Ottawa: Following the 2011 tsunami and nuclear accident in Fukushima, the regulator of nuclear facilities in this country put into motion a series of improvements to safety requirements that now apply to all major nuclear facilities in Canada. The Canadian Nuclear Safety Commission (CNSC) began the process by launching a review of all major nuclear facilities in Canada. The review, led by a multidisciplinary CNSC Task Force, was completed in 2011 and confirmed the facilities’ ability to withstand and respond to credible external events, such as earthquakes.
Following the review, the CNSC established a four-year action plan to strengthen the defenses at Canada’s nuclear power plants and further minimize risk. The action plan includes measures that improve emergency preparedness and the Canadian nuclear regulatory framework. The CNSC is also working to enhance its ability to communicate during an emergency. Both the Task Force Report and the Action Plan were subject to several rounds of public consultation, as well as two independent evaluations.
Some examples of the new requirements at nuclear facilities include the following:
• Acquiring additional emergency mitigating portable equipment, such as power generators and pumps, which can be stored onsite and offsite and used to bring reactors to a safe shutdown state, in the unlikely event of a severe accident (short term).
• Increasing capabilities to control hydrogen and other combustible gases (e.g., procurement of passive autocatalytic recombiners (PARs) and monitoring equipment to be installed in reactor buildings and spent fuel pool areas; PARs can prevent hydrogen concentration from rising to combustible or explosive levels (medium term).
• Preventing containment failure or maintaining integrity so as to prevent unfiltered releases of radioactivity resulting from an accident not previously considered credible (e.g., installing emergency filtered containment venting) (long term).
• Nuclear power plant operators are being asked to conduct a comprehensive review of onsite emergency capabilities. This includes assessments of arrangements in place for external support to be brought in onsite and of the primary and backup emergency response facilities. It also includes assessments of all emergency response equipment that requires electrical power to operate (e.g., electronic dosimeters, two-way radios).
The Action Plan identified further improvements to be made to existing regulations and supporting regulatory documents. These improvements include proposed amendments to the Class I Nuclear Facilities Regulations and Radiation Protection Regulations to integrate new requirements for emergency situations. The Action Plan also calls for additional studies, supported by state-of-the-art modeling tools, to analyze accident scenarios not previously considered credible, with special attention to multi-unit events, accidents triggered by extreme external events, and catastrophic spent fuel pool accidents.
In addition to the proposed changes to the regulations, the CNSC is also working on an “omnibus” project to amend documents on environmental protection, safety analysis and severe accident management. Revisions to documents that provide the CNSC's design requirements and site evaluation expectations are also being prepared. Finally, new documents are being developed for emergency preparedness and accident management.
The public will be consulted on all proposed changes to the regulatory framework through the CNSC's document development and consultation process. To comment on CNSC consultation documents, readers may visit www.nuclearsafety.gc.ca/eng/lawsregs/comment/index.cfm.