Isotope behavior of Uranium in coastal area of the East Coast of Malaysia: Determination of activity ratio of 234U/ 238U

The determination of uranium isotopes activity concentration and their distributions in the seawater and surface sediment along the coastal area of the East Coast of Malaysia Peninsular have been performed using alpha spectrometry counting system. The sampling of both seawater and surface sediment for this study was carried out in August 2003 as part of the Marine Radioactivity Database Development Project for Malaysia. This results show that the distribution of uranium radionuclides (234U and 238U) in seawater and surface sediment is not consistent, their activities are fluctuated depending on the sampling locations. Generally, the 234U and 238U activities measured in the seawater are in the range of 2.94 to 45.80 and 2.12 to 38.10 Bq.m-3, respectively, whilst in the surface sediment they are in the range of 28.00 to 60.05 and 25.15 to 55.15 Bq.kg-1 dry weight, respectively. In general, the activity ratios of 234U/ 238U at all sampling locations are nearly uniform in the range of 1.08 to 1.39 for seawater and 1.01 to 1.12 for surface sediment. These ratios are comparable with those found in published literatures. (author)