Abstrak
Masalah pokok yang dikaji di penelitian ini adalah pemetaan dan analisis aktivitas jenis kandungan radioisotop dalam sampel batuan di muara sungai Sumlili Kupang Barat. Tujuan penelitian meliputi : menentukanrange cacah dan aktivitas jenis massa (C) kandungan radioisotop dalam sampel pasir di muara sungai Sumlili Kupang Barat, mengestimasi tingkat kontaminasi radioisotop sesuai standar di sekitar muara sungai Sumlili, dan memetakan sebaran cacah radioisotop pada luasan daerah tertentu yang terjangkau survei di lapangan. Metode penelitian meliputi : observasi/survei, sampling, serta analisis dan interpretasi data. Kisaran cacah radiasi di lapangan, di laboratorium, dan nilai aktivitas jenis massa kandungan radioisotop dalam 52 sampel pasir dari lokasi penelitian dimuara sungai Sumili Kupang Barat secara berturut-turut adalah 19 cpm sampai dengan 60 cpm, 29 cpm sampai dengan 73 cpm, dan 0,107 x 10-5μCi/gram sampai dengan 0,269 x 10-5μCi/gram. Berdasarkan kontur dan kurva tiga dimensi radiasi cacah radioisotop dalam sampel pasir di lapangan dan di laboratorium serta kontur dan kurva tiga dimensi aktivitas jenis massa di muara sungai Sumlili Kupang Barat dapat diketahui bahwa sebaran kontaminasi radioisotop di muara sungai Sumlili Kupang Barat lebih tinggi ke arah barat dan cenderung menurun ke arah timur. Hasil perhitungan aktivitas jenis massa kandungan radioisotop dalam sampel pasir di muara sungai Sumlili Kupang Barat, termaksud dalam kontaminasi rendah untuk radiasi alpha (α) dan beta (β), namun daerah ini perlu diwaspadai karna terdapat beberapa titik di lapangan, cacah radiasi nuklir kandungan radioisotop dalam deposit mineral cukup tinggi melebihi standar IAEA.
Kata kunci : Radioisotop, Aktivitas Jenis Massa, Daerah Kontaminasi.
ABSTRACT
The main problem studied in this study is mapping and analyzing the activity of the types of radioisotope content in rock samples at the mouth of the Sumlili river in West Kupang. The research objectives included: determining the counting range and mass type activity (C) radioisotope content in the sand samples at the Sumlili River mouth in West Kupang, estimating the level of radioisotope contamination according to the standards around the Sumlili river estuary, and mapping the distribution of radioisotope counts in the area covered by surveys in field. Research methods include: observation / survey, sampling, and analysis and interpretation of data. The range of radiation counts in the field, in the laboratory, and the value of the type of mass activity of radioisotope content in 52 sand samples from the study locations in the West Kupang Sumili River are 19 cpm to 60 cpm, 29 cpm to 73 cpm, and 0.107 x 10-5μCi / gram up to 0.269 x 10-5μCi / gram. Based on the three-dimensional contour and curve of radiation from radioisotope counts in sand samples in the field and in the laboratory and three-dimensional contours and curves the activity of mass types in the Sumlili estuary of West Kupang can be seen that the distribution of radioisotope contamination in the Sumlili estuary of West Kupang is higher west and tends to decline to the east. The results of the calculation of the type of mass activity of radioisotope content in sand samples at the mouth of the Sumlili River in West Kupang, are referred to in low contamination for alpha (α) and beta (β) radiation, but this area needs to be watched out for there are several points in the field, nuclear radiation in mineral deposits quite high exceeding IAEA standards.
Keywords : Radioisotopes, Mass Type Activities, Contamination Areas.
Guarantee rate of freshwater in a river mouth intruded by saltwater with respect to the joint impact of runoff and tide
