An article from Detroit mentioning the Bruce 'Leaky Cauldron' (yeah Potter!). I especially like the OPG response, citing the 'superior geology' that will stop all chance of leaks.
But anyway, you can locate near the lakes, or right under them, if you have a diffusion situation, which means extremely tight and impermeable rock.
ps. I was just thinking that when the Sir Adam Beck tunnel boring machine finally gets hopelessly stuck, the uncompleted tunnel would make a great nuclear waste disposal facility! Just backfill the tunnel with nuclear waste! That Queenston shale is very impermeable, even though it doesn't hold up, but the rock squeeze will just seal up the waste forever!