[en] The operating conditions of commercial LMFBR's can result in material performance problems. Corrosion, radiation damage, temperature requirements, plastic deformation, and the superposition of these effects have been defined as important limiting factors for the design of components. A detailed knowledge of the various parameters which can influence the behavior of materials under LMFBR conditions is therefore necessary. The objective of the paper is to identify the influence of the sodium environment on the most important properties of materials which are used for the construction of heat transfer components. The paper considers the fuel cladding, the IHX, and the steam generator to be the major heat exchange units to be evaluated