Water Chemistry Data Acquisition, Processing, Evaluation and Diagnostic Systems in Light Water Reactors

Abstract

Water chemistry data acquisition, processing and evaluation systems have been applied in major Japanese PWRs and BWRs to prepare for reliable and quick data accumulation with saving in manpower in plant chemical laboratories and to establish smooth and reliable information transfer from chemists to plant operators and supervisors. The following features of the systems were noted. 1. X-ray fluorescence analyses and ion chromatography were widely applied in automatic chemical analysis procedures. 2. Water chemistry data were stored in PC base-data storage systems along with other major plant data to evaluate reliabilities of the data themselves and to prepare for official documents. 3. Clear data displays were effectively applied to support quick response to instances of fuel leakage and long-term analysis for better understanding of the plant's own water chemistry responses. 4. Evaluation of SG tubing integrity is successfully carried out by estimating crevice pH based on ion chromatographic data. 5. Application of in-situ high temperature water chemistry sensors is still restricted in laboratories. Only ECP monitoring has been applied for BWR hydrogen water chemistry. Plant diagnosis systems have been applied in only restricted areas and so serve limited purposes due to the lower benefit against cost.