assure that the containment design 

conditions important to safety are not exceeded for as long as postulated accident 

conditions require. 

Criterion 50 - Containment Design Basis. The reactor containment structure, 

including access openings, penetrations, and the Containment Heat Removal System 

shall be designed so that the containment structure and its internal compartments can 

accommodate, without exceeding the design leakage rate and, with sufficient margin, 

the calculated pressure and temperature conditions resulting from any loss-of-coolant 

accident. This margin shall reflect consideration of (1) the effects of potential energy 

sources which have not been included in the determination of the peak conditions, 

such as energy in steam generators and energy from metal-water and other chemical 

reactions that may result from degradation but not total failure of emergency core 

cooling functioning, (2) the limited experience and experimental data available for 

defining accident phenomena and containment responses, and (3) the conservatism 

of the calculational model and input parameters. 

• Codes and Standards 

The design, materials, fabrication, construction, testing and inspection of the containment 

structure conform to the applicable sections of the following codes and specifications: 

ASME Boiler and Pressure Vessel Code, Section III, Division 2, Code for Concrete 

Reactor Vessels and Containments - 1975 Edition 

The design, materials, fabrication, and inspection of seismic Category I structures other than 

containment and internal structures are covered by the following codes, standards, and guides 

that are either applicable in their entirety or in portions thereof: 
--Non-Proprietary Version--

ACI 318-71 Building Code Requirements for Reinforced Concrete (with 

Commentary) 

• Regulatory Guide 1.92, Revision 1, "Modes and Spatial Components in Seismic Response 

Analyses" 

Seismic analysis results for three orthogonal directions were combined using the grouping 

method in Regulatory Guide 1.92, Revision 1. 

The proposed analysis method changes to the UFSAR are necessary to demonstrate that 

containment and other seismic Category I structures continue to meet the acceptance criteria in 

the ASME Code and ACI 318-71, as appropriate to the structure. With the implementation of 

the proposed change, Seabrook Station will continue to meet the applicable regulations and 

requirements listed above. Incorporating the ASR deformation loads into the design basis load 

combinations for Seabrook will ensure the ability to safely shutdown the plant and maintain it in 

a safe shutdown condition during the spectrum of design basis accidents specified in the 

Seabrook UFSAR. 

4.2 No Significant Hazards Consideration 

The proposed change would revise the licensing basis as documented in the Updated Final Safety 

Analysis Report (UFSAR) to identify alkali-silica reaction (ASR) as a degradation mechanism 

for seismic Category I structures at Seabrook Station. The loads associated with the effects of 

ASR would be added to the original design loads of ASR-affected structures in accordance with 

the requirements of the Codes, Standards, and Specifications used for original design of the 

structures. Alternate analysis methods are used to demonstrate that the capability of structures to 

withstand design basis loads with the effects of ASR included. The methods would continue to 

use the acceptance criteria that were used in the original design of Seabrook Station structures. 

The proposed change would also establish limits for the allowable ASR expansion in structures 

and propose criteria for monitoring potential changes of ASR expansion and structure 

deformation to ensure structures and component supports continue to meet design requirements. 

NextEra has evaluated whether or not a significant hazards consideration is involved with the 

proposed amendment by focusing on the three standards set forth in 10 CFR 50.92, "Issuance of 

amendment," as discussed below: 

1. Does the proposed amendment involve a significant increase in the probability or 

consequences of an accident previously evaluated? 

Response: No. 

The proposed amendment is requesting approval of changes to the updated final safety 

analysis report (UFSAR) to allow a new method to analyze Alkali-Silica Reaction (ASR) 

related loads. The new methodology will verify that affected structures continue to have 

the capability to withstand all applied loads used in the original design of Seabrook 
--Non-Proprietary Version--

structures. The proposed changes do not impact the physical function of plant structures, 

systems, or components (SSCs) or the manner in which SSCs perform their design 

function. The proposed changes do not alter or prevent the ability of operable SSCs to 

perform their intended function to mitigate the consequences of an event within assumed 

acceptance limits. 

The ASR-affected structures are not initiators of any accidents previously evaluated, and 

there are no accidents previously evaluated that involve a loss of structural integrity for 

seismic Category I structures. Approval of the UFSAR changes will demonstrate the 

structures affected by ASR will continue to maintain the capability to withstand all 

credible conditions of loading specified in the UFSAR. 

Therefore, the proposed changes do not involve a significant increase in the probability or 

consequences of an accident previously evaluated. 

2. Does the proposed amendment create the possibility of a new or different kind of 

accident from any accident previously evaluated? 

Response: No. 

The proposed amendment is requesting approval of changes to the UFSAR to allow the use 

of a new method to analyze ASR related loads to verify that affected structures continue to 

have the capability to withstand applied loads used in the original design of Seabrook 

structures, with the addition of ASR loads and loads previously considered negligible. 

Approving the use of the new methodology will not create the possibility of a new or 

different kind of accident previously evaluated. The new methodology will demonstrate 

that structures continue to satisfy the design requirements of the code of construction and 

other applicable requirements with the additional load from ASR. Structures will respond 

to applied loads consistent with their original design. 

The proposed changes to the UFSAR do not challenge the integrity or performance of any 

safety-related systems. The changes do not alter the design, physical configuration, or 

method of operation of any plant SSC. No physical changes are made to the plant, other 

than as a result of the revised monitoring program, so no new causal mechanisms are 

introduced. 

Therefore, the proposed change does not create the possibility of a new or different kind of 

accident from any previously evaluated. 

3. Does the proposed amendment involve a significant reduction in a margin of safety? 

Response: No. 
--Non-Proprietary Version--

The proposed amendment is requesting approval of changes to the UFSAR to allow the use 

of a new method to analyze ASR related loads to verify that affected structures continue to 

have the capability to withstand all applied loads used in the original design of Seabrook 

structures. 

The proposed methods for re-evaluating seismic Category I structures will demonstrate 

that structures satisfy the acceptance criteria in the current licensing basis when the loads 

associated with ASR expansion are included with other design loads and load 

combinations. The safety margin provided by the design codes in the current licensing 

basis will not be reduced since the proposed change is not requesting any change to the 

codes of record. 

The proposed changes to the UFSAR do not affect the margin of safety associated with 

confidence in the ability of the fission product barriers (i.e., fuel cladding, reactor coolant 

system pressure boundary, and containment structure) to limit the level of radiation dose to 

the public. The proposed changes do not alter any safety analyses assumptions, safety 

limits, limiting safety system settings, or methods of operating the plant. The changes do 

not adversely impact plant operating margins or the reliability of equipment credited in the 

safety analyses. The proposed changes do not adversely affect systems that respond to 

safely shutdown the plant and to maintain the plant in a safe shutdown condition. 

Therefore, the proposed change does not involve a significant reduction in a margin of 

safety. 

5.0 ENVIRONMENTAL CONSIDERATION 

NextEra has evaluated the proposed amendment for environmental considerations. The review 

has determined that the proposed amendment would change a requirement with respect to 

installation or use of a facility component located within the restricted area, as defined in 

1 OCFR20, or would change an inspection or surveillance requirement. However, the proposed 

amendment does not involve (i) a significant hazards consideration, (ii) a significant change in 

the types or significant increase in the amounts of any effluent that may be released offsite, or 

(iii) a significant increase in individual or cumulative occupational radiation exposure. 

Accordingly, the proposed amendment meets the eligibility criterion for categorical exclusion set 

forth in 10CFR51.22(c)(9). Therefore, pursuant to 10CFR51.22(b), no environmental impact 

statement or environmental assessment needs to be prepared in connection with the proposed 

amendment. 

6.0 REFERENCES 

1. American Concrete Institute (ACI) Standard 318-71, "Building Code Requirements for 

Reinforced Concrete." 
--Non-Proprietary Version--

2. American Society of Mechanical Engineers (ASME) Boiler & Pressure Vessel Code (1975 

Edition), Section III, Division 2. 

3. ASTM C289-71, "Standard Test Method for Potential Alkali-Silica Reactivity of 

Aggregates (Chemical Method)," American Society for Testing and Materials, 1971. 

4. MPR-3727, Revision 1, "Seabrook Station: Impact of Alkali-Silica Reaction on Concrete 

Structures and Attachments," May 2012. (Seabrook FP# 100716) 

5. IE Bulletin 79-02, "Pipe Support Base Plate Designs Using Concrete Expansion Anchors," 

Revision 2. 

6. Root Cause Report for Seabrook Station Containment Enclosure Building Local 

Deformation, CR Number 2014325. 

7. Letter w/Attachment from Mr. C. Miller (NRC) to Mr. K. Walsh (NextEra), "Seabrook 

Station, Unit No. 1 - Confirmatory Action Letter Follow-Up Inspection - NRC Inspection 

Report 05000443/2012009," dated December 3, 2012. 

8. Letter w/Attachment from Mr. R. Lorson (NRC) to Mr. K. Walsh (NextEra), "Seabrook 

Station, Unit No. 1 - Confirmatory Action Letter Follow-Up Inspection - NRC Inspection 

Report 05000443/2012010," dated August 9, 2013. 

9. Letter w/Attachment from Mr. G. Dentel (NRC) to Mr. K. Walsh (NextEra), "Seabrook 

Station, Unit No. 1 - NRC Integrated Inspection Report 05000443/2013005," January 30. 

2014. 

