The situation at the Fukushima Daiichi nuclear plant has been an ongoing disaster since the March 11 earthquake and tsunami. According to an estimate by the Federation of Electric Power Companies of Japan, by April 27 approximately 55 percent of the fuel in reactor unit 1 had melted, along with 35 percent of the fuel in unit 2, and 30 percent of the fuel in unit 3; and overheated spent fuels in the storage pools of units 3 and 4 probably were also damaged. The accident has already surpassed the 1979 Three Mile Island accident in seriousness, and is comparable to the 1986 Chernobyl accident.
To prevent this kind of nuclear disaster from happening again, both the nuclear industry and government officials worldwide must seriously consider making at least five major changes to the safety systems at nuclear power plants, as well as to security measures and international agreements.
