Cementitious Barriers Partnership

siennatearfulUrban and Civil

Nov 25, 2013 (3 years and 6 months ago)

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1

Cementitious Barriers Partnership

DOE Project Overview

C. Langton (PM/PI)

D. Esh, M. Furman, J. Phillip, US NRC

S. Mahadevan, A. Garrabrants, K. Brown, CRESP, Vanderbilt U.

H. Van der Sloot, R. Comans, J.C.L. Meeussen, ECN (NL)

E. Garboczi, K. Snyder, NIST

E. Samson, J. Marchand, SIMCO, Inc.

C. Langton, R. Dimenna, G. Taylor, SRNL


2

Partnership Members


Department of Energy


Office of Environmental
Management


Principal supporting agency


Primary end
-
user


Nuclear Regulatory
Commission


Oversight & Research
Divisions


Primary end
-
user



National Institute of Standards
and Technology


Savannah River National
Laboratory


Consortium for Risk Evaluation
with Stakeholder Participation
(CRESP)


Energy Research Centre of the
Netherlands


SIMCO

Expert Advisory Panel organized through

CRESP Independent Peer Review Board

3

Project Description



Technology Needs / Requirements


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., >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

4

Project Description


Risk / Cost Issues


Current PA approach may not adequately represent risk and
uncertainty of disposal and containment systems and practices


Waste form selection, contaminant loading, optimization


Disposal decisions


Remediation and D&D options evaluations


Design improvements of future facilities may not be realized due
to lack of mechanistic understanding of cementitious barrier
performance


Need for transparency, consistency, and peer review for
evaluation of long
-
term performance may give rise to increased:


Cost


Schedules


Stakeholder concerns

5

Project Description



Technical Approach:


Phase 1


State of the Art reviews (LLW / ILW CBs andPAs)


Phase 2


Computational tool enhancements including uncertainty
analyses (STADIUM, LEACH XS, THAMES)




Parameter value determinations / measurements


Suite of parameter test methods


Improved mechanistic models


Test bed workshop and recommendations for US program


Phase 3


Integration of component models


Model validation


Uncertainty evaluation (parameter, model, numerical)

6

DOE Applications

LAW Disposal

Perimeter riser
Center riser
Concrete dome
Steel tank
Concrete wall
Concrete base mat
Intruder Barrier
Backfilled
soil
Backfilled
soil
Undisturbed soil
Solidified Mass (10 CFR 61.56 Stabilization)
Bulk Fill
Tank 17 Closure
Top Dressing
Saltstone Vaults

Components in Grout

Tank Closure

D & D Entombment

7

Nuclear Facility Applications

Reinforced
Concrete

Pool Building

Natural

Soil

Spent Fuel Pool

Fuel Pool

Structural fill

Ground
Surface

Water Table

Water Table

Containment
Structure

Structural Fill

Atmosphere

Nuclear Power Plant

Ground Surface

Reactor
Internals

Entombed Structure

Structural fill

Cover

Ground
Surface

Water Table

Entombed
Structure

Waste
Materials

Entombment

Water Table

Cover

Reinforced
Concrete

Wasteform

Ground
Surface

Structural fill

LLW Disposal

Atmosphere

Natural

Soil

8

CBP Interest Area

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 process.

9

Important Parameters

Hydraulic Properties


Hydraulic Conductivity (dual porosity: matrix and cracks)


Total and Transmissive Porosity, Density


Water Diffusivity (e.g., Richard’s Eqn)


Dissolved ion Diffusivity


Tortuosity

Chemical Properties


Retardation Factors (K
ds
), Chemical Reduction Capacity,
Buffering Capacity


Mineralogy (matrix, radionuclides, other phases)


Constituent Speciation


Chemical Degradation (e.g., carbonation, oxidation, sulfate
attack, rebar corrosion)

Structural Properties:
Physical loads or seismic events

10

Technical Strategy/Approach


Integrated Long
-
Term Degradation

Chemical degradation and physical
structure evolution are coupled.

