OTTAWA - When Prime Minister Stephen Harper departs for Australia on Tuesday for a summit of pan-Pacific leaders, he'll be carrying with him a secret agenda that is quite literally radioactive.

Harper will face questions from both Australian Prime Minister John Howard and U.S. President George W. Bush over Canada's participation in a sweeping American-led initiative still in its infancy.

The initiative, called the Global Nuclear Energy Partnership, proposes that nuclear energy-using countries and uranium-exporting countries band together in a new nuclear club to promote and safeguard the industry.

Central to the plan is a proposal that all used nuclear fuel be repatriated to the original uranium exporting country for disposal.

That should be big news in Canada, the world's largest uranium producer.

But to date, the Canadian government's response is a closely guarded secret. In fact, there's been virtually no public debate at all.

This weekend in Sydney when Harper sits down with the 21 leaders of the Asia-Pacific Economic Co-operation forum, the nuclear question will hover like a plume.

That's because climate change and energy policy are a key item on the agenda, and some of the GNEP's biggest proponents, including the United States and Japan, are at the table.

Bush and Howard will sign a bilateral nuclear technology pact before the main summit.

In Australia, where Harper shares an ideological soul-mate in Howard, the debate over the GNEP has raged for more than a year. Ausralia and Canada are the world's biggest uranium exporters and the GNEP threatens to become an election issue this fall as opposition parties charge the country is in danger of becoming a "radioactive dump.''

Yet Harper's minority Conservative government clearly does not want to engage the Canadian public in any discussion about the initiative.

At a pre-APEC briefing last week, one of the prime minister's most senior officials, flanked by his director of communications Sandra Buckler, carefully skirted a question on the GNEP.

"It doesn't feature on the APEC agenda, per se,'' said the official. "Whether the initiative has disappeared off the global agenda or the U.S. agenda, I really can't say.''

The next day, in response to a separate and unrelated media inquiry, a spokesperson from Foreign Affairs confirmed Canada has been invited to a Sept. 16 meeting in Vienna to discuss the initiative.

"Canada has been invited to join the Global Nuclear Energy Partnership and to participate in the next meeting scheduled to take place on September 16 in Vienna,'' said the official.

"Canada is reviewing the proposed GNEP Statement of Principles and a decision on Canadian participation will be made shortly.''

That carefully neutral response _ which left Canadian attendance in doubt barely a fortnight before the Vienna meeting _ stands in contrast to earlier draft "talking points'' obtained by The Canadian Press under an Access to Information request.

Those heavily censored documents show much greater enthusiasm.

"Canada is very interested in examining potential areas for partnership in the Global Nuclear Energy Partnership (GNEP) given that we are the world's largest uranium producer,'' said one undated talking point from 2006.

The same memo continues: "Canadian officials . . . have begun discussions with their counterparts in the U.S. to consider possible parameters of Canadian involvement.''

As recently as April 7 this year, Peter Harder, the then-assistant deputy minister of Foreign Affairs, was corresponding with Robert Van Adel, the president of Atomic Energy of Canada Ltd., about the partnership plan.

As Van Adel wrote, the initiative "if implemented, would have significant technical and commercial implications for Canada, which need to be assessed.''

Internal government correspondence also indicates the nuclear initiative was on the agenda at the 2006 meeting between Harper, President Bush and then-Mexican president Vicente Fox in Mexico, and again at the 2006 G8 meeting in St. Petersburg, Russia.

Neither Harper nor his officials made any public mention of the GNEP before or after these high-profile summits.

Contrast that to Australia.

Last week, Australia's foreign minister, Alexander Downer, publicly stated "it makes a lot of sense for Australia to be involved,'' and suggested the country would participate in the Sept. 16 meeting.

Liberal MP David McGuinty, the Opposition environment critic, excoriated the Conservative government for its secrecy.

"This is the kind of subterfuge and hidden agenda that the government has on such an important issue,'' said McGuinty. "It's not intending to bring it to the floor of the House of Commons. We've never had notice of it. There's been no White Paper. There's been no discussion.

"It's time for them to come clean on this.''

Bernard Bigras, environment critic for the Bloc Quebecois, noted Ontario and New Brunswick already have issues with dealing with nuclear waste from domestic reactors.

"We have a big problem here in Canada and in the world: how can we manage the waste produced by nuclear (energy)?''