Distortion of the Neutron Flux Profile in Reactor Core Induced by Control Rods, V.N. Kolykhanov, I.E. Kozlov – V.I. Skalozubov

The method designed to calculation the axial profile of neutron flux in reactor core based on diffusion theory are presented. The core model describes two zones – upper part containing control rods (additional absorber) and unrodded bottom part of core. The solution of the system of diffusion equations is obtained using the criticality condition.

The change of the amplitude and shape of the axial profile of neutron flux at varied withdrawal of control rods are calculated. An estimation of the non-uniformity of heat release rely on the elevation of core has been obtained and a comparison with the acceptable value of axial offset has been made.

Keywords: control rods, neutron flux, diffusion model, axial offset, reactor core.