Radioactivity
Radioactivity is a natural phenomenon. For example, the sun, soil and certain types of materials emit “radiation” that occurs naturally.
In the Outaouais, the risks are related to the Chalk River Canadian Nuclear Laboratories (CNL). In the event of an emergency at CNL, the amount of radiation emitted into the environment would most likely not have an immediate health effect. However, the risk of developing cancer in subsequent years could increase very slightly, depending on the type and amount of radiation received. The presence of radioactive iodine in accidentally released materials could contribute to an increase in the number of cases of thyroid cancer, especially among children.
However, these health risks will be significantly reduced if the safeguards in the nuclear emergency plan are implemented in a timely manner.
Canadian Nuclear Laboratories 9 km primary zone protection measures
The 9 km area around the CNL reactor stack is the “primary” zone for contingency planning in the event of exposure to a “plume” of radioactive dust. On the Québec side of the Ottawa River, part of the St-Patrice Controlled Zone (ZEC) located south of Greer Lake is included in this primary zone. Two bodies of water primarily affected, namely Lac Esher and Lac à l’Oiseau.
Residents in the primary zone are the subject of an information campaign and a preventive pre-distribution of potassium iodide tablets. In the event of a general emergency at the Chalk River Laboratories, a warning signal (siren) will alert residents and all other individuals present in the primary zone of the St-Patrice ZEC. Authorities will also inform the public through various means, including radio (Pembroke stations Star 96 FM or CIMY 104.9 FM) or by patrols inside the ZEC.
Upon hearing the alert, seasonal residents who have access to a cottage or other dwelling will need to follow the instructions below:
- Take shelter in their homes, close the doors and windows, and turn off ventilation, heating or air conditioning systems. Please note that rooms located in the centre of the building or basement provide better protection.
- If, however, a car is required to travel to a sheltered location, close the windows and turn off the ventilation system.
- Keep pets indoors.
- Listen to the radio (Pembroke stations Star 96 FM or CIMY 104.9 FM) for the latest instructions from public authorities, such as stay indoors, take potassium iodide tablets according to the dosage indicated on the box, or evacuate their homes according to specific procedures.
Daily or occasional users of the ZEC who do not have a cottage or seasonal dwelling will receive written information on what to do in the event of an alert by the authorities each time they enter the zone. In the event of an alert, daily or occasional users must:
- Cover up with long clothing and a hat if possible;
- Proceed calmly to their vehicle and close the windows and turn off the ventilation system if possible;
- Leave the area and go to the ZEC reception centre;
- Follow the instructions of the public authorities provided by the reception centre attendants.
Boaters using the Ottawa River when the CNL siren sounds should take the following steps:
- Leave the area immediately, travelling upwind if possible.
- After landing, proceed to the nearest building.
- Listen to the radio (Pembroke stations Star 96 FM or CIMY 104.9 FM) to find out the instructions given by the public authorities.
Please note: the siren on the CNL site is tested on the 4th Sunday of every month at 2 p.m.
Canadian Nuclear Laboratories 50 km secondary zone protection measures
The secondary zone of the CNL is the planning zone for ingestion. In Québec, the 50 km secondary zone, measured from the CNL stacks, includes the following municipalities:
- Sheenboro
- Rapide-des-Joachims
- Waltham
- Iles-aux-Allumettes
- Chichester
- Mansfield-et-Pontefract (western part)
In the event of a severe accident at the CNL site, people in the secondary zone will be notified by the public authorities of the protective measures to be taken. These measures will aim to protect the population from contamination of the environment (soil and sources of drinking water) and the food chain. Avoidance advisories for drinking water or locally produced foods may be issued as required.
Potassium iodide tablets
Taking potassium iodide tablets avoids the harmful effects of exposure to radioactive iodine that can be released into the environment during a severe nuclear accident. Potassium iodide tablets help to “fill” (saturate) the thyroid gland with “stable,” non-radioactive iodine. Tablets therefore help prevent the thyroid gland in exposed individuals from absorbing radioactive iodine. This measure is particularly important for young children and pregnant women (fetuses) as they are at the highest risk of developing long-term thyroid cancer from exposure to radioactive iodine. When potassium iodide tablets are taken before or within hours of a nuclear accident, the risk of developing thyroid cancer is greatly reduced.
Potassium iodide tablets will be available in emergency situations for the people living near the CNL. It is important to note that the use of potassium iodide tablets should be recommended by public health authorities. It is therefore necessary to listen to authorities’ instructions through the media during an emergency situation.
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