Corrosion of 316L exposed to highly concentrated borated water used as shield in nuclear fusion experimental reactors cooling circuits
Claudia Gasparrini, James O. Douglas, Arshad Yazdanpanah, Robert M. Stroud, Giorgio Divitini, Manuele Dabalà, G.G. Scatigno, S. Pedrazzini, M.R. Wenman, Denis Badocco, Paolo Pastore, Nicholas Terranova, G. Mariano, Frédéric Dacquait, M. Dalla Palma, R. Villari, P. Sonato
Abstract
Borated water is used as a shield in nuclear fusion cooling circuits. General corrosion, activated corrosion products (ACPs) formation and stress corrosion cracking initiation of 316 L steels exposed to ultrapure water (UPW) or 8000 ppm B water at 80 °C were tested. A Ni enriched sub-oxide layer, a transition layer and oxide layer were observed using advanced characterisation (STEM-EELS, APT). The oxide formed in UPW was protective (Cr:O 40:45), the oxide formed in 8000 ppm B was non-passivating. 8000 ppm B led to higher release of Fe, Cr and Mo, 316 L was more prone to SCC initiation and enhanced ACPs formation.