Technetium and Iodine Separations in the UREX Process.

The Accelerator Transmutation of Waste (ATW) program is being developed to determine the feasibility of separatin and transmutating the transactinides (Pu-Cm) and long-lived fission product (99Tc and 'I) from spent light water reactor (LWR) fuel. This approach would help with the disposal of spent commercial fuel. In addition, since the residual waste after ATW treatment will have much lower levels of long-lived species, this process may improve the performance and acceptability of long-term geologic disposal of nuclear waste. A roadmap for the Accelerator Transmutation of Waste (ATW) was submitted to Congress in 1999.' This document gave an overall view of the ATW concept and program. A subsequent document prepared by the Technical Working Group for ATW Separations Technologies and Waste Forms issued a second roadmap that dealt more specifically with the radionuclide separations and waste disposal needs for the ATW program.' This latter document discusses the UREX (Uranium Extraction) process. The latest iteration of the UREX flowsheet is shown in Figure le3T his flowsheet anticipates the co-extraction of technetium with uranium from dissolved LWR fuel by tributylphosphate (TBP) and their subsequent sequential bwk-extraction from the TBP stream