Canada's *deuterium-moderated* reactors are responsible for the world's tritium supply. This isn't that; this is the wrong type of fission reactor.
- "If not for CANDU reactors, D-T fusion would be an unattainable dream. “The luckiest thing to happen for fusion in the world is that CANDU reactors produce tritium as a byproduct,” Abdou says. Many nuclear reactors use ordinary water to cool the core and “moderate” the chain reaction, slowing neutrons so they are more likely to trigger fission. CANDU reactors use heavy water, in which deuterium takes the place of hydrogen, because it absorbs fewer neutrons, leaving more for fission. But occasionally, a deuterium nucleus does capture a neutron and is transformed into tritium."
- "If too much tritium builds up in the heavy water it can be a radiation hazard, so every so often operators send their heavy water to the utility company Ontario Power Generation (OPG) to be “detritiated.” OPG filters out the tritium and sells off about 100 grams of it a year, mostly as a medical radioisotope and for glow-in-the-dark watch dials and emergency signage. “It’s a really nice waste-to-product story,” says Ian Castillo of Canadian Nuclear Laboratories, which acts as OPG’s distributor."
I think there's probably quite a few "commercially valuable" isotopes (since Tritium is just good old Hydrogen with extra neutrons) that have similar low yearly yield, but I would honestly expect most of them are for medical or industrial imaging or upstream inputs to those industries.
In some cases the half lives of the isotopes are so short they literally have to be produced on demand at a facility nearby, which usually means they can only be produced/used by facilities with their own equipment for producing them, or they are colocated on some sort of larger campus where they happen to have a suitable isotope producing accelerator as their neighbour.
Technetium-99m is one of the most commonly used radioisotopes for medical imaging and has a half life of just over 6 hours https://en.wikipedia.org/wiki/Technetium-99m so the usual mechanism is to ship the material that decays into Technetium-99m because the Molybdenum-99 parent isotope has a half life of 66 hours so lives long enough you can actually ship usable amounts around. So while this one is obviously not a low yield isotope, it really shows how the half life of the isotope can be worked around to make an an isotope a useful product.
Its a little hard to give simple numbers for a lot of these since they get measured by "activity" in Becquerels (Bq) as that's the useful metric based on how they get used, so giving "mass" would involve a lot of math and some guesses based on how efficient supply chains are (since you might produce twice as much and just "eat the difference" letting it decay if you have no other good way to get it to the user faster) but its a very fascinating industry.
Theres some fascinating information about how this sort of stuff gets made https://www-pub.iaea.org/MTCD/publications/PDF/te_1340_web.p... if you want to find out just how "fiddly" it can be to do chemistry with elements that might just decide to change what they are while you're working with them.
I was going to say rhodium, but it's actually 30 tonnes a year, so quite a lot.
Most of the synthetic elements (like technetium, it's in the name) probably have similar or far lower yields to tritium since they all are produced by transmutation and that requires monstrous amounts of energy.
Not an element, botulinum toxin has billions of doses made, but the total production is well under a gram.
The entire premise the founders of nuclear energy wanted was a cycle of fission byproducts into other useful things. Nuclear waste wasn’t. The war on nuclear proliferation scuttled that.
- "If not for CANDU reactors, D-T fusion would be an unattainable dream. “The luckiest thing to happen for fusion in the world is that CANDU reactors produce tritium as a byproduct,” Abdou says. Many nuclear reactors use ordinary water to cool the core and “moderate” the chain reaction, slowing neutrons so they are more likely to trigger fission. CANDU reactors use heavy water, in which deuterium takes the place of hydrogen, because it absorbs fewer neutrons, leaving more for fission. But occasionally, a deuterium nucleus does capture a neutron and is transformed into tritium."
- "If too much tritium builds up in the heavy water it can be a radiation hazard, so every so often operators send their heavy water to the utility company Ontario Power Generation (OPG) to be “detritiated.” OPG filters out the tritium and sells off about 100 grams of it a year, mostly as a medical radioisotope and for glow-in-the-dark watch dials and emergency signage. “It’s a really nice waste-to-product story,” says Ian Castillo of Canadian Nuclear Laboratories, which acts as OPG’s distributor."