Statistical prediction on the location and amount of maximum radiation dose during accidental emission

The location and amount of maximum radiation dose must be known early so that protective arrangements can be taken in time after accidental emission in the expected area of maximum exposure. Diagrams are presented which allow to predict with a certainty of 90% the approximate location of maximum dose, i.e. a sector having a defined aperture angle and a given region of source distance. The diffusion category, the wind direction and the wind velocity prevailing at the beginning of the accident are assumed to be known. Also, the expected duration of the emission and the development in time of the source strength should be known. Moreover, the diagrams include a correction factor allowing to establish a relationship between the amount of the actual maximum dose and the amount of the dose calculated on the assumption that the meteorological conditions applicable at the beginning of emission remain constant. (orig.)