Underreported: Thorium Reactors

Thursday, February 23, 2012

Journalist Richard Martin discusses thorium as a potential nuclear fuel and looks at the efforts to promote it as a new form of green energy.


Richard Martin

Comments [20]

George Lerner from San Francisco Bay Area

@William from Manhattan "weaponizing thorium or its byproducts?" See Thorium Worthless for Nuclear Weapons

@Amy from Manhattan - "How would thorium be obtained & processed for use as a nuclear fuel? What would be the effects of its extraction & processing... less vulnerable to a terrorist attack?"

Thorium in a solid-fueled, water cooled reactor = same high pressure containment failures, same loss of coolant accidents. LFTR very different!

Uranium fuel rods: Mine 250,000kg uranium, to make 35,000kg enriched uranium. 250,000kg nuclear waste per gigawatt-year electricity, store for 100,000+ years or use as fuel for LFTRs.

Thorium in LFTR: 800kg to make 1GW-yr electricity, 83% of waste non-radioactive in 10 years, 17% (135kg or 300lbs) store less than 350 years. See Useful LFTR Fission By-Products

Mine rare earth elements (for iPads, TVs, headphones, windmills, etc), always get thorium too (currently discarded, except by Chinese gov't planning for their LFTR rollout). Thorium barely radioactive, radiation stopped by skin or thin layer of plastic; used in some eyeglass lenses. Chemically like other rare earth metals, don't eat the stuff. A few grams in most cubic yards of earth. See Thorium Converts to Uranium Inside the Reactor and No Long-Term Toxic Waste Storage.

Terrorist attack, earthquake, tsunami, etc: No high pressure to explosively release. No explosive or combustible chemicals (including hydrogen). No water used (electric turbine use steam or inert gas, via heat exchangers, no contact with radioactive material). Salt coolant won't boil away, so no loss of coolant accidents. No electricity = fuel drains to passive cooling tanks. Fuel chemically bound to the coolant, which doesn't react with air or water, doesn't dissolve in water, quickly cools to glass-like solid. Hit the reactor with a cannon, fuel drains to the cooling tanks. Can be installed 10m underground. If use high-heat from LFTR to break water and CO2 to make vehicle fuels, the "gas tank" is only dramatic target; more effect if terrorists just blow up a building or train. See How Might LFTRs Fail?, and Passive and Inherent Safety.

Mar. 04 2012 02:51 AM
George Lerner from San Francisco Bay Area

@Barbara Garrity - "The unresolved question about nuclear remains how we deal with spend fuel rods."
@morfin - "What are the negative effects? Disposal?"

Fuel rods are a small % of the waste from solid-fueled reactors. To run a GigaWatt solid-fueled, water-cooled reactor for a year, take 250 tons of natural uranium, make 35 tons enriched uranium. When done, 215 tons of depleted uranium, 35 tons spent fuel (33.4 tons U-238, 0.3 tons U-235, 1.0 tons of fission products, 0.3 tons plutonium).

Option 1: Encase it all in glass, like the $12.2 Billion Hanford nuclear waste vitrification plant (in trouble, ), store it for 100,000+ years.

Option 2: Separate out the uranium, plutonium, and other transuranic elements; a fairly simple chemical operation. Separate the "other stuff" into "completely safe in 10 years or less", or "completely safe in 350 years". We can safely store things for 350 years, and none of these chemicals are as hazardous as uranium or plutonium. (See the Radiotoxicity charts on Wikipedia).

How much gets stored 10 years, vs 350 years? 83% of the fission products are completely safe in 10 years, 17% take up to 350 years. There aren't any other fission byproducts that take longer than 350 years.

What do we do about uranium, plutonium, and the other transuranics left by solid-fueled reactors, uranium fuel rod preparation, nuclear weapons, even uranium from every coal plant? Put it in a molten-salt reactor, and fission it. All of it.

In a LFTR the fuel is molten, so fission products are easily removed from the fuel, LFTRs get 99+% fuel usage. The fuel is Gone, transformed into other elements.

