Civic Improvement Program. Volume 2. Fallout Protection Factor Analysis Capability

The Vehicle Code System VCS, originally developed to calculate initial radiation environments and protection factors for three dimensional shield systems, has been modified to calculate protection factors for fallout radiation environments. This report describes the modifications to VCS and gives the results of several test case analyses performed to verify this fallout protection factor version. Fallout radiation protection factor calculations were performed for a number of structures for which simulated fallout experiments had been performed in the late 1950s and early 1960s. The comparisons were generally good, with about half of the results agreeing within 10 percent and three-quarters of the results agreeing within 20 percent. Disagreement was found in some cases where descriptions of the structure were not adequate. We believe, based on these overall results, that the fallout protection factor version of VCS is performing correctly. Calculations were also performed to assess the potential effect on fallout protection factors of a number of variations in typical structures. Variations explored included the effects of internal partitions, attached garages, basement depth, structure length-to-width ratio, and fallout contaminated balconies. Keywords Civil Defense, Casualty assessment, Radiation transport, Vehicle code system.