Shiro Oguro, a former Toshiba nuclear design engineer, speaking at the Foreign Corresponds’ Club of Japan in Tokyo Wednesday night said that stress criteria he was given to design equipment used in the Dai-1 Fukushima Nuclear Plant were rated to withstand an 8.0 magnitude earthquake.
He said he received such design specifications when working on designing “the pumps and heat-exchange systems involved in the structural safety of reactors numbers 1, 2, 3, 5 and 6 used in the Dai-1 Fukushima Plant.” The earthquake that hit the area last Friday afternoon had a magnitude of 9.0.
Oguro is one of a group of engineers and scientists who support the Citizens’ Nuclear Information Center, and anti-nuclear group based in Tokyo, which arranged the press conference. Oguro said that the basic thinking behind these design conditions at the time was that an earthquake having a magnitude of 8 or greater would not occur.
Though we now know the servere threat tsunami pose for nuclear plants, that wasn’t the case back when Ogura was working on the Fukushima Dai-1 Nuclear Plant design, he added.