A method of reducing radiotoxicity in an aqueous acidic solution is disclosed. The method comprises oxidizing actinide ions in an aqueous acidic solution to hexavalent actinide ions. An organic phase comprising at least one organophosphorus extractant is added to the aqueous acidic solution. The at least one organophosphorus extractant comprises a compound having from one oxygen atom to three oxygen atoms bonded to a phosphorus atom and having one of the oxygen atoms bonded to the phosphorus atom through a phosphorus-oxygen double bond. Complexes are formed between the hexavalent actinide ions and the at least one organophosphorus extractant. The complexes are separated from the aqueous acidic solution. An additional method and a reaction system for removing actinides from an aqueous acidic solution are also disclosed.
 This invention was made with government support under Contract Number DE-AC07-05ID14517 awarded by the United States Department of Energy. The government has certain rights in the invention.