Extraction and retention of technetium with irradiated 30% TRPO-kerosene

The distribution ratio of Tc does not change remarkably when absorbed dose varies from 1×106 Gy to 5×106 Gy and pre-equilibrated acidity ranges from 0.5 mol/L to 4 mol/L, and the stripping performance of Tc changes noticeably when 5.5 mol/L HNO3 and 5% Na2CO3-H2O are used as tripping agent, respectively. In order to ascertain the reason of retention, some acidic degradation products of TRPO, including phosphinic and phosphonic acids, are synthesized. By lavation with 5% Na2CO3, deionized water and vacuum distillation, irradiated 30 % TRPO-kerosene-1 mol/L HNO3 system is separated into alkali-extracting substance, aqua-extracting substance and high boiling point substance. The influences of these degradation products are studied by adding them into the original extraction system respectively. The results indicate that the component of high boiling point is the main factor causing retention, while others have no apparent influence.