Pre-Conceptual Core Design of a Micro-LBE-Cooled Fast Reactor

Abstract

Abstract Generation IV nuclear reactors feature better performance in safety, economy, spent fuel burning and a higher breeding ratio, thus are becoming an important direction for the development of future nuclear industry. In the world, the special supply-demand relationship and flexibility requested by users of the energy market make small and micro nuclear reactors a key development trend, while small and micro lead-cooled fast nuclear reactors show great competitiveness. In the present paper, a micro LBE (lead-bismuth eutectic) - cooled Fast Reactor is proposed, on which a preliminary conceptual core design has been conducted. This micro LBE-cooled Fast Reactor has thermal power of 12 MW, while the reactivity controlled by 12 control drums. Neutronics analysis was performed by a Monte-Carlo code cosRMC jointly developed by State Power Investment Corporation Research Institute of China and Tsinghua University. The calculation results showed that the reactivity control performance meets the safety criteria, giving a coolant reactivity of −0.0976 pcm/K at BOL, −0.1955 pcm/K at MOL, and −0.1195 pcm/K at EOL, coolant voiding coefficient −31.24 pcm/% at BOL, −24.16 pcm/% at MOL, and −17.72 pcm/% at EOL, and fuel Doppler coefficient −0.6981 pcm/K at BOL, −0.7239 pcm/K at MOL, and −0.6902 pcm/K at EOL. The power distribution was flattened enough with a radical power peak factor 1.185 at BOL, 1.136 at MOL, and 1.155 at EOL.