Understanding and Assessing Impacts
Climate change is expected to disrupt thermal generators around the world in multiple ways. The impacts of today’s climate on nuclear power-plant cooling are already felt in Canada. For example, one of the nuclear stations operated by Ontario Power Generation (OPG) on the shores of Lake Ontario is directly affected by seasonal climate fluctuations and their impacts on lake conditions, because it draws its water from the surface of the lake. The Pickering station recently experienced several episodes of unwanted blooms of Cladophora algae during periods of sustained high lake temperatures. In 2007, OPG had to shut down one of its reactors and reduce its power output because of clogged screens and filters in one of its water intakes. Climate change can also favour aquatic invasive species, such as zebra mussels, which stick to, and clog, water intakes and outlets. Overall, the risk to OPG facilities of higher water temperatures and other climate related hazards remains relatively low because its nuclear stations have large design margins. However, should new nuclear or thermal power-generation assets be commissioned in Canada, rising temperatures could become an important design consideration for cooling systems.