Quantitative assessment of the possible loss of radiation protection in above ground fallout shelters due to window breakage and internal contamination requires consideration of the mechanism of the settling of fallout, the radiation shielding of buildings, distances of blast damage, and wind characteristics. The factors are discussed in a manner which would allow assessment for a particular area with marked fallout shelters in tall buildings. In a particular example of a seven-story building, the internal contamination on each floor is estimated to be 2.5% of that on the roof. This contamination, if spread uniformly over the floor, reduces the protection factor on the fifth floor from 28 to 18 and in the unexposed, uncontaminated basement from 420 to 200.
(C)1967Health Physics Society