IN THE country that gave the world the word tsunami, the Japanese nuclear establishment largely disregarded the potentially destructive force of the walls of water.
The word did not even appear in government guidelines until 2006, decades after plants - including the Fukushima Dai-ichi facility - began dotting the coastline.
The lack of attention may help explain how, on an island nation surrounded by clashing tectonic plates that commonly produce tsunamis, the protections were so puny in the face of the nearly 46ft tsunami that overwhelmed the Fukushima plant on 11 March. The wave grew three times as tall as the land on which the plant was built.
After an advisory group issued non-binding recommendations in 2002, Tokyo Electric Power Company (Tepco), the plant owner and Japan's biggest utility, raised its maximum projected tsunami at Fukushima Dai-ichi to 18.7ft - considerably higher than the 13ft-high land on which it stands. Yet the company appeared to respond only by raising the level of an electric pump near the coast by 8in.
"We can only work on precedent, and there was no precedent," said Tsuneo Futami, a former Tepco engineer who was director of Fukushima Dai-ichi in the 1990s. "When I was in charge, the thought of a tsunami never crossed my mind."
The earthquake that shook the ground at Fukushima also exceeded the intensity used in the plant's design, according to Tepco's data.
There is no doubt that when Fukushima was designed, seismology in relation to nuclear power plants was in its infancy, said Professor Hiroyuki Aoyama, 78, an expert on the quake-resistance of nuclear plants. Engineers adopted a standard that structures inside plants should have three times the quake-resistance of other buildings. "There was no basis in deciding on three times," he said. "They were shooting from the hip."