Nuclear futures: thorium could be the silver bullet to solve our energy crisis

The Conversation ^ | 22 May 2013 | Robert Cywinski

[neverdem]

The only source of energy that can meet global demand while avoiding greenhouse gas emissions is nuclear power. But our perception of nuclear power is coloured by issues of safety, radiotoxic waste, and the threat of nuclear proliferation.

Yet there is a safer alternative to current nuclear technology…

Author

1. 

   Robert Cywinski

   Professor, Special Research Advisor at University of Huddersfield

Disclosure Statement

Robert Cywinski receives funding from the EPSRC and STFC

The Conversation is funded by CSIRO, Melbourne, Monash, RMIT, UTS, UWA, Canberra, CDU, Deakin, Flinders, Griffith, JCU, La Trobe, Massey, Murdoch, Newcastle. QUT, Swinburne, UniSA, USC, USQ, UTAS, UWS and VU.

The only source of energy that can meet global demand while avoiding greenhouse gas emissions is nuclear power. But our perception of nuclear power is coloured by issues of safety, radiotoxic waste, and the threat of nuclear proliferation.

Yet there is a safer alternative to current nuclear technology: new reactor designs inherently safer than conventional reactors, that produce little waste, and are proliferation resistant. The new designs allow us to reuse our legacy of radiotoxic waste as fuel.

The secret is a shiny, silver-coloured element called thorium, and it’s not new. Thorium has long been regarded as a potential nuclear fuel. Unconventional prototypes such as the Oak Ridge thorium molten salt reactor (MSR) in the US were demonstrated in the 1960s. Since then the US, Germany and Britain have all used thorium fuel to produce electricity in conventional reactors. The technology is proven.

Thorium is four times more plentiful than uranium, about as common as lead. A mere 5,000 tons of thorium could meet the entire planet’s energy needs for a year. Known deposits alone would provide enough energy for 10,000 years. Unlike conventional uranium fuel, thorium is burnt, leaving much less radiotoxic waste and almost no plutonium. It is often claimed that thorium’s inability to generate plutonium for weapons was the reason it was abandoned during the Cold War.

There is considerable support for thorium as a nuclear fuel. With uranium or plutonium additives it could be used in current nuclear reactors with only minor modifications. And it brings the opportunity to exploit the latest innovations in reactor design. A molten salt reactor, for example, is meltdown-proof because the fluoride-based fuel is already molten. Theoretically self-regulating, the design might suit small modular units for remote communities, generating electricity or heat.

Another approach is the accelerator-driven subcritical reactor (ADSR). In this still theoretical design, high energy protons are fired at atoms of heavy metals such as lead, chipping off individual neutrons. The thorium fuel absorbs these free, high-energy neutrons and is converted into uranium. This uranium in turn absorbs more neutrons and splits (“fissions”), releasing energy.

The ADSR is extremely safe as the thorium-uranium process is “subcritical”. That is, if the accelerator is switched off the reactor is fail-safe, unable to sustain a chain reaction. Furthermore, the high-energy neutrons it generates can break down the toxic radioactive waste from conventional reactors, turning our stockpiles of nuclear waste into more fuel.

India, with its substantial deposits of thorium, is now pursuing thorium-based nuclear technology using a thorium-plutonium mix. In Japan, research is underway to resurrect the thorium molten salt concept. Norway is considering the potential for its very substantial thorium reserves to provide energy for the years after North Sea gas and oil. China, which produces great quantities of thorium as a toxic by-product of mining rare earths, is investing heavily in molten salt reactors and ADSRs.

And in the UK? Unfortunately there is no coherent government, industry or academic stance. Yet the UK is rich in engineering and materials expertise, reactor and accelerator design.

Even a modest investment in an advanced thorium research and development programme could provide the UK with a unique opportunity to build and sustain a multi-billion pound nuclear industry based upon safe, inexhaustible, low waste and proliferation-resistant nuclear power generation. As well as providing national energy security, it would deliver the means for the UK to compete in existing nuclear markets, and open new international markets that are closed to uranium and plutonium-based reactors.

Academics, businesspeople and social reformers alike are working towards a consensus on a thorium-fuelled nuclear future. But with no government support or leadership, and a nuclear industry wedded to existing uranium-based designs it’s likely the UK will miss yet another golden, or in this case silver, opportunity.

[neverdem]

Thanks for your link.

[bandleader]

Yet another IDIOT ENGLISHMAN!There is more”GreenHouse Gas”in the atmosphere than EVER before and it’s getting Colder,you BOOB!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

[Lurkina.n.Learnin]

“as GWB calls it Nucular, power”

They always made fun of George Bush for that. Jimmy Carter minced the word horribly but I never heard people make fun of him. He was a nuk-e-er scientist after all.

[Paladin2]

"Running out of water" is so hilarious given that I learned about the "water cycle" in elementary school in the 60's.

If you aren't pulling water out of an aquifer faster than it is replenished, you're good to go.

(Plus a nuclear powered desalinization plant could easily provide a fix if you have the scratch.)

