Evaluation of impurity behavior in the reactor water of a boiling water reactor

A system has been developed for evaluating the effect of impurity intrusion on reactor water as part of the chemistry diagnostic system for boiling wa ter reactor water. Past records of anomalous changes noted in reactor water quality were first surveyed to identify the substances presenting the high est probability of intrusion into reactor water. The ions and their concent rations were derived, taking into account mutual chemical reactions among t he substances and the plant operating conditions affecting the balance equa tion of the reactor primary system. The results predicted for the peak conductivity of reactor water during pla nt startup were within +/-15% of the measured data. This good agreement fou nd on a comparison of estimated results with measured data from an actual p lant substantiated the validity of the present method.