Group wants tighter radiation standards for drinking water

THE CANADIAN PRESS : March 4, 2009

OTTAWA - A group of environmental activists is urging tougher standards for the amount of radioactive tritium allowed in drinking water.

Members of the Tritium Awareness Project say limits for the substance -- which occurs naturally but is also a byproduct of Canada's nuclear reactors -- are far higher than in other jurisdictions and should be lowered.

They also say that a recent spill of heavy water at the Chalk River, Ont., reactor released a large quantity of tritium into the air.

"They talked about 47 kilograms of heavy water being leaked, but they didn't mention that there were trillions of becquerels of radioactive tritium in that heavy water," Gordon Edwards of the Canadian Coalition for Nuclear Responsibility told a news conference Wednesday.

The Canadian Nuclear Safety Commission has said there was a small release of tritium well within safety limits.

Michael Binder, the commission chairman, said in a letter to Edwards that the tritium posed no danger to the public.

"Such an airborne release could only result in an extremely small does of radiation to the public, with a maximum dose being about one ten-thousandth of (the commission's) regulatory maximum public dose," the letter said.

The environmentalists worried that the Chalk River reactor, and other Canadian reactors, contaminate nearby water supplies. Chalk River, for example, releases tritium into the Ottawa River on a controlled basis.

The commission, however, said sampling of the Ottawa River found tritium levels far below the national standard of 7,000 becquerels per litre. Samples from 18 kilometres downstream showed levels of seven becquerels per litre.

Binder's letter said releases of tritium from Chalk River are 1,000 times lower than the internationally accepted limit.

Edwards, however, said that's not good enough.

"For known carcinogens, there is no safe threshold level," he said.

He said tritium is a problem for Canada because Candu reactors produce more of it as a byproduct than other reactors.

Michel Duguay, a professor at Laval University and a PhD in nuclear physics, said European limits are much lower than Canada's standards.

He said tritium, if ingested, can harm cells and cause genetic damage.

"Tritium is like a little pistol that lodges itself in your cells," he said. Every now and then, it fires an electron capable of damaging whatever it hits.

Edwards and his colleagues say they also want a new law to ensure that the safety commission has a more arm's-length relationship with the nuclear industry.

"We are not really up to date with our legislation," he said. "CNSC works with industry under same minister."

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