Tugas Akhir
Imobilisasi limbah radioaktif yang mengandung uranium dengan matriks bitumen
Limbah radioaktif berasal dari fasilitas pemurnian asam fosfat PT. Petrokimia Gresik berupa sludge (lumpur) yang mengandung uranium. Kandungan uranium dalam limbah sludge sebesar 263,73 mg U/L dengan aktivitas uranium sebesar 7,27 x 10-5 Ci/m3 masih di bawah batas limbah aktivitas rendah sebesar 1 Ci/m3. Bitumen (aspal) merupakan bahan matriks untuk imobilisasi limbah radioaktif aktivitas rendah berumur panjang. Proses imobilisasi dilakukan dengan memvariasi aspal (komposisi matriks) dari 30, 40, 50, 60, 70, 80, 100 % dan memvariasi waste loading dari 10, 20, 30, 40, 50, 60, dan 70 % berat limbah untuk mendapatkan kondisi blok bitumen-limbah hasil imobilisasi terbaik. Karakterisasi blok bitumen-limbah hasil imobilisasi dilakukan dengan menentukan densitas, kuat tekan, dan laju pelindihan. Densitas ditentukan dengan mengukur berat dan volume blok bitumen-limbah hasil imobilisasi, kuat tekan ditentukan dengan alat uji tekan Bullocks, dan laju pelindihan dilakukan dengan alat uji lindih Soxhlet pada suhu 50 oC dan tekanan 1 atm selama 4 jam. Hasil penelitian menunjukkan bahwa matriks bitumen mampu mengikat muatan limbah dari variasi waste loading 10, 20, 30, dan 40 %. Hasil blok imobilisasi bitumen-limbah terbaik terjadi pada waste loading 40 % dan variasi aspal 50 % (aspal : pasir = 1:1) dengan memiliki densitas sebesar 1,8 g/cm3, kuat tekan sebesar 1,2 kN/cm2, dan laju pelindihan dari blok bitumen-limbah sebesar 10-2 – 10-3 g/cm2.hari.
Kata kunci: limbah radioaktif, imobilisasi, kandungan limbah, bitumen (aspal)
Radioactive waste derived from phosphoric acid purification facilities of PT. Petrokimia Gresik in the form of sludge containing uranium. The content of uranium in the waste sludge was 263.73 mg U/L with uranium activity of 7.27 x 10-5 Ci/m3 still below the limit of low activity waste 1 Ci/m3. Bitumen is the material matrix for a low activity of long-lived radioactive waste immobilized. Immobilized process was carried out by varying asphalt (matrix composition) of 30, 40, 50, 60, 70, 80, 100 % and waste loading of 10, 20, 30, 40, 50, 60, and 70 % by weight of waste to get condition of bitumen-block the best waste immobilized. Characterization of the bitumen block-waste immobilized was done by determining the density, compressive strength, and leaching rates. Density was determined by measuring weight and volume of the bitumen-block waste immobilized, compressive strength was determined by means of press test Bullocks, and levels leaching was carried out by Soxhlet leach test equipment at a temperature of 50 oC and 1 atm pressure for 4 hours. The resulted research showed that the bitumen matrix capable of binding waste loading from waste loading variation 10 20, 30, and 40 %. The best resulted blocks immobilized bitumen-waste occurs at waste loading of 40 % and 50 % of asphalt (asphalt : sand = 1:1) having density of 1.8 g/cm3, compressive strength 1.2 kN/cm2, and the rate of leaching of bitumen-waste is 10-2 – 10-3 g/cm2.day.
Keywords: waste radioactive, immobilized, waste loading, bitumen (asphalt)rn
S11-0351 | 30/TA/H/11 546.791(043) AJI i | Perpustakaan Poltek Nuklir | Tersedia |
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