Study of Consequences of a Hypothetical Severe Nuclear Accident and Effectiveness of Mitigation Measures Extended executive summary Introduction The Study of Consequences of a Hypothetical Severe Nuclear Accident and Effectiveness of Mitigation Measures is the result of a collaborative effort of research and analysis that arose out of the Commission's decision on the environmental assessment (EA) [...] Most importantly, it informs the public and other stakeholders of the possible consequences of a hypothetical severe nuclear accident, the effectiveness of emergency planning, and the inherent safety of Canadian nuclear power plants. [...] These EAs included those for the refurbishment and continued operation of the Darlington Nuclear Generating Station (DNGS); construction and operation of new nuclear power plants at Darlington; refurbishment and continued operation of the Pickering B Nuclear Generating Station; refurbishment and continued operation of the Bruce A Nuclear Generating Station; and the refurbishment and continued oper [...] The CNSC is mandated under the Nuclear Safety and Control Act to regulate the use of nuclear energy and materials to protect health, safety, security and the environment, to implement Canada's international commitments on the peaceful use of nuclear energy, and to disseminate objective scientific, technical and regulatory information to the public. [...] Study of Consequences of a Hypothetical Severe Nuclear Accident and Effectiveness of Mitigation Measures Figure 2.1: Barriers to release of radioactivity in a CANDU reactor The fourth barrier, called the containment, is the building that houses and protects the reactor.