Fast correction of cloud dose data files due to changes in dispersion parameters

A consequence assessment computer program (ARANO) is discussed which carries out the calculation of external cloud doses by interpolating from a comprehensive dose data file, which contains the normalized doses for different photon energy groups and dispersion situations. These dose values are based on dispersion parameters which are not corrected to take into account the wind meandering effect. To avoid the recalculation of the whole dose data file a fast approximative method has been developed. In addition to the meandering correction of external doses the method has been generalized to take into account the increase of vertical standard deviation, for instance, due to terrain roughness. The suitability and accuracy of this method have been shown to be satisfactory, by carrying out calculations on a plume by this program, and by a previous one which involved time consuming complete 3-dimensional integrations. (U.K.)