Physical stress


External loading


Drying shrinkage


Seismic events


Settlement

Chemical Alteration


Oxidation, Neutralization


Leaching


Pore & crack evolution


Dissolution and cracking


Precipitation & sealing


Expansive reactions & corrosion


Carbonation


Sulfate attack


Rebar corrosion

Microcracks


Increase porosity


Increase interaction
pore water/surface

Through
-
cracks


Preferential flow path


Diffusive and
convective release


Loss of strength

Spalling


Loss of cohesiveness


Two body problem


Eventual release from
“granular” material

11

LAW Waste Disposal Vault


Conceptual Closure
Model

C

G

Soi
l

A

B

C

C

D

Soi
l

(not to scale)

12

Type IIIA Tank


Conceptual Closure Model

Reducing Grout

Intrusion Barrier

Grout

Tank

Wall

Soil

Grou
t

Tank

Wall

Soil

Tank
Wall

Intrusio
n

Barrier

Grout

13

Spent Fuel Pool


Conceptual Model

Wate
r

Concret
e

Soil

14

CBP Reference Materials

Reference Solids


Waste Form


Reinforced Concrete (historic facilities)


Fill/Entombment Grout


Advanced Design Concrete (future facilities)


Soil

Reference Solutions


Deionized Water


Porewater (e.g., LAW
wasteform
, concrete)


Groundwater (e.g., Hanford synthetic groundwater)


Process Water

Reference Gases


Vadose

Zone Atmosphere


air adjusted for CO
2
, O
2
, moisture

15

Technical Status and Results


Form CBP (Phase 1)


MOU complete


CRADA and IAA complete July 1


IAA in progress


Advisory Committee (being set up by CRESP



State of Art Documentation (Phase 1)


March 2009



Model Development (Phase 2a)


Needs: December 2008


Demonstration of STADIUM, LEACH XS, THAMES on 1
-
D
reference case: May 2009


Enhance Component Modules: December 2009


16

Expected Project Impact


Reduced uncertainty and improved consistency for PAs


Improved system designs (waste management and new facilities)


Monitoring and maintenance approaches for extended

(100s, 1000s yr) service life


Updated guidance documents (assessment tools, test methods,
data)


Industry
-
wide technical basis for evaluation amongst
stakeholders (DOE, NRC, state regulators, others)


Assessment transparency


Improved technology foundation and integration of existing / new
science


Template for assessment of complex systems

17

Supporting Overheads

18

Project Description



Technical Strategy / Approach


Reference Cases


provide basis for comparison and
demonstration of tools under development


Cement Waste Form in Concrete Disposal Vault


Grouted HLW Tank


Spent Fuel Pool


Materials


surrogate LAW cementitious waste form, reducing
grout, reinforced concrete (historical), reinforced concrete (future)


