Stricter limits, smaller footprint, greater protection

The CNSC is proposing changes to the regulation of environmental releases

March 9, 2012

The Canadian Nuclear Safety Commission (CNSC) recently issued a call for public comments on its latest discussion paper on one of the most sensitive topics when it comes to industrial activities: environmental releases.

In the paper, the CNSC is proposing a modernized and consistent approach for determining release limits and action levels. The limits themselves may vary from facility to facility.

Bruce Nuclear Generating Station near Kincardine,
Ontario.

Release limits – which have always been included in CNSC licences – are crucial; they ensure that licensees protect human health and the environment from the potential harmful effects of their nuclear activities. These limits are also in place to ensure that the most appropriate pollution prevention and control technologies are adopted. This second objective is the focus of the CNSC recommendations.

“Our proposal's end goal is to drive pollution prevention to further minimize the environmental footprint of the activities taking place at nuclear facilities” said Dr. Patsy Thompson, Director General responsible for radiation protection and the environment at the CNSC. “It's about aligning our norms with the best national and international practices, harmonizing approaches between licensees, and ultimately driving continuous improvement in the sector we regulate.”

The proposal addresses all main contaminants, not only radionuclides. It would apply to all major nuclear facilities, like nuclear power plants, uranium mines and mills, uranium processing plants and waste management facilities.

The CNSC also wishes to revise the way in which action levels are established. Action levels represent a fraction of the release limits, and trigger automatic regulatory reporting if reached. They are in place to ensure that operators are maintaining constant control over releases at levels below their licence limits.

In the past, limits were based on the public dose limit of 1 mSv/year, which ensured the protection of health but did not include a focus on reducing pollution. In the new proposal, the limits would be based on a substantially lower dose of of 0.05 mSv/year for existing facilities with a design objective of 0.01 mSv/yr for new nuclear power plants. It is important to note that the public dose limit itself is not changing.

“We know that limits set on the proposed dose constraint of 0.05 mSv/yr will be effective as a means to prevent pollution and are achievable, based on historical release data” said Dr. Thompson. Over the past 10 years, the public dose from actual releases at Canada's nuclear power plants has ranged from 0.01 mSv/yr to 0.045 mSv/year.