Experts have long viewed thorium reactors as the next leap in energy innovation. Some scientists estimate that a single thorium-rich mine in Inner Mongolia could theoretically supply China’s energy needs for tens of thousands of years with far less radioactive waste than current uranium-based reactors.
Having never studied physics, it took quite a few conversations to get my head around this tech.
THE CAMPFIRE
Nuclear waste does NOT have to be stored for 100,000 years. The only reason it is radioactive for so long is we have not got all the energy out of it. I’m no physicist and got the following metaphor from chatting with them. But after a regular uranium fuel rod has been in a reactor for about 18 months, it stops fissioning efficiently. It has not run out of energy, but instead is being stopped by ‘nuclear poisons’ - things that dampened the reaction. It’s a bit like a huge campfire that gets rained on. The fire is put out, but the fuel is still there. Only in this case, ‘drying out’ the ‘logs’ involves melting down the fuel rods, separating out the good ‘wood’, and then ‘drying’ it around the reactor core (where the fertile stuff can soak up extra neutrons to become fissile). As a result, breeder reactors can get something like 90 TIMES the energy out of each fuel rod! America has enough waste to run her for thousands of years.
There are many differences between standard fuel rods using uranium, and liquid thorium molten salt reactors - including RADICAL safety advantages. But one of them is my metaphor breaks down, because it's like the 'drying out the logs' process happens continually. They have the liquids in a self-cleaning loop in many models.
WHAT ABOUT THE ‘ASHES’ FROM THIS ‘CAMPFIRE?’
Some of the nuclear fuel is fissioned away into energy. (That’s what E = MC2 is all about.) By the time all the energy has been extracted this way, it’s only about a golf-ball of waste per human lifetime of abundant clean energy! Your whole life. One golf ball! That’s amazing!
So, what to do with the REAL waste - the broken atoms that cannot be fissioned any more?
We can melt it down into glass like ceramic tablets that contain it. (If there’s ever an earthquake or unanticipated event, we don’t want radioactive dust getting out into the water table, etc.) Bury these bricks in a bunker on site, and in about 300 years they are safe! The hotter it is, the faster it burns out. See this Argonne Labs video - 4 minutes.
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Not only this, but they can also supply many medical radioactive isotopes useful for nuclear medicine.
It's an amazing technology. But they're going to have to work hard to bring the cost down, because solar panels are expected to halve in price AGAIN by 2030!