Natural zeolite as a replacement for resin in the cation exchange process of cesium on post-irradiated nuclear fuel

Characterization of natural salts from Bayah, Lampung, and Tasikmalaya, Indonesia has been carried out as a substitute for synthetic resins. The characteristics include zeolite activation with NH4Cl, and heated at 200°C, the bond stability test of 137Cs-zeolite, chemical composition analysis, surface area, pore size, analysis of Cs cation exchange capacity (CEC), diffusion coefficient (Di), activation energy (Ea), and absorption of three zeolites. To do this, pipette 50 μl of a standard solution of 137Cs from the National Institute of Standards and Technology (NIST), put in, 2 ml of 0.1 N HCl, and then add 1 g of zeolite and stir each for 1, 2, 3, 4, 5, and 24 h. Based on this stirring time, the 137C isotope will exchange ions with NH4-zeolite to 137Cs-zeolite in the solid phase. The content of 137Cs in 137Cs-zeolites (solid phase) was analysed using a gamma spectrometer. The results of the chemical composition analysis showed that the character of zeolite from Lampung has a Si/Al ratio, with a CEC value of 1.448 mEq/g which is greater than Bayah and Tasikmalaya, while the Di and Ea values for the three select types were obtained almost the same. Moreover, the stability test of the Cs ion bond with zeolite showed no significant release of Cs ions from the zeolite structure. It can be concluded that the three soloists tested that the zeolite from Lampung has better characters. The results of 137Cs isotope separation in 150 μl of U3Si2/Al fuel solution post-irradiation using zeolite from Lampung and Dowex resins obtained almost the same recovery around 98–99%, so it can be concluded that zeolite from Lampung can be used as a substitute for synthetic resin in the cation exchange process for the 137Cs isotope in nuclear fuel post-irradiated.