Thorium nuclear reactor trial begins in Norway

http://www.extremetech.com/extreme/160131-thorium-nuclear-reactor-trial-begins-could-provide-cleaner-safer-almost-waste-free-energy

by sasoon • 13 years ago

419 137 13 years ago

extremetech.com

tehabe• 13 years ago

"[Thorium reactor] could provide cleaner, safer, almost-waste-free energy" Always when somebody claims this, it almost never works that way.

embolism• 13 years ago

Therefore it never will.

nawitus• 13 years ago

More like the claim will be true but ignored, atleast when it comes to cleaner and safer.

welterde• 13 years ago

At least pebble bed reactors (like the already mentioned THTR-300) are not really safe. Get a bit of water into the primary cooling cycle, while the reactor is running at capacity and you won't have that power plant for long (happened at the AVR.. luckily it was running at lower temperature at the time so they only had to run the reactor quite a lot reduced capacity for a year to get the water out).

As for molten salt reactors.. still lots of problems to be solved related to the combination of molten salt and high temperature (I recall there being an US based molten salt reactor that got it's cooling cycle contaminated somehow.. but can't seem to find it right now)

danmaz742• 13 years ago

"but not in the sense that most people think of when they hear the word thorium [...] they haven’t created a cold fusion thorium reactor"

What is this supposed to mean? Who ever talked about cold fusion thorium reactor? Was the author thinking about toroidal fields in Tokamak (which is very hot fusion)??

hughes• 13 years ago

Keep in mind, this article was written by the same author as "Cold Fusion reactor independently verified"[1]. He seems somewhat obsessed with the idea.

[1] http://www.extremetech.com/extreme/156393-cold-fusion-reacto...

danmaz742• 13 years ago

So maybe he should know that thorium has nothing to do with fusion :)

ramidarigaz• 13 years ago

And, as a couple people have pointed out, Thorium isn't even used in fusion. This author could stand to do a little more reading on the subject.

jaggederest• 13 years ago

Nothing like fusing Thorium into some ??? 462

scrumper• 13 years ago

This is interesting and encouraging stuff. I'm a big believer in fission power as our best option for a clean source of huge amounts of electricity (which we'll only need more of as electric cars start to become popular).

My main reason for commenting is to congratulate Thor Energy on coming up with a trebly relevant name.

ownagefool• 13 years ago

There was an enegry debate here a couple of months ago and it was suggested that the future of enegry is everyone will have a solar panels and a battery which is charged by the sun.

Once you think about distributed power, the need to generate mass amounts in one place seems to be less important, though having access to cleaner and safer ways of doing so are still good things as no doubtsome of us will still rely on the grid sometimes.

lostlogin2• 13 years ago

Give us decent batteries and all will be well. My parents just scrapped their solar set up. Summer days in the Bay of Plenty, New Zealand, provides enough sun to have the charging switch off at about 9am, batteries full. Big Mac Pro, lots of IT gear, coffee machine, vacuum cleaner etc all used normally. No problem. But come winter the batteries would be perilously low, risking damage. Days and days of torrential rain prevented any meaningful charging. The ability to store more power economically would be so very handy. The panels would provide vastly more power than was used during a year, but were uneconomic due to not being able to feed it back to the grid (!!?!) and not being able to store enough. I'd say that decent power storage was a bigger problem than the generation.

r00fus• 13 years ago

Solar (and Wind) power both are not good base load power solutions - primarily because battery tech to store power for long periods isn't practical yet, and due to their cyclical availability.

Also to note - the framework to transfer/sell power from an area of excess to another (i.e., P2P power supply) is nonexistent, let alone trying to merge that with centralized power (for right now, you can only really sell your power to the utility - and they don't like it because it costs a lot for them to manage it).

Solar/Wind are very very important to a diverse and strong power mix (and for low stable energy prices), but combined with fission (or fusion once it's feasible) or other traditional power sources, you get a lot more stability and predictable power generation.

alephnil• 13 years ago

Distributed power may work in sparsely populated areas, but urban areas have a too high population density for that to work. That is even the case for whole countries, like Germany, where all the available renewable energy resources amounts to no more that 25 % of the current energy uses. That number is even unrealistically high, requiring to cover almost any available surface with solar panels and all usable spots with wind turbines etc.

