Canada’s nuclear regulator will allow Ontario Power Generation to reuse a 2011 impact assessment in its application for a new reactor at its Darlington station, raising red flags for environmental and safety experts.
With the Canadian Nuclear Safety Commission’s (CNSC) April 19 decision in hand, Ontario Power Generation (OPG) can move forward with the licencing process to build the first of four small modular nuclear reactors (SMRs) at Canada’s second-largest nuclear facility, a project dubbed the Darlington New Nuclear Project (DNNP).
Review Dates Back to 2011
The existing environmental assessment (EA) for the new project—completed in 2011 without considering a specific reactor for the site—is applicable to the reactor technology that OPG has recently selected, namely the General Electric Hitachi BWRX‑300 reactor, the commission said.
Rather than considering a single technology for the site, OPG had completed the EA using a “plant parameter envelope” (PPE) approach, which examined potential impacts based on a range of design factors and variables from several reactor technologies it was considering.
This dated, hypothetical nature of the EA has observers concerned.
“They took some of the characteristics of the different types of the three technologies they looked at previously, and used those to characterize what they call the outer boundaries—or boundary limits—of different aspects of the EA,” Theresa A. McClenaghan, executive director and counsel for the Canadian Environmental Law Association, told The Energy Mix.
“And so they conducted the environmental assessment on this fictitious amalgam—no actual technology, just aspects of potential impacts from various technologies.”
The Darlington site is licenced for a new nuclear plant under an application process that dates back to 2006. The project that passed that process was cancelled in 2014, but OPG maintained the licence and resumed planning activities for the site in 2020, with an operational power plant expected in 2028.
OPG’s EA is from 2011, before the original project was cancelled. But in 2012, the federal government “accepted” or “accepted the intent” of the EA, asserting that “responsible authorities would need to determine” whether a future OPG proposal was fundamentally different from the specific reactor technologies assessed—and whether a new EA would be required.
After that, OPG received a 10-year ‘Licence to Prepare Site’, which was re-issued for another 10 years in 2021. The project completed the first phase of site preparation earlier this month.
But intervenors at the CNSC’s more recent public hearings—including several First Nations and environmental, nuclear, and community organizations—raised concerns about differences in the new design.
They warned that the BWRX-300 is a novel reactor technology that is not currently in operation, that there would be different air emissions because of its release height and thermal emissions, that the BWRX-300 would have fundamental differences in radioactive waste inventories and the weight of the spent fuel cask, and that there was insufficient information and analysis on effects of multi-unit accidents.
The CNSC responded that it did not consider the BWRX-300 to be “fundamentally different” from the technologies assessed in the original EA.
“It is important to note that this decision does not authorize the construction of a BWRX‑300 reactor” for the DNNP,” the regulator added. “The Commission will hold a future public hearing to consider OPG’s application for a licence to construct one BWRX‑300 reactor at the Darlington nuclear site.”
Responding to concern about groundwater flow, a representative said OPG had used three-dimensional modelling to investigate the impacts. “The results showed a temporary impact during the construction phase due to dewatering requirements,” they said, but no permanent problems once groundwater levels were allowed to return to pre-construction levels.
OPG Must Work with First Nations
First Nations intervenors said the original EA process had a narrow focus regarding cumulative effects and did not reflect the broad scope of Indigenous knowledge systems. They said it wasn’t clear if the OPG’s assessment included an understanding of the existing Darlington station’s legacy impacts. An OPG representative acknowledged that its process may have satisfied Western, but not Indigenous, expectations. But CSNC ruled that the cumulative effects associated with deploying the BWRX-300 were within the EA’s parameters.
But the regulator said it still expected OPG to “work collaboratively” with local First Nations to scope out the extent, timing, and content of an updated cumulative effects assessment, including effects on Indigenous rights, while incorporating Indigenous knowledge.
Intervenors also raised concerns about regulatory gaps in the requirements of the 2011 EA, which was subject to less comprehensive impact assessment legislation than it would be today. In response, the Commission said the EA remains valid regardless of its age or any changes to legislation that have occurred since.
McClenaghan responded that not all the impacts that would be assessed today were on the table during the original review.
“If the new environmental assessment legislation was applied, yes, there would be additional factors,” she said. At the same time, other amendments exempt SMRs under a 200-megawatt threshold—so a single installation on an existing nuclear plant site might not be subject to an EA under new legislation.
McClenaghan says the EA’s plant parameter approach fell short of a thorough assessment of the issues associated with the BWRX-300, like waste disposal and accident risk, which are “very, very specific to the type of technology.”
She also expressed doubts about the process that led to the hearing’s outcome. “The way these hearings work is that there’s no cross examination of witnesses,” she explained. “There’s no qualification of experts, there’s no sworn testimony.”
“So all of these things that had a very crude valuation 15 years ago now have doubly potent evaluation when you’re trying to extrapolate them to a specific technology that wasn’t even on the table back then.”
