cementitious barriers partnership doe project overview
DESCRIPTION
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 - PowerPoint PPT PresentationTRANSCRIPT
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 ApplicationsLAW Disposal
Perimeter riser
Center riserConcrete dome
Steel tank
Concrete wall
Concrete base mat
Intruder Barrier
Backfilledsoil
Backfilledsoil
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
NaturalSoil
Spent Fuel Pool
Fuel Pool
Structural fill
Ground Surface
Water Table
Water TableContainment
Structure
Structural Fill
Atmosphere
Nuclear Power Plant
Ground Surface
Reactor Internals
Entombed Structure
Structural fill
Cover
Ground SurfaceWater Table
Entombed Structure Waste
Materials
Entombment
Water Table
Cover
Reinforced Concrete
Wasteform
Ground Surface
Structural fill
LLW Disposal
Atmosphere
NaturalSoil
8
CBP Interest Area
Integration of CBP Tools with PAs
Atmosphere
Soil layers
Cap layers
Source
Vadose Zone(s)
Saturated Zone(s)
Surface Water
EngineeredSystem
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 ParametersHydraulic 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 (Kds), 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 GSoil
A
B
C
C
D
Soil
(not to scale)
12
Type IIIA Tank – Conceptual Closure Model
Reducing Grout
Intrusion Barrier
Grout
Tank Wall
Soil
Grout
Tank
WallSoil
Tank Wall
Intrusion
Barrier
Grout
13
Spent Fuel Pool – Conceptual Model
Water
Concrete
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 CO2, O2, 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
SaltstoneSaltstone Saltstone
Infiltration
AnnualPrecipitation
Infiltration Barrier
Evaporation &Transpiration
Run-off to surface stream or river
Ground Water
LeachedContaminants
Contaminant levels withinacceptable limits
Water Table
Top Soil
Run-off MonitoringWell
Saltstone Vaults
Atmosphere
Soil layers
Cap layers
Source
Vadose Zone(s)
Saturated Zone(s)
Surface Water
EngineeredSystem
Exposure Scenarios
Failures
Risk
Screening Risk Evaluation
Cap: Poisson(Cap Type)Drum: Weibull(Stacking, Liner, etc.)
Near-field: GS Cell Pathway ElementFar-field: Gaussian Plume Model
All layers: GS Cell Pathway Elements
All layers: GS Cell Pathway Elements
Loose: GoldSim (GS) Source ElementBoxes: GoldSim (GS) Source ElementDrums: 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 ElementsWorker: GS Receptor Elements
Airborne (diffusion)
Waterborne (advection)
Airborne (barometric pumping)
Airborne (resuspension/deposition)
Plant-induced
Animal-induced
Exposure: Morbidity, mortality, cancer, HQAccident: 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 ElementsWorker: GS Receptor Elements
Exposure: Same + cumulative, YPLLAccident: 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
OPC = Ordinary Portland Cement (Type I & II)
FA = Fly AshSF = Silica FumeBFS = Blast Furnace
Slag
24
Fill/Entombment Grout Parameters at DOE Sites
OPC = Ordinary Portland Cement (Type I & II)
FA = Fly AshSF = Silica FumeBFS = Blast Furnace
Slag