PENGARUH BURN-UP TERHADAP KARAKTERISTIK PELET SINTER SIMULASI BAHAN BAKAR BEKAS

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ABSTRAK

PENGARUH BURN-UP TERHADAP KARAKTERISTIK PELET SINTER SIMULASI BAHAN BAKAR BEKAS. Telah dilakukan penelitian pengaruh burn-up terhadap karakteristik pelet sinter simulasi bahan bakar bekas dengan variasi burn-up 40 MWd/kgU dan burn-up 60 MWd/kgU. Penelitian ini bertujuan untuk mendapatkan karakter bahan bakar bekas simulasi yang diharapkan mampu mendekati sifat dan karakter bahan bakar bekas yang sebenarnya. Karakterisasi serbuk simulasi hasil fisi dengan variasi burn-up yang dianalisis antara lain bulk density, tap density, surface area dan rasio O/U. Hasil pengukuran serbuk simulasi hasil fisi dengan burn-up 40 MWd/kgU antara lain bulk density : 1,0250 g/cm³, tap density : 1,9330 g/cm³, surface area : 0,8751 m²/g dan rasio O/U : 2,0319, sedangkan untuk serbuk simulasi hasil fisi dengan burn-up 60 MWd/kgU diperoleh bulk density : 1,3410 g/cm³, tap density : 2,0443 g/cm³, surface area : 2,6688 m²/g dan rasio O/U : 2,0381. Kemudian serbuk simulasi hasil fisi dengan burn-up 40 MWd/kgU dilakukan pengompakan pada tekanan 3 Mp, 4 Mp, 5 Mp, 6 Mp, 8 Mp dan 9 Mp. Serbuk simulasi bahan fisi dengan burn-up 60 MWd/kgU pengompakan pada tekanan 4 Mp, 6 Mp, 7 Mp, 8 Mp dan 9 Mp. Masing-masing hasil proses pengompakan dilakukan penyinteran menjadi pelet sinter simulasi bahan bakar bekas kemudian dikarakterisasi densitas dan mikrostrukturnya. Densitas tertinggi pelet sinter simulasi hasil fisi dengan burn-up 40 MWd/kgU maupun burn-up 60 MWd/kgU terdapat pada tekanan pengepressan 9 Mp yaitu masing-masing sebesar 9,9959 g/cm³ dan 9,5490 g/cm³. Pengamatan mikrostruktur menunjukkan semakin besar burn-up menyebabkan semakin kecil ukuran butir pelet sinter.

Kata kunci: simulasi hasil fisi, tap density, bulk density, surface area, rasio O/U, mikrostruktur.

ABSTRACT

EFFECT OF BURN-UP ON THE CHARACTERISTICS OF SINTERED PELLETS OF SIMULATED SPENT FUEL. Effect of burn-up on the characteristics of sintered pellets of simulated spent fuel with burnup variation of 40 MWd/kgU and 60 MWd/kgU has been studied. The aim of this research is to obtain simulated spent fuel whose properties and characteristics are in close agreement with sintered pellets of spent fuel.  The characteristics of simulated fission products powder for variation of burn-up such as bulk density, tap density, O/U ratio, and surface area were measured. The measurement result for simulated fission products powder of 40 MWd/kgU burn-up are bulk density : 1.0250 g/cm³, tap density : 1.9330 g/cm³, O/U ratio: 2.0319 and surface area : 0.8751 m²/g, while the measurement result of simulated fission products powder of 60 MWd/kgU burn-up are bulk density : 1.3410 g/cm³, tap density: 2.0443 g/cm³, O/U ratio: 2.0381 and surface area : 2.6688 m²/g. The simulated fission products powder of 40 MWd/kgU burn-up were pressed at a pressure of 3 Mp, 4 Mp, 5 Mp, 6 Mp, 8 Mp and 9 Mp, and the simulated fission products powder of 60 MWd/kgU burn-up were pressed at a pressure of 4 Mp, 6 Mp, 7 Mp, 8 Mp and 9 Mp to produce green pellets. The green pellets were sintered to produce simulated sintered pellets of spent fuel. The characteristics of simulated sintered pellets of spent fuel such as density and microstructure were measured. The highest density of the simulated spent fuel for 40 MWd/kgU burn-up and 60 MWd/kgU burn-up was obtained at a pressure of 9 Mp, i.e. 9.9959 g/cm³ and 9.5490 g/cm³ respectively. The microstructure analysis shows that the grain size of the sintered pellets decreases with increasing burn-up.

Keywords: simulated fission product, tap density, bulk density, surface area, O/U ratio,

microstructure.