Ontario Power Generation
Frequently Asked Questions
Q: Who regulates OPG’s Nuclear Facilities?
A: OPG’s nuclear reactors are licensed and regulated by the Canadian Nuclear Safety Commission (CNSC). The CNSC establishes stringent operating parameters, which include limits for the radiation dose that members of the public may receive as a result of reactor operations. Radioactivity release limits for the effluents from each nuclear plant are derived from these dose limits. As well, a number of municipal, provincial, and federal agencies provide both oversight and reporting checks on our operations.
Q: How do we know what is being released from the nuclear stations?
A: Nothing is more important than safety to our staff, the public, and to the environment. It guides our focus for every task we do, each and every day. Effective monitoring of our station operations assures us and the public that we are operating well below our operating licence allows for emissions. In fact, as a company, we voluntarily set more stringent operating targets for ourselves than others ask of us. The design of OPG’s nuclear plants minimizes these releases through robust safety equipment, high international standards when it comes to our operating procedures to protect the health of our employees and the public, and multiple safety barriers including a one kilometer exclusion zone separating the public from the reactor building.
The data from these tests is compiled and provided to the public in annual reports. Preparation of these annual reports is a regulatory requirement of the Canadian Nuclear Safety Commission. For copies of our recent reports released to the public as required by the CNSC click here.
Q: What is the REMP program?
A: Airborne and waterborne effluents from the Pickering and Darlington nuclear stations are routinely monitored for radioactivity. The 2006 radioactivity levels in all effluents remained at a small fraction of the regulatory limits.
Each year OPG conducts radiological environmental monitoring programs (REMP) in the vicinity of our Darlington and Pickering Nuclear Power Stations to determine the radiological impact to the public resulting from the operation of these stations. These annual reports contain the results of extensive monitoring programs, which include concentrations of radionuclides in the air, water, soil, sediments, vegetation and fish samples. These samples are taken in the vicinity of Darlington and Pickering, and at provincial locations to determine naturally occurring radiation levels in areas away from the influence of nuclear stations. Preparation of these annual reports is a regulatory requirement of the Canadian Nuclear Safety Commission.
“Critical Group Dose” is a method used to measure radiation exposure to members of the public who live in close proximity to our nuclear stations. Critical Group Dose calculations focus on the public’s actual eating and drinking habits as obtained from survey data. The program is referred to as REMP – Radiological Environmental Monitoring Program.
The survey includes six age groups: three month old nursing infant, one-year old infant, children aged 5, 10, 15 years and adult. Critical Group Dose is measured in microsieverts, an international unit of measurement.
Q: How much radiation is being released by the nuclear stations?
A: In 2006, the microsievert* Critical Group Dose levels were 2.8 and 1.1 for Pickering Nuclear and Darlington Nuclear respectively. This is substantially well below the limit of 1,000 microsieverts set by the Federal Government and well below our own internal OPG target of 10 microsieverts.
The average person receives 1,770 microsieverts per year from non-nuclear sources, including the radiation from the sun, the earth’s crust, natural materials in our bodies, building materials, consumer products, and for some X-rays, and jet travel.
As further comparison, sleeping next to someone for eight hours results in 20 microsieverts (exposure comes from the naturally radioactive potassium in the other person's body). An airline trip to the south (four hours each way for a total of eight hours in an airplane) would result in 80 microsieverts.
***Definition – Microsievert – a measurement of radiation dose by an individual. (Sievert is a measure of dose – 1 mirosievert is one one million of a sievert.)
Healthy and Safe
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