METODE PENGENDAPAN DAN PENUKAR KATION UNTUK PEMISAHAN CESIUM DALAM BAHAN BAKAR U3Si2-Al

Abstract

¹³⁷Cs isotope was one of the fission products which could be used as a burn up monitor to study the performance of the fuel during irradiation in a reactor. For analyzed ¹³⁷Cs isotope in post-irradiation U₃Si₂-Al fuel element plate (PEB), it was needed a valid method to obtain accurate data. Several methods could be used for ¹³⁷Cs separation from U₃Si₂-Al PEB solution were precipitation method in CsClO₄ salt form according to ASTM E 320-79 and cation exchange method using Lampung zeolite. The precipitation process was done using CsNO₃ powder as a carrier substance and HClO₄ reagent, while the cation exchange process was done by the addition of Lampung zeolite. The objective research was getting a valid method for ¹³⁷Cs separation in post-irradiation U₃Si₂-Al PEB, especially for the aspects of CsNO₃ powder weight influence and weight of zeolite Lampung was added. ¹³⁷Cs isotope precipitation process was done by pipetting 150 mL U₃Si₂-Al PEB solution which was added to the 500; 625; 700; and 1000 mg weight variation CsNO₃ powder and 4 mL HClO₄ in ice media for 1 hour. The precipitation process results were obtained CsClO₄ precipitate separated from the supernatant as a liquid phase. Meanwhile, the cation exchange process was done by adding 700; 900; 1000 and 1200 mg weight variation Lampung zeolite by shaking for 1 hour. The cation exchange process results was obtained ¹³⁷Cs-zeolite in the solid phase and the other isotopes in the liquid phase. The¹³⁷Cs content in ¹³⁷CsClO₄ precipitate,¹³⁷Cs-zeolite solid phase and supernatant was measured using spectrometer-g. The analysis showed that the optimum weight of CsNO₃ addition when most binding of ¹³⁷Cs occurred was 700 mg equal to 0.0472 g ¹³⁷Cs isotope, while the optimum weight addition of Lampung zeolite was 1000 mg until 1200 mg equal to ¹³⁷Cs isotope content in¹³⁷Cs-zeolite obtained was 0.0557 g. The ¹³⁷Cs isotope separation process using both methods could be concluded that the cation exchange method using zeolite by the addition of 1000 mg Lampung zeolite until 1200 mg had better result than the precipitation method. The other advantages of this method were easier and safer than precipitation methods that the process should be in ice batch (-4^oC), using chemicals HClO₄, acetone and ethanol which had volatile and exothermic character.