( CNN ) -- It 's been three years since Japan was hit with its worst-ever earthquake , causing serious damage to Fukushima Daiichi nuclear power plant . The 9 magnitude quake and subsequent tsunami sent three of Fukushima 's reactors into melt-down , shocking the world . Japan , a fully industrialized country with high safety requirements , was facing a nuclear disaster of a similar scale to the deadly 1986 Chernobyl accident , in Soviet Ukraine . As a result , many countries decided to review their energy policies . Before the accident , 442 nuclear power reactors in 30 countries produced 14 % of all world 's electricity . This number dropped to just 11 % in 2012 , as 15 reactors exited service -- mainly in Germany and Japan . Today , 435 reactors operate in 31 countries , and a further 68 are under construction . After the Fukushima disaster , Japan pulled back its nuclear ambitions , ordered large-scale inspections and introduced new safety regulations . All of its 48 remaining reactors have been kept offline and a proposal to restart the program awaits parliament 's approval . Germany shut down eight of its oldest reactors almost immediately after Fukushima , focusing instead on renewable energy , and phase-out all of its nuclear power by 2022 . Switzerland adopted a similar approach when the government decided not to build any new reactors and phase out its nuclear production by 2034 . This was despite a national referendum in which a majority of people voted in favor of more reactors . But not all countries got scared . Both France , which has the world 's highest share of nuclear power for its electricity production , and the U.S. , the world 's largest producer , reaffirmed their positions on the power source . Both countries continue to invest heavily into safety improvements . All four `` BRIC '' countries are boosting their nuclear power production , with India aiming to supply 25 % and Russia 45 % of their electricity from nuclear power by 2050 , and Brazil planning to build five new reactors by 2030 . China is facing pressure to cut its pollution levels and reliance on coal . China already operates 20 reactors and aims to more than triple its nuclear capacity by 2020 . Read more : The 'nuclear renaissance : ' What went wrong ? Read more : Five big questions about Fukushima 's nuclear power mess . Read more : Inside Fukushima damaged power plant . Editor 's note : Due to variations in terminology , various sources quote slightly different numbers of nuclear reactors worldwide . For the purpose of this report , CNN used World Nuclear Association data and considered only the reactors connected to the grid and supplying electricity to consumers as active .
The Fukushima nuclear disaster changed attitudes towards nuclear power . Germany shut down its oldest reactors and plans to phase-out nuclear by 2022 . Emerging markets are investing heavily into nuclear power .