Seabrook Station

License Renewal Application Consideration of ASR April 28, 2016
Seabrook is one of the newest plants in the United S

was acquired by NextEra Energy in 2002

Seabrook at a Glance

• B i l ti i 1990 Began commercial operations in 1990

– Initial operating license until 2030 – 20-year license extension (2030-2050) in 

progress

• INPO Excellence Rating for eightconsecutive rating periods (16 years)•

Reco d u ead g to t e atest r

d r

un leadin

g into

t

h

e latest

refueling (525 days)

• Approximately 520 permanent 

employees 

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Seabrook Station provides approximately half of the 

electricity for New Hampshire, which is enough clean, 

reliable power for 1.2 million homes
NextEra Seabrook & MPR Attendees

• Ken Browne Seabrook ASR Project Manage• Mike Ossing Seabrook Licensing Manager• Ed Carley Seabrook License Renewal Sup• Brian Brown Brian Brown Seabrook Principal Engineer Seabrook Principal Engineer• Larry Nicholson Fleet Licensing Director• John Simons MPR General Mgr Power Projec• Chris Bagley MPR Lead Engineer

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Agenda

• U d t UT/FSEL t ti Update on UT/FSEL testing wrap-up

• Overview of Timeline

– Core testing– Extensometers– AMP refinement– LAR development LAR development– Walkdowns

• AMP Discussion• Closing remarks

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Update on MPR/UT Testing

St t a

tus

• All test programs complete• Owner s’ Acceptance Review of test reports in pro

Acceptance Review of test reports in pro

Results• Structural test programs showed no reduction in 

for ASR expansion levels greater than plant for ASR expansion levels greater than plant

– Shear– Reinforcement Anchorage and Flexure– Anchor Bolts

• Instrument program demonstrated accuracy and 

reliability of extensometers

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UT T ti

Seabrook Alkali Silica Reaction Issue Timeline 2016

Refined CEB

LAR Internal

Review with all LAR Document

April May June July

Schedule NRC Staff

LAR Pre‐Submittal

Meetings

(NEE/SGH/MPR)

UT Testing

Draft Roll‐up

Report to NEE

(MPR)

Refined CEB

Analysis &

Submit to NEE

(SGH)

LAR Drafted to

NEE Seabrook for

Review (MPR)

Review with all

Comments

Incorporated

at NEE

LAR Document

Submittal to NRC

(NEE)

LAR

LAR NRC Pre-submittal Meeting Window (April -May )

MPR‐4153 Correlation

Report Revision

Correlation Core

Bores Extracted& Tested &

ExtensometersInstalled

Commence Re

Remainder of Tier 3 Core

Bores/Extensometers

Installation

C Wk

January May

Core Bores &

Sampling/

Extensometer

Susceptibility

Evaluation on 1st

Group of 12 Most

Vulnerable

Structures

June 

Commence Work

September 

FEA

Analysis

Structures

RHR Vault

Core Bores January March April

Crack Gauges Installed/Core Bores Taken

Petrography/Inspection 

Periodic Monitoring

Analytical F

Analysis on 6 

Vulnerable Stru

Commence Work

Core Bores SMP/AMP P

CEB

Walkdown January March Periodic Structures Monitoring for Equipment Effects

Monitoring Plan Review (RAI) LAR Submitted

Commence Work Inspections/ Walk downs Completed

SMP/AMP Process

SMP/AMP Process

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July 

License Renewal
NRC Questions

Topic:Incorporation of future research into ASR AMPResponse:• Seabrook will remain fully engaged in ongoing re

and industry experience

– Seabrook plant specific OE will be documented for ana– Industry leadership role with EPRI and NEI– Monitoring of various government sponsored and inter

research

• Insights will be evaluated against adequacy of AM• AMP will be revised to ensure effectiveness

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NRC Questions

Topic:Validation that Large-Scale Testing Results are Comto Behavior of Seabrook Structures to Behavior of Seabrook Structures• Expansion behavior• Applicability of modulus/expansion correlation fr

MPR-4153 for determining expansion to date at pl

4153 for determining expansion to date at pl

Response:• AMP will include evaluation of plant data for cons

wih i b h i b di ith expansion behavior observed in test program

– Qualitative comparison of trends for in-plane versus thr

thickness expansion

– Expansion within limits set based on test programs

– Cores inspected to confirm lack of edge-effect cracking

• Modulus correlation in MPR-4153 compares favor

8

p 

published data for expansion
NRC Q estions NRC Questions

Topic:ASR effect on rebar ASR effect on rebarResponse:• AMP to be revised as a result of ASR effects with 

to current licensing basis

• Structural analysis to confirm rebar stresses will 

within Code provisions

• Expansion limits will be set from building structu

analyses

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NRC Questions

T i op c:Effect of Concrete Backfill on Below Grade Structur• Reconciliation of 12/2015 RAI response against p

Reconciliation of 12/2015 RAI response against p

experience with building deformation

• Representativeness of testing

Response:• Clarification: expansion of structures monitored 

directions

• Effect of concrete backfill on structure

– Applies an external load to the adjacent structure Applies an external load to the adjacent structure– Does not prevent expansion in through-thickness direc

move inward)

• Structural analysis will account for the external lo

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Structural analysis will account for the external lo
NRC Questions

Topic:Uniform ASR versus Localized ASR Response:• Structural Cap y acit

– Uniform ASR expansion has a higher impact on struct

performance. 

