A massive quantity of fish trapped in the intake channel took a Bruce Power reactor offline last month and the company is investigating ways to prevent the environmental loss from happening again.
A number of Gizzard Shad, estimated to be in the millions, have been affected, though the company is still in the process of trying quantify it. The species is known to be sensitive to prolonged cold and is attracted to the warm water from Bruce Power's thermal discharge.
John Peevers, Director of Community, Media Relations and Economic Development, said they had to shut down a reactor for a week and a half as a result.
"Our analysis and our understanding is Gizzard Shad is fairly elastic as far as the numbers year to year," he saud. "February 14th it really started to impact Bruce A facility and that was when we had to take the proactive measure to shut down Unit 2 due to just the extremely high volume inhibiting our ability to bring in water for cooling purposes."
Peevers said the quantity of fish trapped in the intake was at a level not matched since the winter of 1997, which had similar lake temperature conditions.
The plant has a number of deterrents to keep fish out. A large concrete and steel velocity cap spans over the top of the intake tunnel, redirecting the flow of water in a way for fish to naturally avoid. Ones that do make it down the intake tunnel will get stuck on screens used to catch debris.
The company is working with Saugeen Ojibway Nation, the Canadian Nuclear Safety Commission, Department of Fisheries and Oceans, and local municipalities to understand what happened and ways to mitigate fish loss moving forward.
"We'll look at, are there other methods that we can use to stop fish from getting in the forebay," said Peevers. "It's probably too early to go into any detail on what we might do, because we just don't know yet. We're looking at all options to improve... our goal is to never have any negative impacts on the environment and that's what we're going to try to achieve."
Peevers added the company normally offsets fish losses, by supporting projects like the removal of the Truax Dam in Walkerton.
As Bruce Power plans an expansion to create the Bruce C Plant, mitigating this issue will be a part of those environmental impact discussions.
"We're still along way away from that with the Bruce C project, we're in the early days of impact assessment. Absolutely we're going to consider all of the baseline data we've got and experience we've got and make sure that if we do go ahead with that project, that we implement any improvements that are available to us."
Along with the Gizzard Shad, the company mentioned in a statement it is aware of the presence of dead waterfowl in Baie du Dore north of the Bruce Power site. The birds have been sent for lab testing to check for conditions like avian flu. Peevers said there's no indication it's related to the finish, but once they know more, an update will be shared.