A radiological accident involves the release of radioactive materials outside the containers or facilities designed to house them. Such an accident could occur if there was a complication during the transport or use of radioactive material for medical or industrial purposes, or a serious operational problem at a nuclear facility.

In Canada, the risk of a radiological or nuclear incident is very low because of the stringent controls that govern the transport and use of radioactive material.

What are the risks in Québec?

The Canadian Nuclear Laboratories in Chalk River are in Ontario, on the Ontario side of the Ottawa River, some 200 kilometres northwest of Gatineau and Ottawa. In the event of a radiological accident at those laboratories, several Québec municipalities on the territory of the Pontiac RCM (regional county municipality) could be affected to varying degrees. That is why protection measures have been implemented (French only) to protect the population, the bio-food chain and the environment.

Located in the Centre-du-Québec region, the Gentilly-2 nuclear power plant ceased operations in December 2012. The nuclear facility is no longer a danger for the neighbouring population since decommissioning in 2013.

What to do before

Prepare an emergency kit.

Find out about any facilities in your region that are a risk and the protection measures in place.

If you have iodine tablets at home, store them in a safe, temperate place (15°C to 30°C) not accessible to children and away from light and humidity.

In an emergency or disaster, you are the first person responsible for your safety (in French only), your family's safety, and the safeguard of your property. When disaster strikes, however, municipalities have a duty to help the people affected and take the necessary action.

When the scope of an event is beyond the capacity of a municipality, the Governement of Québec steps in (in French only) with its own resources to help get things back to normal, per the provisions of the Québec national civil protection plan.

What to do during

Take shelter inside a home and stay there as long as required by the authorities. Radioactive material released into the environment is invisible and odourless.

Close the doors and windows and turn off the ventilation, heating or air conditioning system. Rooms at the centre of the building or in the basement provide better protection.

Follow your municipality and Urgence Québec social media feeds and consult local media outlets for information about the current situation and steps to be taken.

Do not try to return home if you have taken shelter elsewhere; your safety will be ensured by the on-site personnel, by the police or by firefighters.

Do not pick up your children from school or the daycare centre; they are sheltered and safe where they are.

If a safe shelter is nearby, such as a home, do not take shelter in a car because a vehicle is not as effective as a building in protecting you from radioactive material.

If you have no other choice than to shelter in a vehicle, close the windows and do not turn on the ventilation. 

Iodine tablets

Iodine tablets are available to individuals who live near a nuclear site. Residents who live within a 9-km radius of the reactor stack of the Canadian Nuclear Laboratories in Chalk River have received these tablets.

When recommended the regional public health direction, take the iodine tablets according to the prescribed dosage. It is one way to reduce the danger of contamination. Taking iodine tablets saturates the thyroid gland with stable (non-radioactive) iodine. As a result, the thyroid gland can no longer absorb or retain radioactive iodine, which is then eliminated naturally by the body.

Iodine tablets only protect the thyroid gland against radioactive iodine. Their use is complementary to taking shelter, which protects the entire body from radiation.

There are very few individuals for whom taking stable iodine is contraindicated, except people with:

  • a known allergy to iodine (allergies to seafood or to contrast agents used for radiological examinations are not contraindications)
  • a thyroid disorder, such as hyperthyroidism, in association with a cardiac disorder
  • one of the following rare disorders: dermatitis herpetiformis, hypocomplementemic vasculitis, congenital myotonia, pemphigus vulgaris and tuberous iododerma

Secondary effects associated with taking iodine tablets are very rare. Mild and temporary discomfort may occasionally occur. In most cases those symptoms disappear without treatment.

What to do after

Follow the instructions of local authorities. If the situation requires it, these may ask you to:

  • prohibit the consumption of fresh food and water or certain outdoor activities.
  • order the preventive evacuation of a sector before the release of radioactive material, or the evacuation of a sector within the immediate vicinity of the accident, in the event of prolonged exposure to a radioactive release.

Follow the social media accounts for your municipality and Urgence Québec, and listen to local news for the instructions and recommendations to follow for a safe return to normal.

Keep an eye on how you and your loved ones are responding. Watch for the following:

  • Anxiety, distress or frequent crying
  • Apathy or lack of energy
  • Aggressiveness
  • Difficulty concentrating or confusion
  • Increased use of alcohol or drugs

Help is available. Professional social and psychological workers are available to provide support and counselling or refer you to the resources you or your loved ones need. Call Info-Social by dialling 811 and selecting option 2 to talk to one of them. It’s free, confidential and available 24 hours a day, 7 days a week.

For more information on what happens to people after a disaster and how to get help, see the Getting better following a disaster webpage. 

Last update: January 29, 2026

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