MAN-MADE RADIOACTIVITY IN THE ALMANZORA GULCH AND BEACH EDGE OF PALOMARES, SPAIN

The Pu-239+240, Pu-238 and Cs-137 distribution along the Almanzora Gul ch and beach edge have been studied. These areas were affected by the accident of 1966, in which a non-nuclear explosion of two thermonuclea r bombs occurred. Fluvial sediments at 0-5 cm (in 1990) and 0-10, 10-2 0, 20-30 cm depth (in 1991) were sampled. The surface inventory (0-5 c m) of radionuclides ranges from 0.4 to 1.8 Bq . m(-2) of Pu-239+240 an d from 1 to 60 Bq . m(-2) of Cs-137. The estimated total inventory (0- 30 cm) shows values from 20 to 264 Bq . m(-2) of Pu-239+240 and from 3 28 to 1147 Bq . m(-2) of Cs-137. The ratio Pu-239+240/Cs-137 changes s ignificantly close to the river mouth, probably due to the different b ehaviour of both radionuclides. At one sampling station a contribution from the Palomares accident was noted based on the ratio Pu-238/Pu-23 9+240. It seems evident that until now no influence from the Chernobyl accident has been detected in this area. The granulometry of the sedi ments manifests the river hydrodynamics, a dry gulch with periods of f loods typical of certain Mediterranean,rivers. An important input of t errigenous material containing radionuclides to the adjacent continent al shelf occurs in these periods.