Failure analysis of a reducer section in the creep loop of INSOT facility

•Sodium leak was observed in a reducer component of the INSOT (in-sodium testing) facility.•The reducer component was fabricated out of Ni based Alloy 600.•Cracked and pinhole regions were identified as the sites for sodium leak in the reducer section.•Pitting corrosion and IGSCC led to the failure of the reducer component.•304l/316l stainless steel reducers are recommended for service to avoid sensitization.