Earthquakes and aseismatic design standard for nuclear power stations in F.R. Germany

Brief history of the earthquakes in F.R. Germany for the period from 1000 to 1969 is reviewed, and comparison of the aseismatic design of nuclear power stations between F.R. Germany and Japan is made. Earthquakes of intensity 7 (maximum acceleration value of 70 to 220 gal) and 8 (that of 150 to 300 gal) could be expected to occur in F.R. Germany, according to European seismic committee. The definitions of safety earthquake (Sicherheitserdbeben) and design earthquake (Auslegungserdbeben) are compared with the Japanese terms, S-2 (maximum possible earthquake giving the strongest vibration to site base) and S-1 (maximum probable earthquake giving the strongest vibration to site base). The total area of F.R. Germany is classified into four zones according to dangerousness. Aseismatic design in F.R. Germany is classified into two classes, whereas that in Japan into three or four classes. In F.R. Germany, either dynamic analysis, simple analysis, or omission of analysis is employed. F.R. Germany employs the waves of E1-centro, Taft, etc. of USA as standard, referring to U.S.N.R.C. 1.60 and Housner's equation. The attenuation coefficient and the allowable stress are also compared. A power plant to be exported to Iran is designed at SE of 500 gal and AE of 250 gal, which are approximately equal to the maximum earthquake acceleration for design in Japan. (Iwakiri, K.)