Accurate fast method with high chemical yield for determination of uranium isotopes (~(234)U, ~(235)U, ~(238)U) in granitic samples using alpha spectroscopy

摘要

The present study aims to use the α-spectroscopy at Nuclear Materials Authority (NMA) of Egypt A radiochemical technique for analysis uranium isotopes was carried out for ten mineralized granitic samples together with the International standards RGU-1 (IAEA) and St_4 (NMA). Several steps of sample preparation, radiochemical separation and source preparation were performed before analysis. Uranium was separated from sample matrix with 0.2 M TOPO in cyclohexane as an extracting agent with a chemical yield 98.95% then uranium was purified from lanthanides and actinides present with 0.2 M TOA in xylene as an extracting agent. The pure fraction was electrodeposited on a mirror-polished copper disc from buffer solution (NaHSO_4+H_2SO_4+NH_4OH). Rectangle pt-electrode with an anode-cathode distance of 2 cm was used. Current was 900 mA and the electrodeposition time reach up to 120 min. The achieved results show that the chemical yield ranged between 87.9 ± 6.8 and 98 ± 8.6.