sounds good but is anybody except India and Netherlands interested ?


Should Australia consider thorium nuclear power?
Nigel Marks Associate Professor of Physics, Curtin University March 2, 2015 6.21am AEDT

Australia has developed something of an allergic reaction to any mention of uranium or nuclear energy. Blessed as we are with abundant reserves of coal, oil and gas, we have never had to ask the hard questions many other nations have had to ask – questions the answer to which has been “nuclear” for many of those nations.

Yet with the looming spectre of climate change and greater calls for a shift away from fossil fuels, nuclear power is once again on the agenda. The South Australian government has even called for a royal commission to investigate the plausibility of nuclear power in this country.

With discussion of uranium seeming to be out-of-bounds in some quarters, a growing community of devotees has sprung up around an alternative nuclear fuel: thorium. But is it right for Australia?

The call for thorium power is not without precedent worldwide. India has pursued thorium technology for decades. And China is revisiting a molten salt reactor design mothballed by the USA in the 70’s. Recently, several companies have sought to commercialise thorium energy, including an Australian-Czech alliance.

Thorium: critically different
Thorium (atomic number 90) shares several similarities with its neighbour two doors down on the periodic table, uranium (atomic number 92). Both elements are silvery metals and are mildly radioactive as ores. They are each moderately abundant in the Earth’s crust, and can release prodigious amounts of energy under the right conditions.

https://images.theconversation.com/files/72886/original/image-20150224-32241-1bu1u5i.jpgixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1
Thorium, named after the Norse god of thunder, and is a lightly radioactive metal that is slightly lighter than uranium. W. Oelen, CC BY-SA

One critical difference is that thorium, in its natural state, is resistant to fission. This is the process whereby the atomic nucleus splits apart, thus releasing energy that can then be harnessed to generate electricity.

Uranium can undergo fission relatively easily, but for thorium to undergo fission – and be useful in a nuclear power plant – it must first be converted into a usable form. This is done via a process known as “breeding”, where the thorium absorbs a neutron, thus transmuting into a heavier element that can later undergo fission.

Thorium was first studied as an energy source during the Manhattan project, but uranium proved much easier to work with. During the post-war commercialisation of nuclear energy this dominance was reinforced. Engineers identified myriad paths to design reactors based on uranium, while the added complexities of thorium meant that alternatives didn’t get much of a look in.

Today, advocates of thorium typically point to a variety of advantages over uranium. These include fail-safe reactor operation, because most thorium reactor designs are incapable of an explosion or meltdown, as was seen at Chernobyl or Fukushima. Another is resistance to weapons proliferation, because thorium reactors create byproducts that make the fuel unsuitable for use in nuclear weapons.

Other advantages include greater abundance of natural reserves of thorium, less radioactive waste and higher utilisation of fuel in thorium reactors. Thorium is often cast as “good nuclear”, while uranium gets to carry the can as “bad nuclear”.

Not so different
While compelling at first glance, the details reveal a somewhat more murky picture. The molten salt architecture which gives certain thorium reactors high intrinsic safety equally applies to proposed fourth-generation designs using uranium. It is also true that nuclear physics technicalities make thorium much less attractive for weapons production, but it is by no means impossible; the USA and USSR each tested a thorium-based atomic bomb in 1955.

Other perceived advantages similarly diminish under scrutiny. There is plenty of uranium ore in the world and hence the fourfold abundance advantage of thorium is a moot point. Producing less long-lived radioactive waste is certainly beneficial, but the vexed question remains of how to deal with it.

Stating that thorium is more efficiently consumed is the most mischievous of the claimed benefits. Fast-breeder uranium reactors have much the same fuel efficiency as thorium reactors. However, they weren’t economic as the price of uranium turned out to rather low.

The thorium dream continues overleaf

Don't believe the spin on thorium being a greener nuclear option
Eifion Rees for the Ecologist Fri 24 Jun 2011 01.52 AEST First published on Fri 24 Jun 2011 01.52 AEST

Ecologist: It produces less radioactive waste and more power but it remains unproven on a commercial scale.


A lorry transporting nuclear waste with low radioactivity, La Hague, France Photograph: Olivier Laban-mattei/AFP

In a world increasingly aware of and affected by global warming, the news that 2010 was a record year for greenhouse gases levels was something of a blow.

With the world's population due to hit nine billion by 2050, it highlights the increasingly urgent need to find a clean, reliable and renewable source of energy.