For every 1000kg of fuel (thorium, waste uranium, or plutonium) in a LFTR, we get 1 gigawatt electricity for over a year, left with 830kg of waste safe in 10 years, and 170kg of waste safe in 350 years. We all know people heavier than 170kg (300lbs).

We have a Lot of nuclear waste. Build enough LFTRs to supply the entire world with USA levels of energy (including coal, oil, natural gas, uranium), 6600 x 1000kg of LFTR fuel per year, and we eliminate our current nuclear waste in about 75 years.

See No Long-Term Toxic Waste Storage, and LFTRs Can Consume Nuclear Waste

Mar. 04 2012 01:15 AM
George Lerner from San Francisco Bay Area

In the interview, said that nuclear waste from a LFTR would be 10% the volume of what you would get in a conventional reactor. No, a LFTR has much lower waste than that.

To produce 1 gigawatt electricity for a year, takes less than 1,000kg of thorium (or nuclear waste from other reactors). 83% of the fission byproducts are completely safe in 10 years, 17% within 350 years, no uranium or plutonium left as waste.

(Compare to 250,000kg uranium to make 35,000kg enriched uranium for a solid-fueled reactor, all needing storage for 100,000+ years.)

The interviewer asked if LFTRs "give off U-232".
No, a LFTR would generate small amounts of U-232, but there is no method of "giving it off" (or "releasing into the atmosphere" somehow). The uranium is chemically bound to the coolant, and even in an accident won't evaporate, won't dissolve in air or water, quickly cools to a stable solid. In normal operation, U-232 would be fissioned, just like any other isotope of uranium.

The cost of developing LFTR technology and installing LFTRs nationwide was skipped over completely. All estimates I've seen, to develop the technology and build assembly line construction, are much less than the $10-12 Billion for a single traditional reactor or nuclear waste processing plant. Then make and install 200MW reactors, with electric generators, for about $200 million each.

India is building solid-fueled water-cooled thorium reactors, not molten-fueled salt-cooled; just a slight improvement (less cost, less waste) over using solid uranium. Completely different technology than a LFTR.

China is building LFTRs, as rapidly as they can, and plan to patent every advance they make.

For much more detail how LFTRs work, and the other benefits of the design not mentioned in the interview, written very clearly for people not in the nuclear energy field, go to I even cover what it would take to build them, some economics of building them, technical solutions to the few problems that weren't resolved in the 1960s but we have figured out since then, how they would fare in accidents or terrorist attacks. How about carbon-neutral vehicle fuels?

Mar. 01 2012 11:37 PM
Dr. A. Cannara from Menlo Pk., Calif.

Rick is well meaning, but several things in this interview are misleading or incorrect. Thorium isn't "the" solution alone. The reactor design by Weinberg & team at ORNL in the 1960s indeed worked and the Chinese are now copying all our R&D. It didn't use Thorium, though that was intended as the next step, until Nixon chose wrongly in 1974: Weinberg co-invented the reactors we now use (LWRs) in 1946, but he wanted something better & safer and followed the advice of Nobellist Eugene Wigner to use liquid rather than solid fuel; and, to use liquid salt, for a variety of safety, efficiency and chemistry reasons. That's the key -- liquid salt fuelling & heat exchange to the power system makes for a "walk-away-safe" design potential.

Thorium gives a separate benefit -- low amounts of long-lived wastes, because it takes 7 neutron hits in a row to get from 232Thorium to 239Plutonium -- not a good reactor for making bombs to scare the Russians in the Cold War. Thorium, being so abundant and a waste product of rare-earth mining (the materials our iGadgets & missiles depend on) is simply piled around the world as waste. It's used a little in welding rod, gas-lantern mantles, even decades ago in toothpaste, but it's so abundant & cheap, a reactor running a city from a ton of it per year would have essentially no fuel cost and no emissions costs.

