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Independent Environmental Monitoring Program: Gentilly site

Site name Gentilly site
Licensees

Canadian Nuclear Laboratories: Gentilly-1 (G-1)

Hydro-Québec: Gentilly-2 (G-2)
Facility name Gentilly 1 and 2 nuclear facilities
Facility location Bécancour, Quebec
Land acknowledgement The CNSC acknowledges that the Gentilly site is located within the traditional and unceded territory of the Abenaki people and the W8banaki confederacy and the traditional land of the Wendat.
Facility description

The 675 megawatt electric (MWe) G-2 nuclear power reactor was permanently shut down in December 2012. In December 2014, the reactor completed the transition to a safe storage state, with its fuel stored in used fuel pools (wet storage) or in CANSTOR modules (dry storage). In December 2020, the transfer of all irradiated fuel to dry-storage CANSTOR modules was completed. Ongoing activities at G-2 are aimed at reaching a safe storage state under surveillance.

Near G-2 is the 250 MW G-1 facility, which went into service in 1971 and produced power intermittently until 1979. Both G-1 and G-2 are solid radioactive waste and used-fuel dry storage facilities.
Environmental protection requirements In accordance with regulatory requirements under the Nuclear Safety and Control Act, all licensees must maintain a comprehensive environmental protection program to monitor and control nuclear and hazardous substances released from the facilities they own and operate. As part of every licensee’s environmental protection program, concentrations of contaminants in the environment must be determined and the potential exposure pathways to the public must be assessed and mitigated.

Our IEMP results from 2015, 2016, 2018, 2023 and 2024 are consistent with the results submitted by Hydro-Québec and Canadian Nuclear Laboratories, supporting our assessment that the licensees’ environmental protection programs are effective. The results add to the body of evidence that people and the environment in the vicinity of the Gentilly site are protected and that there are no anticipated health impacts from the operation of the facilities on the site.

Legend

Gentilly site

1 The < symbol indicates that a result is below the provided laboratory analytical detection limit.

2 N/A – not available.

3 For radiological parameters (expressed as Bq/L, Bq/kg or Bq/m3) where no federal or provincial guidelines exist, our screening levels were established based on conservative assumptions using CSA standard N288.1-20, Guidelines for Modelling Radionuclide Environmental Transport, Fate, and Exposure Associated with the Normal Operation of Nuclear Facilities. The screening level for a particular radionuclide in a particular medium (e.g., water, air, food) represents the activity concentration that would result in a dose of 0.1 mSv/year, a dose at which no impacts on human health are expected. For more information, please refer to the IEMP technical information sheet.

4 Tritiated water (HTO) is a radioactive form of water where the usual hydrogen atoms (H2O) are replaced with tritium. Elemental tritium (HT) refers to the radioactive form of hydrogen gas. Organically bound tritium (OBT) is tritium that is bound to an organic molecule, such as a carbohydrate, fat or protein.

5 For water samples, the results for non-radiological parameters are compared to the Canadian Council of Ministers of the Environment (CCME) Water Quality Guidelines for the Protection of Aquatic Life. Where no CCME guidelines exist, Health Canada’s Guidelines for Canadian Drinking Water Quality are used.

6 The screening level for a particular radionuclide in food represents the activity concentration in food that would result in a whole-body effective dose of 0.1 mSv/year to an individual, based on the ingestion exposure pathway. This aligns with the methodology in CSA N288.1-20. The dose of 0.1 mSv/year was chosen to align with the approach used by the World Health Organization and Health Canada for drinking water standards and it represents one tenth of the public dose limit. A conservative regional Indigenous diet, including the consumption rate, was used in the calculations.

7 The screening level for a particular hazardous substance represents the concentration of that hazardous substance that would have to be present in food in order for one tenth of Health Canada's total Tolerable daily intake (TDI) of the substance to be exceeded. A TDI is the amount of food that can be consumed over a specific period of time without significant health risks. The screening levels are based on one tenth of the TDI in order to account for exposure to the contaminants from multiple primary exposure pathways. A conservative regional Indigenous diet, including the consumption rate, was used in the calculations.

2024 results

The 2024 IEMP sampling plan for the Gentilly site focused on radioactive substances. A sitespecific sampling plan was developed based on the licensees’ approved environmental monitoring programs and our regulatory experience with the site. We endeavour to incorporate traditional Indigenous land use, values and knowledge by engaging with Indigenous Nations and communities on the sampling plan. More information on this engagement is provided in the “Indigenous Nations and communities’ participation” section.

In July 2024, we collected air, water, soil, sediment, sand, vegetation and food samples in publicly accessible areas outside the facility perimeter.

The levels of radioactivity measured in those samples were below available guidelines and our own screening levels. Our screening levels are based on conservative assumptions about the exposure that would result in a dose of 0.1 millisieverts (mSv) per year (one tenth of the regulatory public dose limit of 1 mSv per year). Measurements conducted by the IEMP to date have consistently found levels of radioactivity in the environment to be low and well within the range of natural background radiation levels. As a result, no effects on human health are expected.

2023 results

The 2023 IEMP sampling plan for the Gentilly site focused on radioactive substances. A site-specific sampling plan was developed based on the licensees’ approved environmental monitoring programs and our regulatory experience with the site. We endeavour to incorporate traditional Indigenous land use, values and knowledge by engaging with Indigenous Nations and communities on the sampling plan. More information on this engagement is provided in the “Indigenous Nations and communities’ participation” section.

