Author name:
جعفر جليل سلطان الطائي
Supervisor name:
ندى فاضل توفيق
Abstract:
The objectives of the present study were to measure the level of the radioactivity Al - Dora refinery and surrounding area. The study includes : The first. the radon gas concentration in soil samples from Al - Dora refinery and dust samples from surrounding area by using "sealed can technique" and CR - 39 track detector to registration alpha tracks emitted from radon gas in (soil and dust) samples. The second. Detect of the radionuclides and measure the specific activities in soil and water samples using gamma ray spectroscopy system with HPGe detector. The measured soil, water and dust samples were taken from (40) samples, 27 soil samples (surface, 15 and 30cm depth), 8 water samples and 5 dust samples. The detecting of naturally occurring radionuclides (226Ra belong to 238U series, 228Ac belong to 232Th series and one natural radionuclide 40K) in the (soil and water). And estimate the radium equivalent (Raeq), absorbed dose rate in air (ADRA), hazard index (Hex, Hin) and annual effective dose equivalent (AEDE) in soil samples of Al - Dora refinery and surrounding area.The radon concentration in surface soil samples ranged from (290.709 to 394.534 Bq/m3 with an average 365.925 Bq/m3). The radon concentration in soil at the depth 15 cm was ranged from (294.862 to 346.775 with an average 324.164 Bq/m3) and at the depth 30 cm was ranged from (228.633 to 288.414with an average 254.947 Bq/m3). The surface exhalation rate in surface soil samples ranged were ranged from (0.601, to 0.816 with average 0.757Bq·m−2.h−1), in soil samples at the depth 15 cm ranged from (0.61 to 0.717 with average 0.671 Bq·m−2·h−1) and in soil samples at the depth 30 cm ranged from (0.47 to 0.597 with average 0.527 Bq·m−2·h−1). The mass exhalation rate in surface soil samples were ranged from (0.469 to 0.639 with average 0.59 Bq·kg−1·h−1), in soil samples from depth 15 cm ranged from (0.457 to 0.559 with average 0.523 Bq·kg−1·h−1) and in soil samples at the depth 30 cm ranged from (0.368 to 0.465 with average 0.411 Bq·kg−1·h−1).The specific activities for radionuclides (226Ra, ٢28Ac) in surface soil samples were ranged (from 11.725, 15.41 to 59.08, 36.17 Bq/kg respectively) with an average (33.621 and 22.375 Bq/kg respectively) and the specific activity of 40K radionuclide ranged (from 328 to 424.9 with average ٣٦٣.٤٥ Bq/kg). At 15 cm depth ranged (from 18.047, 14.613 to 39.71, 21.673 Bq/kg respectively) with an average (30.527 and 19.66Bq/kg respectively), the specific activity of 40K radionuclide ranged (from 201.3 to 391.3 with average٣٢٦.٧٣ Bq/kg). At 30 cm depth ranged from 17.94, 12.89, to 45.766, 23 Bq/kg respectively) with an average (30.393 and 18.124 Bq/kg respectively), the specific activity of 40K radionuclide ranged (from 231.4 to 351.3 with average ٣١٠.٩٤Bq/kg).For water samples ranged (from 1.60, 1.025 to 8.805, 13.52Bq/kg respectively) with an average (5.031 and 2.925 Bq/kg respectively), the specific activity of 40K radionuclide ranged (from 11.462 to 18.58 with average ١٥.٧٧٨Bq/L).The average values of Raeq, Hin, Hex, ADRA, and the annual effective indoor and outdoor doses in soil and water samples were, in surface (93.70 Bq/kg, 0.309, 0.226, 39.755 nGy/h, 0.198 mSv/y, 0.049 mSv/y), in 15cm depth (83.582 Bq/kg, 0.34, 0.2٥2, 44.34 nGy/h, 0.227 mSv/y, 0.055 mSv/y), in 30 cm depth (80.253 Bq/kg, 0.299, 0.217, 38.051 nGy/h, 0.189 mSv/y, 0.047 mSv/y), and in water (10.428 Bq/kg, 0.042, 0.028, 4.788 nGy/h, 0.024 mSv/y, 0.006 mSv/y).
