Our previous paper reported the effect of acidity and temperature on uranous-uranil isotope exchange reaction in sulphuric acid solutionJ It was found that the half-life of the isotope reaction tu2 is around 10 seconds, when the acidity and the temperature of the reaction system are reasonably selected. However, when the uranium isotopes are enriched by ion exchange the single separation factor could be 1.00l. Thus, the half-life, tu2 is less than one second for potential industrial application.