India hopes it has the answer: thorium, a naturally occurring radioactive element, four times more abundant than uranium in the earth's crust.

The pro-thorium lobby claim a single tonne of thorium burned in a molten salt reactor (MSR) – typically a liquid fluoride thorium reactor (LFTR) – which has liquid rather than solid fuel, can produce one gigawatt of energy. A traditional pressurised water reactor (PWR) would need to burn 250 tonnes of uranium to produce the same amount of energy.

They also produce less waste, have no weapons-grade by-products, can consume legacy plutonium stockpiles and are meltdown-proof – if the hype is to be believed.

India certainly has faith, with a burgeoning population, chronic electricity shortage, few friends on the global nuclear stage (it hasn't signed the nuclear non-proliferation treaty) and the world's largest reserves of thorium. 'Green' nuclear could help defuse opposition at home (the approval of two new traditional nuclear power reactors on its west coast led to fierce protests recently) and allow it to push ahead unhindered with its stated aim of generating 270GW of energy from nuclear by 2050.

China, Russia, France and the US are also pursuing the technology, while India's department of atomic energy and the UK's Engineering and Physical Sciences Research Council are jointly funding five UK research programs into it.



China did announce this year that it intended to develop a thorium MSR, but nuclear radiologist Peter Karamoskos, of the International Campaign to Abolish Nuclear Weapons (ICAN), says the world shouldn't hold its breath.



Others see thorium as a smokescreen to perpetuate the status quo: the world's only operating thorium reactor – India's Kakrapar-1 – is actually a converted PWR, for example. 'This could be seen to excuse the continued use of PWRs until thorium is [widely] available,' points out Peter Rowberry of No Money for Nuclear (NM4N) and Communities Against Nuclear Expansion (CANE).

In his reading, thorium is merely a way of deflecting attention and criticism from the dangers of the uranium fuel cycle and excusing the pumping of more money into the industry.

And yet the nuclear industry itself is also sceptical, with none of the big players backing what should be – in PR terms and in a post-Fukushima world – its radioactive holy grail: safe reactors producing more energy for less and cheaper fuel.

In fact, a 2010 National Nuclear Laboratory (NNL) report (PDF)concluded the thorium fuel cycle 'does not currently have a role to play in the UK context [and] is likely to have only a limited role internationally for some years ahead' – in short, it concluded, the claims for thorium were 'overstated'.

Proponents counter that the NNL paper fails to address the question of MSR technology, evidence of its bias towards an industry wedded to PWRs. Reliant on diverse uranium/plutonium revenue streams – fuel packages and fuel reprocessing, for example – the nuclear energy giants will never give thorium a fair hearing, they say.

But even were its commercial viability established, given 2010's soaring greenhouse gas levels, thorium is one magic bullet that is years off target. Those who support renewables say they will have come so far in cost and efficiency terms by the time the technology is perfected and upscaled that thorium reactors will already be uneconomic. Indeed, if renewables had a fraction of nuclear's current subsidies they could already be light years ahead.

A bit more here

[url]https://www.theguardian.com/environment/2011/jun/23/thorium-nuclear-uraniu

Thorium Reactors: Fact and Fiction. These next-generation reactors have attracted a nearly cultish following. Here are the real facts. 
by Brian Dunning Skeptoid Podcast #555 January 24, 2017



Today we're going to take a second look at a technology that, in the past few years, has become something of a cult icon.

Thorium reactors, some say, can provide limitless energy; with a fuel that's cheap, safe, and abundant; using reactors that can't melt down, can't be used for nuclear weapons production, and produce almost no appreciable waste. Such a system would seem to be a virtual miracle.

So today we're going to examine these claims, and see if we can find some facts in (what appears to be) an inordinate amount of hype. Cultish support for anything should always raise a red flag or two.

First, I have two disclaimers for you. One is that the technical discussions in this episode are oversimplified. They have to be. It takes decades to design a nuclear power plant, and we can't make a comprehensive comparison in only a few minutes. So don't email telling me that I grossly oversimplified something. I'm already telling you now that I will.

Second, there are far more different types of reactors than we could possibly address. There are a lot of basic reactor designs. There are different fissile materials that can be used as fuel. There are different fuel cycles. There are fast reactors versus thermal reactors, and burners versus breeders.

