Some considerations on the environmental radioactivity in the area of the National Radioactive Waste Repository, Baita-Bihor

National Radioactive Waste Repository for low and intermediate levels of activity is located nearby Uranium quarry Baita, in the South-Eastern part of the Bihor Mountains. Consequently, a complex environmental monitoring is necessary. The goal of our study was to identify the artificial radionuclides (originating in the radioactive waste), and the natural ones from the investigated area and to establish the contamination level inside the platform of the drum unloading as well as a possible migration in the immediate vicinity. The water, soil and plant samples were collected from the selected points seasonally (except for the winter) in 2001 and 2002. The samples were prepared according to our specific procedures and measured by gamma ray spectrometry. The radionuclides 60 Co and 137 Cs, originating from radioactive waste, were found in the platform area, their concentration ranging between 50-2400 Bq/kg. 60 Co was not put in evidence outside the platform, but the activity concentration values of 137 Cs were due to Chernobyl fallout or slightly increased. The radionuclides 238 U, 234m Pa, 226 Ra and its progeny were evidenced on the platform area and in its immediate vicinity, in almost all analyzed samples, several values being 10 kBq/kg. Also, 137 Cs and 226 Ra were evidenced in vegetation samples. The soil plant transfer factors were calculated (when possible) for 137 Cs and 226 Ra. 60 Co was not evidenced in vegetation. For future projects we intend to measure the vertical concentration distribution for 137 Cs and 226 Ra. (authors)