To the determination of the RBMK-1500 fuel assembly critical power

A multiparametrical approximating analytical expression for calculation of the RBMK-1500 fuel assembly critical power is obtained. The expression takes into account the form of axial power distribution, input temperature and coolant flow rate. It permits to determine the value of critical power with mean square error of 1.6%. The obtained expression makes it possible, first of all, to essentially accelerate determination of the RBMK-1500 fuel assembly power factor in the reactor control system, that positively affects its operational and technical-economic parameters. Secondly, it may be the ground for development of operative recommendations on choice of most reliable regime of axial power distribution control