NWMO wrapping up drilling, starting water testing near Ignace, Ont.
Age dating, checking porosity, water movement all part of site research
Concerns about groundwater near a proposed site for a nuclear waste repository are top of mind for many who have worries about the Nuclear Waste Management Organization's (NWMO) plan near Ignace, Ont.
The NWMO wrapped up the drilling of its sixth borehole earlier this month, but work on figuring out how water flows to and from the area will continue.
CBC News recently travelled to Ignace and Dryden, to hear about the public's perception of the project. One theme emerged, with many people concerned about water.
Jasmine Papassay lives at Wabigoon Lake First Nation, which is one of the closest communities to the proposed site.
"If it gets into the lakes, if it gets into the lakestream," Papassay worries, that the water, and areas within the watershed would be destroyed.
"If that gets ruined, that's my home. That's my children, my grandchildren's history."
Water is a concern
Alexander Blyth, a section manager and hydrologist with the NWMO said much of the research currently being done, has to do with water.
"It is all about the water, and from a layman's standpoint, that's what concerns people is the water. Where is this going to go, potentially, and that's why we need to understand how the water moves, or doesn't move underground."
Blyth said one challenge his crew is running into, is a lack of water underground. It's a good thing, Blyth said, knowing there is little water, however, researchers need to find some water in order to study its movement.
He said things like porosity and underground water flow are major components of the NWMO study.
"This is really key to our project. We want to make sure that ultimately, our site is tight to water movement, and that our fuel is safe against water getting into contact with our fuel, and fuel getting into contact with the environment."
Blyth said that the team is also checking pressure differences in different portions of the borehole, which is looking at the ability of water to move, or not move through the rock.
"We tend to find very low values, that this rock is very, very right."
During the drilling process, Blyth said the group is looking for any changes in water pressure, pH or temperature, which can also determine if there is water in the rock.
"We'll usually pump for three days, and the volumes are extremely low. In fact in our last two bore holes, we didn't' get any water opportunities to sample."
"If the water that you see that you encounter during drilling, it's really old water, that's telling you there's no connection to the surface water, and the water that's down there."
Water is being aged through carbon dating
Blyth said water being pulled up is aged through carbon dating, similar to archeology work, but that process only can date back about 60,000 years.
"Our water is much older than that," he said. So, other processes, using gases to date water are used.
"So noble gases are things like helium, argon, krypton, those are gases you can find in our atmosphere. So, we will sample those, those can get you back huge timeframes, even billions of years."
"Because there's so little water, we actually go for the groundwater that's in the pores of this rock."
Blyth said it's a misconception that water is found in veins or river or lake structures that are deep underground.
"The water only moves through the fractures of this rock," he said, noting that most water found at the 500 metre level, or lower, is stagnant.
Testing of the rock, along with its pores, is done by the University of Toronto, along with other researchers, Blyth said.
"You get down to a deeper zone, and that water is extremely tight, it doesn't move, it's ancient, ancient water. It can be millions of years old, or older."
"That's the kind of site conditions that we're looking for, it just doesn't move. There's so little of it, in fact, and we can't get all of it, so we use our pieces of core. In that core, there's a minute amount of water, it's in the pores of that rock. You look at the porosity of that and it's one third of one percent. And, we're trying to age date that water."