The Cementitious Barriers Partnership:
Predicting the Long
-
term Chemical and Physical Performance
of Cementitious Materials used in Nuclear Applications
K. G. Brown (Presenter)
; CRESP, Vanderbilt U.
D. Esh, M.
Fuhrmann
,
J. Phillip; US NRC
D. Kosson, S. Mahadevan, A.
Garrabrants, S. Sarkar,
J. Arnold; CRESP, Vanderbilt U.
H. Van der Sloot
†
, J.C.L. Meeussen
‡
, P.
Seignette
, R.
Comans
; ECN (NL)
E. Garboczi, K. Snyder, J. Bullard, P.
Stutzman
; NIST
E. Samson, J.
Marchand
; SIMCO Technologies, Inc. (CA)
C. Langton, G.
Flach
, R. Seitz, S.
Marra
, H. Burns; SRNL
DOE
-
EM Project Manager: Pramod Mallick
29 November 2011
†
Hans
van der Sloot Consultancy
after
01JAN2010
‡
NRG after 01SEP2010
Project Goal
Develop a reasonable and credible set of tools to predict the
structural, hydraulic and chemical performance of cement
barriers used in nuclear applications over extended time
frames (e.g., up to or >100 years for operating facilities and
> 1000 years for waste management).
•
Mechanistic / Phenomenological Basis
•
Parameter Estimation and Measurement
•
Boundary Conditions (physical, chemical interfaces)
•
Uncertainty Characterization
2
Partnership Members
•
Department of Energy
–
Office of
Environmental Management
Scenarios & Key Uncertainties
Primary end
-
user
•
Nuclear Regulatory Commission
Scenarios & Key Uncertainties
Primary end
-
user
•
Savannah River National
Laboratory
Performance Assessment (PA)
Interface
Model Integration
Cracking Scenarios
Test Beds
•
NIST
THAMES
–
Microstructure Evolution &
Properties
•
SIMCO Technologies, Inc
.
STADIUM®
–
Physical & Hydraulic
Performance
•
Energy Research Centre of the
Netherlands
(w/ Nuclear Research Group,
Hans van der Sloot Consultancy)
LeachXS
™/ORCHESTRA
–
Chemical
Performance & Constituent Release
•
Vanderbilt University/CRESP
Chemical Performance & Constituent
Release (experimental)
Uncertainty Analysis Framework
Model Integration
3
Technical Strategy / Approach
•
Reference Cases
–
provide basis for comparison and demonstration of tools
under development
Cementitious waste form in concrete disposal vault with cap
Grouted
high
-
level
waste
(HLW) tank
closure
Spent fuel pool
Nuclear processing facilities
closure /
D&D (e.g., canyons)
Grouted
vadose
zone
to immobilize contamination
Materials
–
surrogate
low
-
activity waste (LAW)
cementitious waste form, reducing
grout, reinforced concrete (historical),
and reinforced
concrete (future)
•
Extension/enhancement of existing tools
–
CEMHYD3D/THAMES, STADIUM®,
LeachXS
™/ORCHESTRA,
GoldSim
Performance Assessment (PA) framework
•
Coordinated experimental and computational program
Conceptual model
development and improvement
Define test methods and
estimate important parameters
Model
calibration and validation
4
CBP Toolbox Development
5
Integration of CBP Tools with PAs
Atmosphere
Soil layers
Cap layers
Source
Vadose Zone
(
s
)
Saturated Zone
(
s
)
Surface Water
Engineered
System
Exposure
Scenarios
Failures
Risk
Airborne
(
diffusion
)
Waterborne
(
advection
)
Airborne
(
barometric pumping
)
Airborne
(
resuspension
/
deposition
)
Plant
-
induced
Animal
-
induced
CBP Focus:
•
Cementitious materials
performance as part of
engineered system and their
interfaces with natural system
•
To provide near field source
term
•
Uncertainty approach being
developed to be broadly
applicable to PA and design
process
CBP Interest Area
Landfills Partnership (CRESP)
Craig Benson (U of Wisconsin)
6
Key Degradation Phenomena
Phenomena
•
Chloride ingress & corrosion
•
Leaching
•
Sulfate attack
& cracking /
damage (2011
)
•
Carbonation (2012)
•
Oxidation (2012)
•
Cracking (2013)
•
Pore structure relationships
with mass transfer and
hydraulic properties
(TBD
NIST
)
Integration with
Conceptual Models
•
Coupled
degradation
phenomena
•
Saturated, unsaturated and
variable saturation
•
Liquid,
vapor mass transfer
•
System geometry and boundary
conditions
7
Specifications,
Properties, and
Phenomena for
the Evaluation of
Performance of
Cementitious
Barriers
8
Linking Prototype
Cases to
Performance
Models through
System
Abstraction
GoldSim & ASCEM
9
CBP Progress and Impacts
•
Demonstrated coupling of
LeachXS
™/ORCHESTRA
and
STADIUM® with GoldSim (
using a Dynamic
-
link Library / DLL)
•
Understanding potential for sulfate attack during salt waste
disposal in a concrete vault
•
Supporting
DOE
-
ORP
Secondary Waste treatment evaluation
•
Participation in inter
-
laboratory validation of
draft EPA
leaching test procedures
•
Data for evaluation of environmental impact of fly ash usage
in cementitious materials (grout, concrete, etc.)
