Status of 137Cs concentrations in sea water at the inlets of the Indonesian Through Flow (ITF)

There is a lack of available data on Cs-137 water concentrations at the Indonesian Through Flow (ITF). The data is required for evaluation of the possible impact of the Fukushima accident in Indonesia's marine environment. Cs-137 monitoring at inlets of ITF were conducted in order to address this possible impact. Monitoring was performed by the Baruna Jaya III research vessel during the Sail Morotai campaign of 2012. Surface sea water (0-10 m depth) samples were collected at 7 stations. The AMP (Ammonium molybdophosphate) method was used for separating radiocesium from seawater. The radiocesium were measured by a HPGe detector of gamma spectrometer system. The measured concentrations of Cs-137 in the Flores Sea ranged between 0.29-0.30 Bq m(-3). At another inlet of the ITF in the Halmahera Sea which the concentration of Cs-137 were founded varied between 0.20-0.38 Bq m(-3). The water concentrations of Cs-137 in the Lifamatola Passage, at the Eastern of Sulawesi, ranged between 0.20-0.30 Bq m(-3). There was no detection of Cs-134 at any of the monitoring stations. The result showed that the input Cs-137 from the Pacific Ocean to Indonesian Seas was not from Fukushima but was characteristic of global fallout in the Pacific Ocean. (C) 2017 Elsevier B.V. All rights reserved.