437 nuclear power plantThermal power plant, primarily used for electricity generati... units with a total electrical net output of 372 GWGigawatt, one billion times the power unit of watt; 1 GW = 1... were in operation in 31 countries in January 2013. The cumulative operating experience amounted to 15,080 years by end of Dec. 2012. (See ‘nuclear power plants, world-wide’).