How did you arrive at that number? Going by one of the comments in this thread it would be 760 TBq of tritium, which would require 76,000,000 m^3 of water to get below the 10 Bg/m^3 limit of the world health organization.

(granted I don't know where the 760 TBq figure came from either, I'm just trying to get some clarity)

The process for releasing typically dilutes to a standard level before releasing into the ocean/ other water way. So when it's released, it's already at a level you could swim in (drink?), there's no process for it accumulating into a more concentrated form in the ocean, and it has a half-life of 12 years.

Ah I see I may have misinterpreted the comment. I took it to mean it should somehow fit in a regular size swimming pool.

As far as I can figure out it probably does not.