New technical guideline concerning aseismatic design of nuclear power stations in Japan

The development of the aseismatic design of nuclear power stations in Japan is roughly divided into three stages. The first stage is the period of stepwise development till 1978, and the second stage is the period till 1986, in which the aseismatic design technology was almost standardized, but the conservative design was carried out. The third stage is the present transient period of the rational design after the JEAG was revised by compiling recent aseismatic design methods, and when the preparation of the bylaw by the Ministry of International Trade and Industry advanced, and it began to be used for the design. The guideline which took effect in 1978 is compared with the former guideline. The main contents of the revision of the JEAG and the latest aseismatic design technology are explained on the fundamentals of aseismatic design, earthquake motion, geological survey and the evaluation of ground stability, the aseismatic design of buildings, structures, machinery and equipment, and piping system. The new bylaw on aseismatic design technology was prepared by the Japan Electric Association entrusted from the MITI, and the main contents of 11 items among 19 items in total are shown. (Kako, I.)