Abstract: AN IMPROVED TECHNOLOGY FOR DECONTAMINATING RUTHENIUM IN URANIUM PURIFICATION CYCLE BY HYDROXYLAMINE PRETREATMENTQi Zhanshun;Zhu Zhixuan;Zhang Pilu (China Institute of Atomic Energy,P. O.Box 275 (26) ,Beijzng 102413)Abstract:The Influences of hydroxylamine concentration , pretreatment time , acidity and the concen tration of stabilizer have been studied ,and the best pretreatment condition for the improvement of Ru decontamination in uranium purification cycle by hydroxylamine pretreatment has been ob tained. The results show that the no satisfactory result can be obtained by solely using hydroxy lamine as pretreatment agent unless a small amount of hydrazine is added into the pretreatment system as stabilizer.Keywords: Hydroxylanune Uranium purification cycle Pretreatment Ru decontamination