Abstract: A system for monitoring the operation of a plant, which includes the facility of simulating the corrosion potential of a material and which can assess the effect of a countermeasure for mitigating the corrosion environment of the material, with the corrosion potential obtained by the simulation. The corrosion potential of the structural material of the plant is computed through a numerical analysis by applying an electrochemical mixed-potential theorem on the basis of the analytical result of a charge transfer reaction. Programs for such potential computations are prestored in a computer system from which data are accepted into a host computer. The computed corrosion potential is related with water quality data (for example, the concentration of hydrogen injected into the plant), and the relationship is output to a display unit.

Abstract: A water chemistry factor which is specific to a specific portion of a primary cooling system and universal is decided to be a standard target. The concentration of an agent for mitigating corrosion damage of structural material of the primary cooling system is controlled so that the target will be in a desirable range. All sensor groups provided in the primary cooling system are separated into sensor groups in different lines, of which a specific sensor group are connected to an arithmetic unit and a data base and are for always monitoring a plant process. For example, concentration distribution agreed with measured value oxidation component in the reactor water at the measurement points is selected from the data base, and it is used to estimate the standard target.