Thus in such areas, a centralized grid is needed to transport electricity from where it is available to where it can be used. This can be nuclear, but it can also be renewable energy, e.g solar energy from southern Spain and Sahara or wind power from Norway in the case of Germany, but to produce everything locally won't work a lot of places.

kmfrk• 13 years ago

Interesting contrast to the German reaction to Fukushima.

Ashuu2• 13 years ago

I hope such technology comees to India soon!

DennisP4• 13 years ago

You may know this but India's been working on it, since it has substantial thorium reserves and not much uranium.

pjg2• 13 years ago

Here's the link: http://en.wikipedia.org/wiki/Prototype_Fast_Breeder_Reactor#...

apendleton• 13 years ago

I'm super-interested in thorium reactor research, but this author seems to lack even a cursory understanding of the issues at play. This reactor differs from what lots of thorium advocates are aiming for because it's a solid-fueled, high-pressure, water-cooled reactor, instead of the proposed LFTR designs, which involve a reaction taking place in a liquid at very high temperature, but at atmospheric pressure, and thus have a different set of tradeoffs as far as efficiency, safety, proliferation resistance, etc.

This article discusses none of that, and instead suggests that this reactor is sub-optimal because it's not a cold fusion reactor -- what? Thorium atoms are big and somewhat-unstable, which is what you want for fission. For fusion, you want little atoms you can ram together to make slightly-bigger little atoms. They're totally separate.

dragontamer2• 13 years ago

You're right, the author clearly doesn't know what he's talking about. But the story is still interesting nonetheless. :-)

Its great to hear news that Thorium is finally on the path to adoption.

tankenmate• 13 years ago

Unfortunately the type of reactor they are building is not as safe as a LFTR, nor does the fuel in this type of reactor last as long; the LFTR reactor is a type of fast breeder reactor. It will still need to be fed pellets continually. The only two material difference between this kind of reactor and a normal boiling water reactor is that it is capable of "burning" a small amount of uranium and/or plutonium a year (either from spent fuel or new sources), and the spent fuel is far less radioactive after a full burn (a full burn is not always the case). It still has most of the other safety issues of a boiling water reactor.

mrsebastian2• 13 years ago

You're right, I know very little about nuclear reactors. (I'm the author.) Enough to get by, but not enough to be an authority on every variety of them.

Hopefully enough to write an interesting story, though :)

ChuckMcM• 13 years ago

In order to make Thorium successful you have to consider the consequences. The Nuclear Power industy has been under attack now significantly longer than it was "the next big thing" (during the 50's it was 'cool' and starting in the mid-sixties on it has been 'un-cool') Long enough that all it knows is 'attack.' If someone says "This will make all our Nuclear reactors obsolete!" it makes Thorium an enemy that must be killed. But if you say "This works with your existing reactor and the spent rods are more easily disposed." Then its a 'friend' of the industry. So making fuel rods with Thorium that are compatible with existing designs is a Big Deal(tm).

jshen5• 13 years ago

How long can we continue to believe our energy needs can rise at the level we've become accustomed too?

This is scary: http://physics.ucsd.edu/do-the-math/2011/07/galactic-scale-e...

danbruc• 13 years ago

This is probably rather pointless - first normalize the energy consumption by the population. Because population growth was exponential for a long time, the energy consumption per capita was probably more or less constant. It will get very crowded way before our energy consumption starts to melt the earth.

jshen5• 13 years ago

I think the global energy consumption per capita is rising rather quickly as other countries adopt American levels of consumption.

sliverstorm2• 13 years ago

No one with even a rudimentary understanding of exponential growth believes energy consumption can grow exponentially forever. But the problem is self-fixing; one day, the supply of energy will stop growing as fast as demand. The day will come, the day will pass, and the world will adjust.

jcrites2• 13 years ago

In particular, prices will rise gradually over time, which will encourage investment in cost-lowering research and development, as well as into energy generation.

The market is what helps the world adjust. Unless a dramatic event causes a significant change in prices in a short time, things will carry on just like they always have.

jshen5• 13 years ago

How painful will the adjustment be? Potentially very painful.

lalc• 13 years ago

That is a really silly article. The author extrapolates hundreds and then thousands of years into the future.

dasil003• 13 years ago

I'm sure in 2400 years we'll have a Mr Fusion™ that we can chuck galaxies into for our home energy needs, so there's really no need for this kind of cynical hysteria.

ommunist• 13 years ago

This may be the beginning of new era. Thorium is easy to get for developed nations in the 3rd world.

pjg2• 13 years ago

India has been working on a Thorium reactor for some time already: http://en.wikipedia.org/wiki/Prototype_Fast_Breeder_Reactor#...