Some designs use fuel in solid rods, and some have the fuel dissolved in the cooling liquid itself. Some are high pressure, some are low pressure. Most of these variations can be put into any combination, resulting in more designs than you can shake a stick at. So when you say "nuclear reactor", that's an almost uselessly vague term. And when we talk about thorium reactors, we're only narrowing it down somewhat. There are still competing types with different sets of benefits and drawbacks.

About the only thing they have in common is the basic idea, which is exactly the same as geothermal energy. Heat from radioactive decay — either from the Earth's mantle or in a reactor core — is used to boil water and turn a steam-powered generator. We've just synthesized the Earth's natural process to a point where we can optimize and control it.

Uranium-238 is the one that does most of the Earth's underground heating, because there's a lot of it. Hold a chunk in your hand and it's very safe, because it's quite stable and barely decays at all. But a bit less than 1% of it is fissile Uranium-235, which is what we need for fuel.

Reactor fuel has two basic parts: a "fissile" material that emits neutrons, and a "fertile" material that absorbs the neutrons and continues the cycle. For uranium fuel, we take that natural uranium, separate out a lot of the U238 to create "enriched uranium" which has about 4% of fissile U235, and the rest is fertile U238.

This gets combined with other material to make ceramic pellets which are stacked into metal rods, and these are the familiar fuel rods that most of today's reactors use. Installed in a reactor core, those rods are very hot because of the reactions happening within them, and they boil the water and make electricity.

After about six years, a typical 2-meter fuel rod is no longer hot enough to run the reactor, and it becomes nuclear waste. It's still very hot, and remains so for decades.

Inside that rod, a lot of that U235 has decayed by spitting out heat and neutrons. Some of the U238 has captured those neutrons and become plutonium, which also decays.

The uranium decays into thorium, which decays into protactinium, which decays into actinium; we get more thorium, francium, radium, radon, polonium; the chain goes on and on.

That spent fuel rod ends up with just about anything you can imagine in there. It's a lot of waste, though some of it can be recycled via any of numerous costly and inefficient processes, after enough time has gone by. That whole process is what we call the uranium-plutonium fuel cycle.

So now let's contrast that with the thorium-uranium fuel cycle, that has so many people excited. Thorium-232 is what's found in nature. However, thorium is not fissile. Thorium is the fertile element of the fuel; it still needs a fissile element to get it started. And here is one place the thorium-uranium fuel cycle differs from the uranium-plutonium fuel cycle.

Most thorium-fueled designs are breeder reactors, meaning they produce more fissile material than they consume. So once the thorium fuel cycle is started by adding fissile U235, theoretically, no more fissile material will ever need to be added. We can continue adding only fertile thorium.

This arrangement generally works best in a reactor type called an LFTR (pronounced "lifter"), a liquid fluoride thorium reactor. The thorium, and all the other elements that are part of the fuel cycle, are dissolved in molten fluoride salts.



See the full story here

https://skeptoid.com/episodes/4555

Hi Juliar,
I wish you would have put this in
the Environment forum.

juliar wrote on Oct 2^nd, 2019 at 12:14pm:



But the new ice age thread is now hidden.

Kelpie,
Fine when the sun shines but do not forget that the energy density of sun light is quite low and so it takes a few square kilometers of solar panels to generate anything even remotely worthwhile.

And the solar panels only work for a few hours around midday.

And there is the ever present problem of cleaning dust and bird droppings off the solar panels.

And keep you fingers crossed if there is a big hailstorm.

So without the as yet undeveloped magic storage solar is a waste of time really.

There is talk of using hydrogen to store the energy as it is limitless.

But when you are talking of supplying big industry like an aluminium smelter then you need man size power generation like coal or hydro or nuclear or thorium.

Why thorium is not very popular.  Lots of further discussion.





Why doesn't Australia or other countries use Thorium based nuclear power plants?
Mike Miller, Materials Engineer

India has spent decades working toward thorium-based nuclear power, which is an indication that the thorium fuel cycle isn’t a quick-and-easy thing to implement.

For other nations, there are a number of sensible problems with thorium:

Uranium is currently inexpensive and plentiful. After mining, enrichment, and assembly of fuel rods, you’re good to go with uranium fuels. You get your megawatts.

Thorium won’t fuel moderated reactors by itself. It needs to be bred into uranium-233, like the fuel cycle link above indicates. This means:

You have to start a reactor with regular enriched uranium fuel or MOX fuel, and fill the reactor with thorium targets. This may be mixed into the regular fuel or be in a separate breeding blanket.

