Development of Simulated Process for Medical Fission 99Mo Production Using Electroplating UO2 Target with Low Enriched Uranium

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 UO2 layer on inner wall of a hollow stainless cylinder, dissolution procedure of UO2 target with heated 6 mol/L HNO3 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 UO2 target preparation, optimum parameters for electrodeposition were as follows: 5 mg/mL of uranium concentration, pH=7, 0.5-2 mA/cm2 of current density and the temperature of 75-90 ℃. After about 210 hours of electroplating, the resulting film thickness was 42 mg/cm2 UO2 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.

Keywords

• fission 99mo leu electroplating uo2 target 99mo production process