[Sherman Logan]

Here’s the difference between CO2 and H2O. Both have a natural cycle whereby they go into the atmosphere and then are removed back out of the atmosphere. There’s a “normal” amount of each in the biosphere, in the air, in the oceans, in plants and animals, etc.

The difference is that the total amount of H2O in the biosphere is not increasing, while the amount of CO2 IS. Due probably, though not certainly, primarily to the burning of fossil fuels, which are carbon that WAS part of the biosphere long ago but had been stored away.

Now we’re talking very different scales here. In the air (at sea level) water vapor fluctuates from perhaps 5,000 to 30,000 ppm (a lot less at higher altitudes where it’s cold), while CO2 is presently less than 400 ppm. There is also the fact of the immense amounts of water in the oceans, for which there is nothing remotely comparable for CO2.

It is as if we were suddenly adding hundreds of cubic miles of “new” water to the biosphere each year. (Not sure on the numbers here. But somebody could run them if they wanted to.)

There would be consequences. Now I think there is great scientific uncertainty on what the effects of increased CO2 will be. In particular, I suspect there are negative feedbacks that will control it at some point.

But the CO2 released by the oceans you mention is not “new” CO2. It’s part of the normal carbon cycle, and is as irrelevant to the total as rainfall is to the amount of water in the biosphere. It just moves it around.

BTW, Jimmuh Carter also pronounced it nucular, and I don’t recall anybody making fun of that. It’s merely a southern regional pronunciation, and anybody who makes judgments about a person’t intellect or education on such a basis is an idiot.

[Jim from C-Town]

I worked for an absolute genius. He was a mechanical and engineering genius. He worked with aluminum. He couldn’t say aluminum. He always mumbled it. Just couldn’t pronounce the word.

[Lurkina.n.Learnin]

I believe your story but I still don’t believe Jimmy Carter was any kind of a genius.:-)

[piytar]

Harry Reid made a real difference in the world: he basically killed Thorium reactor research in the 70s for political reasons.

Well done, Reid, may you rot in H###.

[piytar]

Clueless comment.

[ransomnote]

But our perception of nuclear power is coloured by issues of safety, radiotoxic waste, and the threat of nuclear proliferation.
_________________________________________

Actually, “our” perception of nuclear power is significantly coloured by the incompetence, hubris, failure, and lies of the nuclear power industry.

[Jim from C-Town]

I didn’t call Carter a genius. I called my former boss A mechanical genius. He was also a jack ass but that is besides the point

[RayChuang88]

One of the most potentially promising forms of nuclear power plants is the liquid fluoride thorium reactor (LFTR). Unlike conventional uranium-235 based reactors, LFTR's have a lot of advantages:

1. It uses thorium-232, which is far more common than uranium (it's found anywhere there are rare-Earth deposits).
2. The fuel is essentially thorium-232 dissolved in molten sodium fluoride salts, a form of nuclear fuel very cheap to make.
3. The same reactor can use reprocessed spent uranium-235 fuel rods or even plutonium-239 from dismantled nuclear weapons dissolved in molten sodium fluoride salt as fuel, which means we eliminate a huge nuclear waste problem by turning it into reactor fuel.
4. The reactor does not need an expensive, potentially dangerous pressurized reactor vessel.
5. A SCRAM emergency shutdown is essentially dumping the liquid fuel from the reactor into a holding tank, which is much safer than trying to reinsert control rods into the reactor in an effort to stop the chain reaction.
6. By using closed-loop Brayton turbines to generate power from the heat generated by the reactor, we eliminate the need for large, expensive cooling towers or locating the reactor near a large body of water.
7. Because of #6, LFTR's can be scaled up and down in size depending on the customer who needs the power. It could be big enough to generate 1,500 MW to power a whole city or as small enough to generate 85 MW to power a single factory or computer server facility.
8. The amount of nuclear waste generated is very small compared to uranium reactors, and the waste has a half-life of under 300 years, which means cheap waste disposal by dumping it into disused salt mines or salt domes (if the nuclear medicine industry doesn't grab it first!).

So what are we waiting for?

[BenLurkin]

[Islander2]

” They keep tearing down the damns”

Just which damn dams are you referring to ?

[PA Engineer]

You posted two rather intesting statements. One you blame on man and the other on a natural cycle.

while the amount of CO2 IS. Due probably, though not certainly, primarily to the burning of fossil fuels

But the CO2 released by the oceans you mention is not “new” CO2.

The CO2 sequestered in the oceans is far greater than that which man has released with the burning of fossil fuels. The release of CO2 from the oceans has always been a leading and not lagging indicator of warming.

An example would be to play a game of Beer Hunter. Now there are special rules for the global warming version. Use two sets of beer. One almost frozen and the other at room temperature. Which beer would you want to play Beer Hunter with?

If atmospheric CO2 begins to decline, I would recommend moving south. There is no way increasing it is going to stop the inevitable cooling period.

[Go_Raiders]

I never once heard Jimmy Carter say ‘nucular’, he pronounced it ‘newkeyyah’ every single time I heard him use the word.

[piytar]

Lol

[chopperman]

ColdFusion is a scam.

[1010RD]

Is anyone in the UK listening to this guy?

[Cuttnhorse]

Uh...I think you mean “Dam”