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MortalPhantom t1_iyvhxac wrote

Reply to comment by NetworkLlama in Why not use hydrogen and deuterium in fusion reaction rather than tritium and deuterium? by Curious_user4445

I know it's rare but then why was it used on watches? Even current watches some of them use tritium and you can find them prelaatively cheap 500-1000 usd, and I doubt tritium is a considerable part of that price.

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karlnite t1_iyvm70b wrote

Canadian nuclear plants pay millions a year to remove tritium from our cooling and moderator water. It’s a pesky problem and we are always looking for ways to get rid of tritium. We currently keep barrels upon barrels of our most tritiated water sitting around to decay off so we can use the deuterium content again safely one day. We would pay fusion companies to take our tritium away. They could set up a device to harvest it from our reactors or waste just like we do for the global supply of medical isotopes currently. We have determined a myriad of medical isotopes that could be harvested, we just need investors willing to set up the systems to harvest them who have connections to medical companies that can utilize the isotopes (our industry doesn’t have the experience to do this all ourselves as we make power and that is hard enough). I don’t see why we couldn’t do that for tritium too.

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NetworkLlama t1_iywq9xk wrote

There's probably not as much tritium in that water as you think. According to this paper on sourcing tritium, a 700 MW CANDU-6 reactor can make only about 130 grams of tritium per year. There probably aren't dozens of kilograms of tritium sitting in those barrels.

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karlnite t1_iywuaul wrote

That’s very likely, I have not done the math to calculate to mass of tritium in the systems.

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chemhobby t1_iyvlxfh wrote

the amount used in gaseous tritium light sources is absolutely miniscule

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NetworkLlama t1_iyvmmco wrote

A tiny fraction of a gram is used, with a maximum of 25 millicuries allowed per timepiece. A little bit goes a long way for that purpose.

Edit: I looked up some numbers, and the amount of tritium in any given timepiece is apparently measured in micrograms, not even milligrams. I'm having trouble finding exact amounts, but a very rough calculation based on a specific activity of 9650 Cu/g and 25 millicuries results in .025 mCu-g/9650 Cu = 2.6 micrograms per watch. That's a very, very tiny amount.

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vokzhen t1_iyx4njh wrote

For those who don't grasp what this means very well, those numbers mean a gram of tritium is enough for about 400,000 watches.

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ukezi t1_iyvjtw7 wrote

Before tritium paint they used radium to get the phosphor to glow. The problem is that radium is highly toxic and carcinogenic.

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boycey10802002 t1_iyvl6qk wrote

That I had heard the horror stories of. It just didnt seem to make sense to me to use a super-limited resource like tritium for watches and thought titanium would be a more likely candidate for a mid-level, rugged watch.

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Lazzer555 t1_iywefn7 wrote

Tritium is only used for making the hands and face of the watch glow in the dark, titanium would be used for something like the body of the watch.

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[deleted] t1_iyvjddl wrote

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