CURRENT STATUS OF REGULATORY ASPECTS RELATING TO WATER CHEMISTRY IN JAPANESE NPPs

摘要

In nuclear power plants, water chemistry of cooling water is carefully monitored and controlled to keep integrity of structures, systems and components, and to reduce occupational radiation exposures. As increasing demand for advanced application of light water cooled reactors, water chemistry control plays more important roles on plant reliability. The road maps on R&D for water chemistry of nuclear power systems have been proposed along with promotion of R&D related water chemistry in Japan. In academic and engineering societies, non-governmental standards for water chemistry are going to be established. In the present paper, recent trends of water chemistry in Japan have been surveyed. The effects of water chemistry on plant safety and radiation exposures have been discussed. In addition, possible contributions of regulation regarding water chemistry control have been confirmed. Major water chemistry regulatory aspects relating to reactor safety and radiation safety are also outlined in this paper.