Continuous on-line analysis of soluble impurities in PWR primary coolant by automated ion chromatography

Two ion chromatographs have been developed and evaluated for the measurement of soluble transition metals, particularly cobalt, in PWR primary coolant. Complete automation has been achieved, including automatic injection of standards and analysis from multi-sampling points together with continuous and unattended operation. Data processing of the chromatograms and automatic control has been possible by interfacing the instruments to microprocessor control systems. An absolute detection limit of 0.1 ng cobalt has been achieved which, with an on-line sample preconcentration (100 ml), has allowed measurements to be made down to the one part per trillion level (0.001 ppb). Experience with the long term stability and performance under continuous operation to monitor experimental PWR loops and operating reactors is reviewed and further development identified. (author)