Tasks

Task QA Plan Compliance: Perform All Work in Accordance with the CBP QA Plan

The objective of this task is to address the need for all CBP work to be performed in accordance with the CBP QA Plan.  Each task has unique QA requirements and it is the responsibility of the partner performing the task to be familiar with the CBP QA Plan and to comply with the Plan.

QA Plan >>
STATUS: Complete

Task 1: Current Performance Assessment Modeling Approaches

The objective of this task is to document the current approaches, methodology, and parameters used for PA modeling of cementitious barriers to provide a baseline for identifying research and development needs applicable to low-level radioactive waste disposal sites.  (This task will be limited to the engineered cementitious barriers portion of nuclear facilities.)  A summary of the current PA modeling approaches including probabilistic analyses and potential opportunities for uncertainty reduction will be prepared for the DOE complex-wide and NRC licensed sites.

Task 1 Reports >>
STATUS: Complete
Cement Barriers Testing

Task 2: Review State-of-the-Art Mechanistic and Process Understanding and Approaches to Uncertainty and Integrating Platforms

The objective of Task 2 is to expand the literature review beyond the approaches and techniques currently used in the PA modeling efforts.  Topical reports will be prepared on processes and mechanisms which are important and with respect to the parameters and assumptions in the PA.  Reports on the parameters and assumptions influential to microstructure and mineralogical evolution, structural evolution, and processes and mechanisms that influence contaminant release from engineered barriers will be prepared. Template software for the integrating platform and interfaces for developing the CBP computational architecture / tools will be identified.  In addition areas of uncertainty will be identified and characterized with respect to providing a basis for future uncertainty reduction.  Sub tasks are listed below:

  1. Structural Performance
  2. Initial Conditions (includes shrinkage and thermal cracking)
  3. Matrix Leaching and Contaminant Retention
  4. Hydraulic Properties
  5. Microstructural and Mineralogical Evolution
  6. Chemical Degradation
  7. Approaches to Coupling Physical, Structural and Chemical Mechanisms (includes multi-physics coupling)
  8. Integrating Programs and Code Structures
  9. Thermodynamic and Kinetic Databases

Task 2 Reports >>
STATUS: Complete

Task 3: Detailed Technical Description Candidate Software and Integrating Platform Selected for the CBP Modeling

The objective of this task is to describe: 1) the current status of the candidate software and 2) the computational concept for the CBP integrating platform in order to provide a roadmap for the development work in the other tasks.  Detailed descriptions of the candidate software including inputs and outputs, direction for addressing uncertainty analyses, and guidance to the flow and transport module development.  Methodology for the integrating platform including overall approach, data needs, and information exchange with the various software modules will be provided.  The candidate software options are listed below along with the lead partner responsible for providing the summary information for the report:

  1. LeachXS/ORCHESTRA
  2. STADIUM
  3. THAMES
  4. GoldSim

Task 3 Reports >>
STATUS: Complete

Task 4: Input to Test Beds Program

The objective of Task 4 is to prepare a guidance document for cementitious barrier test bed construction and instrumentation.  The workshop to provide input to this task has been completed.

STATUS: On hold

Task 5: Technical Advisory Committee, CRADA agreements and project task statements (PTS)

Task 6: Description of Prototype Reference Cases.

The objective of this task is to define the features and properties of prototype reference cases (waste form, vault/basin containment concrete, and tank fill grout).  The reference cases and will provide benchmark data to validate the computational methods and the individual physical models in the contributing modules.  Prototype specimens will be fabricated for property measurements that will be used in the physical modules and physical property test methods will be reviewed and selected for making the property measurements.

STATUS: Complete

Task 7: Demonstrate Existing Software on Prototype Cases.

The objective of this task is to demonstrate and test the individual physical/chemical modules and the integrating platform concept on the reference cases using reasonable generic input values in the initial calculations.

Task 7 Reports >>
STATUS: Complete

Task 8: Development of Uncertainty Framework

The overall objective of this task is to define, develop and demonstrate a framework and specific methods for assessing and quantifying uncertainty associated with output of CBP computational tools as a consequence of uncertainty associated with underlying data, parameter estimates, conceptual models and computational methods. The specific objectives of the overall task are:

  1. Define initial framework for uncertainty quantification methodology (uncertainty – data, parameter, numerical, model, e.g., conceptual and representation form),
  2. Develop and implement uncertainty methodology for use as part of CBP tools, and
  3. Define and demonstrate the initial framework for uncertainty assessment using sulfate attack coupled with damage mechanics to assess changes in diffusion processes.

Task 8 Reports >>
STATUS: In Process

Task 9: Computational Code Integration and Tools Development

Prediction uncertainties are reduced when appropriate models are coupled over relevant spatial and temporal scales. Stateof-the-art models were identified that provide predictions of barrier performance over well-defined regimes that represent critical areas of interest. In Phase I of the CBP code integration, these models have been linked to a GoldSim model to better characterize model prediction uncertainties and to provide the first necessary step to coupling the models over relevant spatial and temporal solution domains to provide much more accurate predictions of barrier performance over the relevant periods of performance. The GoldSim model also provides a common graphical user interface to the underlying external codes. Ultimately, the results of this project will enable improved risk-informed, performance-based decision-making and support several of the strategic initiatives in the DOE Office of Environmental Management Engineering & Technology Roadmap.

Task 9 Reports >>
STATUS: In Process

Task 10: Improvements in Phenomenological Modules

The objective of this task is to enhance the phenomenological basis of the simulation models through the development of improved constitutive models for specific relationships, improved conceptual models of coupled processes, and integration of underlying phenomena as appropriate.  Modeling results will be tested against available experimental data produced by the CBP effort (Task 12) and by others.    The purposes of the three primary phenomenological simulation models can be summarized as follows:

  • THAMES (NIST) –  Material model to estimate local (ca. 0.001-5 mm) mineralogical composition, physical structure (micro- structure and physical, hydraulic and diffusive properties based on cement/admixture composition and cure conditions for cement paste.
  • STADIUM (SIMCO) –  Predict/estimate the physical degradation, corrosion and meso-structure (ca. <1 mm – 1 m) evolution of cementitious materials (pastes, mortars, concrete, wasteforms) exposed to ion exchange with the environment.
  • LeachXS/ORCHESTRA (ECN) –  Predict/estimate constituent release, chemical profiles and interfacial phenomena in response to aging and environmental conditions (liquid and gas) at meso-scale for cementitous materials.

Task 10 Reports >>
STATUS: In Process

Task 12: Experimental Plan Development and Execution

This task includes experiments to clarify controlling mechanisms, model parameterization and model validation Experimental planning and design

  1. Preparation and distribution of samples
  2. Aging samples under defined conditions
  3. Measurements for model parameterization
  4. Measurements for clarification of controlling mechanisms
  5. Measurements for model validation

Task 12 Reports >>
STATUS: In Process

Task 13: Performance Assessment Support

Task 13 Reports >>
STATUS: In Process

Tasks