Application of advanced mechanics for the structural design of sodium cooled fast reactor components

Abstract

Some of the safety critical components of sodium-cooled fast reactors (SFR) are large dimensioned thin-walled shell structures. These components hold a large sodium mass and are subjected to high temperatures (820 K), high temperature gradients and cyclic thermal loads. The components are designed for long design life (>40 y). These features introduce complicated cyclic thermo-plastic deformations, the need for applying the principles of fracture mechanics under high cycle thermal fatigue, structural instabilities, fluid-structure interactions including elastic instabilities and high strain rate deformations. Hence, the structural design of such components is performed by addressing the relevant concepts in mechanics. In this paper, results of application of such advanced concepts for the structural design of components of the 500 MWe Prototype Fast Breeder Reactor (PFBR), which is under construction at Kalpakkam, are highlighted. New rules are recommended for inclusion in design codes like RCC-MR.