Canada's Tritium: Too Hot to Handle?

CANADA has a hot new product. It is worth $15,000 a gram, or about 1,000 times the price of gold. But it almost certainly will not sell any of this rare material to the prime potential customer - the government of the United States.

The material is tritium, a vital material for nuclear weapons. All three of the aging US reactors that can produce this radioactive gas are out of service for safety reasons, raising a question about the supply for periodically ``freshening up'' US weapons. Tritium ``decays,'' that is, turns into another element, at a rate of 5.5 percent per year.

At the same time, Canada has two tritium separation plants being started up that can turn out enough of this gas to fill about half of US needs.

In Canada, tritium is an unwanted byproduct of the Canadian-developed nuclear reactor system, known as Candu. It gradually builds up in the heavy-water moderator used in these reactors, making that water radioactive and a nuisance to the operators of the reactors. When the heavy water reaches a certain level of radioactivity, it is removed from the reactor and stored.

For political reasons, however, the Canadian government is highly unlikely to export the material for weapons' purposes.

Canada is protected by the nuclear umbrella provided by the US and does not prevent US nuclear-armed ships or aircraft from entering its waters or overflying its territory. But Canada has never accepted nuclear weapons as part of its military arsenal. Observers feel an attempt to export tritium for use in weapons would cause a political storm.

Indeed, it may be politically difficult for the two owners of the tritium extraction plants - provincially owned Ontario Hydro and federally owned Atomic Energy of Canada Ltd. (AECL) - to export tritium to the US even for industrial use or scientific research. It would result in speculation that the tritium would enable the US to divert all its own tritium to weapons.

An Ontario Hydro spokesman notes that the prospects of Canada exporting tritium for bombs is about as great as that of Canada building a nuclear bomb itself - namely a nonstarter.

``Any hint that Canadian tritium might somehow enter or buttress the US military system would almost certainly dampen Hydro's enthusiasm to market tritium and close it off to other, more humane uses,'' noted the Toronto Globe and Mail editorially Jan. 3.

Ontario Hydro began recovering tritium from its stored heavy water at a new plant in Darlington, Ont., last October. But the plant ran into a corrosion problem which resulted in its shutdown. In full operation, this plant could produce about 2.5 kilograms of tritium a year. The US stockpile is said to be about 100 kilograms, of which about 5.5 kilograms decays per year.

The AECL plant, in Chalk River northwest of Ottawa, is in the early commissioning stages, says W.J. Holtslander, a scientist at the Chalk River Nuclear Laboratories. When it starts up, likely later this year, it will extract some 70 grams per year of tritium.

If more tritium becomes available for commercial or research purposes in Canada, the biggest use likely will be in exit signs and lighting for remote runways. The beta radiation from the gas will make a phosphor glow in the dark for around 20 years. The market could be worth tens of millions of dollars.