10. Letter w/Attachment from Mr. G. Dentel (NRC) to Mr. K. Walsh (NextEra), "Seabrook 

Station, Unit No. 1 - NRC Integrated Inspection Report 05000443/2014002," May 6. 2014. 

11. Letter w/Attachment from Mr. G. Dentel (NRC) to Mr. D. Curtland (NextEra), "Seabrook 

Station, Unit No. 1 - NRC Integrated Inspection Report 05000443/2014005," February 6, 

2015. 

12. Letter w/Attachment from Mr. G. Dentel (NRC) to Mr. D. Curtland (NextEra), "Seabrook 

Station, Unit No. 1 - Integrated Inspection Report 05000443/2015002," August 5, 2015. 

13. Letter w/Attachment from Mr. T. Tran (NRC) to Mr. D. Curtland (NextEra), "Alkali Silica 

Reaction Monitoring Aging Management Program Audit Report Regarding The Seabrook 

Station, Unit 1, License Renewal (TAC No. ME4028)," December 17, 2015. 

14. Letter w/Attachment from Mr. G. Dentel (NRC) to Mr. D. Curtland (NextEra), "Seabrook 

Station, Unit No. 1 - Integrated Inspection Report 05000443/2015004 and Independent 

Spent Fuel Storage Installation Report No. 07200063/2015001," February 12, 2016. 
--Non-Proprietary Version--

15. Report No. 150252-SVR-01-Rl, "Phase IA Investigation of Apparent Movement of the 

Containment Enclosure Building at the NextEra Energy Seabrook Station, NH," June 25, 

2015. 

16. PEG-98, Revision 0, "CEB Extent of Condition Walkdown," July 29, 2015. 

17. Simpson Gumpertz & Heger, Computation of Load Factors for ASR Demands, 160268-

CA-01 Rev. 0, July 26, 2016. 

18. Ellingwood, B. et al., Development of a Probability Based Load Criterion for American 

National Standard A58, NBS Special Publication 577, June 1980. 

19. Not used. 

20. MPR-4153, Revision 2, "Seabrook Station -Approach for Determining ThroughThickness Expansion from Alkali-Silica Reaction," July 2016. (Seabrook FP# 100918) 

21. Report No. 120555-SVR-25-RO, "June 2015 -ASR Inspections and Crack Index 

Measurements on Concrete Structures, NextEra Energy Seabrook Station, NH," August 

2015. 

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

Mitigation of Alkali-Silica Reaction in Transportation Structures," January 2010. 

23. SG&H Report 160268-R-Ol, "Development of ASR Load Factors for Seismic Category I 

Structures (Including Containment) at Seabrook Station, Seabrook, NH," Revision 0 

(Seabrook FP# 101039) 

24. MPR-4288, Revision 0, "Seabrook Station: Impact of Alkali-Silica Reaction on the 

Structural Design Evaluations," July 2016. (Seabrook FP# 101020) (Proprietary) 

25. MPR-4273, Revision 0, "Seabrook Station - Implications of Large-Scale Test Program 

Results on Reinforced Concrete Affected by Alkali-Silica Reaction," July 2016. 

(Seabrook FP# 101050) (Proprietary) 

26. Simpson Gumpertz & Heger Inc., "Evaluation and Design Confirmation of As-Deformed 

CEB, 150252-CA-02," Revision 0, July 2016. 
SBK-L-16071 

ENCLOSURES 

Affidavit in Support of Application for Withholding Proprietary Information 

from Public Disclosure 

l 
Subject: 

NextEra Energy Seabrook Application for 

Withholding Proprietary Information from Public Disclosure 

MPR-4273, Revision 0, "Seabrook Station - Implications of Large-Scale 

Test Program Results on Reinforced Concrete Affected by Alkali-Silica 

Reaction," July 2016. (Seabrook FP# 101050) (Proprietary) 

MPR-4288, Revision 0, "Seabrook Station: Impact of Alkali-Silica 

Reaction on the Structural Design Evaluations," July 2016. (Seabrook 

FP# 101020) (Proprietary) 

Enclosure 1 to SBK-L-16071, "NextEra Energy Seabrook's Evaluation of 

the Proposed Change" (Proprietary) 

Enclosures 1, 5, and 6 to this letter, "NextEra Energy Seabrook's Evaluation of the 

Proposed Change" (Proprietary), MPR-4273, Revision 0, "Seabrook Station -

Implications of Large-Scale Test Program Results on Reinforced Concrete Affected by 

Alkali-Silica Reaction," July 2016 (Seabrook FP# 101050) (Proprietary), and MPR4288, Revision 0, "Seabrook Station: Impact of Alkali-Silica Reaction on the Structural 

Design Evaluations," July 2016 (Seabrook FP# 101020) (Proprietary) contain NextEra 

Energy Seabrook proprietary information. This letter is supported by an affidavit signed 

by NextEra Energy Seabrook, setting forth the basis on which the information may be 

withheld from public disclosure by the Commission and addressing the considerations 

listed in 10 CFR 2.390(b )( 4). Accordingly, it is respectfully requested that the 

information which is proprietary be withheld from public disclosure in accordance 10 

CFR2.390. 

Correspondence with respect to this application for withholding or the accompanying 

affidavit should be addressed to Mr. Kenneth Browne, Licensing Manager at (603) 773-

7932. 
ATTACHMENT 1 

Markup of UFSAR Pages 

(30 Pages) 
SEABROOK INTRODUCTION AND GENERAL DESCRlPTION OF PLANT Revision 16 

STATION Conformance to NRC Regulatory Guides Section 1.8 

UFSAR Page 36 

Regulatory Guide 1.92 presents three other means of combining closely spaced modes. 

Justification for nonconformance is that the methods prescribed in the guide are not here 

applicable since the construction permit application docket date is before the date of issue of the 

guide. In addition, the method used is deemed more conservative. For further discussion, refer 

to Section 3.7(B) and Subsection 3.7(B).3.7. 

(Rev. 3, 1012012) Modes and Spatial Components in Seismic Response 

Analyses 

A procedure for combining the three spatial components of an earthquake for seismic response 

analysis of nuclear power plant structures, systems, and components (SSCs) that are important to 

safety is presented in Subsection C.2.1. The Response Spectrum Method that uses the 100-40-

40 percent combination rule, as described in Regulatory Position C.2.1 of this guide, is acceptable 

as an alternative to the SRSS method. 

The 100-40-40 percent rule is used as an alternative to the SRSS method for combining three 

directional seismic loading in the analysis of seismic, Category I structures that are deformed by 

the effects of ASR. In general, the 100-40-40 combination method produces higher estimates of 

maximum response than the SRSS combination method by as much as 16 percent, while the 

maximum under-prediction is 1 percent. 

Refer to Section 3. 7(B).2.1 for further discussion of this subject. 

Regulatory Guide 1.93 

(Rev. 0, 12/74) Availability of Electric Power Sources 

The Technical Specification (TIS) ac and de power sources allowable out-of-service times 

(action statements) are based on RG 1.93. Where differences exist between the TIS and 

RG 1.93, the TIS are the governing document. 

RG 1.93 does not allow out-of-service times to be used for preventative maintenance that 

incapacitates a power source. These activities are to be scheduled for refueling or shutdown 

periods. This is interpreted to also apply to surveillance activities. Preventative maintenance 

and surveillance activities are performed on-line when permitted by the TIS and with appropriate 

consideration of the effects on safety, reliability, and availability. 

Regulatory Guide 1.95 

(Rev. l , 2/77) Protection of Nuclear Power Plant Control Room 

Operators Against Accidental Chlorine Release 

The relevant portions of Regulatory Guide 1.95 are complied with based on the findings that the 

plant design does not include the storage of chlorine within 100 meters of the control room, 

excluding small laboratory quantities, nor is there chlorine stored in excess of the maximum 

allowable chlorine inventory, as given as a function of distance in Regulatory Guide 1.95 for 

Type I control rooms (refer to Subsection 2.2.3.1 ). 
SEABROOK DESIGN OF STRUCTURES, COMPONENTS, EQUIPMENT AND Revision 11 

STATION SYSTEMS Section 3.7(8) 

UFSAR Seismic Design Page 4 

3.7(B).2 Seismic System Analysis 

This subsection contains a discussion of the seismic analyses performed for seismic Category I 

structures and systems. Included in the discussion are the methods of seismic analysis used, the 

criteria used for mathematically modelling the structures and systems, the assumptions made in 

the analyses, and the effects considered. 

3.7(B).2.1 Seismic Analysis Methods 

The seismic response of Category I structures, systems and components has been determined 

from suitable elastic dynamic analyses. The results of these analyses are used for the design of 

seismic Category I structures, systems and components, and are input for subsequent dynamic 

analyses. 

Two methods of seismic system analysis were used for seismic Category I structures: (I) the 

modal analysis response-spectrum method and (2) the mode-superposition time-history method. 

The time-history method was used to determine the dynamic response necessary to obtain 

amplified response spectra for component design. The input forcing functions (the time history 

of ground motion) are shown graphically in Figure 3.7(B)-l , Figure 3.7(B)-2 and 

Figure 3.7(B)-3. The time history shown on Figure 3. 7(B)-1 is used in both horizontal 

directions. The peak acceleration is 0.25g for the SSE and 0.125g for the OBE. Design response 

spectra for the response-spectrum method are shown in Section 2.5. 

