Improved reactivity table model for liquid metal fast breeder reactor dynamics

Variational expressions are presented for the estimation of the parameters of the adiabatic neutron kinetics model. The accuracy and limit of applicability of these variational estimates is established for liquid metal fast breeder reactor (LMFBR) applications by an extensive numerical study. An extended reactivity-table model, in which the mutual interaction of the different perturbations is treated on the basis of the variational estimates, is developed which is comparable in accuracy to the adiabatic model for a wide range of LMFBR transients.