الخلاصة

Abstract In this work the natural radioactivity were measured of 238U, 232Th and 40K radionuclides in 19 imported cement sample in Iraq markets by using gamma-ray spectroscopy NaI(Tl) "3× 3" crystal dimensions. The specific activity of 238U, 232Th and 40K of cement samples, ranged from 6.13±2.10 - 35.25±3.50 Bq/kg, 8.76±1.74 - 48.04±2.29 Bq/kg and 504.74±10.10 - 946.74±11.01 Bq/kg respectively. Radium equivalent activity (Raeq) and various hazard indexes were also calculated to assess the radiation hazard of the natural radioactivity in the cement samples. Radium equivalent activities of all cement samples were below the worldwide average (370 Bq/kg). The value of absorbed dose rate range from 56.58 nGy/h to 143.75 nGy/h . The external and internal hazard index of cement samples were less than unity.