Analysis of passive shutdown capability for a loss of flow accident in a medium sized liquid metal fast breeder reactor

The passive shutdown capability of a medium sized (500 MWe) liquid-metal fast breeder reactor with oxide, carbide and metal fuels has been analysed for a loss of flow accident using static and dynamic analysis methods. The carbide fuel is assumed to be He-bonded as well as Na-bonded. The dependence of the passive safety on the flow halving time constant of the loss of flow incident and the feedback components, like radial core expansion due to subassembly spacer pad heating and differential control rod expansion due to heating of the control rod suspension mechanism, is highlighted. (author)