OPG submits geologic repository studies

This story has been updated to include information on the review and public comment process. 

Ontario Power Generation (OPG) has submitted further information on its proposed deep geologic repository for low- and intermediate-level waste to Canadian regulators. The studies, carried out in response to a ministerial request, show that relocating the repository from OPG's proposed site at Bruce to one of two alternative locations would increase environmental effects and costs.

The proposed repository would provide permanent storage for low- and intermediate-level waste from the Bruce, Pickering and Darlington nuclear power plants. A federally appointed panel in 2015 approved OPG's environmental assessment for the proposed repository at its Bruce site, but in February 2016 Canada's minister of the environment and climate change asked OPG to carry out three further studies: an assessment of the environmental effects of two technical and economically alternative locations for the project, including incremental off-site and transportation costs; an updated analysis of the cumulative environmental effects of the project, if a separate repository for used nuclear fuel were to be built nearby; and a review of OPG's mitigation commitments and actions.

OPG's proposed site at Bruce would see the repository built 680 metres under the existing nuclear site, in impermeable limestone. The alternative locations - a crystalline granite location in central-to-northern Ontario, and a sedimentary location in the southwest of the province - both met OPG's criteria for technical and economic feasibility. OPG's studies showed that the DGR's primary objectives of public health and safety, worker health and safety and environmental protection could be achieved at any of the three locations.

However, the studies concluded that the environmental effects of a repository at either of the two locations would be greater than the Bruce site due to the environmental impacts of additional waste transportations, as well as effects on land use, vegetation and wildlife from the establishment of a new site.

The study found that an additional 22,000 shipments would be required to move the waste - currently in storage at Western Waste Management's surface storage facility at Bruce - on public roads. This would cause a "small but incremental" risk of radiation exposure to the public and transportation workers as well as creating an incremental risk of conventional transport accidents over the decades that would be required to complete the additional shipments.

Incremental costs of using an alternate location were found to range from about CAD 1.2 billion to CAD 3.5 billion ($0.9 billion to $2.6 billion). Additional costs would come from activities including the redesign and implementation of a site selection process; acquisition of land for the facility; development and implementation of support services; repackaging and transportation; and restarting the licensing process for the new location.

"The studies show that relocating the [repository] to an alternate location would result in increased environmental effects and significant incremental costs, with no assurance of increased safety to workers and the public, or protection of the environment," OPG said yesterday. "Based on the findings, OPG maintains that a [deep geologic repository] is the right answer for its low- and intermediate-level waste, and that the current proposed Bruce nuclear site is the right location."

Cumulative update

The ministerial request also saw OPG update its assessment of cumulative environmental effects at the Bruce site to determine whether combined effects could occur if the same region were to host two different repositories in close proximity.

Canada's Nuclear Waste Management Organization (NWMO) is in the process of selecting a site for a repository for the country's used nuclear fuel, through a long-term program called Adaptive Phased Management. Nine out of an original 21 communities that expressed an interest in the NWMO repository are still involved in the process, but no site has yet been selected.

OPG said the conclusions on cumulative effects presented in its environmental impact statement for the Bruce repository remained valid. The updated analysis showed no potential for likely adverse cumulative effects, and also showed cumulative effects as a result of malfunctions, accidents, and malevolent acts related to both repository projects would be unlikely, it added.

The Canadian Nuclear Safety Commission is assisting the Canadian Environmental Assessment Agency (CEAA) in its review of the additional information that is due for completion by 16 January. They aim to determine whether OPG's information is complete and conforms to the ministerial request. CEAA will then open OPG’s additional information for public comment. The agency expects to submit its final report to the minister this autumn and a decision on the environmental assessment for the repository will be made at the ministerial level.

Researched and written
by World Nuclear News