Forty years after the most serious civilian nuclear accident in U.S. history occurred at Three Mile Island, not a single new nuclear power plant has been built in the United States since. Yet, despite this, the U.S. still leads the world in nuclear power generation. While some countries like China are investing heavily in nuclear energy, others like Germany plan on phasing out nuclear power altogether. Here are the world’s top 10 nuclear power producers by country, based on the latest available data, and where this sometimes-controversial power source fits into their future:
REUTERS/Jonathan Ernst 

9: United Kingdom – 63,886.83 Gwh: 19.3% of total energy needs. The United Kingdom has 15 reactors generating about 19% of its electricity, though almost half this capacity is set to be retired by 2025. A decade ago, nuclear power accounted for 25% of annual electricity generation in the UK, but this has declined as old plants have shuttered and aging has affected plant availability.



REUTERS/Dylan Martinez 

8: Germany – 72,162.80 Gwh: 11.6% of total energy needs.
The German government decided in the wake of Japan’s Fukishima disaster in 2011 to stop producing nuclear power by 2022. REUTERS/Thilo Schmuelgen 

7: Ukraine – 80,405.85 Gwh, 55.1% of total energy needs.
Ukraine is heavily dependent on nuclear energy, with 15 reactors generating approximately half its electricity needs. Two new reactors were commissioned in 2004, and the government plans to maintain its nuclear share of energy production into 2030.
REUTERS/Valentyn Ogirenko 

6: Canada – 95,131.20 Gwh, 14.6% of total energy needs.
With 19 reactors, most of them located in Ontario, Canada supplies almost 15% of its domestic energy needs through nuclear power. Canada has publicly stated it plans to increase its nuclear supply, but has yet to commission any new builds. The country remains a lead in nuclear research, exporting its technology and providing much of the global market for radioisotopes used in medical diagnosis and cancer therapy.
REUTERS/Mark Blinch 

5: South Korea – 141,278.32 Gwh, 27.1% of total energy needs. Home to 23 reactors, South Korea is among the world's most prominent nuclear energy countries. Currently involved in the building of four reactors in the UAE, South Korea is also a growing player in technology export.
REUTERS/Lee Jae-Won 

4: Russia – 190,115.15 Gwh, 17.8% of total energy needs.
Russia is a world leader in fast neutron reactor technology, and moving forward with plans for an expanded role for nuclear production. In 1954, Russia's original nuclear power plant was the first in the world to produce electricity.

REUTERS/Maxim Shemetov 

1: United States – 805,647.33 Gwh, 20.0% of total energy needs. The United States is the world’s largest producer of nuclear power, accounting for 30% of global output, despite no new reactors being constructed since the Three Mile Island accident in 1979. Following that incident, revised federal regulations raised the cost of building new nuclear power plants to almost-prohibitive levels, and public support for nuclear energy fizzled over fears of another meltdown. But there are signs of a renaissance on the horizon. Two new nuclear reactors are expected to go online in 2020.


REUTERS/Jonathan Ernst