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 10,500 reactor years of experience and supplies 16% of global needs. 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 31 have 440 commercial nuclear power reactors with a total installed capacity of 357 000 MWe (see table). This is over three times the total generating capacity of France or Germany from all sources. More than 30 further power reactors are under construction, equivalent to 7% of existing capacity, while a similar number are firmly planned, equivalent to 9% of present capacity.

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

Fifteen 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, Japan, Slovakia, South Korea, Sweden, Switzerland, Slovenia and Ukraine get one third or more.

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 2001, production was 2544 billion kWh, an increase of 4% (97 billion kWh) over the previous year. The increase over the last seven years (414 billion kWh) is equal to the output from 60 large new nuclear plants. Yet between 1995 and 2001 there was a net increase of only two reactors (3.5% in capacity). The rest of the improvement is due to better performance from existing units.

Two thirds of the world's nuclear reactors (apart from Russia and Ukraine) have load factors of more than 75%, compared with only 39% in 1990. For the past 15 years Finnish plants have topped the performance tables, with average load factors now around 92%. Reactors in Belgium, Czech Republic, Germany, Hungary, Japan, South Korea, Spain, Switzerland, Taiwan and the USA achieve at least 80%.

US nuclear power plant performance has shown a steady improvement over the past 10 years, and the average load factor now stands at around 85%, up from 65% in 1990. This places the US among the performance leaders with 17 of the top 25 reactors. The USA accounts for nearly one third of the worldصs nuclear electricity. In 1999-2000 Japanese plants achieved an 80.6% average load factor while French reactors averaged 71.2 %. The contrast in this case is due to many French reactors being run in load-following mode, rather than purely for base-load power.

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 four decades, providing power for submarines and large surface vessels. Over 150 ships are propelled by more than 200 nuclear reactors. The US Navy has accumulated over 5400 reactor-years of accident-free experience. Russia and the USA are now decommissioning many of their nuclear submarines. Russia also operates a fleet of eight large nuclear-powered icebreakers which are more civil than military

Note: Taipower uses nuclear energy to generate 22% of electricity on the island of Taiwan.

SOURCES:

ANSTO, data to March 2002

ENS NucNet background # 16/00

Nuclear Engineering International, February 2001