Thorium is part of our solution for thousands of years, but the most important part is the molten-salt reactor design, which can also consume existing wastes from our existing reactors, which do indeed turn some Uranium into Plutonium. Almost all that waste Uranium & Plutonium can be turned into power in a molten-salt reactor (and it'll last 100 years, because we've so much). The LWR & waste issues we have now were supposed to be gone by 2000. We never seem take good advice seriously, no matter how many Nobel winners give it to us, even when we ask...

If we'd continued in 1974, working toward MSR/LFTR reactor deployments, eliminating LWRs, coal, gas & oil power by 2000, we'd also have eliminated about half of all the nasty effects of CO2 emissions, and we'd have had an amazing economic boost from selling our technology around the world. Now, our foolishness means we may have to buy it back from other countries, and hundreds of millions of people around the world will suffer loss of land, livelihood and maybe life, despite their not having contributed to the missions that do them in. As the old country saying goes: "There's no substitute for human stupidity".

Come & discuss options:

Or, chip in for our descendents' futures...

Mar. 01 2012 04:15 PM
Timothy Maloney

For a thorough discourse on LFTRs in PowerPoint format, see my website .

If really interested, attend the Left Forum Conference in NYC March 17-18; panel title "Thorium-Fueled Nuclear Energy".

Mar. 01 2012 02:32 PM
Mike Conley from Los Angeles

Nuclear power isn’t the problem.

The problem is with the reactors we've been using to make it. If the reactors at Fukushima had been Liquid Fluoride Thorium Reactors (LFTRs) they wouldn’t have a mess on their hands.

Liquid-fuel reactor technology was developed at Oak Ridge National Labs in the 1960s. Although the test reactor worked flawlessly, the project was shelved, a victim of political considerations and Cold War strategy.

A LFTR is a completely different kind of reactor, as different as an electric motor from a gasoline engine. It can’t melt down, and it automatically adjusts its heat generation to meet changing workload demands. It requires no active cooling system and can be installed anywhere on earth, even an underground vault. A tsunami or a tornado would roll right over it, like a truck over a manhole cover.

LFTRs use liquid fuel ⎯- nuclear material dissolved in molten fluoride salt. Solid-fuel reactors are atomic pressure cookers, with the constant danger of high-pressure ruptures, meltdowns, and the forceful ejection of radioactive material into the environment. LFTRs don’t use any water or steam, and they always operate at ambient pressure.

If disaster strikes and a LFTR springs a leak, the spill cools to an inert lump of rock, chemically locking all the nuclear material inside. The fuel can all be recovered and used again. The spill would be measured in square meters, not square kilometers.

LFTRs can deliver 750ºC heat for industrial processes, or spin a high-temperature gas turbine to generate power. They run on Thorium, a mildly radioactive material more common than tin and found all over the world. America has already mined enough Thorium to power the entire country for 400 years. It’s found by the ton in the tailings of our abandoned Rare Earth Element mines.

LFTRs are highly resistant to proliferation. Thorium is bred into 233Uranium inside the reactor, but only enough is made to keep the LFTR running, so no stockpiling occurs. While 233U is an excellent fuel, its harsh radiation makes it nearly impossible to steal, and extremely difficult to use in a weapon.

Liquid fuel can be continuously cleaned of the contaminants that spoil solid fuel. This unique feature enables LFTRs to consume their fuel so thoroughly that they can even use the spent fuel from other reactors, cleaning up our legacy of nuclear waste while producing a minuscule amount of waste themselves.

A 1-gigawatt LFTR, big enough to power a city of one million, will run on one ton of Thorium per year, or about 2 teaspoons per hour. The LFTR’s yearly long-term waste will be the size of a basketball. Compared to the long-term waste of a solid-fuel reactor, a LFTR’s waste would be substantially harmless in just 300 years. Not 300 centuries -- 300 years.

Google: LFTR, liquid fluoride thorium reactor, MSR, molten salt reactor, Thorium energy

See the Wired.Com article “Uranium Is So Last Century"

Mar. 01 2012 01:12 PM
Rudy Stefenel from Milpitas, CA

Why not call LFTRs (Liquid Fluoride Thorium Reactors) Alternative Nuclear Reactors?

