Chemistry of primary coolant in water cooled nuclear reactors

Specific features of the primary coolant chemistry in BWRs, PWRs and PHWRs are described and the existing primary circuit chemical control specifications for these type of units both with respect to control and diagnostic parameters under cold shut down, start-up, normal operation and off normal mode conditions are presented. Details of primary coolant sample manipulations for representative sampling, measurement methodology of various key control parameters and the constraints involving the use of chemical and volume control systems, particularly in PWRs are described. Integrity considerations for core (fuel) materials, structural materials and steam generator tube materials are discussed. Plant radiation level reduction considerations both with respect to (a) source term control (choice of materials with lesser cobalt inventory and lesser corrosion/release rates under transient water chemistry conditions and (b) recepient term control (prefilming, optimisation of Ni/Fe ratio, zinc injection passivation and improvement of CPU performance) are presented. 24 refs, 4 figs, 13 tabs