A decision by Britain on Thursday to build new nuclear power generation plants is the latest example of this trend for countries to renew or to begin building nuclear capacity.

Today there are 442 nuclear power reactors at work in 201 power stations in 31 countries. Of these, 104 are in the United States, 58 in France and 55 in Japan, together accounting for about half of the total.

A plant is under construction in Finland by the world-leading French nuclear power group Areva, headed by Anne Lauvergeon who says that 100-300 reactors will be built around the world by 2030. She wants Areva to build one third of these.

The United States expects to build new nuclear power stations for the first time for nearly 30 years since a dramatic accident at the Three Mile Island plant in March 1979.

Several countries in the Mediterranean basin such as Egypt, Morocco, Algeria and Libya have said in recent months that they intend to build nuclear power plants for the first time.

China, experiencing a huge increase in demand for energy, recently ordered two so-called third-generation European pressurized reactors (EPRs) from France.

India also wants to develop nuclear power but must first sign an agreement with the International Atomic Energy Agency (IAEA) ensuring that any such facilities would not be used to provide material for nuclear weapons.

France has offered to cooperate with several of these countries. However western countries continue to express concern about whether the the nuclear power programme in Iran is purely for civil use or also has a covert military purpose.

There are still deeply different views about nuclear energy within Europe. Italy abandoned the generation of nuclear power in 1987 and Germany has decided to end all of its nuclear generation by 2020.

But the surge of oil prices to around 100 dollars a barrel, and commitments to combat the effect of carbon on global warming, have re-opened debate on the benefits of nuclear power in these countries.

The International Energy Agency, a Paris based offshoot of the Organisation for Economic Cooperation and Development, has warned that if Germany, Sweden and Belgium pursue policies to end nuclear power generation, the amount of energy provided from nuclear material could fall to 11.0 percent in 2030 from 15.0 percent now.

Coal is the main fuel used throughout the world for the generation of electricity, accounting for 40 percent, followed by gas (20 percent), hydro power (16 percent), nuclear energy (15 percent), oil (seven percent), and other renewable energies (two percent).

Nuclear power produces little carbon dioxide and is competitive even with coal if this is taken into account, some experts say.

But nuclear power stations create radioactive waste which is difficult to store with safety. In addition, the construction of a nuclear power station takes 10 years, compared with four years to build a coal-fired plant and two and a half years for a gas-powered station.

The potential market is attracting interest from many companies. The leading builders of nuclear power plants are Areva of France, Westinghouse of the United States and Atomstroyexport of Russia, together with leading groups in the field of electricity generation in general, the makers of turbines and big construction groups.

The prospect of the construction of a nuclear power station is always met by opposition by ecologists and by people living near the planned site.

The head of French electricity generator and distributor EDF, Pierre Gadonneix, says that the biggest challenge for those who support nuclear energy is to make it acceptable to public opinion.

Areva, the world's largest nuclear power group, on Thursday welcomed Britain's decision to build a new generation of such plants and said it wanted to build up to six of them.

Areva said in a statement it was "delighted with the decision, which will boost investment in (Britain's) nuclear power generation." "It is our ambition to build at least four, and possibly six nuclear power plants in Britain," said Luc Oursel, head of Areva's nuclear reactor division.

In June last year, Areva submitted details of its third generation nuclear power plant to the British authorities for review. Only last month, Areva chief executive Anne Lauvergeon said the company wanted to account for a third of all new nuclear reactors built worldwide between now and 2030, "Between now and 2030 we believe there could be 100 to 300 (nuclear reactors built around the world)," she said. "We want a third of that business."