Radiation protection measurements around the TRIGA reactor of the Institute 'J. Stefan', Ljubljana (RS)

Measurements of Ar-41 concentrations in air were performed using GM counters. The Ar-41 from the Lazy Susan coming directly into the atmosphere during sample manipulation is measured. The radioactivity of pool water is also measured. Because some manipulations were performed near the open pool water surface the radioactivity of the gases or vapours leaving the water surface is measured. Doses received by reactor operators, experimental staff and workers are measured using film dosemeters. The lowest monthly evaluated dose is 50 mrem and it is not exceeded by the majority of workers. In the last 4- years no monthly dose over 500 mrem. was noticed, and there were only 25 doses up to 300 mrem. The highest dose rate at which planned work is allowed to be performed is 100 mrem/h Smear tests on predetermined places were taken at regular intervals. Only a few contaminations of the reactor platform were reported, which originated from improper sample manipulations. Since the introduction of automatic sample extraction, no contaminations were observed. Because of the concern for a clean environment and to provide evidence for the competent authorities, measurements of the natural radioactivity of air, of precipitation, of well water and of the waste recipient stream, the Sava, were made. In all the years of reactor operation no influence of reactor effluents on the environment were observed. The average gross beta activity in 1977 of air was 0.12 pCi/m3, of fallout 83 pCi/1, of well water 1.7 pCi/1 and for the water of the river Sava 2.8 pCi/1 after and 3.2 pCi/1 before inflow of reactor effluents, respectively