The mathematical models used for the seismic Category I structures are typically lumped masses 

connected by linear elastic springs. Each structure, then, is described by a finite number of 

degrees-of-freedom chosen to represent the principal overall behavior of the system. The 

modelling is described in Subsection 3.7(B).2.3 in more detail. The number of masses or 

degrees-of-freedom included in the analysis is determined by requiring the total 

degrees-of-freedom to exceed twice the number of significant modes with frequencies less than 

33 Hz. Up to four degrees-of-freedom were considered for each mass point, three translation and 

one torsion. The three orthogonal directions were run separately, and results were combined by 

the grouping method in accordance with Regulatory Guide 1.92. The orthogonal spatial 

components of seismic loads for response spectrum analyses of structures deformed by the 

effects of ASR are combined using the 100-40-40 procedure in Regulatory Guide 1.92 

Revision 3. 

All significant modes with frequencies up to 50 Hz were used in analyses for both local and 

overall effects. 

The effects due to inertial characteristics of fluid contained within a structural component were 

considered in the analysis by techniques described in Reference 1. No soil-structure interaction 

effects were involved because of the rock siting. 
SEABROOK DESIGN OF STRUCTURES, COMPONENTS, EQUIPMENT AND Revision 16 

STATION SYSTEMS Section 3.8 

UFSAR Design of Category I Structures Page 21 

(Section 3.8.1.3 continued ... ) 

(f) Alkali Silica Reaction Loads (Sa) 

These are structural effects caused by ASR expansion of concrete. 

ASR loads are passive and therefore occur during normal operation, 

shutdown conditions, and concurrently with all extreme 

environmental loads. The effects of ASR expansion occurring in 

reinforced concrete structural members are considered. 
SEABROOK DESIGN OF STRUCTURES, COMPONENTS, EQUIPMENT AND Revision 16 

STATION SYSTEMS Section 3.8 

UFSAR Design of Category I Structures Page 109 

(Section 3.8.3.3 continued .. . ) 

a. Design Loads 

The definitions of the loads used in the design of the internal structures include 

the following: 

1. Normal Plant Startup. Operation and Shutdown Loads 

Normal loads are those loads encountered during normal plant start-up, 

operation and shutdown. They include the following: 

(a) Dead Loads (D) 

Dead loads are all permanent gravity loads including the weight of 

concrete walls and slabs, structural framing, piping, cable and 

cable trays, permanent equipment, and static pressures of liquids. 

Concrete creep, shrinkage, and swe lling are considered for 

structures affected by the expansion of concrete from alkali-silica 

reaction (ASR). See Subsection 3.8.4.6 for a description of the 

effects of ASR on concrete. 

(b) Live Loads (L) 

Live loads include any movable equipment loads and other loads 

which vary in intensity and/or occurrence. Live loads are present 

only during shutdown conditions, and do not govern the design of 

any components. 

( c) Operational Thermal Loads (T 0 ) 

The temperature gradient through the walls under normal operating 

conditions is considered in the design. For a discussion of 

minimum and maximum operating temperatures, see 

Subsection 6.2.1. 

( d) Operational Pipe Reactions (R0 ) 

These are pipe reactions due to thermal conditions existing in the 

piping during normal operation or shutdown. They are based on 

the most critical transient or steady-state condition. 

(e) Alkali-Silica Reaction Loads 

These are structural effects caused by ASR. ASR loads are 

passive and therefore occur during normal operation, 

shutdown conditions, and concmrently with all extreme 

environmental loads. The effects of ASR expansion occurring 
SEABROOK 

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DESIGN OF STRUCTURES, COMPONENTS, EQUIPMENT AND Revision 16 

SYSTEMS Section 3.8 

Design of Category I Structures Page 110 

in reinforced concrete structural mern be rs as well as concrete 

backfill are considered. 

2. Severe Environmental Loads 

Severe environmental loads are those loads that result from events that 

could infrequently be encountered during the plant life. The only load 

included in this category is the following: 

(a) Operating Basis Earthquake (E0 ) 

These are the loads generated by the Operating Basis Earthquake, 

which is the earthquake that could reasonably be expected to affect 

the site during the operating life of the plant. Only the actual dead 

load and weights of fixed equipment are considered in evaluating 

the seismic response forces. 

· The horizontal and vertical design response spectra for the OBE 

are derived by applying a factor of 0.5 to the response spectra 

given for the Safe Shutdown Earthquake (SSE) which is described 

below. The effects of two (2) orthogonal horizontal components 

and one (1) vertical component of earthquake are considered and 

combined by the square-root-of-the-sum-of-the-squares rule. 

3. Extreme Environmental Loads 

Extreme environmental loads are those loads which result from events 

which are credible but highly improbable. The only load included in this 

category is the following: 

(a) Safe Shutdown Earthquake (Ess) 

These are the loads generated by the Safe Shutdown Earthquake, 

which is the earthquake based upon an evaluation of the maximum 

earthquake potential in the vicinity of the plant. Dead and fixed 

equipment loads are described under the Operating Basis 

Earthquake, above. The horizontal and vertical forces on the 

internals are developed from the response spectra given in 

Figure 2.5-38 and Figure 2.5-39 the development of which is 

described in Subsection 2.5.2.6. 

The effects of two (2) orthogonal horizontal earthquakes and 

one (1) vertical earthquake are considered and combined by the 

square-root-of-the-sum-of-the-squares rule. 
SEABROOK DESIGN OF STRUCTURES, COMPONENTS, EQUIPMENT AND Revision 16 

STATION SYSTEMS Section 3.8 

UFSAR Design of Category I Structures Page 113 

(Section 3.8.3.3 continued ... ) 

(2) The containment structure functions as an independent 

structure with complete physical separation from the 

internal structures, and therefore there are no loading 

interactions between the two. 

(3) Compartmentalization is considered in the design of the 

internal structures by using the peak subcompartment 

differential pressures, plus a safety margin. This is further 

discussed in Subsection 6.2.1.2. 

(4) Self-Straining Loads 

b. Load Combinations 

The containment internals concrete is analyzed for 

deformation caused by ASR and is designed to withstand 

the effects of ASR expansion, creep, shrinkage, and 

swelling 

Various load combinations are considered in design to determine the greatest 

strength requirements of the structure. Where varying loads occur, the 

combinations producing the most critical loading are used. Basic combinations in 

the design of the containment internal structures are given in Table 3.8-14. These 

load combinations are in agreement with Subsections 11.3 and 11.5 of the Standard 

Review Plan for Subsection 3.8.3 of the UFSAR. The factors which are to be 

applied to allowable stresses have been transposed and applied as load factors 

instead, resulting in acceptance criteria as indicated in the table. Two categories 

of loading conditions and criteria are used in the design of the containment 

internal structures as described below. 

1. Normal Load Conditions 

Normal load conditions e those encountered during testing and normal 

operation. They include dead load, live load, Alkali Silica Reaction 

(ASR) loads, and anticipated transients or test conditions during normal 

and emergency startup and shutdown of the Nuclear Steam Supply, Safety 

and Auxiliary Systems. Normal loading also includes the effect of an 

Operating Basis Earthquake. Normal load conditions are referred to in 

Division 2 as service load conditions. 
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DESIGN OF STRUCTURES, COMPONENTS, EQUIPMENT AND Revision 16 

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Design of Category I Structures Page 119 

4. STAAD III Structural Analysis and Design Software: A proprietary 

computer program of Research Engineers, Inc. (REI), California, for the 

analysis and design of structures. The code has been placed under 

configuration control by Westinghouse and specific features of this 

software utilized in the simplified head assembly calculations have been 

independently verified by Westinghouse. (Westinghouse Letter Number 

EDRE-CSE-134(97), Software Release of STAAD III (22.0W) on 

Windows NT System, 9/25/97, and Westinghouse Calculation 

#CSE-06-98-0001, Rev. 0, titled: "STAAD Verification 

Problem-Response Spectra Analysis.") 

5. GOTHIC Generation of Thermal-Hydraulic Information for 

Containments: GOTHIC is a general purpose thermal-hydraulic computer 

program for design, licensing, safety and operating analysis of nuclear 

power plant containments and other confinement buildings. GOTHIC has 

been developed for the Electric Power Research Institute (EPRI) by 

Numerical Applications Inc, Richland, Washington . The code has been 

placed under configuration control by Westinghouse. (GOTHIC 

Qualification Report for Version 5.0e (NAI 8907-09, Rev. 3, Dec. 1995.) 

Structural Acceptance Criteria 

The bases for the development of the fol lowing stress-strain criteria are the ACI 318-71 and 

AISC codes. 

a. Normal Load Conditions 

Internal structures are proportioned to remain within the elastic limits under all 

normal loading conditions described in Subsection 3.8.3.3. 

Reinforced Concrete - designed in accordance with ACl 318-71 Strength Method, 

which insures flexural ductility by control of reinforcing steel percentages and 

stresses. 

