Skip to Content
A male worker in a safety vest and hard helmet takes readings beside a marsh.

DGR project development

Ontario Power Generation’s Deep Geologic Repository (DGR) is an ambitious project that has undergone extensive reviews and studies.

Discover how a project of this scale evolves by exploring the details of the DGR’s development.

A deep background on the DGR

OPG engaged multiple streams to verify the site’s suitability for the deep geologic repository.

The main project study areas included: geological science (geoscientific site characterization), safety (repository safety analysis), environmental protection (assessment) and project design.

Conducted with support of the regulatory approvals process, the preliminary safety assessment concluded:

  • The facility can be constructed and operated safely
  • The host rock is effective in providing long-term isolation and containment.
  • The majority of radioactivity will decay in and around the repository
  • Future safety scenarios considered include: earthquakes, glaciation, human intrusion into repository, failure of the shaft seal, failure of the borehole seals, and a vertical fault near the repository
  • Even under extreme assumptions about future scenarios, the impacts on people living around the repository site (i.e. around the current Bruce nuclear site) would be at or below the natural background radiation dose rate

Expert review and oversight

The DGR is a collaborative project. Explore some of the input from regulatory bodies and partners.

The Geoscience Review Group (GRG) was established in 2005 to provide peer review and oversight on the research.

The GRG ensures the DGR project will benefit from international experience in all aspects of the geoscientific site characterization

An International Peer Review Team (IPRT) was established from 2009 to 2010.

The team reviewed the interim (2009) and final (2010) post-closure safety assessment reports.

The review team was comprised of safety assessment experts with experience in low-, intermediate- and high-level waste management programs in Belgium, France, Switzerland and the United Kingdom.

The IPRT consisted of the following individuals: Dr. Peter de Preter, Mr. Graham Hickford (2010), Dr. Martin Kelly (2009), Dr. Paul Smith, and Dr. Jean Talandier.

The Technical Review Group (TRG) was formed in September 2009 to advise NWMO on matters related to the design and construction of the proposed DGR facility.

The proposed DGR project has many of the attributes and challenges of a deep underground mine construction project.

The TRG has conducted two formal reviews of the DGR facility design to date. More recently, members of the TRG have participated in NWMO-organized design reviews of the DGR facility.

Project development activity

Explore the step-by-step behind the DGR.

A four-year multi-phase program of geoscientific investigations (Geoscientific Site Characterization) to verify the suitability of the geology beneath the Bruce nuclear site to safely host the DGR was completed in July 2010.

Safety Assessment (Overview)

The safety of the DGR during the operational phase (pre-closure) and over the long-term (post-closure), after operations have ceased and the facility has been decommissioned, was studied.

These technical studies contribute to the Environmental Impact Statement and the Preliminary Safety Report submissions supporting the site preparation/construction licence application.

A preliminary design for the DGR was completed in May 2010. This work updates and advances previous conceptual design work completed in 2008. The scope of the work included all aspects of the DGR, including construction, the receipt of waste from the Western Waste Management Facility (WWMF) and nuclear generating stations, and the emplacement of the waste in the DGR.

The surface features of a DGR.

The surface features of the DGR include the main shaft, ventilation shaft, waste rock management area and various ancillary facilities. The main shaft area will have a headframe equipped with a hoist to handle a 40-tonne payload, a waste package receiving building, and buildings housing equipment to heat air to be delivered underground.

The underground layout of the DGR.

The underground layout of the repository includes two vertical shafts centred on a service area. Two panels of emplacement room extend from the underground service area where the latter area provides space for smaller ancillary rooms to house services, and administrative and maintenance activities.

Vertical shafts in the DGR.

Shafts, access tunnels and emplacement rooms will be excavated by controlled drill and blast methods.

Additional project documents

Historical DGR project documents have been provided for historical reference purposes only, including:

  • Geoscience Reports
  • Safety Assessment Postclosure Documents
  • Site Characterization Technical Reports
  • Historical Project Documents

These documents and reports are available on the OPG Document Archive.

DGR project development