In 2023, we collected air, water, soil, sediment, sand, vegetation and food samples in publicly accessible areas outside the facility perimeter.

The levels of radioactivity measured in those samples were below available guidelines and our own screening levels. Our screening levels are based on conservative assumptions about the exposure that would result in a dose of 0.1 millisievert (mSv) per year (one-tenth of the regulatory public dose limit of 1 mSv per year). Measurements conducted by the IEMP to date have consistently found levels of radioactivity in the environment to be low, and well within the range of natural background radiation levels. As a result, no effects on human health are expected.

2015, 2016 and 2018 results

All IEMP sampling plans for the Gentilly site focused on radioactive substances. A site-specific sampling plan was developed based on the licensees’ approved environmental monitoring programs and our regulatory experience with the site. We endeavour to incorporate traditional Indigenous land use, values and knowledge by engaging with Indigenous Nations and communities on the sampling plan. More information on this engagement is provided in the “Indigenous Nations and communities’ participation” section.

1 The reference samples are taken in a location where there is likely no potential for exposure from the operations of the nuclear facility. The reference location is chosen based on distance from the operation and on meteorological data such as predominant wind direction or precipitation (for airborne releases) and water current (for waterborne releases). This allows us to collect local data that is representative of the region around the facility. The data is then compared with sampling results. This is especially important when background data, guidelines or screening levels do not exist for a certain contaminant or medium in a certain region.

Indigenous Nations and communities’ participation

We have made it a priority to ensure that IEMP sampling reflects traditional Indigenous knowledge, land use and values where possible. In addition to conducting routine IEMP sampling activities, we seek input from local Indigenous Nations and communities on our IEMP sampling plans.

In advance of the 2024 IEMP sampling campaign around the Gentilly site, emails were sent to Indigenous Nations and communities with an interest in the facility to notify them of the sampling campaign and to seek input on the sampling plan. We invited suggestions for species of interest, valued components, and potential sampling locations where traditional practices and activities may take place.

We will continue to engage with interested Indigenous Nations and communities to ensure that IEMP sampling incorporates Indigenous knowledge, values and priorities in future sampling.

Focus on health

We review the results of public health reports and data, international publications, and at times conduct our own health studies to provide additional confidence that the health of people living near the Gentilly site is protected

The Institut de la statistique du Quebec (Quebec statistical institute) and the Registre québécois du cancer (Quebec cancer registry) collect information on the health of people living in Quebec, including in the Mauricie-et-Centre-du-Québec (MCQ) health region, where the Gentilly site is located. Diseases and risk factors are compared to other populations (including larger reference populations such as Quebec and Canada) to detect any potential health outcomes that may be of concern.

Like in the populations of Canada and Quebec, the most commonly diagnosed cancers in MCQ are lung cancer, breast cancer (females), prostate cancer (males) and colorectal cancer. Also similar to the populations of Canada and Quebec, lung, colorectal, breast and pancreatic are the leading causes of cancer deaths. The number of new cancer cases diagnosed and cancer deaths (for all cancer types combined, all ages, both sexes) has been increasing in Canada, Quebec and MCQ since the 1980s.

In 2003, the Régie régionale de la santé et des services sociaux de la Mauricie et du Centre-du-Québec (Regional health and social services board of Mauricie and Centre-du-Québec) compared cancer incidence and mortality in the vicinity of the Gentilly site with the general population of Quebec between 1994 and 1998. The study concluded that there was no excess risk of cancer in the Gentilly area.

Health data often varies by region, and the opportunity to be healthy is not the same for everyone; it is affected by personal, lifestyle, social, economic, environmental and systemic factors.

Health status data for Indigenous Peoples is not reported separately by the Institut de la statistique du Québec or by the Registre québécois du cancer; however, the Institut national de santé publique du Québec (National public health institute of Quebec) provides Indigenous health research monitoring of public health issues relevant to Indigenous Peoples in Quebec.

A 2017 CNSC study on the health of people living near nuclear power plants found that all cancers for all age groups were similar between populations living near nuclear power plants and the provincial reference population. In particular, there was no evidence of increases in childhood leukemia. These findings are consistent with research studies conducted around nuclear power plants in other countries (i.e., the United Kingdom, France, Switzerland and Finland). This body of evidence demonstrates that people who live near nuclear power plants, such as the Gentilly site, are as healthy as the rest of the general Canadian population.

Based on levels of radionuclides in the environment; exposures to people living in the area; the current scientific knowledge about the sources, effects and risks of ionizing radiation; and relevant local, provincial and federal health data, we have not observed and do not expect to observe any adverse health outcomes related to the presence of the decommissioned G-1 and G-2 nuclear generating stations.

For additional information, please visit the following websites:

Conclusions

Our IEMP results from 2015, 2016, 2018, 2023 and 2024 are consistent with the results submitted by Hydro-Québec for G-2 and by Canadian Nuclear Laboratories for G-1, supporting our assessment that the licensees’ environmental protection programs are effective. The results add to the body of evidence that people and the environment in the vicinity of the Gentilly site are protected and that there are no anticipated health impacts from the operation of the facilities on the site.

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