Abstract
Fuel assemblies with tight lattice may allow us to have fast neutron spectrum in boiling water reactor (BWR), which yield to the breeding ratio nearly equal to unity. Such fuel assemblies need wire spacers rather than grid spacers. The effect of wire spacer on coolability in tight lattice core of BWR was investigated by means of an experiment for critical heat flux (CHF) in single pin and three-pin-bundle with triangular arrangement. The experiments were performed with the parameters of mass flux, steam quality and geometry. The results showed that the heat removability of flow channel with wire was better than that without wire. The result was compared with some correlations by means of analytical consideration.
