- The first commercial nuclear power stations started operation in the 1950s.
- There are now some 435 commercial nuclear power reactors operating in 30 countries, with 370,000 MWe of total capacity.
- They supply 16% of the world's electricity, as base-load power, and their efficiency is increasing.
- 56 countries operate a total of 284 research reactors reactors and a further 220 reactors power ships and submarines.
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.
Only in the 1950s did attention turn 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 12,600 reactor years of experience and supplies 16% of global needs, in 30 countries.
Many countries 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 435 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 power reactors are under construction, equivalent to 6% of existing capacity, while over 70 are firmly planned, equivalent to 22% of present capacity.
Sixteen countries depend on nuclear power for at least a quarter of their electricity. France and Lithuania get around three quarters of their power from nuclear energy, while Belgium, Bulgaria, Hungary, Slovakia, South Korea, Sweden, Switzerland, Slovenia 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 reactors
Although fewer nuclear power plants are being built now than during the 1970s and 1980s, those now operating are producing more electricity. In 2006, production was 2658 billion kWh. The increase over the last five years (210 TWh) is equal to the output from 30 large new nuclear plants. Yet between 1999 and 2006 there was no net increase in reactor numberss (and only 15 GWe in capacity). The rest of the improvement is due to better performance from existing units.
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%.
Almost one third of the world's reactors have load factors of more than 90%, and more than 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 Japan.
US nuclear power plant performance has shown a steady improvement over the past 15 years, and the average load factor now stands at around 90%, up from 65% in 1990. This places the USA as the performance leader with 18 of the top 25 reactors - achieving more than 99%. The USA accounts for nearly one third of the worldÕs nuclear electricity.
In 2006 twelve countries averaged better than 80% load factor, while French reactors averaged 78%, 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. 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 more than 280 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.
Source: World Nuclear Association