NEPTUNIUM CONCENTRATION PROFILES IN THE PUREX PROCESS

Numerical simulations of neptunium concentration profiles in the co-de contamination step of the Purer process is carried out in order to und erstand neptunium extraction behavior and to propose a flow sheet for neptunium recovery from the reprocessing process. A simulation result for a flow sheet containing Pu(VI) in the feed solution shows that Pu( VT) plays a role of scavenger of nitrous acid. The rate constant of ne ptunium reduction with n-butyraldehyde is evaluated by using the proce ss data. The determined rate constant is available for the numerical s imulation of neptunium concentration profiles in the reprocessing proc ess. (C) 1998 Elsevier Science S.A.