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

Abstract

Sodium leak was observed in the inlet side of a creep testing chamber in an In-Sodium Testing (INSOT) facility for fast breeder reactor structural materials. The failure occurred during a test campaign after 183 h of operation of the loop at a temperature of 823 K. Based on He and liquid penetrant testing, locations of leaks were identified in a reducer section. Detailed metallurgical characterization of the failed reducer and comparison of the results with a reference specimen helped in identifying the sequence of failure based on which recommendations were made to avoid similar failures in the future.