ASSESSMENT OF NATURAL RADIOACTIVITY LEVEL IN SHORE SEDIMENT SAMPLES FROM NASSER LAKE AT ASWAN, EGYPT

Thirty shore sediment samples taken from the side beach of Lake Nasser in south Arab Republic of Egypt to measuring the terrestrial radionuclides radium-226, thorium-232 and potassium-40 and its associated hazard indices. The activity concentration of natural radionuclides 226Ra,232Th and 40k in shore sediments samples under investigation are ranged from 1.92±0.077 to 17.55±0.676 Bqkg-1 with average value of 5.02±0.194 Bqkg-1, 5.62±0.281 to 28.77±1.441 Bqkg-1 with average value of 13.15±0.641 Bqkg-1 and 123.27±10.604 to 277.38±23.861 Bqkg-1 with average value of 200.26±17.054 Bqkg-1respectively .The radiation hazard indices which resulting from the presence of natural radionuclides in shore sediment samples were calculated and the obtained results indicate that the values of radium equivalent activity varies from 21.85 to 80.04 Bq/kg with average value of 39.25 Bq/kg, representative level index Iˠr varies from 0.16 to 0.58 with average value of 0.29.Absorbed dose rate varies from 10.63 to 37.541 nGy.h−1 with the average value of 18.83 nGy.h−1 . External hazard index Hix varies from 0.059 to 0.216 with average value of 0.105, internal hazard index Hin varies from 0.070 to 0.263 with average value of 0.119, annual outdoor effective dose varied from 0.013 to 0.046 mSvy-1 with average values 0.023 mSvy-1andThe indoor effective dose ranged from 0.052 to 0.184 mSvy-1, with average values 0.092 mSvy-1.