So, due to this crazy heat wave, the great lakes are all pretty warm (with the exception of Superior). This of course means any thermal power plants that is using these bodies of water for cooling are going to be impacted.
Ontario has three nuclear power plants that use the great lakes as their cooling source:
1. Bruce Nuclear, the world's largest NPP at 6,430MW (presently) and consists of 8 units spread over two packs of 4, sites A and B. It is located on the shores of Lake Huron.
2. Darlington Nuclear, a single 4-pack of 3,512MW located on Lake Ontario
3. Pickering Nuclear, two 4-packs, but two units are shuttered, so 6x units totalling 3,100MW located on Lake Ontario
Lake Ontario is of course downstream from the other lakes, and also significantly smaller than Huron. This appears to be having an impact on output:
If we look at Darlington units 1 and 2, these are 878MW nominal units. Contrast those to Bruce B unit 7 at 822MW and we can see how much of a difference lake temperature can have on output. Pickering output is also down, and proportionally, even moreso than Darlington, for the same reason. Overall, Darlington output is down 167MW right now, which isn't a lot in the big scheme of things, but still worth mentioning. I've never seen a unit at Bruce produce more than a unit at Darlington, so this morning, observing just that, was a first for me.
I refer to Bruce Unit 7 as a rock star, because it consistently produces much higher than nameplate. But it is obvious that Lake Huron temperatures and larger sink capacity have a decided advantage when conditions are as they are now.
For those interested in why Pickering output would be more impacted than Darlington, the inlet/outlet arrangements at all three plants, which I've mentioned in a previous thread, are different.
Pickering: Its inlets are directly on the front of the plant, outlets are on the side.
Bruce A/B: Its inlets are offshore (conduit that runs along the bottom for each 4-pack out into the lake), outlets are at the shore
Darlington: Its inlet is roughly 1km offshore similar to Bruce, outlet diffuser is also offshore, run at an angle and distanced downstream from the inlet
So Pickering would be ingesting the warmest water of the group (and can also be impacted by algae blooms) and Darlington and Bruce are simply limited by overall lake temperatures. Current temps offshore from Toronto are 25.5C, whereas Huron is 17C near Bruce.
For those wondering about the absent units:
- Bruce 1 just set a site record of 693 days continuous operation and went down for what appears to be an unplanned maintenance outage
- Bruce 6 is offline for the next two years for refurbishment.
- Pickering 8 is down for a scheduled maintenance outage and I expect will be back soon.
Darlington 1 is currently well on its way to beat the world operation record of 940 days, it hit 895 days yesterday.