[en] Possibilities of power distribution smoothin.g. in the TVR-M research reactor are compared by means of control drives or by filling the liquid control system (LCS) channels by a moderator. The approximate equivalence of both methods is shown. For each method a neutron flux variation in the reactor reflector is determined. The conclusion is drawn that the selective filling of LCS channels by the moderator allows one to improve the power distribution field without affecting the power distribution over the core lergth. The radial power peak value μsub(r) may be decreased from 1.056 to 1.039, the reactivity variation ΔK=-2.4%. By insertion one or several shim rods one can improve μsub(r) only by 0.5%, reactivity variation constitutes Δ=-1% and the height power peak factor of fuel assemblies located near shim rods increases from 1.05 to 1.08. The neutron flux in the reflector upon D₂O removal from LCS channels increases by 8%. The insertion of a shim rod leads to neutron flux decreasing near the shim rod by 15% and to a certain increase of the neutron flux (by 2-3%) far off. The same flux variations are in experimental channels