–
input into
EPA regulatory
process
10
Software integration objectives:
Provide a
common,
unified interface to CBP partner codes through a
GoldSim
Graphical User Interface (GUI)
Provide a
“wrapper”
for probabilistic
uncertainty / sensitivity
analysis
(e.g., Monte Carlo)
Couple
LeachXS
™/ORCHESTRA
,
STADIUM®
and THAMES
in a synergistic manner
Connect to broader
systems
-
level
performance,
safety and environmental
assessment
models
Impact: Comparison
of Cement Data and
Thermodynamic
Model Predictions
1,0E
-
08
1,0E
-
07
1,0E
-
06
1,0E
-
05
1,0E
-
04
1,0E
-
03
1,0E
-
02
1
2
3
4
5
6
7
8
9
10
11
12
13
14
Concentration (mol/l)
[Al+3] as function of pH
0,0001
0,001
0,01
0,1
1
1
2
3
4
5
6
7
8
9
10
11
12
13
14
[Ca+2] as function of pH
1,0E
-
06
1,0E
-
05
1,0E
-
04
1,0E
-
03
1,0E
-
02
1
2
3
4
5
6
7
8
9
10
11
12
13
14
pH
[H4SiO4] as function of pH
1,0E
-
09
1,0E
-
08
1,0E
-
07
1,0E
-
06
1,0E
-
05
1,0E
-
04
1,0E
-
03
1,0E
-
02
1,0E
-
01
1
2
3
4
5
6
7
8
9
10
11
12
13
14
Concentration (mol/l)
pH
[Mg+2] as function of pH
Mortar CEM V/A GBFS
-
CFA
LXS model CEMV/A
CBP concrete VU 2009
1,0E
-
09
1,0E
-
08
1,0E
-
07
1,0E
-
06
1,0E
-
05
1,0E
-
04
1,0E
-
03
1
2
3
4
5
6
7
8
9
10
11
12
13
14
pH
[Fe+3] as function of pH
1,0E
-
06
1,0E
-
05
1,0E
-
04
1,0E
-
03
1,0E
-
02
1,0E
-
01
1
2
3
4
5
6
7
8
9
10
11
12
13
14
[SO4
-
2] as function of pH
Experimental data from USEPA Draft Method 1313
13
Impact:
Uncertainty
Reduction
via Calibration
of Thermodynamic Model Parameters
Prior
Best Fit
Most prominent changes:
Stratlingite
,
hydrogarnet
and ettringite
Al
14
Impact: Influence
of Cement Type on Damage
Ettringite
and Gypsum Profiles
Damage Fronts
•
Damage
depends
on both
ettringite
and
gypsum
formation; primary damage
observed from ettringite for Type I and from gypsum
for
Type V cements.
0
0.005
0.01
0.015
0.02
0.025
0
0.02
0.04
0.06
0.08
0.1
0.12
0.14
0.16
Depth (m)
Volume (m
3
/m
3
of material)
Ettringite (Type I)
Gypsum (Type I)
Ettringite (Type V)
Gypsum (Type V)
0
0.005
0.01
0.015
0.02
0.025
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
Depth (m)
Damage parameter
Type I
Type V
15
CBP Example
Problem:
Salt Waste Disposal System Integrity
Summary of Results for Sulfate Attack
•
Ability to model sulfate attack and
resulting damage based on
concrete
type (cement type, physical properties) and external
sulfate concentration
•
Probabilistic analysis for
both model
and parameter uncertainty
•
Resulting models and parameters can be used for evaluation of
a range of
similar materials
and scenarios
Impact
•
Allows selection of design parameters and materials to insure
long
-
term durability and meeting performance goals
•
Results can be integrated into existing performance assessment
fate and transport
models
16
Sulfate Attack Modeling
1.
