Estimation of Weapon Yield from Inversion of Dose Rate Contours

This research studies the uncertainty in yield estimation from inversion of dose rate contours. The Hazard Prediction and Assessment Capability (HPAC) and a simple FORTRAN95 based Fallout Deposition Code (FDC) are used to recreate dose rate contours from historic nuclear tests. Fallout footprints from six atomic tests are recreated using balloon wind soundings and high resolution mesoscale weather reanalysis data. Dose rate contour plots are created for different yields for a single set of weather conditions. Dose rate contours are compared to determine uncertainty in yield estimation from inversion of dose rate contour plots. Results of these dose rate recreations are compared to historical patterns found in the Defense Nuclear Agency's (DNA) DNA 1251-1-EX Compilation of Local Fallout Data From Test Detonations 1945-1962 Extracted from DASA 1251. Recreated dose rate contours are compared against historic patterns using a Figure of Merit (FOM) developed from the Measure of Effectiveness (MOE) and the Normalized Absolute Difference (NAD) techniques. This research provides a method to estimate the minimum yield required to create a dose rate contour to within a factor of two. This research determined that use of ground zero balloon soundings and reanalysis winds thereafter allowed the most accurate recreation of historic dose rate contours.