RESUMEN
The measurements of activity concentration of radium ( 226Ra ), thorium ( 232Th) and potassium ( 40K ) natural radionuclides using high purity germanium ( HPGe ) detector to assess harmful effects on people residing around Royal Uranium Site, Sikar, Rajasthan, India. The activity concentrations range from 29.03 ± 3.72 to 69.95 ± 4.07 Bq/kg for 226Ra with a mean value of 47.01 Bq/kg, 57.99 ± 6.13 to 113.94 ± 6.54 Bq/kg with a mean value of 86.56 Bq/kg for 232Th,678.19 ± 76.36 to 1426.55 ± 81.32 Bq/kg for 40K with a mean value of 1195 Bq/kg. Average Radium Equivalent Activity was measured 261.59 ± 35.48 Bq/kg. The total outdoor absorbed gamma dose rate ranged from 78.42 to 157.91 nGy/h with a mean value of 122.12 nGy/h.The average annual effective dose equivalent outdoors and indoors was found 0.75 mSv.Mean external (Hex) and internal (Hin) hazard indices are measured 0.70 and 0.82, respectively, for the study area.