You may want to take a look at this article
Experts fear giant ITER reactor will worsen looming shortage of tritium
I've read that, and yes, each CANDU unit produces ~1/2kg of tritium a year, we have 18 of them in Ontario. If ITER uses 1kg/year, as proposed, I don't see how that's an issue when Ontario's fleet alone produces 9x that.
Of course historically, tritium has been viewed more of a nuisance/waste product from CANDU's, which is why global stores aren't as high as one would assume based on the production numbers.
The article gets a few things wrong.
1. Half the CANDU's aren't retiring. At MOST, 6 of them will be retiring in 2025 unless we refurbish Pickering B.
2. There are a LOT more than 19 CANDU's.
There are 19 operating CANDU's in Canada. There are 31 globally.
- 2x CANDU 6's in China
- 3x in South Korea
- 2x in India
- 1x in Argentina
- 2x in Romania (and 2x under construction)
India also has their own (CANDU-derivative) PHWR program with 13 active units and several under construction.
Most CANDU's are presently being refurbished (and the Indian PHWR's require the same thing), which extends their life by another 30-40 years. This is not properly reflected in the article either.