[kenned3]

Your view really depends on the design.

CANDU (Canadian reactor design) is moderated via deuterium in which case there is a LOT of it circulating in the reactor core.

The heavy water is syphoned off to a tritium separation unit for recovery. With a market value of $30,000 a gram, there is a clear incentive to recover it ;)

[theluketaylor]

Some buddies who work on CANDU tell me they have tritium contamination everywhere as a result of this. From what they tell me it's not really a big safety issue, mostly more annoying than anything.

[PaulHoule]

It is annoying because it is detectable!