Corrosion in nuclear fuel reprocessing plants; Corrosion in boiling nitric acid

Kato, Chiaki   

In spent fuel reprocessing plants, various nitric media are encountered throughout the PUREX process, used in the separation of fission products, uranium, and plutonium. The PUREX process is thus highly corrosive as it takes place at high temperatures under high concentrations of nitric acid solution containing oxidizing metal ions from spent fuel. In this review, the unique chemical properties of nitric acid are first described. Secondly, the process of oxidizing power generation in boiling nitric acid under heat transfer is described using the redox potential and a thermodynamic model of boiling nitric acid. Finally, the corrosion behavior and corrosion acceleration mechanism specific to the reprocessing environments are described from the perspective of solution chemistry.