Draft of new maintenance standards for LWR in Japan

Activities of development of new maintenance standards for operating nuclear power plant in Japan are described. The work of drafting the standards has been done by the Committee of Nuclear Plant Operation and Maintenance Standards (POMS), that was organized in the Japan Power Engineering and Inspection Corporation under the entrustment from the Ministry of International Trade and Industry. The articles of ASME Section XI related to inspection, flaw evaluation and repair have been examined and modified, if necessary, so as to introduce latest Japanese database and technological knowledge. In the area of repairs, many repair techniques verified in recent years in Japan were incorporated i n addition to those specified in ASME Section XI. Finally major differences between ASME Section XI and the draft of the standards are listed