Overview: New Nuclear at Darlington

Ontario Power Generation [OPG] is seeking approval to build a new nuclear power plant on the shore of Lake Ontario. The new plant will include up to four new power reactors. It is planned for a small piece of land wedged between the existing Darlington nuclear plant and St. Marys Cement’s large Bowmanville quarry in Clarington (just east of Oshawa).

The proposal is has been a major file for Lake Ontario Waterkeeper since 2007 due to the potential for extensive ecological damage to the lake.

The “once-through cooling” system planned for the new plant will suck in 15 million litres of water every minute.

Between 23,000 and 46,000 fish will be sucked against the intake screens and killed every year.

Approximately 26 million fish eggs and 2 million fish larvae will be killed in the pipes by heat or biocides (chemicals used to keep the pipes clear by killing aquatic life).

Once-through cooling spits heated water and chemicals back into the lake, harming fish and altering fish habitat.

Nuclear plants need cooling systems to prevent overheating, but many different cooling technologies exist. Once-through cooling is the most ecologically destructive of all cooling options. The technology is so harmful, it is banned for new plants in the United States.

Alternatives like dry cooling or cooling towers could drastically reduce the number of fish killed (by up to 90%). OPG insists that once-through cooling will be built at Darlington, predominantly to save money and avoid cooling towers that could be seen from nearby highway 401.

The chosen site is wholly inappropriate for a new nuclear plant. It is too small to fit four new reactors with cooling towers. Even if only two reactors are built, OPG will need to fill in the lake to enlarge the property. The site is in the midst of a growing population centre, close to a rail line and busy highway 401, and on the shore of the drinking water for nine million people.

For decades, nuclear power plants and fuel manufacturers have dotted the Lake Ontario shoreline. Their industrial footprint has contributed to the overall decline of Lake Ontario, which now has the worst coastal wetland health on the Great Lakes. A new plant would extend this legacy by another 130 years, threatening the public’s right to a swimmable, fishable, drinkable lake.