Tuna-Fish• 13 years ago

While the safety of nuclear power plants is hotly contested, no one is arguing the nastiness of plutonium.

Except everyone who knows anything about it. Plutonium is a hot topic because it's what you need to build a nuke, but the public perception that it is a significant as nuclear waste is simply completely misguided.

Because it's half-life is so long, it's only mildly radioactive. It's an alpha emitter, so plutonium not in your body is not a risk to you. It oxidizes easily, and it's oxides are heavy and non-soluble, so when it is released to the environment, it just tends to fall down and stay there. There is negligible biological uptake through eating, and while there is some uptake through breathing, plutonium does not tend to stay airborne.

Various people have denounced environmental plutonium as something capable of killing billions. The toxicity of plutonium in humans is not known, simply because not enough people have died of it. There is no-one in the world who has died of plutonium exposure who did not have it injected into his body (and that's a long and horrible story), and there were a lot of people who worked coated in plutonium dust for a long time. Of the people who were injected with plutonium, most died of other causes. Suffice to say, plutonium is sufficiently non-radioactive that it's chemical toxicity is considered significant in it's lethality. Or, in other words, it's fine to consider toxicity of environmental plutonium as you would consider lead or other heavy metals.

To put it short, plutonium being toxic is simply not a concern as far as nuclear waste is concerned. If all the plutonium produced by civilian nuclear power was pulverized and spread in populated areas, it would not make nuclear reactors as dangerous to people as wind power. (Somewhat ironically, because of the thorium that is released into the environment while separating the REE for the magnets.) Taking all the plutonium produced in a plant and dumping it in one spot doesn't make that spot as dangerous as the ground near a typical fuel station that was in use for the period leaded gas was used.

Nuclear waste is really bad, but that's because of short-lived isotopes, which decay more often, and thus are more radioactive, and light radioactive materials, which are often soluble in water, have high biological uptake, and can stay in the atmosphere.

Plutonium needs to be tracked really closely, but that is not because it's toxic, it's because it can be used to make a bomb.

The more you know.

mikeash4• 13 years ago

"In Massachusetts, 57 developmentally disabled children were fed radioactive oatmeal in an experiment sponsored by MIT and the Quaker Oats Company."

What the fuck. The bit about Quaker is really nuts.

From http://en.wikipedia.org/wiki/The_Plutonium_Files for anyone who doesn't feel like googling it.

joezydeco• 13 years ago

Christ, I used to live a block from Quaker's R&D facility in the Chicago suburbs. They never mentioned anything about radioactive research there. I bet there's all kinds of skeletons buried in the backyard. Oh wait, now there's a Gatorade workout field on top of it...

mseebach• 13 years ago

"In none of these cases were the subjects informed about the nature of the procedures, and thus could not have provided informed consent."

This - and not the plutonium - is the bad part. Your comment is completely irrelevant to argument the parent makes.

curtis• 13 years ago

The oatmeal had radioactive tracers in it. This is described in more detail at http://en.wikipedia.org/wiki/Walter_E._Fernald_Developmental....

Everybody seems to agree that the whole experiment was unethical, but it seems unlikely that that the radiation harmed any of the subjects.

kunai2• 13 years ago

Radioactive tracers, not radioactive material. The media loves to hype this up.

Essentially, what you get injected in you whenever you go for a CT scan, except this was a far, far lower dose.

Stupid sensationalism.

comrade_ogilvy2• 13 years ago

The other thing about plutonium people fail to recognize is that practical uranium civilian power reactors are pretty lousy at producing plutonium. The proliferation risk is non-zero, but processing spent fuel is a pretty nasty business and the amount of plutonium there is so small as to be a big expense for the small yield.

The problem with plutonium is a properly designed military reactor can take the precious U235 you might build only one half a bomb with, and generate enough plutonium to create 2 or 3 implosion devices.

