Materials development and corrosion problems in nuclear fuel reprocessing plants

A broad based materials development programme has been in progress worldwide towards the development of materials for applications in spent nuclear fuel reprocessing plants. International efforts have resulted in the development of advanced materials like nitric acid grade (NAG) special austenitic stainless steels, Ti–5% Ta, Ti–5% Ta–1.8% Nb, Cr–W–Si, Nb–W, zirconium based alloys etc. for highly corrosive nitric acid environments. A critical review of performance of current and promising materials and their associated fabrication technologies for manufacturing is attempted. All-titanium electrolytic dissolver, electrode materials for electrochemical processes, dissimilar joints of titanium-type 304L stainless steel (SS), and double oxide coating on titanium for reconditioning (DOCTOR) have been developed at Indira Gandhi Centre for Atomic Research (IGCAR) based on systematic interdisciplinary R&D efforts. Dynamic nitric acid loop, a unique testing facility built at IGCAR is been described. Directions in materials and components developments, corrosion assessment and challenges ahead are also discussed.