Transport of ions
(saturated porous activity gradients)
•
Driven by concentration and chemical activity gradients
2.
Chemical Reactions
•
Calculation of liquid
-
solid equilibrium and solid phase distribution
using
LeachXS
/ORCHESTRA
3.
Cracking
•
Continuum damage mechanics model (
Tixier
and
Mobasher
, 2003)
4.
Effect of cracking on diffusivity
•
Relationships derived from fracture mechanics and numerical
simulations (
Krajcinovic
et al
., 1992)
17
Sulfate Attack Modeling Framework
Diffusion of Ions
Leaching out of Ions
Chemical Reactions
Volume Change
Change in Porosity
Strain
Cracking
Damage Parameter
Change in Diffusivity
Damage
Assessment
-
Elastic
Properties
-
Strength
18
Sulfate Attack
–
Probability
of Complete
Damage (Example Case)
Complete damage (failure criteria): Time required for cracks to propagate
through the entire structure
Time to complete damage
(years)
Percentiles
Case 1
S = 250
mM
Case 2
S = 120
mM
Case 3
S = 56
mM
5
th
78
109
338
25
th
186
318
772
50
th
285
508
1,135
75
th
513
835
1,849
95
th
1,886
4,354
6,120
19
CBP Example Problem: CO
2
and
O
2
Ingress
3
-
Layer Reference Scenario
Salt
waste form
(1)
Concrete
(2)
Soil
(3)
1000 cm
20 cm
50 cm
CO
2
O
2
•
3
-
Layer, 1
-
D diffusion model for
reactive substances
•
CO
2
and O
2
influx in soil layer
proportional
to partial pressure
difference air
-
soil.
20
CO
2
Ingress & Carbonation Modeling for
Tank Integrity and Closure
Scenarios
All CBP Partners
Provide Unique
Data
Sources
SIMCO Tech., Inc.
experimental results
for validation
21
LEAF Leaching Methods
Method 1313
–
Liquid
-
Solid Partitioning as a Function of Eluate pH using a
Parallel Batch Procedure
Method 1314
–
Liquid
-
Solid Partitioning as a Function of Liquid
-
Solid Ratio
(L/S) using an Up
-
flow Percolation Column Procedure
Method 1315
–
Mass Transfer Rates in Monolithic and Compacted Granular
Materials using a Semi
-
dynamic Tank Leaching Procedure
Method 1316
–
Liquid
-
Solid Partitioning as a Function of Liquid
-
Solid Ratio
using a Parallel Batch Procedure
Note: Incorporation of these methods into SW
-
846 is ongoing; titles and
method identification numbers are subject to change.
22
Develop
a reasonable and credible set of tools to predict the structural, hydraulic and chemical
performance of cement barriers used in nuclear applications over extended time frames (e.g.,
up to or >100 years for operating facilities and > 1000 years for waste management).
CBP Goal
Cementitious waste form in concrete disposal
vault with cap (↔
Landfills
Partnership)
Grouted high
-
level waste (HLW) tank closure
Spent nuclear fuel pool integrity
Nuclear processing facilities closure / D&D
Grouted
vadose
zone to immobilize contamination
Materials
–
surrogate low
-
activity waste (LAW)
cementitious waste form, reducing grout,
reinforced concrete (historical) and reinforced
concrete (future)
Example Uses and Reference Cases
Mechanistic /
Phenomenological
Basis
Parameter
Estimation and
Measurement
Boundary
Conditions
(
physical, chemical interfaces)
Uncertainty
Characterization
Basic Elements of the
Performance Evaluation
Long
-
term
Structural,
Hydraulic &
Chemical
Performance
of
Cementitious
Materials &
Barriers
23
Being
Completed
CBP Coordinated Experimental and Computational Program
Develop and improve conceptual models
Define test methods and estimate important parameters
Calibrate and validate models and perform probabilistic analyses
FY2012 CBP Focus
•
End
-
user licensing and training
•
High
-
level waste (HLW) tank integrity and closure
Carbonation rate as key to external attack
•
ASCEM source term demonstration case
www.CementBarriers.org
For further information and reports
24
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