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The Outfall of a Helium-3 Crisis
astroengine writes "The United States is currently recovering from a helium isotope crisis that last year sent low-temperature physicists scrambling, sky-rocketed the cost of hospital MRI's, and threw national security staff out on a search mission for alternate ways to detect dirty bombs. Now the panic is subsiding, what is being done to conserve, or replace, helium-3?"
based on how the government usually operates I expect this would be a typical response.
Apples and oranges, Helium 3 is an isotope of Helium. It's kind of like saying we need to conserve water because there's Tritium in it. There will be a shortage of regular Helium as well soon so it's ironic it's still cheap. Helium 3 was a bi-product of cold war weapons making but since we stopped trying to see how many Hydrogen Bombs we could make there's been little or no Helium 3 produced in decades. There were once huge stockpiles but they are largely gone now.
It's actually a fundamental physics + policy issue, but a different policy than the one you're referring to. As the article very briefly touched on, He-3 comes from the decay of Tritium. Tritium is the stuff that we put into the H-bomb (Fusion reaction rather than the atomic bomb's Fission reaction, basically redonkulously more powerful). The policy in question came from the end of the Cold War, where nonproliferation, disarmament, and the end of tritium creation.
The physics comes in because tritium has a half life of ~13 years. This means that if someone gave you a canister of pure tritium, after two decades it'd be 1/4 tritium, and 3/4 He-3. Do the math for when the cold war ended, and you start to see why we're feeling the hit from the end of this "production cycle".
It's also important to note that H-bombs, crafted from Tritium (Hydrogen-3), have a different yield once enough of the warhead has decayed into He3, which is actually one of the real main reasons why we're reducing our stockpile even though we didn't agree to the nonproliferation treaty. We're re-refining what tritium is left and putting it into new warheads (as a tanent: using more advanced warhead designs than the previous ones they replace too, so nonproliferation/stockpile-reduction in this case is a very generous casting).
While there are many "alternative" ways to create He-3, it's pretty obvious from this situation that trying to buy $150 dollars of decayed bomb innards is definitely going to be cheaper than trying to buy refined nuclear-reactor extract. But at the same time, that was probably taken into account for the final price adjustment to $1500/L.
The problem is not as easily solved as you make it out to be for a few reasons. The first being demand and the second being supply. The article doesn't really go into much detail but the real demand issue is the rising use by of He3 by the US gov in portal monitors. He3 tubes are by far the best devices available for neutron detection. Since 9/11 the US gov demand for He3 neutron tubes exploded and pretty much ate the entire stockpile. This has caused major headaches for everyone who uses He3 like the medical field and basic science research.
On the supply side He3 is created when tritium decays on a 12 year half-life. The largest supply of this for many years was the US nuclear weapons program. Production now, however, is nothing like it used to be. Without the tritium production we don't have the He3. Even if we did we might not meet the kind of demand we have for He3 now. In order to make 1kg of He3 you need to let 2kg of tritium decay for 12 years. Or you need to let much larger quantities of tritium decay for shorter periods of time. Either way you need a lot more tritium than we have.
Additionally getting He3 from heavy water reactors is probably not an option. The best way (the way the US gov does it anyway) to make tritium presently is by putting lithium rods into a reactor and then removing the tritium from the rods (its a fission product from lithium). While tritium is produced in heavy water reactors by neutron capture, the cross sections are very low. This mean you would need to separate the heavy water out from the tritium rich water (centerfuges) and then remove the tritium form the water molecules with electrolysis and then again separate tritium from deuterium. This ignores the fact that All the commercial reactors in the US are light water (normal H20) and countries that use heavy water (Canada) may not be interested in stockpiling tritium.
Production difficulties aside tritium is just plain expensive. tfa cites the He3 price at $5000 a liter with a goal of more like $1500/L. This puts the price roughly $37500 a gram. Tritium is presently $25000+ / g and that is a subsidized price. Its estimated that actual production cost is upwards of $75000 / g
Given all this, if we had a cheap easy solution laying around we would have done it by now.