Control of neutron flux distribution in a reactor using a liquid absorber

Different versions of designs and characteristics of liquid control elements (CE) intended for three-dimensional control of the neutron distribution in the RBMK-type reactor cores are considered. Combined CE are proposed with hard rods arranged in the top part of the control and safety system channels. The hard rods are intended mainly for emergency protection, whereas the reactor control is exercized by water columns of variable height placed in the control zone. The water column is adjusted by special expellers or by gas cavity. The considered CE are concluded to be ensuring soft control of the reactor core energy distribution both radially and along the height. The potentialities of liquid CE are confirmed by physical calculations and by laboratory and reactor tests