PROSES SIKLUS REDUKSI (U3O8 + 18 HASIL FISI) UNTUK BAHAN BAKAR DUPIC

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ABSTRAK
PROSES SIKLUS REDUKSI (U3O8 + 18 HASIL FISI) UNTUK BAHAN BAKAR DUPIC. Telah
dilakukan proses reduksi ke-1 bahan bakar nuklir yaitu (U3O8 + 18 hasil fisi) di dalam tungku
reduksi yang dialiri gas hidrogen pada temperatur yang bervariasi dari 600 – 900 oC selama 3
jam. Hasil reduksi berupa serbuk (UO2 + 18 hasil fisi) yang kemudian ditentukan densitas curah,
ketuk dan sejati serta rasio O/U dan dipelajari pula efek penggerusan serbuk. Serbuk yang tidak
mengalami penggerusan, mempunyai densitas yang lebih kecil dibandingkan dengan serbuk
yang mengalami penggerusan sehingga penentuan densitas dilakukan melalui tahap
penggerusan terlebih dahulu. Besarnya temperatur di atas mempengaruhi densitas yang
diperoleh, semakin tinggi temperatur, semakin tinggi pula densitas serbuk, sedangkan rasio O/U
mendekati 2. Setelah diperoleh serbuk (UO2 + 18 hasil fisi) dari hasil reduksi ke-1, maka serbuk
tersebut dioksidasi pada temperatur 500 oC selama 2 jam hingga diperoleh lagi serbuk (U3O8 + 18
hasil fisi) yang merupakan bahan untuk proses reduksi ke-2. Proses reduksi ke-2 dilakukan
sebagaimana proses reduksi ke-1, demikian diulangi sampai pengulangan (siklus) ke-4. Hasil
proses reduksi berupa serbuk (UO2 + 18 hasil fisi) yang dikarakterisasi densitas dan rasio O/U.
Proses pengulangan reduksi tersebut memperbesar densitas serbuk dan rasio O/U. Dari
percobaan yang dilakukan diperoleh hasil kondisi proses yang relatif baik yaitu pada siklus yang
ke-3, dan temperatur proses reduksi 800 oC dengan waktu pemanasan selama 3 jam. Pada
kondisi tersebut diperoleh densitas curah, ketuk dan sejati masing-masing 2,4594; 3,2096 dan
10,2866 g/cm3 (93,77% TD) serta rasio O/U sebesar 2,0192.
Kata kunci: Siklus reduksi, UO2, U3O8, hasil fisi, bahan bakar DUPIC.
ABSTRACT
REDUCTION CYCLE PROCESS OF (UO2 + 18 FISSION PRODUCTS) FOR DUPIC FUEL. First
reduction process of nuclear fuel (U3O8+18 fission products) has been done in a reduction furnace
flowed with hydrogen gas at varying temperatures from 600 – 900 °C for 3 hours. The reduction
product was UO2 + 18 fission products, of which bulk, tap and true density, O/U ratio, and effect of
powder crushing were to be determined. Powder that was not crushed has smaller densities than that under going crushing, so that the determination of densities was conducted through crushing
stage. It is indicated that the temperature affects the obtained densities, the higher the
temperature the higher the densities of the powder with O/U ratio approaching to 2. After
obtaining powder of (UO2 + 18 fission) from the first reduction process, the powder was oxidized
at a temperature of 500 oC for 2 hours until the powder (U3O8 + 18 fission) were obtained again
and to be used for the second reduction process. The second reduction process was carried out
in a way similar to the first reduction process and was repeated up to four cycles.The product of
the four-cycle reduction process was in the form of (UO2 + 18 fission products) powder, of which
characterization was done for its densities and O/U ratio. The reduction process repetition
appears to have enhanced the powder densities and resulted in better O/U ratio. The experiment
shows that the relatively good process condition is the third reduction, where the reduction
temperature is 800 oC with heating time for 3 hours. In that condition, the bulkr, tap and true
density obtained are 2,4594; 3,2096 and 10,2866 g/cm3 (93,77% TD) respectively and the O/U
ratio is 2,0192.
Key words: Reduction cycle, UO2,U3O8, fission products, DUPIC fuel.