If you need a separate breeding blanket, then it’s going to be hard to use existing reactors to breed thorium. You might need an all-new design, or a separate breeder reactor.

Certain existing reactors might use thorium, but it’s not trivial. The CANDU family’s rare heavy water moderation and on-load fueling are not present in most power plants. https://inis.iaea.org/collection...

You have to wait years for the thorium to be bred into U-233.

Ideally, you frequently remove thorium targets to give the protactinium-233 formed by bombarding thorium-232 a chance to decay into U-233. Otherwise, the protactinium might be capture another neutron and turn into something else. This is why CANDU reactors and others with on-power refueling are great for the thorium fuel cycle. Unfortunately, they’re not common. Most reactors are stopped and refueled every 18 to 36 months. See point b, above.

You have to reprocess the fuel (usually) to extract the U-233 and form new fuel rods from it. This is an entire Nuclear reprocessing step (and facility) that uranium enrichment doesn’t require.

The end result is that you might need multiple models of reactors (like India) to run on thorium; it takes a long time to set up the thorium-fuel cycle (like India); and it is more expensive than once-through uranium fuel cycles.

Many nations have dabbled in thorium fuel cycles at some point. It’s not impossible to implement. It’s just a lot of work and money in a field that’s pretty expensive already.

https://www.quora.com/Why-doesnt-Australia-or-other-countries-use-Thorium-based-...

Bobby. wrote on Oct 2^nd, 2019 at 2:55pm:


Think your math is a bit off Bobby. There are 1 million square meters in a square kilometer, therefore there is the potential to capture 1 Gigawatt. Of course, you have to consider angle of insolation and the periods of the day when the sun shines, as well as efficiency. With an efficiency of 25%, the maximum output you'd expect in a square kilometer plant is 250 MW. With an Availability Factor of 0.25, which factor insolation angle and periods when the sun is available, and your square kilometer plant has an equivalent output of 62.5 MW.

In the northern parts of Europe, the Availability Factor for solar drops to 0.1. This means that if you wanted, for example, to run Great Britain on nothing but solar and wind, which has an Availability Factor of 0.5, you'd have to allocate 30% of the land surface to provide the region's energy needs!

minichrist has tickled the Achilles Heel of the renewable rubbish.

There is not enough suitable treeless land available to build the the millions of solar and wind farms required to come even close to the continuous reliable stable output of a good coal power station.

And this renewable rubbish is clapped out after about 20 years!!!

Like all dopey Greeny "solutions" renewable rubbish is just a waste of money that doesn't work.

We have been for ages already and everyone was quite happy to be able to afford to switch a heater or air conditioner on.

It is only the ratbag Greenies fabricating lies to try to get the UN One World Govt in a Sustainable world up and going.

These despicable desperate Greeny brutes are now exploiting brainwashed little kiddies who would not know what day it is.

And now there is a plan to cut the Welfare of the Greenies' Rent a Crowd's WELFARE. The Empire fights back.

Or the people's Messiah ScoMo.

How close are we to a commercially viable thorium reactor; i.e. one that could pass several countries' regulatory approval processes, and where the cost of construction and fuel would be competitive with other forms of electricity generation?
Robert Steinhaus
Answered Oct 13, 2015   Originally Answered: What is the economic viability of building a Thorium reactor?

Trying to determine the economic viability of Thorium reactors with our present level of knowledge is very difficult.  There really is no basis for estimating the initial cost of any power plant until there is a pretty solid design concept that is near complete and is engineering detailed. Without a finished commercial Thorium reactor design, any cost estimate is fraught with uncertainty.



In the 1960s and 1970s Oak Ridge National Laboratory produced several Thorium Molten Salt Reactor designs. Those preliminary reactor designs included fair and responsible  project cost estimates specific for their era. Modern Thorium MSR advocates frequently try to use old ORNL MSBR cost estimates while adjusting those preliminary cost estimates by applying a standard inflation adjustment factor.  While this is about the best that is currently possible without a completed and fully engineered TMSR design, it is far from satisfactory.

When trying to explore the cost of power plants to access economic viability, it is worthwhile to apply a consistent method in cost evaluation to make fair comparisons. DOE EIA is expert in evaluating power plant costs and provides information from which more reliable and fair comparisons can be made.

