Structural design optimization of roof slab of a pool type sodium cooled fast reactor

The roof slab of the nuclear reactor supports all the components of the reactor. Roof slab is essentially a box structure with top and bottom plates interconnected by vertical shells and radial stiffeners welded to them. The gap between the top and bottom plates is filled with concrete that provides biological and thermal shielding in the top axial direction of the reactor. The 500 MWe Prototype Fast Breeder Reactor (PFBR) is designed based on the Operating Basis Earthquake (OBE) and Safe Shutdown Earthquake (SSE) which are categorized under level A and level D loadings respectively. The primary objective of this work is to optimize the design of the roof slab and to predict and ascertain the structural integrity of the optimized roof slab under static, harmonic and seismic loading conditions. Regression models for critical design parameters are developed and are used in the optimization algorithm.