Energy

Thorium salt reactor experiments resume after 40 years

This is the first thorium salt experiment since the 1970s
This is the first thorium salt experiment since the 1970s
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Ultra pure thorium salt is carefully put inside the special designed crucible
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Ultra pure thorium salt is carefully put inside the special designed crucible
The inside of the Petten test reactor where the thorium salt is being tested is shining due to charged particles traveling faster than the speed of light in water
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The inside of the Petten test reactor where the thorium salt is being tested is shining due to charged particles traveling faster than the speed of light in water
A scientist at NRG is preparing thorium to enter the Petten reactor for tests
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A scientist at NRG is preparing thorium to enter the Petten reactor for tests
 The custom built test equipment showing the thorium salt in the center
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 The custom built test equipment showing the thorium salt in the center
This is the first thorium salt experiment since the 1970s
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This is the first thorium salt experiment since the 1970s

Scientists at the Nuclear Research and Consultancy Group (NRG) the Netherlands, are looking back to the 1970s to meet the energy needs of the future. For the first time since 1976, the NRG team is conducting experiments in thorium molten salt reactor technology that could lead to cleaner, safer nuclear reactors capable of supplying energy on a global scale.

In a world marked by strong political pressure to create a carbon-neutral economy, nuclear energy seems like an ideal alternative. Despite their reputation, nuclear reactors have a remarkable record for reliability, produce carbon emissions that are lower than even wind and solar when construction, operation, and life cycles are taken into account, and have the lowest fatality rate per watt of any competitor.

However, nuclear power does suffer from four major drawbacks. First, the uranium needed to power reactors is rare and expensive to process. Second, the technology to produce nuclear fuel can also be adapted to create weapons. Third, there is the danger in older reactor designs of an unlikely, but frightening catastrophic meltdown. And fourth, no one has come up with a long-term nuclear waste disposal strategy that is acceptable to everyone.

A scientist at NRG is preparing thorium to enter the Petten reactor for tests
A scientist at NRG is preparing thorium to enter the Petten reactor for tests

One way of overcoming these issues is to replace the uranium and the plutonium derived from it with a different fissile material. Since the 1940s, the most attractive alternative has been thorium. Unlike uranium, thorium is abundant and widespread, it doesn't require the sort of elaborate enrichment process that uranium needs, and it isn't easily made into bombs. In addition, thorium reactors have an inherently safe design that shuts down if the reaction goes out of control, and the radioactive waste products from thorium are relatively short lived – becoming harmless in only a matter of centuries.

The main obstacle is that thorium can't achieve critical mass on its own. If you take enough uranium that's been refined to fuel grade and stack it together, the amount of neutron radiation released will start a chain reaction that will cause the uranium atoms to split in a self-sustaining process. Unfortunately, thorium can't do this, so thorium fuel must be mixed with uranium or subjected to an outside neutron source to start the reaction cycle.

From the 1960s until 1976, the Oak Ridge National Laboratory in the United States carried out reactor experiments using thorium fluoride dissolved in a molten salt instead of solid fuel elements. Though the results were promising, that approach was abandoned. Since then, India, China, Indonesia, and others have been experimenting with thorium reactors and have toyed with the idea of using molten salts as fuel, but it wasn't until NRG took up the baton that the Oak Ridge approach was resumed.

 The custom built test equipment showing the thorium salt in the center
 The custom built test equipment showing the thorium salt in the center

Working in cooperation with the European Commission Laboratory Joint Research Center, NRG's SALt Irradiation ExperimeNT (SALIENT) is a multi-stage experiment aimed at turning Thorium Molten Salt Reactors (TMSR) into an industrial scale energy source with commercial possibilities.

According to advocacy group Thorium Energy World, the first phase of the experiment is focusing on removing the noble metals produced by the thorium fuel cycle. That is, the metals created in the steps in the nuclear fission process where the thorium transmutes into uranium before splitting to give off energy.

Once this has been achieved, the next step will be to determine how well commonplace materials used in the construction of TSRMs stand up to the corrosive high-temperature salt mixture or to find alternatives to keep down maintenance and operation costs. These might include an alloy of nickel called hastelloy, or Titanium-Zirconium-Molybdenum (TZM alloy

Ultra pure thorium salt is carefully put inside the special designed crucible
Ultra pure thorium salt is carefully put inside the special designed crucible

The ultimate goal is to create TMSRs that are modular and scalable to meet local energy demand, yet provides 24-hour power that is available year round. In addition, using molten salts mean that refueling can take place while the reactor is still in operation, drastically reducing downtimes.

The video below introduces the SALIENT experiment.

Source: Thorium Energy World

World’s First Thorium Molten Salt Experiment in over 45 Years

32 comments
SammyC
Finally!
apprenticeearthwiz
Since renewable energy+storage is at price parity with fossil fuel generation, already beyond parity with this or any other nuclear infrastructure and still getting cheaper, I don't see any chance of thorium reactors being remotely competitive economically. That's not to say we shouldn't try. There may well be some niche application for it but it won't be cheap.
Brian M
If the potential use of thorium is so good, then why was it dropped in the first place? Political, economic or technological issues at the time? Questions I haven't understood for a long time!
Roy S
The statement that renewable energy plus storage is at a par on cost is preposterous. This is only made to appear true when the economics are grossly distorted by political interference in the marketplace (subsidizing and false pricing). By far the cheapest energy in the last fifty years has been nuclear, and especially the CANDU system, which is also by far the safest.
Kpar
Roy S, perhaps apprenticeearthwhiz is posting from the future! Brian M, the government was urged (by Edward Teller, father of the H-bomb) to use the TMSR for commercial power production because of its inherent safety, but the gummint wanted Plutonium to make things go bang! This is a good thing, but why isn't the USA at the forefront? After all, we INVENTED the technology, and now we are GIVING it away (mostly to the Chinese, and (no fools, they) are running with it!
watersworm
@ Brian M Just think about nucelar weapons having to use Uranium/Plutonium and you got the (majority of) the answer...
VincentWolf
A simple 100 mile x 100 mile square of PV panels can power the entire USA. We simply don't need it and all the hassles with uranium and thorium and materials to dispose of some day. Today nothing has been done with a long term disposal place for radioactives and most sits in ponds next to the energy plants which is ridiculous if they are hit with bombs they become dirty bombs. No thanks. Our sun provides all the energy mankind will ever need--wind is a product of the sun so wind and solar are all solar derived and all mankind needs.
fen
@VincentWolf, only in theory can you supply enough energy for america in 100 x 100 of solar. You have to account for losses which would be absolutely enormous transporting it all over the country from a single plant. They can make hydrogen transportation more efficient than electricity over powerlines. They can make hydrogen as efficent as natural gas. This reactor could work with green energy to replace battery stores, or make them a lot smaller. If instead of making really, really wasteful batteries that take hundreds of years to degrade anyway we could make a nuclear plant capable of picking up the slack in green, it would make sense. I'm sure these plants are more green than a billion batteries.
f8lee
My question is would it be possible for this type of reactor suffer the kind of catastrophic meltdown that happened at the Santa Susana Field Laboratory in 1959 (here's a link http://theantimedia.org/the-worst-nuclear-disaster-in-us-history-that-youve-never-heard-about/ ) because that would certainly be, er, sub-optimal.
Wolf0579
Thorium was dropped because it wasn't PROFITABLE enough.
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