Natural radionuclides tracing in marine surface waters along the northern coast of Oman Sea by combining the radioactivity analysis, oceanic currents and the SWAN model results.

This study aims to establish a managed sampling plan for rapid estimate of natural radio-nuclides diffusion in the northern coast of the Oman Sea. First, the natural radioactivity analysis in 36 high volume surface water samples was carried out using a portable high-resolution gamma-ray spectrometry. Second, the oceanic currents in the northern coast were investigated. Then, the third generation spectral SWAN model was utilized to simulate wave parameters. Direction of natural radioactivity propagation was coupled with the preferable wave vectors and oceanic currents direction that face to any marine pollution, these last two factors will contribute to increase or decrease of pollution in each grid. The results were indicated that the natural radioactivity concentration between the grids 8600 and 8604 is gathered in the grid 8600 and between the grids 8605 and 8608 is propagated toward middle part of Oman Sea.

The measurement of gamma-emitting radionuclides in beach sand cores of coastal regions of Ramsar, Iran using HPGe detectors.

Radionuclides which present in different beach sands are sources of external exposure that contribute to the total radiation exposure of human. (226)Ra, (235)U, (232)Th, (40)K and (137)Cs analysis has been carried out in sand samples collected at six depth levels, from eight locations of the northern coast of Iran, Ramsar, using high-resolution gamma-ray spectroscopy. The average Specific activities of natural radionuclides viz., (226)Ra, (235)U, (232)Th, (40)K and (137)Cs, in the 0-36 cm depth sand were found as: 19.2±0.04, 2.67±0.17, 17.9±0.06, 337.5±0.61 and 3.35±0.12 Bq kg(-1), respectively. The effects of organic matter content and pH value of sand samples on the natural radionuclide levels were also investigated. Finally, the measured radionuclide concentrations in the Ramsar beach were compared with the world average values, as reported by UNSCEAR (2000). None of the studied beaches were considered as a radiological risk.