The Darlington New Nuclear Project (DNNP) is a proposal by Ontario Power Generation for the site preparation, construction, and operation of up to four new nuclear reactor units for the production of up to 4800 MW of electrical generating capacity. The site was selected by the Ontario Government and is located at the existing Darlington Nuclear site, which is located on the north shore of Lake Ontario and about 70 km east of Toronto, Canada. The regulatory process for the project began in September 2006 and has included the completion of a comprehensive Environmental Assessment (EA), the submission of a Licence to Prepare Site Application, and a three-week public hearing from March 21 to April 8, 2011.
This paper provides an overview of various site evaluation and safety studies that were performed in order to demonstrate that the DNNP site meets the Canadian regulatory requirements. The site evaluation studies are also consistent with the principles in the IAEA document NS-R-3, “Site Evaluation for Nuclear Installations” and its associated guides. Accordingly, the site evaluation studies considered the following hazards: extreme meteorological events, flooding hazards, seismic hazards, geotechnical hazards, external human-induced events, and potential dispersion of radioactive material with off-site dose consequences. These hazards were assessed in terms of risk to the new nuclear units and ultimately to the public and the environment.
Since a reactor technology has not yet been selected for the DNNP, a multi-technology approach was followed for both the EA and site evaluation studies. This involved the use of a bounding Plant Parameters Envelope (PPE), similar to the US-based PPE approach, encompassing the following reactor designs: the US EPR (1580 MWe), the AP1000 (1037 MWe), the ACR-1000 (1085 MWe), and the Enhanced CANDU 6 (740 MWe).
Additionally, to assess the impact of protective measures on the local population (e.g., in terms of temporary evacuation), bounding source terms were derived based on the regulatory safety goals for both Small Release Frequency and Large Release Frequency. These generic source terms are expected to bound the releases from any credible accidents, for any reactor designs considered licensable in Canada.
In each of the hazard areas, the risk was determined to be acceptably low or could be reduced to an acceptable level through design mitigation. The overall conclusion is that the DNNP site is suitable for the new nuclear units.