Routine surveillance of environmental radioactivity in the influence area of the Institute during year 2000

The radioactivity measurements were performed according to the Monitoring Concept for nuclear units in IFIN-HH, which provides the type, the locations and sampling frequency of the environmental factors that were analyzed. The working group has been involved in a project supervised by the IAEA, concerning QA/QC for Nuclear Analytical Techniques. Samples of water, sediments, soils, vegetation and aerosols have been analyzed for both gross beta and gamma activity, as follows: 1004 samples of potential radioactive water, surface, drinking and underground water; 18 sediment and 72 soil samples; 9 samples of spontaneous vegetation and 8 samples of milk, 3 samples of vegetables. We analyzed for gross beta and gamma activity 42 samples of radioactive liquid effluents from the two nuclear units of the institute, CPR and STDR. Airsol samples have been monitored twice a month; the maximum concentration of the total beta activity was of 9.2 mBq/m3 air (absolute error: 4.4). Gross beta activity for samples of drinking water and surface water, was always lower than the maximum allowed concentration (1Bq/l), i.e., lower than the warning limit of 1.85 Bq/l. The maximum value of the gross beta activity recorded for the sewage water (reactor Canal) was 1.92 Bq/l (absolute error: 0.22 Bq/l (95%)), but no influence on the surface water downstream the spillflow was observed, gross beta value determined for this sample being lower than the detection limit (0.30)Bq/l. Gamma spectroscopy analyses performed on annual composite samples of sewage water showed an average activity concentration for Cs-137 of 2.0 mBq/l (absolute error: 0.5 mBq/l), values close to those determined for the surface water samples, 4.2 (with an absolute error: 0.5). Co-60 was detected in the sewage water and sediments collected at the sewage spillflow, with an activity concentration of 8.0 mBq/l (absolute error: 1.0 mBq/l) and 129 Bq/kg (absolute error: 15 Bq/kg) dry mass, respectively. For the surface water and sediment samples collected downstream the discharge site, the Co-60 concentration was of 5.5 mBq/l (absolute error: 0.9 mBq/l), i.e. lower than the detection limit (9 Bq/kg). Gross beta values for cultivated vegetation and milk samples collected from the living area were in the same range to those recorded in the previous years. The concentration level recorded was: 46 Bq/l (absolute error: 4 Bq/l) for milk samples, 55 Bq/kg (absolute error: 4 Bq/kg) fresh mass for tomatoes, 79 Bq/kg (absolute error: 7 Bq/kg) for cabbage, 152 Bq/kg (absolute error: 9 Bq/kg) of potatoes. Since July, a trimestrial surveillance of the 'Fort' radioactive waste storage area has started. Samples of soils and vegetation were analyzed by gamma spectroscopy. (authors)