Structural and Miscellaneous Steel - designed in accordance with AISC 

Specification for the Design, Fabrication and Erection of Structural Steel for 

Buildings, Part I. 

b. Unusual Load Conditions 

Internal structures are designed to maintain elastic behavior under all unusual load 

conditions shown in Subsection 3.8.3.3. The upper bound of elastic behavior is 

taken as the yield strength capacity of the load carrying components. The yield 

strength of structural and reinforcing steel is taken as the minimum guaranteed 

yield stress as given in the appropriate ASTM Specification. 
SEABROOK DESIGN OF STRUCTURES, COMPONENTS, EQUIPMENT AND Revision 16 

STATION SYSTEMS Section 3.8 

UFSAR Design of Category I Structures Page 121 

(Section 3.8.3.6 continued . .. ) 

a. Concrete 

Concrete work is in accordance with ACI 318-71 and ACJ 301 codes, except as 

noted in Subsection 1.8 (Regulatory Guide 1.55). The concrete is a dense, 

durable mixture of sound, coarse aggregate, cement and water. Admixtures were 

added, where required, to improve the quality and workability during placement 

and to retard the set of the concrete. Engineering approval was required prior to 

the use of admixtures. 

Aggregate conforms to ASTM C33 . It consists of inert materials that are clean, 

hard and durable, free from organic material and uncoated with clay or dirt. Fine 

aggregate consists of natural sand and the coarse aggregate consists of crushed 

stone. 

Portland cement conforms to ASTM Cl 50, Type II (moderate heat of hydration 

requirements). 

Water is clean and free from any deleterious amounts of acid, alkali, salts, oil, 

sediment, organic matter or other substances which may be harmful to the 

concrete or steel. 

The reinforced concrete has a nominal density of 150 lb/ft3, which is used for 

determination of dead load. Shielding calculations for the primary shield wall are 

based on a dry concrete density of 139 lb/ft3

; other shielding calculations are 

based on a dry concrete density of 147 lb/ft3. The 28-day standard compressive 

strength of the concrete is 4000 psi. 

Refer to Subsection 3.8.4.6 for a discussion on the material effects of Alkali Silica 

Reaction (ASR) on concrete 

To assure that adequate means of control were used in the manufacture and that 

the properties described above were realized, the following were required: 

1. Suppliers, fabricators and contractors were required to have written quality 

assurance procedures, which were reviewed and approved by United 

Engineers. Material certifications were required in accordance with the 

applicable portions of the quality assurance plan described in Chapter 17 

of the UFSAR and in the material specifications. 
SEABROOK DESIGN OF STRUCTURES, COMPONENTS, EQUIPMENT AND Revision 16 

STATION SYSTEMS Section 3.8 

UFSAR Design of Category I Structures Page 124 

d. Steel and Concrete Coating System 

3.8.3.7 

Materials used for coating the internal structures are the same as those described 

in Subsection 3.8.1.6. These materials meet the requirements of ANSI Standard 

NlOl.2. 

Testing and In-Service Surveillance Requirements 

Quality control testing as discussed in Subsection 3.8.3.6 will be employed. No additional testing 

or in-service surveillance is required. 

Refer to Subsection 3.8.4.7 for a discussion on the Structural Monitoring Program requirements 

for inspection of ASR affected structures 
SEABROOK DESIGN OF STRUCTURES, COMPONENTS, EQUIPMENT AND Revision 16 

STATION SYSTEMS Section 3.8 

UFSAR Design of Category I Structures Page 27 

(Section 3.8.1.3.b continued) ... 

3.8.1.4 

Long-term conditions, such as operating thermal loads, creep and 

shrinkage, which produce compression in the reinforcing steel, do not 

have a significant effect on the structural integrity of the containment 

structure, since the accident loads, whjch are the most significant loads, 

are generally resisted in tension by the reinforcing steel. In addition, the 

accident loads are short once-occurring loads whkh will have negligible 

creep effects. The self-straining loads associated with ASR expansion are 

considered for localized areas affected by ASR in combination with other 

loads as indicated in Table 3.8-1. 

For the design of the liner, the load combinations in Table 3.8-1 are 

applicable with the exception that coefficients for all load cases are taken 

equal to 1.0. 

Steel components of the containment shell that are pressure-resisting but 

unbacked by concrete are designed in accordance with the ASME Code, 

Section III, Division l , using loads described in Subsection 3.8.2. 

Ea11hquake effects are not asswned to occm simultaneously with flooding 

effects since the maximum flood is not associated with an earthquake. 

Effects of a thermal gradient through the concrete section are not 

considered where the effects of the gradient reduce the effects caused by 

an abnormal loading condition. 

Maximum values of time-dependent loads such as accident pressure, 

temperature and pipe break loads are considered. 

The load combinations in Table 3.8-1 are applicable to the computations 

of factors of safety against overturning, sliding and flotation, with the 

exception that the coefficient for live load is zero. Buoyant forces are 

conservatively considered to decrease the dead loads for determination of 

overturrung and sliding. 

Design and Analysis Procedures 

The containment structme is designed as a reinforced concrete thin shell structure in accordance 

with the requirements of Article CC-3000 of Division 2, as described in this Subsection and in 

other subsections of Subsection 3.8.1 , and in accordance with the other applicable codes, 

standards and specifications defined in Subsection 3.8. l.2. The containment structure is 

designed to safely withstand the load combinations as defined in Subsection 3.8.1.3, and to 
SEABROOK DESIGN OF STRUCTURES, COMPONENTS, EQUIPMENT AND Revision 16 

STATION SYSTEMS Section 3.8 

UFSAR Design of Category I Structures Page 32 

(Section 3.8. l .4) 

e. Transient and Localized Loads 

A "hot Liner" transient load was analyzed and accounted for in the design of the 

reinforced concrete wall. A temperature spike was placed on the liner for two 

cases: (a) "hot liner" with no temperature gradient on concrete wall, and (b) "hot 

liner" with a temperature gradient through the wall (see Table 3.8-4). When 

combined with mechanical loads, the effect of thermal loadings is a redistribution 

of stresses and strains on the cross section. The stresses and strains in the Liner 

are discussed in Subsection 3.8.1.4k, "Steel Liner Plate and Anchors." 

The aircraft impact analysis is described in detail in Appendix 2P. Three analyses 

were performed: two of the overall structural behavior and one localized 

elasto-plastic dynamic analysis. The analyses of overall behavior considered the 

conditions of impact on the dome (axisymmetric structure with axisymmetric 

loading) and impact on the springline (axisymmetric structure with unsymmetric 

loading). Both analyses assumed linear behavior and used the Wilson TT finite 

element code. The asymmetric loading of the second analysis was represented by 

a Fourier series. Both analyses showed that yielding would occur local to the 

point of impact. Accordingly, a localized, nonlinear analysis was used to 

determine the extent of damage to the containment shell. The details of this 

analysis are also found in Appendix 2P. In brief, effective mass and stiffness 

properties were determined for an assumed mode of collapse consisting of a 

circular fan yield-Line configuration. 

An equivalent single-degree-of-freedom nonl inear model was then subjected to an 

idealized force-time Loading function and the maximum deformations determined. 

It was shown that the "as designed" containment structure with Enclosure 

Building can withstand impact of an FB-111 aircraft at 200 -mph impact speed 

without collapse or impairment of the leak-tight integrity of the liner. 

The localized strain from ASR expansion is determined from measurements of the 

structure in ASR-affected locations. Closed form analytical equations for 

cylindrical shells subjected to local loadings were used to calculate the forces and 

moments to localized ASR expansions. The ASR loads are combined with other 

loads for the structure to analyze critical areas affected by ASR. 
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DESIGN OF STRUCTURES, COMPONENTS, EQUIPMENT AND Revision 16 

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Design of Category I Structures Page 36 

The forces and moments due to seismic loading are discussed in Subsection 3.7.2. 

Three components of the seismic motion were assumed to exist simultaneously, 

and the resulting component forces and moments were combined by the 

square-root-of-the-sum-of-the squares (SRSS) method. The maximum tangential 

shear from the SRSS combination is assumed to act simultaneously at all points 

on the containment circumference at the given elevation. All forces and moments 

were combined per the specified load combinations. The LESCAL program, 

described in Subsection 3.8.1.4g, was used to calculate rebar stresses for all 

sections and elevations combining the stresses due to in-plane forces and 

moments. Duchon's equations (Reference 3) are incorporated into LESCAL for 

calculating rebar stresses (including inclined rebar) for the combined membrane 

forces. 

(Section 3.8. l .4.i) 

i. Variation in Physical Material Properties 

The effects of variations in material properties were considered in the design and 

analysis. Material properties which can strongly influence both analysis and 

design due to variability or uncertainty include: (1) dynamic modulus of soils, (2) 

the modulus of elasticity of concrete and, (3) material strengths. 

As this containment is founded on rock, the fLrst of these sources of variability is 

removed from consideration. The modulus of elasticity of concrete is a function 

of concrete compressive strength which in turn is typically substantially higher in 

the "as-built" structure than assumed for analysis and design. While variability in 

concrete modulus has no significant effect on structural design, it influences 

structural stiffness and natural frequency, and, subsequently, the amplified 

response spectra of the seismic analysis. This impacts equipment design as 

discussed in Subsection 3.7.3. The variability was accounted for by peak 

spreading when generating envelopes of the response spectra. Variability in 

material strength is taken into account in Division 2, Subarticle CC-3400, design 

allowables. 

Analyses and tests were completed to assess the effects of ASR on structural 

properties of reinforced concrete. The results indicate that using the structural 

properties and code equations from the original design analysis is conservative 

when ASR expansion levels are below the limits defined in Subsection 3.8.4.7. 

