Canadian National Report for the Second Extraordinary Meeting of the Convention on Nuclear Safety – Executive Summary
Canadian National Report for the Second Extraordinary Meeting of the Convention on Nuclear Safety (PDF, 95 pages, 1.07 MB)
In conformance with article 23 of the Convention on Nuclear Safety
This report describes the assessments and measures Canada has taken to address the lessons learned from the Fukushima nuclear accident in March 2011. The information is segmented into six general topics identified by the General Committee of the Convention on Nuclear Safety (CNS) for all national submissions for the Second Extraordinary Meeting, namely: external events, design issues, severe accident management (onsite), national organizations, emergency preparedness (offsite), and international co-operation. In addition, appendix A presents a detailed table of actions being taken by the nuclear power plant (NPP) licensees and by the national nuclear regulator, the Canadian Nuclear Safety Commission (CNSC).
Immediately following the accident, the CNSC launched a national review of nuclear facilities and confirmed their ability to withstand external events, such as large earthquakes and floods. The CNSC first directed licensees to review initial lessons learned from Fukushima, re-examine the safety cases of NPPs, and report on implementation plans for short-term and long-term measures to address any significant gaps. The CNSC then established a Task Force to evaluate the implications of Fukushima on Canadian NPPs and review the NPP licensees’ submissions. The Task Force documented its findings, which can be categorized into four groups:
- defence in depth
- emergency preparedness
- regulatory framework and processes
- international co-operation
Based on a report completed by the Task Force, the CNSC created a comprehensive Action Plan to apply the lessons learned to the safe operation of Canada’s NPPs. The CNSC Action Plan identifies specific deliverables to be completed by the end of 2015, including measures to prevent and mitigate impacts from “beyond-design-basis accidents”, which are of very low probability but have potentially high consequences. This Action Plan has been subject to public consultation and external reviews.
In responding to the lessons learned from the Fukushima nuclear accident, Canada’s NPP licensees have clearly demonstrated their continued commitment to safety and have taken immediate action to confirm the robustness of their NPPs. Guided by the Task Force’s safety review criteria, they initiated improvements that will further enhance safety and accelerated others that were already in progress. The licensees have participated in national and international activities and are taking concrete steps, individually and collectively, to address findings. In addition, most licensees have already implemented significant safety upgrades, as part of refurbishment activities. These upgrades were identified through integrated safety reviews that were conducted against modern standards and practices, and they have been proven to be beneficial during the Fukushima crisis.
Summarized below are the findings of Canada’s national post-Fukushima review and the actions being pursued to further enhance the safety of NPPs and reduce the risks associated with their operation.
External events – The CNSC review reconfirmed the robustness of Canadian NPPs to withstand large external hazards. Conditions taken into consideration at the time of design are site specific, but generally include extreme weather conditions, floods, earthquakes and explosions. All Canadian NPPs are located far from tectonic plate boundaries, making the risk due to a major earthquake, and consequential tsunami, negligible. As part of the Action Plan, NPP operators are conducting comprehensive reassessments of site-specific external hazards by using modern tools, including probabilistic safety assessments. Although gaps are not expected, any that would pose a risk to safety will be addressed promptly.
Design issues – The designs of Canada’s NPPs (all CANDU reactors) include several features that prevent accidents and can help mitigate impacts should an accident occur. They have a large inventory of cool water surrounding the fuel, capable of providing passive cooling, such that adequate time is available for long-term mitigation of accidents. Also, CANDUs have two groups of independent, physically separated, and diverse backup power and cooling water systems. In all, adequate time would be available for long-term mitigation of a beyond-design-basis accident. This conclusion also applies to irradiated fuel bays, which have been assessed to be seismically robust with diverse means available for adding water. Although the risk of an accident is very low, NPP operators are implementing several modifications to improve their NPPs’ ability to withstand a prolonged loss of power and other challenges such as the loss of all heat sinks. The CNSC is taking action and revising regulatory requirements, including those for the design of new NPPs.
Severe accident management (onsite) – Adequate provisions for severe accident management (SAM) and recovery are in place at all NPP sites. Severe accident management guidelines (SAMG) have been largely implemented at all plants except one, where a shutdown for refurbishment is planned for later in 2012. All licensees reviewed their procedural guidance and design capabilities to cope with accidents, including those involving significant core damage. Canada’s national Action Plan nevertheless identifies a number of enhancements, which are currently being pursued by licensees. In the short term, licensees are acquiring emergency equipment, such as portable pumps and generators, to be stored onsite and offsite, to ensure reactors can be brought to a safe shutdown state in any credible accident scenario. Industry is working on modelling enhancements for beyond-design-basis accidents, including for multiunit NPPs. The CNSC will also be making changes to its regulatory framework to reflect the need for SAM programs.
National organizations – Several national, industry-driven organizations are involved in nuclear safety and the response to Fukushima. These include the Canadian Standards Association (CSA) and the operators’ CANDU Industry Integration Team (CIIT), which helps them coordinate their response to Fukushima. CANDU Energy – the original designer and vendor of the CANDU technology – is another key industry participant. The CNSC is Canada’s sole national and independent nuclear regulator; it received two distinct assessments of its own response to Fukushima – a follow-up Integrated Regulatory Review Service (IRRS) mission to Canada and the External Advisory Committee. Two other national government agencies, Health Canada and Public Safety Canada, also play important roles in federal emergency response, and are making progress in updating emergency plans.
Emergency preparedness (offsite) – In its review, the CNSC confirmed that emergency preparedness and response measures in Canada remain adequate. Nonetheless, in order to see where improvements could be made, the CNSC called for a review of emergency plans and capabilities to respond effectively in a severe event and/or multi-unit accident. The conduct of regular and challenging large-scale drills has been one of the key measures identified in the Action Plan. Provincial agencies, which have the lead for offsite emergency preparedness in Canada, are participating in this review. Both Public Safety and Health Canada are reviewing the national-level oversight of offsite nuclear emergency plans, programs and performance. Licensees are also working on improvements to offsite emergency preparedness, related to such areas as severe events, source term estimation, dose modelling and radiation monitoring. The CNSC is also preparing amendments to, among others, the Class I Nuclear Facilities Regulations to require submission of applicable offsite emergency plans, and to the Radiation Protection Regulations to further clarify emergency dose limits.
International co-operation – The CNSC has memoranda of understanding in place with most international stakeholders and also chairs the CANDU Senior Regulators’ Meeting. Canada also has excellent working relationships with the United States for the exchange of nuclear regulatory and emergency preparedness expertise. NPP licensees are involved in various international groups with a focus on nuclear safety, including the CANDU Owners Group and the World Association of Nuclear Operators. Canada is an active participant in the activities of the International Energy Agency and fully supports the IRRS program and missions. The conclusion of Canada’s review is that NPPs in Canada are safe and the risk posed to the health and safety of Canadians or to the environment is very low. Additional safety improvements have been systematically identified to address the lessons learned from Fukushima. These, when completed by both the licensees and the CNSC, will render NPPs in Canada even safer, reducing the associated risk to as low as reasonably practicable.
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