SFWST / SFWD-GDSA Geologic Model Integration

The Spent Fuel and Waste Science and Technology (SFWST) Campaign of the U.S. Department of Energy (DOE) Office of Nuclear Energy (NE) is tasked with conducting research and development (R&D) related to the geological disposal of spent nuclear fuel (SNF) and high level nuclear waste (HLW). Two high priority topics for SFWST R&D are to create design concepts and numerical modeling approaches for disposal systems.
A part of the Geologic Disposal Safety Analysis (GDSA) is Geology Integration which includes: 3D Geologic Framework Software, an UZ Reference case for Alluvial Basin (LANL and SNL), and a Shale Reference Case (SNL). The use of VoroCrust is being explored for Voronoi polyhedral meshing to automate and make more efficient part of the model setup workflow as well as increase the accuracy of the flow and transport simulations.

2019 LANL Contribution to Salt-GDSA Integration Fuel Cycle Research & Development
US Department of Energy Spent Fuel and Waste Science and Technology Milestone M3SF-19LA010303012
P.H. Stauffer, J.J. Beisman, C.W. Gable, D.R. Harp, T.A. Miller, E.J. Guiltinan LANL, M. Ebeida Sandia

Workflow for Geologic Applications

Project 1. GDSA Integration with JewelSuite for Alluvial Basin

Project Page for Alluvial Basin Workflow

All Images for Alluvial Basin Workflow

GitHub Repository for Workflow Files

This work builds an Alluvial Basin Geologic Framework (GFM) which is used to create a computation mesh used in Modeling simulations. Portions of the workflow use well developed methods using LaGriT for meshing and FEHM for model setup. The JewelSuite GFM is new, and the integration between the steps need development.

Workflow for Alluvial Basin Meshing:

Project 2. VoroCrust Meshing for Geologic Models

Project Page for VoroCrust Meshing

Unit Cubes VoroCrust Images

JewelSuite Tests VoroCrust Images

Mortandad Mesa VoroCrust Images

Mortandad Mesa Thin Layer VoroCrust Images

This work explores the use of VoroCrust software to create Voronoi mesh files for FEHM/PFLOTRAN type modeling applications. VoroCrust will be used to mesh various geologic models and methods for VoroCrust input and output methods will be explored for integration into the work flow.

SNL is working with VoroCrust to develop Vornonoi mesh files for PFLOTRAN for use in their Shale model task for GDSA Integration.
LANL is working with VoroCrust to develop a meshing workflow for FEHM/FLOTRAN type models in general.

VoroCrust Papers:

VoroCrust Abstract arxiv.org/abs/1902.08767

VoroCrust: Voronoi Meshing Without Clipping PDF

VoroCrust Supplemental Materials PDF

Polyhedral Meshing and Models:

Polyhedral meshing is important for flow and transport codes which include TOUGH2, FEHM, PFLOTRAN, and MODFLOW which are based on the two-point flux discretization. While the solution to flow/transport is stable without an orthogonal mesh, it is not accurate. Geometry conforming Voronoi tessellations are difficult to produce if the geometry is complex. So, if you want orthogonal discretization and you want complex geometry, you need conforming Voronoi tessellations.
In order to obtain the correct material volumes and material interfaces based on the Voronoi tessellation, the vertices have to be carefully distributed equidistantly to the boundary between different materials so that the resulting Voronoi tessellation will have faces that conform to the boundary between materials. The distinction here is that the Voronoi faces conforms to the material interfaces, the tetrahedral Delaunay mesh faces do not.

Coupling LaGrit unstructured mesh generation and model setup with TOUGH2 flow and transport: A case study
Sentis, Manuel Lorenzo ; Gable, Carl WalterORCID
Published as: Computers & Geosciences ; Vol.108, p.42-49 ; November 2017 LA-UR-17-25234 ; 2017-06-29

Publisher Version

Index Page for Alluvial Basin Workflow

All Images for Alluvial Basin Workflow

GitHub Repository for Alluvial Basin Meshing Files

Index Page for VoroCrust Voronoi Meshing