It is important to NASA engineers to be able to model radiation effects through very complex vehicle structures. This requires (1) integration of modeling tools with Computer Aided Design (CAD); (2) easy and uniform setup of materials, particles sources and tallies; (3) ability to analyze and validate the results across multiple radiation codes. Tech-X will deliver RSim, a across-platform standalone application for radiation modeling. RSim will have a Graphical User Interface that will allow users to perform setup, run and do post-processing for several radiation modeling tools. The setup will include Constructive Solid Geometry creation and CAD import, materials annotation, particles sources setup and choosing tallies. RSim will be able to run several radiation codes to facilitate Validation and Verification. Post-processing in RSim will allow for 3D visualization, 2D plots and histograms. Phase I will concentrate on CAD import and material annotation for MCNP6 and PHITS codes and develop RSim prototype. In Phase II we will fully implement RSim and consider integrating with more codes, for example Geant4.