Various test items are used to validate the calculated radiation environment in reactor test environments. The center image shows Sandia’s Annular Core Research Reactor with the central cavity. The left shows test spheres that contain many internal sensors used for validation. The right figure shows the calculated-to-measured agreement for the sensors as a function of their radial position within an aluminum test sphere. The red bounding lines indicate the RAMSES/NuGET acceptance metric, the central blue line indicates the position corresponding to complete agreement, while the ratios for the C/E values are given with associated uncertainty.