A site next door to the Darlington nuclear power station east of Toronto is Canada's entry in the international bidding. Of the estimated $12 billion cost, $2 billion would come from governments and the private sector in Canada.

Three international partners - Japan, Russia and the European Union - would pick up the remaining $10 billion for ITER, the International Thermonuclear Experimental Reactor.

But Japan, France and Spain are also bidding for the reactor. Thirteen storeys high, it will try to reproduce the same nuclear fusion that occurs in the sun and in hydrogen bombs.

Detailed rules for judging the competing sites should be decided at a three-day session among the four partners set to begin tomorrow in Toronto, says Jim Campbell, a federal official who leads the Canadian team.

The target is to have a recommended site by November, more than two years after Canada made its bid.

"Everyone is anxious to get on with this," said Campbell, who is with the Department of Natural Resources.

If the Clarington site is not chosen, Canada will pull out of ITER because the country has little to contribute other than buildings, electricity and a ready supply of the essential tritium fuel, a byproduct from our Candu power reactors.

The nation's only research program in nuclear fusion was scrapped three years ago in a wave of cost-cutting by the federal government.

Campbell said this week's meeting is also to pull together the expert team that will inspect the four competing sites for ITER and continue the complex process of drafting an international treaty to govern running the reactor.

The experimental reactor would generate a tiny amount of electricity by using superconducting magnets that squeeze ionized gases to reach temperatures of 100 million degrees Centigrade.

The fusing together of isotopes of hydrogen, such as tritium, is the opposite of nuclear fission, the atom-splitting technique of conventional nuclear power stations like Darlington.

The Ontario government has pledged $300 million toward Canada's share of ITER and the federal government is actively supporting the international bid.

More than $1 billion of Canada's $2-billion share would come from industry, according to officials of ITER Canada Fusion Energy Inc., the not-for-profit body behind the bid.

This week's session is a subgroup of the main negotiating body that's to meet in Toronto in mid-September.