How much does it cost to build different types of power plants in the United States?
http://www.eia.gov/forecasts/cap...

https://www.quora.com/How-close-are-we-to-a-commercially-viable-thorium-reactor-...

What are the best generation 4 nuclear reactor designs?
Robert Steinhaus, former Engineering Staff - Field Test Division at Lawrence Livermore National Laboratory (1974-2008)
Updated Oct 2


The worst Gen-4 reactor design is the Gen-4 Sodium-Cooled Fast Reactor (SFR).



Sodium Cooled Fast Reactors operate in the fast neutron spectrum and use an inferior coolant (molten sodium metal) from the standpoint of safety. Sodium Cooled Fast Reactors (SFRs) are capable of producing LARGE accidents (intense sodium metal fire combined with a very energetic hydrogen explosion). The radioactivity contained inside a Gen-4 SFR is greater than any other Gen-4 design. This results from the neutron activation of literally thousands of tons of molten sodium metal coolant to the highly radioactive Na-24 isotope with a half-life of 15 hours.



Although sodium has some safety advantages (low pressure operation), it also has serious drawbacks (metal fires and potential large powerful hydrogen explosions if sodium coolant comes into contact with water or cement).

Perhaps the most serious safety problem with sodium coolant is that it reacts violently with water and burns spontaineously at reactor temperature if exposed to air.

The steam generators used in fast reactor systems, in which molten sodium and high-pressure water are separated by thin metal pipes, have proven to be one of its most troublesome features. Any leak results in a reaction that can rupture the tubes and lead to a major sodium-water fire.

Historically, a large fraction of the liquid sodium-cooled reactors that have been built required being shut down for long periods because of sodium fires.

When sodium coolant absorbs a neutron, it turns into sodium 24, a hard to shield intensely radioactive gamma-emitting isotope.

As an SFR reactor operates, the sodium that cools the fuel rods in the reactor core becomes intensely radioactive.



To ensure that a steam generator fire does not disperse radioactive sodium, reactor designers insert an intermediate sodium loop in which heat generated from the reactor is transferred to non-radioactive sodium through a sodium-sodium heat exchanger. The nonradioactive sodium delivers heat to the steam generators that then generate electricity. The extra sodium loops and associated pumps and intrinsic safety and reliability problems contribute to the higher capital costs of sodium cooled fast spectrum SFR reactors.

Finally, unlike water cooled reactors that cease functioning if they lose their coolant (a valuable safety feature), less dynamically stable fast neutron Sodium Fast Reactors tend to become more reactive in cases where sodium coolant is lost. Furthermore, if the core heats up to the point of collapse and suffers a meltdown, the fuel can assume a more critical configuration and blow itself apart in a small nuclear explosion. Whether such an explosion could release enough energy to rupture reactor containment and cause a Chernobyl-scale release of radioactivity into the environment is the subject of major concern and debate.

Historically, sodium cooled fast reactors have had severe reliability problems. The necessity of keeping air from coming into contact with the sodium coolant makes refueling and repairing fast reactors much more difficult and time-consuming than for water cooled reactors. The fuel has to be removed in an atmosphere free of oxygen, the sodium drained, and the entire system flushed carefully to remove residual neutron activated sodium without causing an explosion. Such headaches have contributed to many fast reactors sitting idle a large fraction of the time. France’s now decommisioned Superphénix SFR, the world’s only commercial-sized breeder reactor, generated on average less than 7 percent of its capacity over its nominal operating lifetime. Japan’s Monju and Britain’s Dounreay prototype fast reactors and the U.S. Enrico Fermi 1 demonstration breeder reactor had similar records. Russia’s BN-600 has managed to maintain a respectable capacity factor (the percent of time it runs at full power), but only because of the willingness of its operators to keep it running despite multiple sodium fires. To date, Sodium Fast Reactors have been poor investments for communities and nations that have invested in them.

Fast reactors and their fuel cycles pose serious proliferation risks. All reactors make plutonium in their fuel, but breeder reactors require that this plutonium be separated from the intensely radioactive fission products in spent fuel and reused. The separation process, so-called reprocessing, also makes the plutonium more accessible to aspiring nuclear weapon makers.

This concern is not just theoretical. India justified its reprocessing program by citing an interest in breeder reactors, but in 1974, India used its first batch of separated plutonium to carry out a “peaceful nuclear explosion”weapons test.

Read on here

https://www.quora.com/What-are-the-best-generation-4-nuclear-reactor-designs