Thorium: the magical solution? Hell, no!
Be careful what you wish for.
The only thing that really matters, is HOW we use nuclear fuel.
This is what we call the “fuel cycle”.
The details of the fuel cycle determine:
- the efficiency of the conversion of the nuclear fuel into heat. This is really important considering nuclear materials are not renewable. Todays nuclear fuel cycles are all incredibly inefficient “open fuel cycles”. I’ll tell you WHY in a later post: it is your own fault, actually.
- the amount of nuclear waste. Nuclear waste cannot be avoided, as waste CANNOT be avoided in ANY energy conversion process. But the amount should be minimised. Today it is not. Again : your own fault.
- the “radio-toxicity” of the nuclear waste, which is a combination of chemical toxicity, neutron radiation levels, beta radiation levels, gamma radiation levels, and migration agility.
- the amount of alpha waste, which mainly determines the nuclear waste evolution as well as the heat production inside the nuclear waste, which in term determines how costly the treatment and the final disposal of the waste will be.
Let’s use the wood analogy.
Up to now, our nuclear reactors have been burning U-235, the only “dry wood” nuclear fuel available in nature.
Historically, this seemed to be the easiest route. However, this route requires enrichment if it is to be used in light water cooled reactors, which is precisely what we have been doing.
Even worse: the amount of mineable U-235 is about as limited as the amount of natural gas and oil.
The real improvement required in nuclear energy conversion is the use of “wet wood”, that needs drying using the “heat” of “dry wood”. This “drying heat” comes in the form of a neutron flux generated by the burning “dry wood”.
Such a drying reactor is a “convertor” if it burns its own dried wood. It’s a “breeder” if it produces dry fuel for another reactor.
Breeders are a bad idea as they require extraction, handling and transportation of “dried” fuel. It’s hazardous and not proliferation resistant.
Brigid therefore only builds “convertors”, not “breeders”.
There are only 2 kinds of “wet wood” in nature: Th-232 and U-238. Th-232 needs to be “dried” into the artificial “dry wood” U-233. Likewise, U-238 needs to be “dried” into artificial “dry wood” Pu-239.
The amount of mineable “wet wood” is sufficient for hundreds of centuries of energy supply. Not only electricity. All energy needs. Worldwide.
The choice between thorium and uranium is a Tomeeto-Tomaato combination of the physics pros and cons, and the economical pros and cons.
In a nut shell:
- The thorium mining still has to be started, while massive uranium mining left us with a huge amount of chemically purified U-238, ready to be “dried”. This pleads for uranium.
- However, a “drying” reactor for thorium is somewhat easier to build and operate than a “dryer” for U-238, generating less nuclear waste. At least if it’s done well, in a proper “closed fuel cycle”. Brigid knows how…
- Both routes do not require enrichment.
In view of the pressing time constraints, Brigid selected thorium. But it could have been uranium as well. Tomato-Patato.
Remember:
It’s the fuel cycle, stupid.