Nearly 440 nuclear reactors churn out electricity across the globe and more than 30 new plants are being built as the world's energy appetite grows and oil prices soar.

Russia, China and India are leading the way in new construction. In the European Union, a push by eastern nations saddled with Soviet- era reactors is fuelling tension with anti-nuclear EU nations.

In Western Europe, the balance is shifting after Prime Minister Silvio Berlusconi's new government said in May it plans to relaunch nuclear power in Italy, 21 years after a referendum sparked by the Chernobyl disaster outlawed it.

"Only a few years ago, supporters of nuclear energy were viewed as witches," Slovakian Prime Minister Robert Fico said last month. "It is clear ... that without nuclear we will be unable to ensure energy security in Europe."

Slovakia, one of Europe's fastest-growing economies, is a case in point. Under its deal to enter the EU in 2004, one communist-era reactor at the Jaslovske Bohunice plant shut down in 2006 and the other is slated to close by 2009.

To make up the shortfall and feed economic growth, Slovakia wants to get two, possibly three, new nuclear plants online over the next few years.

"A war for access to energy sources has started - a war for investment opportunities," Fico said.

Nuclear power seen as greener alternative to oil

For ex-communist Eastern Europe, limiting dependence on Russian oil and gas is a big factor. And as EU governments jointly seek to fight global warming, nuclear power is increasingly attractive because it emits almost no greenhouse gases.

France, which gets more than three-quarters of its electricity from nuclear plants, plans to add another one. Finland wants to build a fifth reactor.

Bulgaria shut down four of six units at its Soviet-era Kozloduy plant under pressure from the EU before joining the bloc last year. But two new reactors are to be finished by 2014 at Belene, across the Danube river from Romania.

Energy fears are particularly strong in the Baltics. Lithuania's hefty 1,185-megawatt Ignalina plant, which uses a design similar to Chernobyl and supplies nearly 70 per cent of the small nation's electricity, is slated to close by the end of 2009.

Lithuania, Latvia, Estonia and Poland are talking about building a new plant together. Not that nuclear power is suddenly getting a free ride.

Safety concerns divide opinion but don't slow return

When a coolant leak at Slovenia's Krsko plant Wednesday led to an alert to all 27 EU nations, rifts between supporters and foes opened up quickly.

"This technology is so complex that breakdowns are the norm," said German Environment Minister Sigmar Gabriel, whose country -- Europe's biggest economy -- has decided to phase out nuclear power.

Austria, where voters rejected nuclear power in a 1978 referendum, slammed Slovenia for initially filing a mislabeled accident report to its neighbors.

In Italy, which also borders Slovenia, leaders dismissed the scare as alarmist and said their country's nuclear revival was firm.

"There will be no turning back," Economic Development Minister Claudio Scajola said. "We have to go forward, because our country, and the entire planet, need energy."

Further north, Slovaks and Czechs are among the biggest supporters of nuclear power. Yet next-door Austria regularly condemns their reactors as safety threats.

Europeans want to see less nuclear power

One third of EU electricity comes from nuclear energy. With EU officials saying that half of Europe's power plants need replacement by 2030, polls show that most Europeans want less, not more, nuclear.

A 2007 poll found that while most EU citizens expected energy prices to rise, 61 per cent wanted a smaller share for nuclear power.

Yet even Slovenia - population 2 million - is considering building a second reactor.

Its current Western-built unit released no radioactivity during Wednesday's breakdown, which was ranked as a minor mishap.

Hans-Holger Rogner, an expert at the UN International Atomic Energy Agency (IAEA), said he doubts the public will long remember.

Other factors are set to play a bigger role: the expense and long lead times of building nuclear plants, or possible shortages of uranium, the metal used to make reactor fuel.

"Right now, I see the pendulum swinging toward nuclear energy," Rogner told reporters. "But it can also reverse course."