Comprehensive assessment of scale formation, corrosion, and biological pollution in a cooling water supply system.

A comprehensive method for the cooling water supply system (CWS) was investigated, which allows for the comprehensive assessment of corrosion, scale formation and biological pollution. Direct and indirect methods were used. Consequently, indirect methods included the calculation of differences in φ and ψ, the Langelier saturation index (LSI), and the Ryznar stability index (RSI), which characterise scale formation and corrosion processes based on the results of the pH, temperature, total dissolved salts, total hardness and total alkalinity measurements were measured using standard methods. Direct methods included bench tests to measure the corrosion rate (V) and scale formation rate (S). Additionally, the colony forming units (CFU) controlling with indication of an yeast and bacteria, the algae cell counts and hydrobox controlling water CWS were carried out. The comprehensive assessment method presented in this article includes adjustments to the existing method to improve its effectiveness, which is used for monitoring of spent fuel storage facilities at a Nuclear Power Plant (NPP).•Introduced a comprehensive methodology combining direct and indirect monitoring for assessing scale formation, corrosion, and biological pollution in nuclear power plant (NPP) cooling water systems.•Enhanced monitoring techniques enable the simultaneous assessment of corrosion resistance and scale formation potential, overcoming limitations of traditional methods.•Incorporated colony-forming unit analysis, algae cell quantification, and hydrobox-based evaluations for a detailed understanding of biofouling.•Validated methodology offers predictive risk modelling and optimised strategies to ensure reliability and safety in NPP operations.