Toward a Thorium Economy: the Future of Nuclear Energy
Part I: the technology. A discussion with D. Walters.
This is not a diary on what we need to do tomorrow to solve fossil fuel carbon particle caused death or an immediate solution to climate change (or even an entry on that debate). No, this is more or less along the same lines as other "Grand Plans" that are presented in the popular press like Scientific American and Greenpeace who try, through smoke and mirrors, to present a non-Nuclear future (but fail miserably).
This Thorium Economy Grand Plan will not use smoke or mirrors or engage in scientific or economic make-believe. It is designed to look outward, forward, to a "Physical Economy" that is based on heavy metal fission with an abundance, not scarcity, of energy.
[I should point out here that I am a left-wing Socialist. That's with a capital "S". I helped found the Marxists Internet Archive and Left-Atomics.blogspot.com. I'm not a liberal, I'm a believer in working class power and an end to religion of the "Marketplace". I want to make this clear from the get-go: I'm a big advocate of "Public Power" and a nationalized energy system. But I oppose those that under capitalism would hinder the development of technological progress because of their unscientific understanding of technology, physics and the need to provide a material basis for a future that puts human needs ahead of profits and is based on a rising, not shrinking standard of living for the world. 'nuf said on politics]
The Liquid Fluoride Thorium Reactor is a Generation IV reactor. The R&D for the basic technology has already been proven and deployed in test reactors at Oak Ridge National Labortories in the 1960s and early 1970s. Because of politics, the link between the Military and the "Uranium Industrial Complex" that sought to marry military nuclear WMD with civilian nuclear energy through the original Fast Breeder Reactor experiments, technologies that did not rely on uranium and produce weapons grade plutonium, like the LFTR, was denied funding. The old Atomic Energy Commission killed the LFTR (called various names like the Molten Salt Reactor) and fired Dr. Alvin Weinberg (holder of the Light Water Reactor patent and original herald of the issue of global warming and who gave Ralph Nader his first 'class' on the issue in the 1970s), then head of the MSR experiment team.
Most of the information garnered here comes from the two leading on line sites for LFTR technology: energyfromthorium.com and The Nuclear Green Revolution [nucleargreen.blogspot.com] sites. Both assemble a multitude of professional engineers and alternative (REAL alternative) energy advocates who are trying to publicize the issue of LFTR and how this does in fact represent a "Thorium Bullet" to the future of the world's energy needs.
This also is not the only diary/blog here that I've done on the LFTR. There will be more as our job is to publicize and develop LFTR concepts and get serious funding to re-start and then jumpstart the LFTR R&D deployment program via either the Department of Energy and/or University/Academic interest and/or private investors and entrepreneurial type interests. We don't really care. We have our preferences (Public Power) but it is the technology I we are focusing on here.
Thorium is No. 90 on the Periodic Table. Its symbol is "Th". Two to the left of Uranium. It is a fertile, not fissile material. This means that while the atoms of Th can split and produce more nuetrons when hit by a nuetron, it can under nuclear 'alchemy' turn into something called "protractium". Protractium, after 27 or so days, decays into another isotope of uranium called "U-233". This material makes excellent fuel for a nuclear reactor. That is the basics.
Our intervenor asks:
OK, since you asked. There is 4 times more Th than uranium in the earth's crust. But wait! There is more! The basis of the LFTR is that it 's a reactor where the fuel is suspended in liquid fluoride salt and thus, because it's liquid, it can be chemically treated. This means that the nasty fission producets and anticides produced by fissioning of U233 can easily be removed.
"But David, that's W-A-S-T-E!".
Yes, it is. But the differences is that the LFTR burns up 99.9% of the U233 and leaves very little waste behind.
"Explain this please?".
OK, the LFTR is a BREEDER. It doesn't breed vast qunatiies of plutonium like a "Fast Breeder". This is what is called a 'thermal spectrum breeder'. Actually it can also be a 'fast breeder' and anything in between. But the basis of this is that Th is totally fertile and ALL of it can be turned into U-233. Unlike a light water reactor (LWR) where only a very small percentage of the overall uranium is used for energy, the LFTR uses all of the Th injected into it.
What do you mean "So What?". This means that you don't need a lot of Th. In fact, you need VERY little of it. The average LWR uses about 30 tons of uranium fuel for a GW year (I'm NOT going to explain what that is, you look it up, ok?). Suffice it to say about the energy out put in electricity for a large power plant that can power a city of a million for about one year. A lot of energy for a mere 30 tons. But that is for a LWR. The LWR then produced about 30 tons a year of Spent Nuclear Fuel, or, coloquealy speaking, "nuclear waste".
The LFTR is different. It uses only ONE TON a year. That's it. And not refined, enriched or otherwise expensive 'manufactured' fuel like in a LWR but RAW Th with only the soil and dirt removed through standard low-energy using milling processes like removing chaf from the wheat. Really. One Ton! For One GW Year! This means that LFTR can supply a city of one million people for a year with enough electrical generation on a fuel that works out to be 6.5 lbs of fuel a day. 4 people with shovels can mine enough of this Th for a LFTR to run for a 1 GW year by digging Th ore between morning coffee break and lunch in one day. See where I'm going with this?
Secondly, but as importantly, because it's one ton of Th a year that goes in, a little less than one ton of SNF comes out. And because the anticides and fission products are removed chemically through recycled chemical reprocessing train on site, never leaving the LFTR compound, the SNF is only dangerous for about 300 years after which the SNF, in the form of a metal, can simply be...recycled for other non-nuclear purposes. The LWR produces over 20 tons of highly radioactive long lived wastes (which is still very little compared to polluting wastes from coal and gas plants).
"But you said it was a 'Breeder'".
Yes, you are correct, and I digressed. The breeding ratio of the LFTR is can be anywhere from <1 to 1.09, meaning it produces as much fuel as it uses or a little bit more, making a doubling of the actual fuel in the form of U233 every 9 years or so. This means we only have to add that 1 ton of Th a year and we actually gain on the fuel used, the U233 for start up charges for new LFTRs.
"What's the start up charge"?
It's the initial 'charge' or supply of fissionable material. Remember, Th is fertile, it can decease into fissionable material, but only after 27 days. So each new LFTR needs needs a charge of something fissionable. This can be highly enriched U235, Plutonium 239 from weapons or the waste of LWRs, or U233 produced in other Th breeder reactors like the LFTR.
"So we need only that 1 ton of Th per gigawatt of power for a year?".
Now you are getting it.
"How much is there? We keep hearing that their are limits to uranium fuel..."
Th is 4 times as more abundant than say, Uranium. The U.S. in particular is blessed with hundreds of thousands of tons of it. The US gov't had refined during the 1960s and 1970s about 3500 tons of Th which are buried in a shallow vault in Nevada. That 3500 tons alone can be used to run 100 1 GW (1,000 MW) LFTR type reactors for 35 years each. 100GWs is about how much nuclear or, 1/5 of the US energy supply. And, we have 200 times that amount that we know if.
"What do you mean "that we know of"?"
No looks for it any more and so we don't know if there are more economically recoverable reserves because we simply haven't prospected for it in the last 30 years. This also true with other heavy metal fuels like uranium.
"David, what then is in Part II of this discussion?"
Part II will deal with both techinical and political aspects of this struggle for a Thorium Economy and will define better what we mean by a "Thorium Economy", what it would look like, how we can get there.
END PART I