{"id":27944,"date":"2015-04-29T00:00:00","date_gmt":"2015-04-29T04:00:00","guid":{"rendered":"http:\/\/ashleydev.com\/2015\/04\/29\/when-is-the-best-time-to-take-a-nuclear-power-plant-offline\/"},"modified":"2020-08-27T11:38:49","modified_gmt":"2020-08-27T15:38:49","slug":"when-is-the-best-time-to-take-a-nuclear-power-plant-offline","status":"publish","type":"post","link":"https:\/\/cna.ca\/fr\/2015\/04\/29\/when-is-the-best-time-to-take-a-nuclear-power-plant-offline\/","title":{"rendered":"When is the Best Time to Take a Nuclear Power Plant Offline?"},"content":{"rendered":"

By Erin Polka
\n<\/strong>Communications Officer<\/em>
\nCanadian Nuclear Association<\/em><\/p>\n

What happens to greenhouse gas emissions when a nuclear power plant goes offline? Let\u2019s look at the Bruce Power complex in Kincardine, Ontario. On April 15, Bruce Power shut down the four reactors in its B building to enable a vacuum building outage<\/a> (VBO). The vacuum building, which is an essential safety feature, needs regular maintenance that should last about a month.<\/p>\n

Shutting down Bruce B means some 3,268 MW of generating capacity needs to be replaced with some combination of hydro, gas and wind. Which combination is better for the environment?<\/p>\n

Hydro capacity is highest in the spring, as winter snows melt and rivers run high. So it stands to reason that hydro power will make up for some of the shortage. (And, yes, the VBO\u00a0was timed to match the availability of hydro.)<\/p>\n

What about wind? Not as much help. Wind provides only four percent of Ontario\u2019s electricity on average. Whether it could provide more would depend on whether the wind blows longer and stronger. Maybe it will, and maybe it won\u2019t \u2013 hardly the reliability needed to replace the steady nuclear workhorse.<\/p>\n

And then there\u2019s gas. It can be fired up quickly and easily, it runs reliably, and it doesn\u2019t cost all that much more than nuclear power \u2013 about twice as much.<\/p>\n

In the best-case scenario, hydro would replace the power from the four Bruce B reactors. It\u2019s the best case because hydro, like nuclear, generates no greenhouse gases. But there\u2019s a problem. Hydro in Ontario is quite limited as a result of the province\u2019s geography, and the province lacks sufficient transmission lines to import replacement power from Quebec. Also, even if the lines did exist, Quebec doesn\u2019t have a spare hydro dam to match the output from the four reactors.<\/p>\n

The next-best scenario would use all the available hydro power, keeping cost and emissions down, and use gas for the rest. Very likely, hydro could replace half the nuclear energy from Bruce B, and natural gas would replace the other half.<\/p>\n

Is that a problem? After all, Ontario businesses and residents will still get steady, reliable electricity \u2013 just as they did with the Bruce reactors. But here\u2019s the thing \u2013 natural gas emits greenhouse gases, especially carbon dioxide, which is primarily responsible for climate change.<\/p>\n

\"Giraffes\"Replacing half the nuclear output with gas means the province\u2019s gas plants will emit an additional 295,095 tonnes of carbon dioxide. For perspective, that\u2019s the weight equivalent of about 300,000 adult giraffes.<\/p>\n

What else would produce 295,095 tonnes of CO2<\/sub>?<\/p>\n