Chalk River, Ontario — A group of scientists at the Atomic Energy of Canada Ltd. research center are delighted: They have just heard that Canada is accepted as a participant in the world's next major fusion project - the International Thermonuclear Experimental Reactor (ITER). The decision was made at a meeting Tuesday of the ITER Council in Vienna. ITER is a $240 million joint effort by the European Community, the United States, Japan, and the Soviet Union to design a reactor to carry forward research on harnessing fusion - similar to the nuclear reaction that powers the sun. Canada will participate under the aegis of the Community.
``We are pleased Canada is making this contribution,'' said John Clark, an American who is chairman of the ITER Council.
Ten physicists and engineers from each of the four major nations have been meeting in Garching, near Munich, to draw up the conceptual design of the engineering test reactor. When that is concluded by the end of 1990, the four must give the go-ahead for a detailed design, perhaps costing $400 million. Then three to five years later, the participating governments must decide whether to construct a fusion machine that could cost $4 billion to $5 billion. When the four nations agreed in April to launch this project, the terms of reference included what has been dubbed the ``Canada clause.'' It says: ``After consultation with the other parties, each party may involve in its contribution to the conceptual design activities other countries which possess specific fusion capabilities.''
Canada's special capability is its tritium technology, obtained through the operation of the CANDU reactors used in Canadian nuclear power plants.
These reactors, designed by Atomic Energy of Canada Ltd. (AECL), utilize heavy water as a moderator for the reaction. Heavy water is composed of oxygen and a heavy isotope of hydrogen, deuterium. In the process, some of the deuterium is converted into another heavier hydrogen isotope called tritium.
Since tritium is mildly radioactive, it is a nuisance and a danger to the human operators of CANDU power plants. So Canadian scientists are building two tritium recovery facilities - one here by the AECL, another in Darlington, Ont., by Ontario Hydro - to remove the tritium from heavy water that has been in a reactor for some years. Said to be the largest and most advanced civil tritium extraction facilities in the world, they are scheduled to be completed this year.
In addition, Canadians have been doing other tritium research.
``We would like to apply this technology to the ITER fusion reactor,'' says Dr. William Holtslander, manager of the international activities for Canada's National Fusion Program. ``They recognized that our capabilities will be needed, not just wanted.''
Canada cannot afford to be a major financial participant in costly future fusion projects. Nonetheless, it would like to keep up with the technology since it could become a vital source of energy in the next century.
Canadian fusion scientists seek access to the research and machines involved in other large fusion projects, such as the Joint European Torus in Culham, England; the Tokamak Fusion Test Reactor in Princeton, N.J.; and the Japanese JT 60. The Soviet Union also has a major fusion project, but Canadian scientists say it has been difficult to obtain much information about it.
Canada itself has a smaller Tokamak-design machine in Varennes, near Montreal. It began operating in April 1987. Research is centered on ``plasma-wall interaction studies in long-pulse conditions.'' Fusion requires extremely high temperatures (plasma heating) that is achieved with short bursts of electrical energy.
The Canadian Ministry of Energy, Mines, and Resources will be expected to contribute both technology and staff to the ITER project. But the cost will not be anywhere near the $1 billion or so contribution apiece anticipated eventually for the Big Four nations.
Ontario has even offered to provide a ``host site'' for the ITER reactor. But its chances are not seen as good, given the greater resources put up by the four.
Canada's tritium recovery facilities, scientists here note, are more open to viewing by scientists from other countries than tritium facilities elsewhere that have military significance. Tritium is one of the ingredients of the hydrogen bomb.
Canada runs a tritium-handling course twice a year for small groups of scientists from around the world.
The AECL, and possibly Ontario Hydro, would also like to sell tritium from their recovery plants for industrial purposes or pharmaceutical research. The AECL last week signed an agreement with a small firm in Prince Edward Island, Cytrigen, which will produce tritium-powered lights. The lights glow for years without any outside source of power. They can be used in exit signs or for airport runways in the far North which lack electrical power.
Since tritium costs about $15,000 a gram - about the same weight as a sugar cube - the business could be lucrative.
``Down the road we are hoping for some payoff from tritium,'' says Gil Phillips, the manager for fusion fuels of the National Fusion Program.
However, Ontario Hydro faces opposition from those fearful of anything radioactive or connected with hydrogen bombs. There is even some question as to whether it will allow tritiated heavy water to be trucked from other nuclear power plants to the recovery plant in Darlington.
Scientists here maintain that the tritium in the heavy water is so dilute that even if the collision-proof containers of heavy water were somehow spilled in an accident, any radiation would quickly disappear as the water evaporated or soaked into the ground.