Evaluation of Foam Stability in Decontamination Foam Stabilized by Silica Nanoparticles with Nonionic Surfactant

Abstract

The decontamination process was needed to remove the radionuclide in nuclear facilities under decommissioning. Among the decontamination techniques, the decontamination foam strongly decreases the amount of chemicals and the secondary wastes and, has wide application in nuclear facilities. The purpose of the present study is to investigate the effects of surfactants, silica nanoparticles (NPs) concentration, and pH for foam stability and oxide dissolution. The foam stability in acid pH has an effect on the concentration of nonionic surfactant, however, in neutral pH does not have concentration effect. The addition of 3 and 5 wt% silica NPs improves the foam stability by a factor of 3 and 5 at pH 2, compared to the foam stabilized with 1 % EM 100 surfactant only, indicating that the increase of silica NPs increased the foam stability. The oxide dissolution was evaluated for the decontamination foam containing 1 M HNO 3 using the corroded specimens. The results of an iron dissolution test showed that increased foam stability enhanced the iron dissolution owing to an increase in the contact time between the chemical reagents and the corroded surface.