Nuclear Power in the World Today

• The first commercial nuclear power stations started operation in the 1950s.
• There are now some 436 commercial nuclear power reactors operating in 30 countries, with 372,000 MWe of total capacity.
• They provide about 15% of the world's electricity as continuous, reliable base-load power, and their efficiency is increasing.
• 56 countries operate a total of about 250 research reactors and a further 220 nuclear reactors power ships and submarines. 
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Nuclear technology uses the energy released by splitting the atoms of certain elements. It was first developed in the 1940s, and during the Second World War research initially focussed on producing bombs by splitting the atoms of either uranium or plutonium.

In the 1950s attention turned to the peaceful purposes of nuclear fission, notably for power generation. Today, the world produces as much electricity from nuclear energy as it did from all sources combined in 1960. Civil nuclear power can now boast over 13,000 reactor years of experience and supplies almost 16% of global electricity needs, in 30 countries.

Many countries have also built research reactors to provide a source of neutron beams for scientific research and the production of medical and industrial isotopes.

Today, only eight countries are known to have a nuclear weapons capability. By contrast, 56 operate civil research reactors, and 30 have some 440 commercial nuclear power reactors with a total installed capacity of over 370 000 MWe (see table). This is more than three times the total generating capacity of France or Germany from all sources. Some 30 further nuclear

 power reactors are under construction, equivalent to 8% of existing capacity, while over 90 are firmly planned, equivalent to 27% of present capacity.

A list of the countries with nuclear power projects is appended.

Sixteen countries depend on nuclear power for at least a quarter of their electricity.  France gets around three quarters of its power from nuclear energy, while Belgium, Hungary, Lithuania, Slovakia, South Korea, Sweden, Switzerland, Sl

ovenia and Ukraine get one third or more.  Japan, Germany and Finland get more than a quarter of their power from nuclear energy, while the USA gets almost one fifth.

Improved performance from existing nuclear reactors

Although fewer nuclear power plants are being built now than during the 1970s and 1980s, those now operating are producing more electricity.  In 2007, production was 2608 billion kWh.  The increase over the six years to 2006 (210 TWh) was equal to the output from 30 large new nuclear power plants.  Yet between 2000 and 2006 there was no net increase in reactor numbers (and only 15 GWe in capacity).  The rest of the improvement is due to better performance from existing units.  In 2007 performance dropped back by 50 TWh due to plant closures in Germany, UK and Japan.

In a longer perspective, from 1990 to 2006, world capacity rose by 44 GWe (13.5%, due both to net addition of new plants and uprating some established ones) and electricity production rose 757 billion kWh (40%). The relative contributions to this increase were: new construction 36%, uprating 7% and availability increase 57%.

One quarter of the world's reactors have load factors of more than 90%, and nearly two thirds do better than 75%, compared with about a quarter of them in 1990. For 15 years Finnish plants topped the performance tables, but the USA now dominates the top 25 positions, followed by South Korea.

US nuclear power plant performance has shown a steady improvement over the past twenty years, and the average load factor now stands at around 90%, up from 66% in 1990 and 56% in 1980. This places the USA as the performance leader with 12 of the top 25 reactors, the 25th achieving more than 97.5%. The USA accounts for nearly one third of the world's nuclear electricity.

In 2007 and 2008 ten countries averaged better than 80% load factor, while French reactors averaged 76-77%, despite many being run in load-following mode, rather than purely for base-load power.

Some of these figures suggest near-maximum utilisation, given that most reactors have to shut down every 18-24 months for fuel change and routine maintenance.  In the USA this used to take over 100 days on average but in the last decade it has averaged about 40 days.  Another measure is unplanned capability loss, which in the USA has for the last few years been below 2%.

Other nuclear reactors

In addition to commercial nuclear power plants, there are about 250 research reactors operating, in 56 countries, with more under construction. These have many uses including research and the production of medical and industrial isotopes, as well as for training.

The use of reactors for marine propulsion is mostly confined to the major navies where it has played an important role for five decades, providing power for submarines and large surface vessels. Over 150 ships are propelled by more than 220 nuclear reactors and over 12,000 reactor-years of experience has been gained with marine reactors. Russia and the USA are now decommissioning many of their nuclear submarines. Russia also operates a fleet of eight large nuclear-powered icebreakers and a 62,000 tonne cargo ship which are more civil than military.

See table of the World's Nuclear Power Reactors which complements this paper.