Long Term OperationLong Term Operation of Concrete ... - LEPAPE - LB60Concrete.pdf · Long Term OperationLong Term Operation of Concrete Infrastructures ... AGING CONCRETE STRUCTURES

Long Term OperationLong Term Operationof Concrete InfrastructuresA joint-effort by EDF & EPRI

Y. LePape EDF Inc.J. Wall EPRIJ. Salin EDF R&D

2010-11 all rights reserved EDF & EPRILB60 - Washington DC Feb. 22-24 2011

OUTLINE

• Does concrete matter?• Aging Management IssuesAging Management Issues• R&D Joint Programs• ConclusionsConclusions


CONCRETE IS A COMPLEX MATERIAL...

2010-11 all rights reserved EDF & EPRI

... MADE WITH LOCAL RAW PRODUCTS...


IN INTERACTION WITH STEEL...


AND SUBJECTED TO DIFFERENT ENVIRONMENTS!


cement aggregates water concrete

A CONCRETE LIFE: GROWING UP AND GETTING OLD...

Initialmixture

hydration (chemical/physical process) with heat release

setting hardening

physical propertiesthermal conductivitydiffusion...

hours months

atio

nol

d

years

upscaling

mechanical propertieselasticity, strength, creep...

solid

perc

ola

thre

sho

i ( bi t l di i t l tt k )

morphological changes

aging (ambient exposure, loading, internal attack...)

decades

aggressive species diffusion dissolution (microscale) ki ( / i l )


aggressive species diffusioninternal pressure cracking (meso/microscale)

Concrete infrastructures may not last forever!

Ferrybridge, 1965

Minneapolis, 2007


OUTLINE



Civil Structures of Interest

1 – Cooling Towers

2 – Containments2 Unit Nuclear Plant (PWRs) 3 – Spent Fuel

Pools/Transfer Canal

4 - Buried (Prestressed)11

4 Buried (Prestressed) Concrete Pipe

5 – Intake Structure245

12

245

12

3


Degradation Causes of Interest for LTO

A NON RANKED LIST

• Chronic radiation exposure (biological shielding and RPV supports)

• Chronic exposure to high temperature (containment near steam generators and steam penetrations)

Chloride attack and re bar corrosion (generic throughout plant)• Chloride attack and re-bar corrosion (generic – throughout plant)

• Boric acid leaching of concrete and attack of rebar (spent fuel pools, transfer canals)

• Corrosive soil attack (foundations, buried pipes, raft)

• Effects of concrete damage on post-tensioning system integrity (containment)

• Creep (containment)

• Internal swelling (ASR, DEF... massive structures)

11

• .........

OUTLINE



EPRI & EDF Strategy2011+20102009 2011+20102009

CIVIL INFRASTRUCTURE LTO TOOLBOX PLATFORM(Continuously Updated, Available to Utilities)

SOFTWARE DEVELOPMENT (400K) - structural & materials modeling

EDF Reference Manual Input

COMPILATION OF DATA AND MATERIALS CHARACTERIZATION STUDIES

PILOT PROJECT 1 – Leaking Spent Fuel Pools

AGING CONCRETE STRUCTURESREFERENCE MANUALOperational IssuesAging Mechanisms

Basic mechanismsDetection/characterization/NDE

RADIATION DAMAGE

CHLORIDE ATTACKDetection/characterization/NDEModeling

AGING ISSUES MATRIX

TENDON MONITORING

PILOT PROJECT ‘n’ (TBD)

EPRI LTO/TI Funded MAI Funded

ADVANCED NDE FOR CONCRETE


Funding to be designated (EPRI/DOE/MAI/Utilities)

DOE Funded (Project approved but funding not committed yet)

EPRI & EDF Strategy: Aging Issue Matrix

2011+20102009 2011+20102009






RADIATION DAMAGE

CHLORIDE ATTACK



TENDON MONITORING


Detection/characterization/NDEModeling

AGING ISSUES MATRIX






Ranking Priorities and Gaps Identificationbasic detection and characterization

bilit

ybasic

mechanismdetection andsimple model

characterizationand refined model

? boric

scep

tib

LTO

?creep

FR NPPDEF

acidattack

TENTATIVE ONLY!

