Ontario Power Generation is seeking federal approval to build underground vaults near Lake Huron to store low- and intermediate-level radioactive nuclear waste.
The utility has submitted 12,500 pages of documents, including an environmental impact statement on the Deep Geologic Repository, to support its claim that the project "will not likely result in any significant adverse environmental or public health effects."
What little moisture there is 680 metres below the surface of the proposed site is trapped in rock so dense it doesn't move, said Albert Sweetnam, an executive vice-president at OPG who is in charge of the project.
"You actually have to crush the rock to get the moisture out of it, and when you test that moisture, it's actually from a sea hundreds of millions of years ago," said Sweetnam. "It shows you that nothing is moving down there, it's not going anywhere. That's why the safety case is a good one."
The underground vaults would be used to store everything from mops and used protective suits to irradiated core components from the refurbishment of reactors at Pickering, Darlington and Bruce. They would not be permitted to store used nuclear fuel.
OPG wants to build the storage facilities about one kilometre inland from Lake Huron near Kincardine, on the site of the existing Bruce nuclear plant.
That is too close to the Great Lakes for the New Democrats, who pointed to Japan's current nuclear crisis as proof that scientists are limited in their ability to predict what's going to go wrong.
"There are a bunch of Japanese engineers who never expected a wave big enough to come in and knock out their backup electricity for a nuclear plant," said NDP environment critic Peter Tabuns.
"All of this is really conjecture on the part of those putting together these waste holding areas, and if they go wrong right beside the lake, the consequences are very high."
The vaults, which would be capable of holding a total of 200,000 cubic metres of radioactive waste, would be built 680 metres below ground in low permeability limestone, beneath a 200-metre thick layer of low permeability shale.
"These sedimentary bedrock formations, that provide multiple natural barriers, will safely isolate and contain the low- and intermediate-level nuclear waste," OPG said in its documents.
"The tests indicate that this area has been undisturbed for over 450 million years, so we would expect that it would remain undisturbed for another 450 million years," added Sweetnam.
Earthquakes are not a big concern at the proposed site of OPG's underground vaults.
"The site is within the tectonically stable interior of the North American continent, which is a region characterized by low rates of seismicity, where large earthquakes are unlikely," said the utility.
However, Greenpeace Canada said the crisis at Japan's Fukushima plant shows scientists aren't foolproof when claiming an area is safe.
"Japan shows us that geology is not a predictive science," said Greenpeace spokesman Shawn-Patrick Stensil. "I think OPG is trying to bury its biggest public relations problem: radioactive waste."
Ontario's low- and intermediate-level nuclear waste products have been stored "on an interim basis" at the existing Bruce nuclear plant in Kincardine for 40 years. The local community asked OPG to build the underground facility as a permanent home for the materials.
OPG said the radioactivity in the low-level waste will decay within about 300 years, while the intermediate-level radioactivity will take many thousands of years to decay.
Greenpeace argues there is no safe way to store such radioactive materials.
"There is no fail-safe way of isolating these radio toxins from the environment for hundreds of thousands of years," said Stensil.
The reports submitted by OPG to the Canadian Nuclear Safety Commission are needed to secure an approved environmental assessment and a site preparation-construction licence for the repository, and will undergo a six-month review and comment period.
There will also be a public hearing into the project, expected in 2012, and OPG said the earliest the repository could begin to receive nuclear waste, if approved, would be around 2018.
Local communities near Kincardine have signed on as "willing hosts" for the repository, and OPG says there are existing examples of such facilities operating safely in Sweden, Finland and the United States.