STUDY OF AIRBORNE RADIOACTIVITY NEAR TO THE HIGH WATER MARK AT DRIGG POINT

Measurements are reported on radionuclides collected at Drigg Point us ing muslin screen aerosol collectors arranged along two transects lead ing inland from the high water mark for similar to 300 m. The results of seven long-term exposures, taken over periods of 1.0-8.2 weeks, and three short-term exposures, taken over 1.5-2.2 h at different states of the tide, are presented. A determination of gamma-ray emitting radi onuclides collected by the screens wets used to determine the relative concentrations of radioisotopes in the air as a function of distance inland. Average wind speeds were calculated for each exposure using da ta obtained from the nearby Eskmeals weather station. Reductions in th e radionuclide concentrations vs distance inland calculated using the SALT model of Nelis et al. (Atmos. Environ. 1994, 28, 3213-23) are sho wn to reproduce the data reasonably well. It is concluded that the res ults are useful for testing models of the radionuclide dispersion and deposition. (C) 1996 Elsevier Science Limited