and 2008: Tsunami studies ignored An in-house TEPCO report in 2000 recommended safety measures against seawater flooding, based on the potential of a tsunami. TEPCO leadership said the study's technological validity "could not be verified." After the tsunami a TEPCO report said that the risks discussed in the 2000 report had not been announced because "announcing information about uncertain risks would create anxiety." In 2007, TEPCO set up a department to supervise its nuclear facilities. Until June 2011, its chairman was Masao Yoshida, the Fukushima Daiichi chief. A 2008 in-house study identified an immediate need to better protect the facility from flooding by seawater. This study mentioned the possibility of tsunami-waves up to . Headquarters officials insisted that such a risk was unrealistic and did not take the prediction seriously. Yukinobu Okamura of the Active Fault and Earthquake Research Center (replaced in 2014 by the Research Institute of Earthquake and Volcano Geology (IEVG)], Geological Survey of Japan (GSJ)), AIST) urged TEPCO and NISA to revise their assumptions for possible tsunami heights upwards, based on his team's findings about the 869 Sanriku earthquake, but this was not seriously considered at the time. The U.S. Nuclear Regulatory Commission warned of a risk of losing emergency power in 1991 (NUREG-1150) and NISA referred to that report in 2004, but took no action to mitigate the risk. Warnings by government committees, such as one in the Cabinet Office in 2004, that tsunamis taller than the maximum of forecast by TEPCO and government officials were possible, were also ignored. Vulnerability to earthquakes Japan, like the rest of the Pacific Rim, is in an active seismic zone, prone to earthquakes. Seismologist Katsuhiko Ishibashi wrote the 1994 book titled A Seismologist Warns criticizing lax building codes, which became a best seller when an earthquake in Kobe killed thousands shortly after its publication. In 1997 he coined the term "nuclear earthquake disaster", and in 1995 wrote an article for the International Herald Tribune warning of a cascade of events much like the Fukushima disaster. The International Atomic Energy Agency (IAEA) had expressed concern about the ability of Japan's nuclear plants to withstand earthquakes. At a 2008 meeting of the G8's Nuclear Safety and Security Group in Tokyo, an IAEA expert warned that a strong earthquake with a magnitude above could pose a "serious problem" for Japan's nuclear power stations. The region had experienced three earthquakes of magnitude greater