ure

sus

e’hl id

TENTATIVE ONLY!On-going parallel projects

stru

ctu

nten

anceradiation

damage

creepUS NPP

chlorideattackEPRI/MAI and NRC/DOE/E-PMDA

infr

as

‘mai

n

15

knowledge of the degradation

EPRI & EDF Strategy: Software development2011+20102009 2011+20102009






RADIATION DAMAGE

CHLORIDE ATTACK



AGING ISSUES MATRIX

TENDON MONITORING








3D d li 0D d li

2 strategiesMAI strategy for modeling concrete

microscalecement paste

3D modeling 0D modeling

build 3D microstructurefrom initial cement particles

build 0D microstructure (volumefraction) from initial cement

distribution and virtual hydration composition and virtual hydration

l build 3D microstructure from compute effective propertiesmesoscalemortar & concrete

build 3D microstructure fromaggregate distribution andcompute effective properties

compute effective propertiesusing homogenization schemes

17

R&D purpose practical purposefeed

EPRI & EDF Strategy: Pilot Projects

2011+20102009 2011+20102009







Basic mechanismsDetection/characterization/NDE CHLORIDE ATTACK

RADIATION DAMAGE


AGING ISSUES MATRIX


TENDON MONITORING






QUANTITATIVE ESTIMATION OF NPP CONTAINEMENTRESIDUAL LIFE WITH REGARDS TO DELAYED STRAINS

Example of a recent success at EDF

MATERIALS SCIENCE- basic mechanisms- lab tests

MONITORING- feed-back- bayesian approach

²

FEM/MONITORINGPREDICTION

PALIER-N4 CIVAUX1:maillage sechage PALIER-N4 CIVAUX1:maillage sechage

COMPUTATION


COMPUTATIONTH-M FEA

Chloride attack and corrosion of prestressed reinforced concrete

Example of an on-going Pilot Project at EPRI

prestressed reinforced concrete

step 0lab test

step 1degradation of refurbished materials(crack vs. corrosion patterns, NDE...)

lab test(crack vs. corrosion patterns, NDE...)

step 2NDE benchmark during outage

[Mullard & Stewart, 2011] experiment

step 3probability- based structural assessment


EPRI & EDF Strategy: LTO Toolbox Platform

2011+20102009 2011+20102009SOFTWARE DEVELOPMENT (400K)

- structural & materials modeling







RADIATION DAMAGE

CHLORIDE ATTACKDetection/characterization/NDEModeling

AGING ISSUES MATRIX

TENDON MONITORING







Aging Management#1 safety#2 economically viable operation


THE THREE PILLARS OF DECISION...

grow

ing

t/co

mpl

exity

StructuralAnalysis

cos

DecisionMaking

InspectionMaterial

Aging


THE THREE PILLARS OF DECISION...

ComputationalComputationalanalysis

grow

ing

t/co

mpl

exity

StructuralAnalysis Analytical

CalculationCode

Requirement

cos

Non Destructive Material

q

Strengthening/Additional monitoringReplacement

DecisionMaking

Non DestructiveCharacterization

MaterialSimulation

InspectionMaterial

AgingLocalizedMaintenance


VisualInspection

Non DestructiveDetection

DegradationMechanism

Lab testing

WHAT ABOUT LTO?

ComputationalLTOComputationalanalysis

grow

ing

t/co

mpl

exity

3StructuralAnalysis Analytical

CalculationCode

Requirement

cos3

Non Destructive Material

q

Strengthening/Additional monitoringReplacement2

DecisionMaking

Non DestructiveCharacterization

MaterialSimulation

InspectionMaterial

AgingLocalizedMaintenance

1


VisualInspection

Non DestructiveDetection

DegradationMechanism

Lab testing‘routine’

OUTLINE

• Does concrete matter?• Aging ManagementAging Management• R&D Joint Programs• ConclusionsConclusions


Some important reminders

1. Recent major events regarding concrete:

- tritium contamination of site groundwater

- large outer containment delamination

2. Costs associated to Civil Infrastructures can be huge

- CR3 shutdown for nearly 1 ½ yr.

- FHWA estimation $8.3B/yr (bridges)

3 There are generic degradation modes b t each concrete/en ironment is3. There are generic degradation modes but each concrete/environment is specific

4. Effective aging management programs require basic materials knowledge inspection techniques and structural analysesknowledge, inspection techniques and structural analyses

5. Not all issues find their answers in ‘expertise-based’ qualitative analysis

27

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Long Term OperationLong Term Operation of Concrete ... - LEPAPE - LB60Concrete.pdf · Long Term OperationLong Term Operation of Concrete Infrastructures ... AGING CONCRETE STRUCTURES