IGCAR : Annual Report - Indira Gandhi Centre for Atomic Research

Chapter -3
R&D FOR FBRs
III.A. Modeling and Simulation Experiments
III.A.1. Effects of Interconnection of Reactor Vault with Nuclear Island
Connected Buildings on Seismic Behaviour of an FBR
In a pool type sodium cooled fast breeder reactor, the entire radioactive primary circuit is
housed in a single vessel called main vessel, which is the most critical component of the
reactor assembly system. The main vessel transmits about 2500 t to the top shield,
contributed by core mass, self weights of main vessel and reactor internals and 1150 t of
primary sodium. The weight of top shield along with the components supported by it is about
1200 t. With all these, the reactor assembly weighing about 3700 t is supported at the top.
The dynamic forces that are developed by a seismic event cause a great concern to structural
integrity of thin shell structures, core subassemblies, etc.