Claims by anti nuclear groups that Japan's ageing fleet of atomic power stations pose serious risks and should be replaced by clean energy technologies such as wind took on a new ring of truth last month. Serious safety flaws were exposed in the country's biggest utility's nuclear reactors. Cracks in several reactors belonging to Tokyo Electric Power Co are now public knowledge. One plant in Fukushima prefecture had to be closed temporarily after its chimney was found to be emitting more than one hundred times the usual level of radiation. Leaked records reveal that many of Japan's 53 nuclear reactors are operating well into their third decade. Opposition to nuclear power took hold in 1999 following the country's most serious accident in which three people were exposed to radiation. Japan has poured billions of dollars into development of plutonium breeding reactors. But many governors have vetoed plans to build new nuclear plants in their prefectures. Increased public awareness of environmental issues and the presence of big companies among the ranks of wind developers appears to be influencing policy towards alternative energy sources.