A study of baffle's influence on core neutron economics for PWR plant

The influence of baffle on core neutron economics is investigated and theoretic prediction has been verified through experiments conducted at a zero power reactor with baffles of various thicknesses. Although stainless steel is usually considered as a parasitic neutron absorber, some beneficial results of baffle on core neutron economics is discovered. Since the fast neutron is reflected by stainless steel baffle of various thicknesses, the baffle thickness increases from 2.5 cm (this is a typical thickness of baffle used in PWR) to 20 cm (the 20 cm baffle will be changed into reflector assembly of stainless steel in the construction design), then the fuel burnup lifetime for the first cycle in a 300 MWe PWR will prolong 40 EFPD. When the first cycle lifetime is converted into the equilibrium cycle lifetime (360 EFPD), a burnup lifetime gains for the stainless steel reflector of 20 cm is 33 EFPD. During 40 years (0.8 loadfactor) plant design lifetime, it may give out 7600 GMW extra power production. If the stainless steel reflector is replaced by Zr-4, the economic benefits will be much larger