Integration with GoldSim PA framework


Coordinated experimental and computational program


Conceptual model improvement


Define test methods and Parameter measurements


Model validation

19

Project Management Summary


Work ongoing for less than one month


Budget summaries are unavailable


WBS is being developed for project
management tracking


Project management meeting scheduled for
5
-
8 August 2008


FY’09 scope will be developed in PTS
-
03

20

DOE Applications

Saltstone

Clean Cap

Saltstone

Saltstone

Saltstone

Infiltration


Annual

Precipitation




Evaporation &

Transpiration


Run
-
off to surface
stream or river

Ground

Water


Leached

Contaminants




Contaminant levels within

acceptable limits

Water Table

Top Soil

Run
-
off

Monitoring

Well

Saltstone Vaults

Atmosphere
Soil layers
Cap layers
Source
Vadose Zone
(
s
)
Saturated Zone
(
s
)
Surface Water
Engineered
System
Exposure
Scenarios
Failures
Risk
Screening Risk Evaluation
Cap
:
Poisson
(
Cap Type
)
Drum
:
Weibull
(
Stacking
,
Liner
,
etc
.)
Near
-
field
:
GS
Cell Pathway
Element
Far
-
field
:
Gaussian Plume Model
All layers
:
GS
Cell Pathway
Elements
All layers
:
GS
Cell Pathway
Elements
Loose
:
GoldSim
(
GS
)
Source
Element
Boxes
:
GoldSim
(
GS
)
Source
Element
Drums
:
GoldSim
(
GS
)
Source
Element
All layers
:
Network Pathway
Elements
All layers
:
GS
Pipe Pathway
Elements
All layers
:
N
Cell Pathway
Elements
N
Public
:
GS
Receptor
Elements
Worker
:
GS
Receptor
Elements
Airborne
(
diffusion
)
Waterborne
(
advection
)
Airborne
(
barometric pumping
)
Airborne
(
resuspension
/
deposition
)
Plant
-
induced
Animal
-
induced
Exposure
:
Morbidity
,
mortality
,
cancer
,
HQ
Accident
:
Injuries
,
fatalities
,
probabilities
Possible Detailed Risk Evaluation
Cap
:
Poisson
(
Cap Type
)
Drum
:
Weibull
(
Stacking
,
Liner
,
etc
.)
Other types
/
distributions possible
Near
/
Far
:
AERMOD
plume model
(
EPA
)
Various other models available
Cap
/
soil
:
HELP
landfill model
(
EPA
)
Other landfill
/
engineered barrier models
available
All
:
DUST
-
MS

release model
(
INL
)
Other source release models available
All layers
:
TETRAD

transport model
(
INL
)
Various other transport models available
Public
:
GS
Receptor
Elements
Worker
:
GS
Receptor
Elements
Exposure
:
Same
+
cumulative
,
YPLL
Accident
:
Injuries
,
fatalities
,
probabilities
All layers
:
TETRAD

transport model
(
INL
)
Various other transport models available
All layers
:
GSFLOW
coupled model
(
EPA
)
Other surface water models available
CBP Interest Area

Technical Strategy/Approach


Integration of CBP Tools with PAs

22

Technical Status and Results


Task 1


Review of DOE and NRC PA Approaches


PA R&D needs


Task 2 (a to f)


State of art for modeling, chemical degradation, uncertainty


Task 3


Review of candidate software


Advisory Committee


Task 6



Reference cases and Model abstractions


Task 7


Computational tool design


23

Reinforced Cement Parameters at DOE Sites

Parameter

SRS

Saltstone
Vaults

ORP

Tanks

Others

Water/Cement

0.35

V1/4, V2

Gunite

0.4

Reactor Basins

0.45

Reactor Basins

0.5

Base mat (≤
3000
psi)

Cement

OPC

X

OPC + FA

X

Reactor Building (
3000
-
5000
psi)

OPC + SF

V2

OPC + BFS

V1/4

OPC + BFS +
FA

V2

OPC + BFS +
SF

OPC + FA +
SF

Aggregate (
sand sized)

Silicate

granite

basalt

Carbonate

Rebar Material

coated carbon steel

OPC =


Ordinary Portland
Cement (Type I &
II)

FA =

Fly Ash

SF =

Silica Fume

BFS =

Blast Furnace
Slag

24

Fill/Entombment Grout Parameters at DOE Sites

Parameter


SRS

Hanford

Idaho

Water/Cement

0.9

0.9

0.5
-
1.0

0.38

>1.5 (air entrained)

Binder

OPC +
BFS + FA +
SF

OPC + FA

OPC + BFS +
bentonite

OPC +
BFS+ FA

OPC +
BFS + FA

OPC +
BFS

+
FA

OPC +
BFS + FA
+ lime

Aggregate

Sand size

quartz

basalt
(air entrained)

Gravel size

granite

basalt

Rebar/Coils

yes/no

yes/no

yes/no

Rebar Material

carbon steel

carbon steel

stainless steel

Coil Fill

No aggregate or <sand size aggregate

OPC =


Ordinary Portland
Cement (Type I &
II)

FA =

Fly Ash

SF =

Silica Fume

BFS =

Blast Furnace
Slag