Concrete expansion from ASR imposes a localized tensile strain in the 

reinforcement. 
SEABROOK DESIGN OF STRUCTURES, COMPONENTS, EQUIPMENT AND Revision 16 

STATlON SYSTEMS Section 3.8 

UFSAR Design of Category I Structures Page 136 

(Section 3.8.4.3a. l continued .. . ) 

(a) Dead Loads (D) 

Dead loads are all permanent gravity loads including, but not 

limited to, concrete walls and slabs, structural framing, piping, 

cable and cable trays, permanent equipment and miscellaneous 

building items. Hydrostatic pressures of liquids are also 

included in this category. Concrete creep, shrinkage, and 

swelling are considered for structures affected by the expansion 

of concrete from alkali-silica reaction (ASR). See Subsection 

3.8.4.6 for a description of the effects of ASR on concrete. 

(b) Live Loads (L) 

Live loads are all temporary gravity loads including but not 

limited to normal snow loads, conventionally distributed and 

concentrated floor loads, and movable equipment loads, such as 

cranes and hoists. 

Equipment operating loads and impact factors are the greater of 

those recommended by the manufacturer or the applicable building 

codes. 

Unusual snow load (L5) , which is greater in magnitude than normal 

snow load, was also used where applicable. Lateral earth 

pressures due to soil backfill (H) were used where applicable. 

Three types of lateral earth pressure loading, active, at rest and 

passive, were considered, with pressures determined by 

acceptable theories of soil mechanics. 

( c) Operational Thermal Loads (T 0 ) 

These are the thermal effects and loads occurring dming normal 

operating or shutdown conditions, based on the most critical 

transient or steady-state condition. 

( d) Operational Pipe Reactions (R0 ) 

These are the pipe reactions occwTing during normal operating or 

shutdown conditions, based on the most critical transient or 

steady-state condition. 
SEABROOK 

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D ESIGN OF STRUCTURES, COMPONENTS, EQUIPMENT AND 

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Design of Category I Structmes 

(e) Alkali-Silica Reaction Loads 

Revision 16 

Section 3.8 

Page 137 

These are structural effects caused by ASR. ASR loads are 

passive and therefore occur during normal operation, 

shutdown conditions, and concurrently with all extreme 

environmental loads. The effects of ASR expansion occurring 

in reinforced concrete structural members as well as concrete 

backfill are considered. 

- 2 -
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1. Normal Load Conditions 

Normal load conditions are those encountered during testing and normal 

operation and are referred to in the standard review plan as service load 

conditions. They include dead load, live load and anticipated transients, 

loads occurring during normal startup and shutdown, and loads occurring 

during emergency shutdown of the nuclear steam supply, safety and 

auxiliary systems. Normal loading also includes the effect of an operating 

basis earthquake and normal wind load. Under each of these loading 

combinations the structures were designed so that stresses are withjn the 

e lasti c limits. Design and analysis procedures are presented in 

Subsection 3.8.4.4 and stress limitations are presented in 

Subsection 3.8.4.5. 

2. Unusual Load Conditions 

Unusual load conditions are those resulting from combinations of 

accident, wind, tornado, earthquake, live and dead loads and are referred 

to in the standard review plan as factored load conditions. 

For these loading combinations, the structures were designed to remain 

below their ultimate yield capacity such that deformations will be small 

and structural components will respond elastically. Design and analysis 

procedures are presented in Subsection 3.8.4.4 and stress limitations are 

presented in Subsection 3.8.4.5. 

(Section 3.8.4.3 continued .. . ) 

c Other Load Considerations 

1. Creep 

Effects of concrete creep are negligible due to the low sustained concrete 

stresses associated with conventionally reinforced concrete structures and, 

therefore, were not a governing factor in design. Concrete creep is 

included with other self-straining loads in the design of structures with 

deformation caused by the effects of ASR expansion. 

2. Stability 

The other seismic Category I structures were checked for overturning, 
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sliding, and flotation using the load combinations of Table 3.8-16 with the 

exception that the coefficient for live load is zero. Buoyant forces were 

considered to decrease the dead load in computing both overturnjng and 

sliding. 

3. Self-Straining Loads 

Structures that are analyzed for deformation caused by ASR are designed to 

withstand the effects of ASR expansion, creep, shrinkage, and swelling. 
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3.8.4.4 

a 

DESIGN OF STRUCTURES, COMPONENTS, EQUIPMENT AND 

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Design of Category I Structures 

Design and Analysis Procedures 

Design and Analysis 

Revision 16 

Section 3.8 

Page 141 

Categ01y I structures other than the containment are constructed of reinforced 

concrete with structural steel framing used to support vertical loading on floor 

slabs. Structural steel is also used to provide enclosure for some areas, as 

described in Subsection 3.8.4.1 , and for other miscellaneous purposes. 

Reinforced concrete structures consist of a system of walls and slabs generally to 

provide a continuous, integral framing system. Vertical forces are transferred to 

the foundation mats through the walls and structural steel and reinforced concrete 

columns. Lateral forces are transferred to the foundation mats primarily by the 

action of shear walls; some load is also transferred by means of flexural action of 

the walls, all of which are rigidly attached at the mat. 

The Containment Enclosure Building, due to its cylindrical and hemispherical 

shape and relative dimensions, was analyzed as a three-dimensional, thin-shell 

structure. Boundary conditions were consistent with the support on rock and the 

lateral restraint provided by backfill concrete placed against the structure. 

Internal resultant forces and moments were determined by integration of the 

appropriate shell stresses through the thickness. Critical transverse shear force 

was derived by considering the variations in bending moments across the surface, 

in conjunction with the applied hydrostatic load (which produces additional local 

shear not reflected in the finite element analysis). Reinforcing was subsequently 

designed for these internal forces. 

Columns are designed to resist other lateral loads, such as pipe loads or building 

displacements, in addition to those forces transmitted to the columns at floor 

levels. Steel columns are generally pin-connected at the foundation mat, and 

reinforced concrete columns are rigidly attached. Structural steel framing for 

floor systems primarily consists of pin-connected framing with some members 

being continuous. Rigidity is provided by the box-like concrete walls and slabs. 

Structures with deformation were analyzed by calculating the self-straining load 

associated with the combined effects of ASR-expansion, creep, shrinkage, and 

swelling as determined from measmements of the structure. ASR expansion 

loads were combined with other loads and the appropriate load factors from 

Table 3.8-16 were applied. 

Several computer programs were used for static analysis and are described in 

Appendix 3F. 

Table 3.8-17 contains a list of these programs and the respective structures for 

which they were used. The load combinations are given in Subsection 3.8.4.3. 
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SYSTEMS Section 3.8 

Design of Category I Structures Page 143 

In the Waste Processing Building only those areas housing radioactive gaseous 

waste equipment were designed for tornado loads; the other areas do not contain 

safety-related equipment. Procedures by which the structures were checked for 

missile loads, tornado-generated as well as internally generated, are described in 

Section 3.5. Determination of pressures on structures due to tornado is described 

in Subsection 3.3.2. Pressure loadings from wind are described in 

Subsection 3.3. l. 

The seismic analysis of seismic Category I structures is described in 

Subsection 3.7.2. All cranes in these structures are furnished with hold-down 

devices to ensure that they are not dislodged by earthquake forces. Monorails, by 

nature of their support mechanisms, cannot be dislodged by earthquake forces. 

Using methods outlined in TID-7024, "Nuclear Reactors and Earthquakes," the 

effects of hydrodynamic forces were included in the seismic analyses of the 

Service Water Cooling Tower. Also using methods outlined in TID-7024, the 

weight of constrained water and sloshing effects of water in motion were included 

as equivalent static loads in the final design of the Service Water Cooling Tower, 

Service Water Pumphouse and Fuel Storage Building. 

Reinforced concrete design of Category l structures was in accordance with the 

strength design procedures of the ACJ 318-71 code, except as indicated in 

Subsection 3.8.4.5. Structural steel design was in accordance with the provisions 

of the AISC Specification for the Design, Fabrication and Erection of Structural 

Steel for Buildings (1969 Edition). Refer to Subsection 1.8 (Regulatory 

Guide 1.142) for a statement concerning compliance with ACl-349. 

(Section 3.8.4.4 continued .. . ) 

b. Material Properties 

Material properties were selected from the normal range of values to produce a 

conservative design. See Subsection 3.8.1.4 for a detailed discussion of the 

influence of material properties on design and analysis. 

Analyses and test of ASR-affected concrete concluded that the capacity of 

structural members and embedded concrete anchors in ASR-affected struchlres is 

not reduced when ASR expansion levels are below the limits included in 

Subsection 3.8.4.7. 

c. Computer Programs 

The computer programs used in analysis and design of other Category I structures 
SEABROOK 

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D ESIGN OF STRUCTURES, COMPONENTS, EQUIPMENT AND 

SYSTEMS 

Design of Category I Structures 

Revision 16 

Section 3.8 

Page 147 

T n June 2010, concrete cores were removed for examination and testing from the walls of the 

lower electrical tunnel in the Control Building, as part of preparations for license renewal 

inspections. The purpose was to evaluate potential concrete aging effects in below grade areas of 

the plant that had been subjected to historical groundwater wetting of the concrete. In general 

the removed cores showed the expected quality materials and placements from original 

construction. There were no obvious visual signs of aging distress or concrete degradation. 

Petrographic examinations were performed which involved sectioning and polishing the core 

samples and analysis under magnification by a qualified professional petrographer. This analysis 

revealed micro cracks and other features indicative of Alkali Silica Reaction (ASR). Materials 

testing of the removed cores also resulted in lower than expected mechanical properties 

consistent with low levels of ASR. The impact of ASR in the material strength testing of 

removed cores is not indicative of actual in situ performance and cannot be directly correlated to 

actual structural impact. Once removed from the structural context (e.g., reinforcement or 

confining loads) the behavior of the cores no longer reflects that of the confined structure. 