• Building Deformation

– Impact of localized expansion addressed in analyses

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Scop g e of Program

Topic:Define structures in scope of AMP for deformation aDefine structures in scope of AMP for deformation a

discrete macro cracking due to ASR

Response:• All buildings within the scope of License Renewa

currently included in the revised AMP program

• Deformation and discrete macro cracking will be 

as a program element for all buildings in scope of License Renewal

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P t M it d I t d Parame

ters 

Monitore

d or Inspec

t

e

d

Topic:Provide the link between the 

parameters monitored 

structural functionality and building deformationResponse:• AMP monitoring AMP monitoring will include will include localized localized ASR

-induc

induc

expansion strain as well as deformation of the costructures

– Data

- CCI, through CCI, through

-thickness expansion, deformation thickness expansion, deformation

inspections, crack gauges, invar wire

– Limits defined in the structural analysis will corroborate 

of degradation including determination of limits prior to 

i t d d f ti in

ten

d

e

d

function

• Link to structural functionality is established via 

of the structure to assess rebar yielding 

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• Analysis will establish parameters monitored 
Parameters Monitored or Inspected

Topic:Monitoring for discrete macro cracking and deformaResponse:• Parameters to be monitored will include localized 

i d d i i ll in

duce

d expansion strain as well as df i e

formation 

concrete structures.

– Examples include Seismic gap measurements, buildin

measurements building specific monitoring methods (measurements, building specific monitoring methods (

Laser targets), SMP walkdowns

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Parameters Monitored or Inspected 

Topic:Aging management of non-structural components fResponse:• In-scope Non-Structural Equipment and Compon

impacted by deformation will be by deformation will be age managed by 

managed by

plant specific AMP

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Detection of Aging Effects

Topic:Early detection of degradation before loss of intendfunction.Response:• A new 

p p lant s

pecific AMP will be develo

p g ed usin

g 

approach based on available margin.

– Monitoring and detection prior to significant margin red– Enter into corrective action program Enter into corrective action program– Input into SMP– Restore equipment to original condition

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Detection of Aging Effects Continued Detection of Aging Effects Continued

Topic:Monitoring of structures not adjacent to misaligned Monitoring of structures not adjacent to misaligned

components

Response:• Misaligned components are not the only paramet

monitored for building deformation

• M it i ill tili bi ti f i t i 

Monitoring will utilize a combination o

f inpu

ts inc

ASR monitoring techniques, (CCI, extensometersdeformation) and monitoring of key assumptions 

structures analysis along with equipment impactestructures analysis along with equipment impacte

deformation

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M it i d T di Monitoring and Trending

Topic: Monitoring and trending activities will provide a preof the extent and rate of degradationResponse:• Data will be trended based on design limits and 

freque c es n i ut g a t e ed app oac a d eque 

ilizing a tiered approach and freque

established to ensure that timely corrective actio

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Monitoring and Trending

Topic:Data collection and evaluationResponse:• Analysis of the structure includes additional mar

structural design to ensure that timely corrective structural design to ensure that timely corrective 

are taken prior to exceeding design code limits. be trended based on limits and frequencies estabin the structural analysis.

• Margin is defined through a tiered approach whe

threshold limits are defined as the maximum allomeasurement for each monitoring element that li

self

-straining loads to some straining loads to some fraction of the maxim

fraction of the maxim

allowable self-straining load.

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Monitoring and Trending

T i op c:Describe how the data will be trended over timeResponse:• Data will be trended based on limits and frequenc

established in the structural analysis to established in the structural analysis to ensure th

ensure th

timely corrective actions are implemented prior texceeding design code limits.

• Parameters monitored will be established and Parameters monitored will be established and tre

tre

based on bounding limits in the structural analys

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Acceptance Criteria 

T i op c:Process for calculating conditional acceptance criteensure structure and component intended functions maintained under all CLB design conditions maintained under all CLB design conditionsResponse:• A structural model is developed where ASR induc

expansion is applied to the structure.

• Added load due to ASR is load due to ASR is combined combined with other C

with other C

• Resultant load combinations are evaluated to val

compliance with CLB structural design code requ

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Operating Experience

Topic:Impacts of internal Operating Experience will be adeconsidered in AMP.Response:• AMP ill consider operating e perience AMP will consider operating experience—c rrent 

current 

• Assigned Project Manager• Engg g g a ed structural engineering firms

– Inspection of concrete structures– Analysis of concrete structures

• Leveraging CEB experience to other ASR Leveraging CEB experience to other ASR-affecte

affecte

structures

– Walkdown process

E l ti

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– Evaluation process
Closing Remarks

• MPR/UT t ti d t t d d ti i t 

MPR/UT testing demonstrated no reduction in str

capacity and the effects can be monitored 

• Extensive onsite work in 2016 

– Withdrawing 115 core bores samples in areas througho– Installing 52 extensometers to provide monitoring capa– Insta g 9 c ac gauges lling 19 crack gauges

• Seabrook plans to submit in July 2016

– Part 50 License Amendment Request to reconcile the c

licensing basis to address ASR and deformation licensing basis to address ASR and deformation

– Revised Part 54 Aging Management Program to addre

and deformation

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