The 1979 Three Mile Island accident and 1986 Chernobyl disaster, along with high construction costs, also compounded by delays resulting from a steady schedule of demonstrations, injunctions and political actions, caused by the anti-nuclear opposition, ended the rapid growth of global nuclear power capacity. A release of radioactive materials followed the 2011 Japanese tsunami which damaged the Fukushima I Nuclear Power Plant, resulting in hydrogen gas explosions and partial meltdowns classified as a Level 7 event. The large-scale release of radioactivity resulted in people being evacuated from a 20 km exclusion zone set up around the power plant, similar to the 30 km radius Chernobyl Exclusion Zone still in effect. But published works suggest that the radioactivity levels have lowered enough to now have only a limited impact on wildlife.