I've recently seen a watch (in person) with Tritium tubes and it was quite impressive lume. I wasn't able to get an answer how long it would last. Half life for tritium is 12.32 years. Does this mean the lume would be half as bright in 12 years? Wikipedia says tritium costs $30,000 per gram and that it is basically hydrogen and therefore hard to contain. So...do tritium tubes leak? Can they leak?