(Section 3.8.4.6 continued ... ) 

The expansion of concrete from silica gel formation and cracking results in a small, but 

measurable, change in the dimensions of ASR-affected concrete. Tn 2014, Engineering 

determined that damage to a vertical seismic gap seal between the Containment Enclosure 

Building and the Containment Building was caused by relative building movement and not seal 

degradation. A subsequent evaluation of the condition determined that the seal damage was 

caused by radial deformation of the Containment Enclosure Building. The building deformation 

was caused by the expansion of ASR-affected concrete in the building and the backfill concrete 

that abuts the structure below grade. 

Engineering evaluations of the extent of deformation in each structure determined the impact of 

the ASR on affected structures. Subsection 3.8.4. 7 and the Structural Monitoring Program 

includes criteria for monitoring the effects of ASR.Additional concrete core sampling has been 

performed to determine the eJEtent of condition both from the perspective of additional areas that 

might be affected by ASR and also the eJttent of ASR degradation v>ithin a given area and 

control areas (non wetted adjacent areas). Subject Matter E1cperts from around the country 

were consulted and a specific monitoring and action plan for ASR was added to the Structural 

Monitoring Program. Engineering evaluations that were performed and documented in foreign 

print I 00716, (Subsection 3.8.6, R~f. 6) established that although the concrete can be considered 

degraded, the structures and embedded concrete anchors ar~ capable of petforming all required 

design basis functions. ASR is considered to be a degraded nonconforming condition pursuant to 

R~gulatory Issue Summary (RIS) 2005 20. An operability determination \Vas performed which 

established reasonable assurances that the structures and embedded/drilled in concrete anchors 

are capable of performing all required design basis functions. Design basis calculations will 

be reconciled to account for ASR following completion of the actions delineated in the ASR 

corrective action plan. 
SEABROOK DESIO OF STRUCTURES, COMPONE TS, EQUIPME TAND Revision 16 

STATION SYSTEMS Section 3.8 

UFSAR Design of Category I Structures Page 147 

3.8.4.7 Testing and In-Service Surveillance Requirements 

Normal quality control testing is discussed in Subsection 3.8.3.6. A general visual inspection of 

the exposed accessible interior and exterior surfaces of the Containment Enclosure Building will 

be periodically conducted as discussed in Subsection 6.2.6.1 . 

The Structural Monitoring Program includes requirements for inspecting structures affected by 

ASR. The total expansion of ASR-affected areas is limited to less than the amounts specified in 

Table 3.8-18. Periodically verifying that ASR expansion levels are below the limits is necessary 

to ensure structural properties of ASR-affected areas are similar to areas with no evidence of 

ASR. 

The Structural Monitoring Program also has limits on structure deformation from ASR concrete 

expansion. Structures with increasing levels of deformation, as determined by an analysis of the 

self-straining loads, are classified as Stage l, 2, or 3. Monitoring criteria for each structure are 

included in the Structural Monitoring Program and inspection requirements are defined based on 

the analysis and classification of each structure. 

3.8.4.7.1 STRUCTURES MONITORING PROGRAM 

The Structures Monitoring Program is implemented through the plant Maintenance Rule 

Program, which is based on the guidance provided in NRC Regulatory Guide 1.160 

"Monitoring the Effectiveness of Maintenance at Nuclear power Plants" and NUMARC 

93-01 "Industry Guideline for Monitoring the Effectiveness of Maintenance at Nuclear 

Power Plants", and with guidance from ACI 349.3R, "Evaluation of Existing Nuclear 

Safety-Related Concrete Structures". The Structures Monitoring Program was developed 

using the guidance of these three documents. The Program is implemented to monitor the 

condition of structures and structural components within the scope of the Maintenance 

Rule, such that there is no loss of structure or structural component intended function. 

3.8.4.7.2 ALKALI-SILICA REACTION (ASR) MONITORING 

The ASR Monitoring Program manages cracking due to expansion and reaction with 

aggregates of concrete structures. The potential impact of ASR on the structural strength 

and anchorage capacity of concrete is a consequence of strains resulting from the expansive 

gel. 

The Structures Monitoring Program performs visual inspections of the concrete structures 

at Seabrook for indications of the presence of alkali-silica reaction (ASR). ASR involves 

the formation of an alkali-silica gel which expands when it absorbs water. This expansion is 

volumetric in nature but is most readily detected by visual observation of cracking on the 

surface of the concrete. This cracking is the result of expansion that is occurring in the inplane directions. Expansion is also occurring perpendicular (through the thickness of the 

wall) to the surface of the wall, but cracking will not be visible in this direction from the 

accessible surface. Cracking on the surface of the concrete is typically accompanied by the 

presence of moisture and efflorescence. Concrete affected by expansive ASR is typically 
SEABROOK DESIGN OF STRUCTURES, COMPONENTS, EQUIPMENT AND Revision 16 

STATION SYSTEMS Section 3.8 

UFSAR Design of Category I Structures Page 148 

characterized by a network or "pattern" of cracks. Micro-cracking due to ASR is generated 

through forces applied by the expanding aggregate particles and/or swelling of the alkalisilica gel within and around the boundaries of reacting aggregate particles. The ASR gel 

may exude from the crack forming white secondary deposits at the concrete surface. The 

gel also often causes a dark discoloration of the cement paste surrounding the crack at the 

concrete surface. If "pattern" or "map" cracking typ ical of concrete affected by ASR is 

identified, an evaluation will be performed to determine further actions. 

Monitoring of crack growth is used to assess the in-plane expansion associated with ASR 

and to specify monitoring intervals. In selected locations, cores will be removed for 

modulus testing to establish the level of through-thickness expansion to date. Instruments 

(extensometers) will be placed in the resulting bore holes to monitor expansion in this 

direction going forward . 

ASR is primarily detected by non-intrusive visual observation of cracking on the surface of 

the concrete. The cracking is typically accompanied by the presence of moisture and 

efflorescence. ASR may also be detected or confirmed by removal of concrete cores and 

subsequent petrographic analysis. 

A Combined Cracking Index (CCI) is established at thresholds at which structural 

evaluation is necessary (see table below). The Cracking Index (CI) is the summation of the 

crack widths on the horizontal or vertical sides of 20-inch by 30-inch grid on the ASRaffected concrete surface. The horizontal and vertical Cracking Indices are averaged to 

obtain a Combined Cracking Index (CCI) for each area of interest. A CCI of less than the 

1.0 mm/m can be deemed acceptable with deficiencies (Tier 2). Deficiencies determined to 

be acceptable with further review are trended for evidence of further degradation. The 

change from qualitative monitoring to quantitative monitoring occurs when the Cracking 

Index (CI) of the pattern cracking equals or is greater than 0.5 mm/m in the vertical and 

horizontal directions. Concrete crack widths less than 0.05 mm cannot be accurately 

measured and reliably repeated with standard, visual inspection equipment. A CCI of 1.0 

mm/m or greater requires structural evaluation (Tier 3). All locations meeting Tier 3 criteria 

will be monitored via CCI on a Yi year (6-month) inspection frequency and added to the 

through-thickness expansion monitoring via extensometers. All locations meeting the Tier 

2 structures monitoring criteria will be monitored on a 2.5 year (30-month) frequency. CCI 

correlates well with strain in the in-plane directions and the ability to visually detect 

cracking in exposed surfaces making it an effective initial detection parameter. 

Structural 

Tier Monitoring 

Program Category 

Unacceptable 

3 (requires further 

evaluation) 

Recommendation for Individual 

Concrete Components 

Structural Evaluation 

Impl ement enhanced ASR 

monitoring, such as throughwall expansion monitoring 

usin g Extensometers. 

Criteria 

1.0 mm/m or greater Combined 

Cracking Index (CCI) 
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2 

DESIGN OF STRUCTURES, COMPONENTS, EQUIPMENT AND Revision 16 

Acceptable with 

Defici encies 

Acceptable 

SYSTEMS 

Design of Category I Structures 

Quantitative Monitoring and 

Trending 

Qualitative Monitoring 

Routine inspection as prescribed by 

the Structural Monitori ng Program 

Section 3.8 

Page 149 

0.5 mm/m or greater CCI 

CI of greater than 0.5 mm/m in 

the vertical and horizontal 

directions. 

Any area with visual presence of 

ASR (as defined in FHW A-HlF-12-

022) accompanied by a Cl of less 

than 0.5 mm/m in the vertical and 

horizontal directions. 

Area has no indications of pattern 

cracking or water ingress- No visual 

symptoms of ASR 

The Alkali-Silica Reaction Monitoring Program was initially based on published studies 

describing screening methods to determine when structural evaluations of ASR affected 

concrete are appropriate. Large scale destructive testing of concrete beams with accelerated 

ASR has confirmed that parameters being monitored are appropriate to manage the effects 

of ASR and that acceptance criterion of I mm/m a used provides sufficient margin. 

