ABSTRAKSTUDI PENINGKATAN RADIONUKLIDA ALAM KARENA LEPASAN ABU TERBANG DI SEKITAR PLTU LABUAN. Abu terbang dan abu dasar hasil pembakaran batu bara mengandung radionuklida alam dengan konsentrasi tertentu. Lepasan abu terbang ke lingkungan dapat berpotensi meningkatkan konsentrasi radionuklida alam di lingkungan sekitarnya. Tujuan penelitian ini adalah mengukur konsentrasi radionuklida alam di tanah dan menganalisis kemungkinan adanya peningkatan konsentrasi radionuklida alam di tanah sekitar PLTU Labuan. Metode penelitian diawali dengan pengambilan sampel tanah yang lokasinya disesuaikan dengan sampling sebelum PLTU Labuan beroperasi. Selanjutnya dilakukan preparasi dan pengukuran sampel tanah menggunakan spektrometer gamma detektor HPGe selama 61.200 detik. Hasil pengukuran konsentrasi yang didapat dibandingkan dengan data konsentrasi sampel tanah sebelum PLTU Labuan beroperasi. Perbandingan ini menggunakan komparasi dengan uji-t. Hasil pengukuran rata-rata konsentrasi radionuklida alam di sampel tanah saat ini adalah untuk Ra-226, Th-232, dan K-40 masing-masing sebesar 23,15±3,05 Bq/kg; 35,89±4,07 Bq/kg; dan 153,52±16,71 Bq/kg, sedangkan saat sebelum PLTU Labuan beroperasi adalah 22,94±1,92 Bq/kg; 38,60±2,58 Bq/kg; dan 122,10±8,90 Bq/kg. Hasil uji komparasi ketiga radionuklida antara sebelum dan sesudah PLTU Labuan beroperasi menunjukkan tidak ada perbedaan signifikan. Kesimpulan penelitian ini adalah tidak ada peningkatan rata-rata konsentrasi radionuklida alam di sekitar PLTU Labuan yang signifikan.Kata kunci : radionuklida alam, TENORM, abu terbang, PLTU batu bara, PLTU Labuan. ABSTRACT STUDY OF INCREASING NATURAL RADIONUCLIDE DUE TO FLY ASH DISCHARGED AT AROUND LABUAN COAL POWER PLANT.Fly ash from coal-fired power plants containing radionuclides will probably potentially improve concentration of natural radionuclides and radiation dose rate in the surrounding environment. The object of this study are to measure and analyze presence of increasing natural radionuclides concentrations around Labuan power plant after 6 years operation. The research method begun with soil sampling whose location was adjusted to the sampling before Labuan power plant operates. The next step was measurement of soil samples using HPGe spectrometers The last step was comparing radionuclide concentration in soil samples on this time with the previous data before Labuan coal-fired power plant operated using t-test comparation. The average concentration of natural radionuclides in soil samples today are Ra-226 23.15 ± 3.05 Bq/kg, Th-232 amounted to 35.89 ± 4.07 Bq/kg, and K-40 amounted to 153.52 ± 16.71 Bq/kg. The value of this radionuclide concentrations did not differ significantly compared with the concentration of radionuclides in soil before Labuan power plant operation. It is concluded that there is no significant increase in the average natural radionuclide concentrations around Labuan power plant.

Cellulose obtained from rice straw was grafted with polyvinylpyrrolidone (Cell-g-PVP). The process was induced by simultaneous gamma iradiation (Co-60). The presence of the grafted PVP chains was confirmed by FT-IR, XRD and EDS methods. The influence of the iradiation dose (20 and 30 kGy) on the reaction efficiency and thermal stability of Cell-g-PVP was investigated. The grafting yield at the dose of 30 kGy was about 56%. The higher dose of radiation resulted in better thermal stability. The AAS results showed that Ni(II), Cu(II), and Cr(II) ions can be adsorbed by Cell-g-PVP. The order of ion metals adsorption capacity of Cell-g-PVP was Cu(II) > Ni(II) > Cr(II). The adsorption isotherm of Cu(II) metal ion using the Cell-g-PVP followed the Langmuir adsorption isotherm whereas the chemical adsorption and the adsorption energy were constant on all sides of the copolymer.