The Expert Group on Reactor Coolants/Components Technology (EGCoCoT), operating under the auspices of the Working Party on Scientific Issues of Advanced Fuel Cycles (WPFC), launched an activity to produce a state-of-the-art report on the effects of liquid metal coolants on materials in 2019. This initiative involves a systematic examination of the interactions between liquid metal coolants - sodium (Na), lead (Pb), and lead-bismuth eutectic (LBE) - and the structural materials used in Sodium-cooled Fast Reactors (SFRs) and Lead-cooled Fast Reactors (LFRs). The objective is to provide a detailed, technically rigorous assessment of the latest research on how these coolants affect material properties under various operational conditions.

This activity aims to examine the multifaceted challenges posed by liquid metal coolants in fast reactors. These coolants, while advantageous for their superior heat transfer properties and neutron economy, introduce complex thermalhydraulics phenomena and aggressive chemical environments that can lead to material corrosion. This activity aims to document the current knowledge, expertise, and R&D gaps in specific mechanisms such as thermal and mechanical loads, radiation-induced damages, and mass transfer phenomena, offering a granular analysis of their impact on material integrity. 

The goal of this initiative is to apply the latest fundamental scientific understanding of the above mentioned concepts to support:

• Development of construction codes used for design,
• understanding of key technical issues for licensing, and
• development of procedures for operations, inspection and handling. 

The participants of this activity include the official members, invited experts and observers of The Expert Group on Reactor Coolants/Components Technology (EGCoCoT).