CCI's limitation for heavily reinforced structures is that in-plane expansion, and therefore 

CCI, has been observed in the large scale test programs to plateau at a relatively low level 

of accumulated strain (approximately 1 mm/m). No structural impacts from ASR have 

been seen at these plateau levels in the large scale testing program at the University of 

Texas at Austin, Ferguson Structural Engineering Laboratory. While CCI remains useful 

for the detection and monitoring of ASR at the initial stages, an additional monitoring 

parameter in the out-of-plane direction is required to monitor more advanced ASR 

progression. ASR expansion in the out-of-plane direction will be monitored by borehole 

extensometers installed in drilled core bore holes. 

Although the observed strains due to ASR are of very small magnitude and adequately 

monitored by CCI and extensometers, over large distances and with the right building 

geometry, they can result in discernable dimension changes in a structure. Additional 

monitoring of this relative displacement potential and its impact to plant systems and 

components is included in the ASR Monitoring Program. Specifically, monitoring includes 

identifying signs of relative displacement or building deformation (e.g., fire seal 

displacement, seismic gap width changes, pipe/conduit misalignments at penetrations or 

between adjacent structures, bent or displaced pipe/conduit and supports, doorway 

misalignments). Critical building geometry locations where the potential for deformation is 

likely will be monitored for displacement via location-specific techniques. 

3.8.4.7.3 BUILDING DEFORMATION MONITORING PROGRAM 

The Building Deformation Monitoring Program is a plant specific program implemented 

under the existing Maintenance Rule Structures Monitoring Program. Building 
SEABROOK DESIO OF STRUCTURE , COMPONE TS, EQUIPME TAD Revision 16 

STATION SYSTEMS Section 3.8 

UFSAR Design of Category I Structures Page 150 

Deformation is an aging mechanism that may occur as a result of other aging effects of 

concrete. Building Deformation at Seabrook is primarily a result of the alkali silica reaction 

(ASR) but can also result from swelling, creep, and shrinkage. Building deformation can 

cause components within the structures to move such that their intended functions may be 

impacted. 

The Building Deformation Monitoring Program uses visual inspections associated with the 

Structures Monitoring Program and cracking measurements associated with the AlkaliSilica Reaction program to identify buildings that are experiencing deformation. The first 

inspection is a baseline to identify areas that are exhibiting surface cracking. The surface 

cracking will be characterized and analytically documented. This inspection will also 

identify any local areas that are exhibiting deformation. The amount of components 

experiencing deformation and the extent of surface cracking will be input into an analytical 

model. This model will determine the extent of building deformation and the frequency of 

required visual inspections. 

For building deformation, location-specific measurements (e.g. via laser target and gap 

measurements) will be compared against location-specific criteria to evaluate acceptability 

of the condition. 

Structural evaluations will be performed on buildings and components affected by 

deformation as necessary to ensure that the structural function is maintained. Evaluations of 

structures will validate structural performance against the design basis, and may use results 

from the large-scale test programs, as appropriate. 

Evaluations for structural deformation will also consider the impact to functionality of 

affected systems and components (e.g., conduit expansion joints). NextEra will evaluate the 

specific circumstances against the design basis of the affected system or component. 

Structural evaluations will be used to determine whether additional corrective actions (e.g., 

repairs) to the concrete or components are required. Specific criteria for selecting effective 

corrective actions will be evaluated on a location-specific basis. 
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3.8.6 

1. 

2. 

3. 

4. 

5. 

6. 

7. 

DESIGN OF STRUCTURES, COMPONENTS, EQUIPMENT AND SYSTEMS Revision 16 

Section 3.8 

Design of Category I Structures Page 153 

References 

Wilson, E.L., "Structural Analysis of Axisymmetric Solids," AIAAJ. Vol. 3, No. 

12 (1965) pp. 163-182. 

Wilson, E.L., "A Digital Computer Program for the Finite Element Analysis of 

Axisymmetric Solids with Orthotropic, Nonlinear Material Properties," November 

1969. 

Duchon, N.B., "Analysis of Reinforced Concrete Membrane Subject to Tension 

and Shear," ACI Journal, September, 1972, pp. 578-583. 

Wilson, E.L. and Nicholl, R.E., "Application of the Finite Element Method to 

Heat Conduction Analysis," Journal of Nuclear Engineering and Design, Vol. 4, 

1966. 

Alexandria, S. C., Effects of Irradiation of Concrete, Final Results, Research 

Reactor Division UKAEA, Harwell, AERE-R-4490, December 1963. 

Foreign Print l 00716, Im pact of ASR on Structures. 

MPR-4288, Revision 0, "Seabrook Station: Impact of Alkali-Silicia Reaction on 

the Structural Design Evaluations," July 2016. FP#101020 
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DESIGN OF STRUCTURES, COl'vfPONENTS, EQUlPMENT AND Revision 14 

SYSTEMS Section 3.9(8) 

Mechanical Systems and Components Page 40 

(3) The stiffness values used for support design were: 

Pipe size COD. in.) Stiffness Cl b./i n.) 

Upto2Yi lxl 04 

2Yi to6 lxl05 

Above 6 1xl06 

In those cases where the support stiffness was less than that 

specified above, the piping analysis was reviewed to 

determine the impact on the component. 

( 4) Component supports are designed to be in the rigid range 

(natural frequency fn ::'.:33 Hz). T n cases where the 

frequency is less than 33 Hz, the analysis of the piping 

system was reviewed to assure that the piping analysis 

remained valid. 

(5) The thermal movement of the component at the support 

was accommodated through clearance included in the 

component support design. 

(6) Component supports are connected to concrete walls and 

slabs by either welding to embedded plates, or by bolting to 

the concrete with either concrete expansion anchors (wedge 

type) or concrete inserts. The response to the NRC's TE 

Bulletin No. 79-02, (Reference 2), was used as a guide for 

the de sign of the concrete expansion anchors. The 

maximum allowable design loads for the concrete 

expansion anchors for ASME Class I , 2, and 3 supports 

were developed using the manufacturer's ultimate loads and 

a safety factor of 4 for worst case loading (normal and 

upset or faulted loads). Embedded plates, expansion 

anchors, and concrete inserts installed in concrete degraded 

by ASR provide full structural capacity up to the ASR 

expansion level defined in Table 3.8-18. 

Baseplate flexibility and shear-tension interaction were 

accounted for in the design of the concrete expansion 

anchors. 
SEABROOK DESIGN OF STRUCTURES, COMPONENTS EQUIPMENT AND SYSTEMS Revision: 8 

STATION 

UFSAR TABLE3.8-I SheeJ: I of2 

TABLE 3.8- 1 CONTALNMENT LOAD COMBINATIONS ANO LOAD F ACTORS(S) 

LOADING'"1 

R. 

(OBA Local Effcc1s) 

i J; ~ i ~ ~ -i ~ I ~ ~ °§ i ~ l i .. g . j h ~ ~ " ~ "' " " ! . ~ ] ~ § "' ~ .!: 1 "' §..i'E" 

u J Cat'-'gOl)' ~ j j 

~ j j 5. ~ ~w " ~~ ~ ~ ~ " ~ ~ ~ f-

~ ,;: 1 ~ ~ '.:,i 8 i! l ;J f .. r < f- Cl ~ i= ..5 i"' l ] °' § .li .5 15 ,; 

LoadingNotntion D s. p, P, T, T. T U\ E. E. w w, R. R. R. R. R. p m F'" 

j] fot 1.0 1.0 1.0 1.0 1.0 

Nonnal 1.0 1.0 1.0 1.0 1.0 1.0 

SC'\·ereEnvironmcntal I 0 1.0 1.0 1.0 1.0 1.0 1.0 

s~ ' ' n '·" n .0 

Extreme ,, 1.0 1.0 1.0 1.0 J.(117! 1.0 1.0 1.0 

En\ironrnental Sb 1.0 1.0 I 0 I 0 1.0 l.<f'.SJ 1.0 1.0 

Abnormal 6o 1.0 1.0 1.0 J.51.fJ J.O'.fl 1.0 

] 6b I 0 1.0 I 0 1.0'4) I JP1 115 

!! Abnonnal&\·ere 1.0 1.0 I 0 115' .... 1.()1 .fl 115 I 0 1.0 I 0 I 0 g En\-iroruncntal 

~ AboommVE\tren'Je 

Emironmental I 0 1.0 1.0 I Jj > l()i<ll 1.0 1.0 1.0 1.0 1.0 
TADLE 3.3-14 INTERIOR CONTAINMENT STRUCTURES BASrC LoAD COMDlNA'flONS AND LOAD FACTORS 

Material LOADING"' 

Loeding Nou.tiom ~ 

·~ I " ~ !! B = " !: !!> g ii ll 0 ] .8 ~ ....l ] .;g ~ ~ g 5~ ~ -8 j ii: ·a. g E 8. ·.::: "i .!! μ 

e 8 !I: . ~ o::~ ~ -~ .;;: ~i E ~ 

~ " j !i ..J ... e &. :l1 8. ~ g 15 ~1 ~3 - -g 

8 ;>:; e "' ;; ~ e '! "€ " j.3 .. 0 

!l "i ~ ::i "' :ii &. 6 .!! rE ·.g ..J ; 

~ ~....l ~ ....l 

§ < " o~ ~ 8. ~ 8. ·g a d &' " 0 ~ . < i ~ Ji :s ~ 'O < 0 

.s I I D L S11 P, T. T, I E. F..,. R. R. R. R.: R..n M 

IS 1.0 1.0 - - . - I . . . . . . . . 2S 1.0 I 1.0 . . . . 1.0 . . . . . . .,, - Structural Steel 3S 0.67 I 0.67 . 0.67 . 0.67 I . . - 3 . . 4S 0.67 0.6'7 . 0.67 I 0.67 0.67 I - . . 

