Radiological study of Mersing District, Johor, Malaysia

A potential site has been selected for a nuclear power plant (NPP) in Mersing District of Malaysia. This study aims at providing the base line data of this district for the first time, in line with the International Atomic Energy Agency (IAEA) for NPP sitting criteria. The mean dose rate, mean population weighted dose rate and annual effective dose are found to be 140 nGy h−1, 0.836 mSv y−1 and 0.857 mSv, respectively. A hyper Purity Germanium Detector (HPGe) is used in determining the activity concentrations of 232Th, 226Ra and 40K. The activity concentration ranges from 16±1 to 410±15 Bq kg−1 for 232Th, 17±1 to 271±8 Bq kg−1 for 226Ra and 13±3 to 1434±57 Bq kg−1 for 40K. In addition, a Low Background Alpha Beta Series 5 XLB Automatic was used in the determination of gross alpha and gross beta activity. The result ranges from 202±50 to 2325±466 Bq kg−1 for gross alpha and 164±17 to 2447±103 Bq kg−1 for gross beta. Contour maps were produced for isodose, activity concentration of 232Th, 226Ra, 40K, gross alpha and gross beta for the study area. The results are compared with UNSCEAR (2000).

► A station in Mersing District has been identified as a possible site for nuclear power plant.
► The average dose rate found to be two times higher than the world average.
► The activity concentration of 232Th is four times world average.
► The activity concentration of 238U is two times and 40K is lower than world average.
► A digital map plotted for isodose, 232Th, 238U, 40K, gross alpha, gross beta activities.