Chloride (Cl -) salt processing in strong acids is used to recycle plutonium (Pu) from pyrochemical residues. The Savannah River National Laboratory (SRNL) is studying the potential application of nitrogen dioxide (NO 2 ) gas to effectively convert dissolved pyrochemical salt solutions to chloride-free solutions and improve recovery operations. An NO 2 sparge has been shown to effectively remove Cl -from solutions containing 6-8 M acid (H + ) and up to 5 M Cl -. Chloride removal occurs as a result of the competition of at least two reactions, one which is acid-dependent. Below 4 M H + , NO 2 reacts with Cl -to produce nitrosyl chloride (ClNO).Between 6 M and 8 M H + , the reaction of hydrochloric acid (HCl) with nitric acid (HNO 3 ), facilitated by the presence of NO 2 , strongly affects the rate of Cl -removal. The effect of heating the acidic Cl -salt solution without pre-heating the NO 2 gas has minimal effect on Cl -removal rates when the contact times between NO 2 and the salt solution are on the order of seconds.