~ JC 1.4 1.7 2.U . I i - . . . :;;: 2C 1.4 1.7 1.3 - 1.9 . . . - . Concrete JC . . - . . . . . . 4C 1.05 1.28 1.0 . I 1.28 ' l.43 . !.28 . . . . ) SS 0.63 0.63 . I 0.63 . j - 0 63 0.63 . . . . - (') .!! 6S 0. 63 0.63 . 0.63 . 0.63 I . . . 0.63 . . ii . iil 75 0.63 0.63 . 0.63 0.63 f 0.63 . 0.63 0.63 0.63 0.63 0.63 

8S 0.59 0.59 ~9 0.59 . 0.59 . 0.59 0.59 0.$9 0.59 0.59 

55 l.l 1.1 l.l . . J.l l.l . - . . . 

] Structural Steel 68 J.l 1.1 . 1.7 . 1.1 . . 1.1 . . . .!! 

to 7S l.l 1.1 . 1.4 . 1.1 1.4 . . 1.1 l.l I.I l.l 1.1 

] ., {)) i:: SS I.I 1.1 l.l . l.l - 1.t . I.I l.l I .I l.1 1.1 

c !') ::> 

Conc:-c:e SC 1.0 1.0 1.0 1.0 . . 1.0 1.0 . . . . c-c 1.0 1.0 1.0 1.5 . 1.0 . . 1.0 . . . . 

7C 1.0 1.0 1.0 l.25 1.0 1.25 . 1.0 1.0 1.0 1.0 1.1 

8C l.O 1.0 1.0 1.0 . 1.0 1.0 . 1.0 1.0 l.O 1.0 1.0 !'l 

(F_, = Allowable Stress) 11

' See Sub. ection 3.8.3.3 fo r discussion of loadings. 

!1 • Jn above load combinations, the peak values of P., T., R., R,;. R,,, Rm, and M shall be combined (when they act concurrently) unless time history analysis 

is perfonned 10 j ustify otherwise. (] ) 

i4) 

[SJ 

For these load combinations eith er elastic or plastic design may be used. 

Load combinations 7S, 8S. 7C and 8C are ;ilso checked without R.,., Rrj. R00 • 

Where ASR strains are greater than 0.05% (0.5 mm/ m), ASR load fac tors may be reduced by 20% but shall not be taken as less than 1.0. 

rr Ll mitor 

Design Criteria 

~, uAISC 

ACJ 318-71 

SF, Per AJSC 

AJSC, J>artll 

A-Cl 318·71 
SEABROOK 

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UFSAR 

TABLE 3.8·16 

Material 

Loading Nota io ~ 

DESIGN OF STRUCTURES, COMPONENTS EQUD'MENf AND SYSIBMS 

TABLEJ.8- 16 

CATEGOR\' I, STRUCTURES OT!lt::R TllMI REACTOR co.-.'T,\INMt'.l"l'TSTRUCTUR£ 0R ITS b TERXALS BASIC loADCO:\IBINATIONS ASD l..0.\1) FACTORS 

All Structures 

D T, E. .. w w, 

Loadin(l).(4) 

ConcrctcOnlv Certain StruclUR:il. Where A . IC 

Pipe Break Loads 

.. 

11 0 II, S. Ro P. R.. Rg R,.. R,. M 

Revision: 8 

Sheet: I of I 

S~ss lrnu S) 

DesignCntcria 

T, L• 

,_1 -+~"-+--+--+---+--+--+--<f--<f--+--+--+--+--<--+--+---<--+--+--+---< SF.rerAISC 1.0 10 I 0 

SlrUelurol St«l 1.0 10 I 0 

0.67 0.67 0.67 0.67 

0 67 0 67 0.67 0.67 0.67 

067 067 067 067 067 

>--" -+~:~-+---+- ~ .• -+- -+---+---+~: ;,--,_19,--+--+-=;,=o-+--+--+--+--+--+--+--+- -<--+---< ACI 318-71 

1 4 17 17 1 7 17 

I OS 1.28 1.28 1.28 I S 1.28 

I.OS 1.28 1 28 IAJ 1.28 IAJ I 0 1.28 

I.OS I 28 1.28 1.3 12' 1.28 1.28 

12 1.7 17 1.7 

1.9 11 1.9 u 

~ ~2) l-"=~-+= -+-=~=~-+---+- 6l-+---+~ 6l-+---t---t--+---+-' ~--+-+--<f--+-+--+---+---+--i SF, PcrAISC 

06J 063 063 0.63 063 @ (2) 063 063 0.63 063 0.63 0.63 0.63 063 063 063 

O.S9 059 0.59 0.59 0.59 0 59 0.29 0.29 0 29 0.59 

5tfU(tur.il Steel f-'l=l-+~1~1-+-~l=l-+--+-=l~l-+--+--+---t---t--+---+-~"-+--+--+--<f--+--+--+---+---+--i AISC. Partll I.I 11 J I 11 I.I 

I.I 11 1.7 I.I I.I I.I I.I I.I I.I 

I.I I.I 1.4 1.4 I.I I.I 

LI I.I I.I I.I LI I.I I.I I.I I.I I.I 

Com:re!e t-;:-;:6-+_,:c;:~-+-;:-;:6-t---t-~ -t---t--,'°'-+-;c6;-t--t- -1--; -t-7'::6;-+--+--t--f--t---t---t----t---+---I ACI 318-71 

1.0 I 0 I 0 I 0 1.S LO I.I 1.0 

LO 1.0 I 0 1.2.S I 0 115 LO 1.0 1.0 1.0 1.0 

I 0 I 0 1.0 I 0 10 10 1.0 1.0 1.0 J O J O 1 0 10 

1.0 I 0 1.0 I 0 I 0 I 0 {]) 10 1.0 I 0 I 0 I 0 I 0 I 0 10 10 

(1) In abonk>adcombwolKlnt.. lllcpgl.nluclofP .. T .. R. R.. R.., R..i.rMiM"'allbeooml>Nd(•hal..._"'t.,t~tl))llllku 111nclu1loryW11l)'l1& 1& pcrl"onnal iojl>stif) ollla'\l•isc.. 

(2) El.uti..:caoa 1ot.ccho.i..cd for O\"Cflll11bbilitybylhcplHli.: k>adcombN1ionasc:1ui.di..:.atodil)'(" ) 

{3) Fordaignb-flooJk>adcuc,cln1tionWUt.cdiccff...:t!\cm.a.'Wnum..-nd1.-atcrc..,.,.1tio.i.• .• El • 20'-o" 

{-I) SccSubso.."1.i""l.IA.Jf.wdit;;u.uioftofloadinp 

(SJ (l', • Allo.o·abloStra1) 

1\1(6) V."hcn::ASR 11ninoan:tn:11c:r tNn om•.(o.s-'111). ASR I.Nd &don mayt.c rcitu.:cdb)'20"•but- beu"'"' u la.1 lhM 1.0 
SEABROOK 

STATION 

UFSAR 

DESIGN OF STRUCTURES, COMPONENTS EQU1PMENT 

AND SYSTEMS 

TABLE3.8-17 

Revision: 8 

Sheet: 1of1 

TABLE 3.8-17 COMPUTER PROGRAMS USED IN THE ANALYSIS AND DESIGN OF OTHER SEISMIC 

CATEGORY I STRUCTURES 

Computer Program Structures On Which Used 

1. lvlRT/STARDYNE Control & Diesel Generator Building (Static Analysis) 

Fuel Storage Building 

Main Steam and Feedwater Pipe Chase (East) 

Main Steam and Feedwater Pipe Chase (West) 

Pre-Action Valve Area 

Primary Aux:iliaiy Building Including Residual Heat 

Removal Equipment Vault 

Se1vice Water Cooling Towers Including Switchgear Room 

Se1vice Water Pumphouse 

2. MARC-CDC (Static Analysis) Containment Enclosure Building 

3. LESCAL (Design ofReinforcing Containment Enclosure Building 

Steel) 

Main Steam and Feedwater Pipe Chase (East) 

4. GENSAP (Static Analysis) Containment Enclosure Ventilation Area 

Emergency Feedwater Pump Building Including Elect1ical 

Cable Tunnels and Penetration Areas 

Piping Tunnels 

5. MULTISPAN (Static Analysis) Se1vice Water Cooling Towers 

6. ANSYS (ASR Deformation) Containment Enclosure Building 
SEABROOK 

STATION 

UFSAR 

DESIGN OF STRUCTURES, COMPONENTS EQUJPMENT 

AND SYSTEMS 

TABLE3.8-18 

TABLE 3.8-18 ASR EXPANSION LIMITS FOR STRUCTURAL LlMrT STATES 

Structural Limit State ASR Expansion Limit 

Shear See FP# 10 I 020 - Section 2.1 (Ref 7) 

Flexure See FP# I 0 I 020 - Section 2.1 (Ref 7) 

Reinforcement Anchorage See FP# I 0 I 020 - Section 2.1 (Ref 7) 

Anchors See FP# I 01020 - Section 2.1 (Ref 7) 

Compression Note I 

(1) Compressive load from ASR in the direction ofreinforcement is combined and evaluated with other 

applied compressive loads. 

Revision: 8 

Sheet: 1of1