Determination of the weight and composition of the precipitates formed in the course of dissolution of irradiated WWER oxide fuel

• Published in: Radiochemistry (New York, N.Y.) N.Y.), 2010-08, Vol.52 (4), p.403-407
• Main Authors: Burakov, B. E., Pokhitonov, Yu. A., Ryazantsev, V. I., Savin, R. A., Saprykin, V. F., Rance, P. J. W.
• Format: Article
• Language: English
• Subjects: Chemistry; Chemistry and Materials Science; Chemistry/Food Science; Nuclear Chemistry
• ISSN: 1066-3622; 1608-3288
• DOI: 10.1134/S1066362210040144

The amount and composition of insoluble precipitates formed in the course of dissolution of spent fuel samples with the burn-up from 15 to 54 MW day (kg U) −1 were examined. The weight of the insoluble precipitates was from 0.03 to 0.44% of the fuel weight. The major elements determining the composition of the precipitates were platinum group metals (Pd, Rh, Ru), Zr, and Mo. The specific β- and α-activity of the precipitates obtained was 30–840 and 0.01–8 Ci kg −1 , respectively. The major factor determining the concentration of α-emitting nuclides is the fuel burn-up. Depending on the dissolution conditions, the U content was 0.2–4, and the Pu content, 0.1–3%. The weight of secondary precipitates was from 0.005 to 0.3% of the irradiated fuel weight, or 11–50% of the total weight of the precipitates obtained in the experiments. The specific β-activity of the secondary precipitates obtained varies from 5 to ∼300 Ci kg −1 and is determined by the same radionuclides as in the primary precipitates. The α-activity of the secondary precipitates increases with the burn-up and amounts to 0.1–30 Ci kg −1 . The values obtained vary only slightly depending on the dissolution conditions and on the time of solution keeping before control filtration.