Near Surface Disposal Facility

The Near Surface Disposal Facility will contain only low-level waste.  The classes of radioactive waste in Canada are determined by the Canadian Nuclear Safety Commission with information available here, on their website.  These waste classes are also consistent with definitions of the Canadian Standard Association (CSA).

Low-level waste contains primarily short-lived radionuclides and restricts the amount of long-lived radionuclides thus requiring isolation and containment for periods of time up to a few hundred years. The engineered containment mound design life of 500 years has been established to meet the required time period to allow for radiologic decay of the waste inventory.

Low-level waste includes items such as soils from remediation activities, demolition debris from decommissioning work and general trash such as used personal protection clothing or equipment.  These items are considered low-level waste as they have become contaminated at some point with low levels of radioactivity.  Low-level waste mostly contains short-lived radioactivity (thus decays relatively quickly) and can be safely handled with limited precautions.

An estimation of the total inventory is required to inform the safety assessments where the inventory is tested against selected scenarios to determine the long-term consequences of the proposed facility.  It also informs design criteria such as the Waste Water Treatment Plant.

The reference inventory below establishes a representative radionuclide inventory by extrapolating waste already currently in storage, as well as waste forecasts from environmental remediation projects and decommissioning projects data to an assumed total volume of the NSDF at time of closure.  All waste that is expected to be generated is meticulously described, or “characterized” before its generations to ensure the cumulative total inventory of NSDF is tracked against the reference inventory.

NSDF Reference Inventory at Closure

CNL employees live along and utilize the Ottawa River and its protection is as important to us as it is to you.  We are taking the time to ensure the design of the facility is robust enough to contain the waste under all contemplated environmental conditions.As part of the ongoing federal environmental assessment, CNL is providing the necessary evidence and the science-based explanation that supports placing the facility at the Chalk River location. This includes providing details on how we will control and treat any liquid effluent discharges.

Controls will be in place to minimize the generation of waste water.  A state of the art waste water treatment plant has been designed to remove both radiological and chemical contaminants.  CNL has performed pilot testing of the proposed wastewater treatment process utilizing simulated waste water representative of what we expect to collect and treat when the NSDF is in operation.  Through pilot testing we have demonstrated that we can achieve the effluent discharge targets that are protective of the public and the environment.  Furthermore, the plant is designed for batch releases, which means all liquid effluent must be sampled and proven to meet our targets before discharge.

This short conceptual video explains the process in more detail.

CNL has a comprehensive environmental and effluent monitoring program in place which includes monitoring of the Ottawa River water quality and fish.  CRL’s Annual Environmental Monitoring summarizes monitoring activities regularly conducted on various sources, including ambient air, surface water, vegetation, soil and sediments, and game animals, at various locations on and off the CRL site.  This environmental and effluent monitoring program will be expanded to include the NSDF waste water treatment plant effluent, surface water in the Perch Lake Basin, and groundwater to confirm performance of the engineered containment mound and ongoing monitoring of the Ottawa River.

When the draft EIS was submitted, CNL had completed the preliminary design of the NSDF. Since then, CNL has continued development of the design of the engineered containment mound, waste water treatment plant and supporting facilities. While the overall design has generally remained the same, several improvements have been made in many cases as a result of the decision to include only low-level radioactive waste, but also in response to valuable public and Indigenous input.

A number of comments were received questioning CNL’s confidence in the 550 year design-life of the engineered containment mound, a key component of which is are the High Density Polyethylene (HDPE) Geomembranes (GMB). Over the past three years, Dr. Kerry Rowe, a globally recognized expert in geomembrane systems based at Queens University has undertaken testing of the NSDF geomembrane and provided the scientific evidence to demonstrate with confidence that 550 year service-life will be met.  Methods for testing and data analyses were performed in accordance with applicable standards and have been published in a number of peer-reviewed journals.

To ensure the integrity of the HDPE materials and quality of installation, the project will apply a Construction Quality Assurance (CQA) program. The CQA Program will include confirmatory tests and inspection by qualified personnel prior to and during liner installation. The design also includes systems to monitor and detect any leakage.

In 2019, Dr. Rowe presented the findings of this study at a public event in Deep River.

As the owner of the CRL site and of the associated liabilities, Atomic Energy of Canada Limited (AECL) – a federal Crown corporation – will ensure that the site is safely managed and controlled for as long as necessary.

Other disruptive environmental events have been further analyzed in the safety assessments, considering both during the operational phase and post-closure.  This includes:

Earthquakes

The analysis has shown that the design of the engineered containment mound is robust and can with stand a 1:10,000 year earthquake.

Design changes to the engineered containment mound have been made to mitigate liquefaction potential. A replacement of the liquefiable soils with graded granular material from the bedrock excavation at site was considered as an optimal solution and included in the design of the engineered containment mound.

Tornadoes

The design of the waste water treatment plant has been made more robust to withstand potential tornadoes and high winds.

Precipitation

The design basis increases the capacity for the equalization tanks for the waste water treatment plant to accommodate for 100 year back to back storm events.

Flooding

The base of the proposed NSDF is located approximately 163 metres above sea level, which is approximately 50 metres above the current water levels of the Ottawa River. Local residents can be assured that the proposed site is situated well outside of a flood plain.

The Ottawa River posed no flooding threat to the Chalk River Laboratories site or its operations during the 2019 high-water conditions, nor would it have impacted the NSDF.

The EIS has an expanded Alternative Means section to better clarify the process that was followed to determine the NSDF location and design features.  Based on questions and comments received, a summary of some of key information is provided below.

Why the Chalk River site?

Chalk River Laboratories is the most suitable host site as more than 90% of the waste to be managed in the NSDF is already on the CRL site. This location for the facility avoids the time, cost and risk in transporting the waste to another location (an effort which would require ~ 45,000 transport truck trips) and reduce the unnecessary generation of tons of greenhouse gas emissions.

Why the East Mattawa Road Location on the Chalk River Site?

Fourteen potential sites within the Chalk River Laboratories (CRL) site were initially screened against mandatory criteria such as minimum area, access to power, water and gas.  Sites that passed the first review were further evaluated using a number of exclusion criteria, such as the floodplain, geotechnical considerations and presence of species at risk. Based on this review two candidate sites were identified for further evaluation. Both sites were technically feasible, however they differed in relation to monitoring complexity, lifecycle costs and the potential for environmental impacts.

The chosen East Mattawa Road (EMR) site is closest to the CRL main campus and therefore closest to the mandatory support services (e.g. electricity, water, heat). It is located within the Perch Lake drainage basin (Figure 2), which has been impacted by other historic waste management practices. Groundwater flow and contaminant migration at CRL site has been studied for over six decades and the Perch Lake Basin is well understood, better enabling CNL to mitigate any potential impacts from the NSDF facility.

Placing the NSDF at the EMR site allows us to consolidate it within an area that is currently affected by historic and ongoing operations. The Alternate site is in a “greenfield” area, which means it is an unaffected, natural site. There are no pre-existing plumes or contamination from waste storage in the vicinity of the Alternate site.  CNL and AECL would prefer to retain the Alternate site as a greenfield area, providing protected habitat for species at risk such as the Blanding’s Turtle and bats.