It seems to me that we should not take any existing Light Water Reactors off until they have lived their useful lifetime. In the mean time, we need to get a bunch of LFTRs going here.

What can we do to get the R&D going and the regulations fixed to get them going in the USA?

Mar. 01 2012 12:06 PM
Keith D. Swartz from Corinth, Alcorn, Mississippi, USA

Sounds great... for the power grid problem. But when it comes to the petroleum "crisis" that we are in, what about the replacement the Nazis came up with and went into WW-II with, conqueroring Europe and almost bringing the world under the rule of Nazism?!

I'm speaking of synthetic oil/gasoline/fuel that POWERED their armies! In fact, patton took to draining it from damaged NAZI' TANKS, ARMORED VEHICLES AND THE LIKES TO POWER HIS MARCH ACROSS EUROPE AT THE END OF IT!!

We got all the formulaes and technology they were using and even developed it further over a short time-frame during the 1940's & 1950's. If we can just stop the OIL INDUSTRY from shutting down this PROVEN type of synthetic fuel production in this country again; PROBLEM SOLVED?!


Feb. 26 2012 06:52 PM
Alex from Brooklyn

Thanks for this segment. Certainly much remains to be explored with thorium. When it comes to addressing energy -- and the tricky technology of nuclear -- we'll need to explore all the good ideas we've got. More fodder for discussion here: a documentary I co-produced on the thorium movement, with a stop at Indian Point.

(Rick was one of our interviewees, but regrettably ended up on the cutting room floor. Looking forward to the book.)

Feb. 24 2012 01:22 PM
Rob from Cuddebackville

The Low Energy Nuclear Reaction, LENR - Cold fusion world is about to explode. Just Google LENR and NASA or SPAWAR or DIA or CERN. All big names are trying to capture a piece of the current action while at the same time distancing themselves from their previous denials of cold fusion, thus the name change.

Feb. 23 2012 10:19 PM


A 1 GWe Liquid Fluoride Thorium Reactor (LFTR) should produce 1 ton of nuclear waste per year. Most of which will have decayed to background radiation levels within 50 years. The rest decaying to background radiation levels within ~300 years.

That is a completely manageable waste problem. It actually really isn't a problem anymore, it is our best hope for cheap abundant clean energy. A golf ball size amount of thorium placed into this reactor could provide all the energy an average American citizen would need (including transportation energy) in their lifetime.


Feb. 23 2012 03:47 PM
Amy from Manhattan

Barbara Garrity, what happened in the Fukushima nuclear plant had nothing to do w/spent fuel rods. Not that that isn't important, but it's not relevant to that specific incident.

Feb. 23 2012 01:56 PM
antonio from bayside

Can this help fuel the "Bloom box" createdby K. R. Sridhar...

Feb. 23 2012 01:33 PM
Barbara Garrity from NJ

The unresolved question about nuclear remains how we deal with spend fuel rods. Until we find safe and permanent disposal methods, I can't fathom why we would build more nuclear power plants. Look what happened in Japan!

Feb. 23 2012 01:33 PM

How much energy can such a reactor create? Can it be done on a small scale?Great Show!

Feb. 23 2012 01:31 PM
William from Manhattan

What about the risk of nations and others weaponizing thorium or its byproducts? Is it possible?

Feb. 23 2012 01:28 PM
John A

"No-one would argue that Windows is the perfect operating system." Lovely.

Feb. 23 2012 01:25 PM
Amy from Manhattan

How would thorium be obtained & processed for use as a nuclear fuel? What would be the effects of its extraction & processing on the people who would do this work & on the environment?

Would a thorium nuclear plant be less vulnerable to a terrorist attack?

Feb. 23 2012 01:25 PM
William from Manhattan

Fascinating. Underreported is such a good series - always something new!

Feb. 23 2012 01:24 PM

What are the negative effects? Disposal?

Feb. 23 2012 01:21 PM

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