Purpose of I&C system is monitor and control of processing procedure and equipment for reaching main goal of NPP – electric energy generation providing nuclear and radiological safety and economic efficiency of processing procedure. One of the main functions of NPP I&C system is control of technological processes in nuclear unit equipment via automatic regulators providing optimality of electric energy generation process. Algorithms of I&C systems, especially laws of control, are realized on hardware and software complex (HSC) TPTS (technological hardware-software instrumentality). Control functions implemented on functional modules TPTS51.1412 and TPTS51.1411, which perform linear and pulse control. A great number of automatic regulators is used in process of electric energy generation on NPP. All automatic regulators can be divided to 4 groups. Despite nuclear units are standard (they have same reactor system project), they have unique characteristics – nuclear units differ by technological characteristics of reactor system equipment and technological equipment providing electric energy generation process control. That’s why parameters of respective automatic regulators for each nuclear unit correct after theoretical calculations in nuclear unit checkout process that cause specific economic and energetic losses. For solving this problem there is provided to use analytical simulators of NPP nuclear units, which are used for researches of reactor system physics and researches of behavior of technological equipment respective nuclear unit.