Modeling and Simulation ( NEAMS ) Workbench — II

Complex, coupled physical systems that occur in various domain sciences present several serious challenges in implementing an efficient and seamless simulation workflow. These challenges impact the productivity of scientific research and the overall time it takes to verify simulation results. To overcome these computational modeling barriers, specifically in nuclear reactor analysis, one must rely on flexible and scalable tools that simplify modeling complexity. The geometry model of the reactor core can consist of a large number of volumetric regions and surface boundaries. For example, an advanced burn test reactor (ABTR) core can have over twenty thousand volumes and over a hundred thousand surface boundaries. Many simulations require a discretized representation of the geometry that can be made with a variety of meshing tools such as CUBIT [1] and MeshKit[2]. CUBIT is a hexahedral mesher that is developed by Sandia National Laboratories, and MeshKit is part of the Scalable Interfaces for Geometry and Meshbased Applications (SIGMA) toolkit [3]. This summary presents a modeling/visualization tool that aims to simplify the preprocessing workflow tasks for various reactor models (light-water reactors, or LWRs, and sodium-cooled fast reactors, or SFRs) [4,5]. The techniques employed by this tool provide the abilities to model complex cores, simplifies the process of assigning material and boundary specifications, and interactively visualize their three-dimensional (3D) geometry. With the above motivations to simplify computational workflows, we present the development of innovative techniques within an open-source tool: Reactor Geometry (and mesh) Generator (RGG) [6]. RGG simplifies the traditional reactor modeling process and the mesh generation of the core. The tool uses Qt for the twodimensional (2D) user interface components, and it uses the Visualization Toolkit (VTK) [7] to visualize the core in 3D.