We’ll run out of uranium in X years!!!
Heard that one before, have you? Well, the truth is not so simple, and there is a virtuous cycle involving uranium and things that can be made from it via the neutrons spontaneously lost by the lighter of its two common isotopes.
I have pictures, I promise this will be understandable …
FISSION
First, this is what fission of a
uranium 235 atom looks like:
That diagram is a tad confusing due to layout – the U-235 atom meets one loose neutron, and it produces barium and krypton, as well as three additional loose neutrons. These are pretty fast neutrons, so in nature fission is pretty rare, because the reaction has to have water around to slow them down so they’re the right speed to get captured.
NEUTRON CAPTURE
We toss literally 99.3% of the uranium we mine – did you know that? Just 0.7% is the fissile U-235, the rest is stable U-238. But if free neutrons move at the right speed the U-238 nucleus captures them and becomes plutonium. We’re touchy about this stuff because it’s hard to handle and easy to use in bombs, but it is a fuel source, too.
When nuclear reactions need to be slowed or stopped they inject boron, in the form of boric acid, into the reactor. Boron 10 happily consumes slow neutrons, putting a break on the overall reaction, and forming boron 11.
FUSION
Fusion is similar to fission, in that it releases energy, only instead of breaking things down large nuclei are built. It’s possible to directly fuse hydrogen into helium (proton/proton) and stars like ours run on a carbon cycle, in which carbon fuses to nitrogen, then oxygen, then splits back to carbon and a newly formed helium nucleus. These methods both produce additional neutrons.
But if we could figure out how to get the Maxwell density up for boron 11 bathed in a flow of hydrogen nuclei … we’d have aneutronic fusion.
So … nice, safe boron, nice safe hydrogen, add a little electricity, get a lot of heat and nice safe helium that can be sold for medical and industrial applications.
That last bit has occupied the minds of many scientists and inventors. We have to be much, much safer in where we put nuclear reactors, but if we want the fuel they can breed, and perhaps a clean, portable energy source in the form of boron 11, we would need to focus on this.
I’m a big proponent of solar and, wait for it … wind, but we need baseload power and that’s one of large scale hydro, coal, or nuclear. Coal sucks, hydro might start sucking as climate change spoils output for existing large dams, but nuclear will be there … if only we can manage it safely.
Well … come on … call me an industry shill or something. You know you want to …