Abstract:
99Mo is a kind of important medical radioisotope in nuclear medicine. Conversion from high enriched uranium (HEU) to low enriched uranium (LEU) is a trend for fission
99Mo production. In this study, the whole production procedure of fission
99Mo had been developed with an emphasis on LEU target by electroplating UO
2 layer on inner wall of a hollow stainless cylinder, dissolution procedure of UO
2 target with heated 6 mol/L HNO
3 solution and radiochemical extraction process of fission
99Mo from simulated solution by α-benzoin oxime precipitation, followed by AG1×8 anion exchange and activated charcoal chromatography for further purification. For UO
2 target preparation, optimum parameters for electrodeposition were as follows: 5 mg/mL of uranium concentration, pH=7, 0.5-2 mA/cm
2 of current density and the temperature of 75-90 ℃. After about 210 hours of electroplating, the resulting film thickness was 42 mg/cm
2 UO
2 on the inner surface of the tube. In the final
99Mo solution, the ratios of the radioactivity of impurities such as
131I,
90Sr,
95Zr,
103Ru,
238U to that of
99Mo are 4.47×10
-6%, 7.40×10
-7%, 8.67×10
-7%, 2.57×10
-6%, and 1.69×10
-14% respectively that are less than those specified in European Pharmacopoeia, indicating that
99Mo purified by the established processing procedure in this work can meet the requirements for medical usage. This work will be expected to pave the way for fission
99Mo production at a large scale with LEU target.