Keywords: linear reactivity models, multicycle analysis, nodal methods, boiling water reactors, BWR, neutron diffusion theory, fuel batch burnup, fuel power sharing, nuclear reactors, nuclear energy, nuclear power
A nodal formulation method relating assembly power and reactivity for a boiling water reactor
A second-order nodal method is derived for the one and a half-group version of neutron diffusion theory in X-Y geometry. Based on the linear reactivity model, two reactivity relations are developed to treat fresh and depleted loading batches as a way to account for the spatial variation of moderator properties due to the substantial fraction of steam void present as well as the effect of the control rod positioning. Based on these ideas a programme was developed to predict fuel batch burnup and fuel power sharing in a Boiling Water Reactor (BWR) operating cycle. The method was tested by assessing two consecutives current BWR operating fuel cycles.