Author:
Putra D I P,Prihatiningsih W R,Makmur M,Yahya M N,Priasetyono Y,Untara
Abstract
Abstract
Studies on the radionuclide distribution of some naturally occurring radioactive materials (NORM) and anthropogenic radionuclides in the sediments of the coastal areas of North Sulawesi were conducted to provide baseline data for the effective monitoring of radioactive fallout in these areas. Sediment samples were collected by a van Veen grab samples about 100 – 300 m from the shoreline, and 60 L of seawater was pre-concentration to precipitated 137Cs. Activity concentration of the three main natural radionuclides (222Ra, 232Th, and 40K) and 137Cs were determined using a high-resolution HPGe gamma-spectroscopy system and presenting background about the radiological levels and assessing the associated hazards. The activity of 226Ra ranged from 2.1 to 9.5 Bq kg−1 with an average value of 5.9 Bq kg−1. The activity of 232Th varies from 2.4 to 10.4 Bq kg−1 with an average value of 5.2 Bq kg−1. The 40K ranges between 169.1 to 492.7 Bq kg−1 with an average value of 238.8 Bq kg−1. The average activity concentration of 40K (238.8 Bq kg−1) in the sediment samples was lower than the worldwide average concentration (420 Bq kg−1). The current level of activity 137Cs varied from 0.05 to 0.40 Bq kg−1 in sediment samples and 0.98 to 1.33 Bq m−3 in seawater samples. 134Cs in all samples were not detected or below the detection limit. This fact indicated that radioactive cesium in Celebes Sea areas of North Sulawesi still originated from global fallout and insignificant influenced by the FDNPP accident. All radionuclide radiation values in the recent study are lower than the world average. Therefore, the potential danger of radiation generated from the surrounding environment has not yet caused a radiological health impact for the people living on the coast of North Sulawesi. Natural and artificial radionuclide activity data in this study will be used as the basis for sedimentary activity along the coast of North Sulawesi.