That is a big reason the neighbors to Iran and NK are not panicking. NK might have a bomb or two. Iran might eventually build a bomb or two. In both cases, their expertise is limited to uranium (so far), so the number of bombs they are likely to ever own within my lifetime is very few -- their stockpiles of uranium too modest to create a larger weapons stockpile. To actually use a bomb is so reckless that you need a couple dozen bombs in your back pocket to deter the overwhelming payback. Both NK and Iran are a million miles away from getting there; they need both much more uranium and plutonium expertise to even start an attempt.

If they believed their safety were at stake, South Korea or Japan would build 50 bombs -- they are skilled at the requisite technologies. Likewise Saudi Arabia would write a check $100 billion and acquire a nuclear stockpile of their own -- their defense expenditures are so astronomically high that a modest cut to their conventional forces over a decade would foot the bill.

caf3• 13 years ago

The first two devices that North Korea has tested are thought to have been Plutonium-based (the third is inconclusive). North Korea is known to have produced and reprocessed Pu at its Yongbyon complex.

speeder• 13 years ago

North Korea seemly can use both Plutonium and Uranium (or something else entirely even).

South Korea kinda does not care, because they know North Korea wants the entire Korea, not half-korea and half burned slab of ground.

North Korea in the past had enough non-nuclear firepower to flatten South Korea many times over, seemly they STILL have that firepower AND nukes, yet South Korea knows they won't use it...

Japan on the other hand, IS kinda paranoic, in the last elections a new party was formed, with a militaristic and nationalistic tone (including visiting WWII shrines and reacalling WWII as the good times), and they got expressive votes, also the current prime minister proposed heavily remilitarize Japan (to irritation of China, and both Koreas), including scratch the current constitution, and use a new one that follow confucionism (instead of illuminism).

rdtsc• 13 years ago

Let's consider a scary scenario. Someone defects and shares with them all the knowledge, the blueprints, all the data related to handling and processing plutonium. How much closer would they be then to be considered dangerous. In other words is it just a matter of having information, or a matter of resources and money?

threeseed• 13 years ago

North Korea will never use nukes against South Korea. They want a reunified Korea under Kim Jong Un. And the best way to do this without killing innocent people is to do what they've attempt countless times before.

Dig a tunnel under the DMZ and send people in to capture/assassinate the key people within the government.

_b8r0• 13 years ago

There are several problems when it comes to gulf states for your anecdote.

The problem isn't a stable country like Saudi having the bomb, the problem is triggering an arms race. If Iran gets the bomb then what does that mean for Lebanon? If Iran gets the bomb what does that mean for Hezbollah? If Iran gets the bomb what does that mean for Syria?

If Iraq had the bomb in the 80s what would that have meant for the Iran/Iraq war, or the first Gulf war? Saddam Hussein may have felt that nuking Kuwait as part of a scorched earth policy would've been valid. After all, he used chemical weapons against Iran (and his own people).

I can't speak for asia but in the middle east nuclear bombs change the balance of power substantially.

pekk• 13 years ago

To actually use a bomb is so reckless that you need a couple dozen bombs in your back pocket to deter the overwhelming payback.

Assuming that there is a clear return address on any use of the weapon. How much time do you have to determine where to send the answering salvo? This argument made some kind of sense during the cold war, but it's dangerously naive if nearly everyone has a bomb and a long-range launch capability.

klapinat0r• 13 years ago

The more you know.

Thanks for an insightful post.

While procrastinating for an exam a while back, I decided to read up on the Chernobyl accident. It always remembered it as a horrible accident (which it was), significantly due to the errors involved, and the massive impact it had on the victims involved.

If I read your post correctly, it should not be attributed to plutonium. Would you mind elaborating on what kind of radioactive fumes/waste this could've been?

While the number of victims may be high, the number of casualties is impossible to determine: could range from 50s to 200,000s. In either case, I assume this is due to other radioactive waste (airborne?), or am I mistaken?

lostlogin2• 13 years ago

I too went down the Chernobyl history rabbit hole during so-called study. It's absolutely incredible. The big thing that gets me (which seems to happen at work in rather less cataclysmic style, and in every industry all the time) is the way that every misstep was followed by those involved making the worst possible decision. Then the next thing done compounds the earlier events - often with the chain of events occurring over months. Why do people universally do the worst possible thing at the worst possible time, and miss every opportunity for course correction?

caf3• 13 years ago

Highly active fission products - things like Iodine-131 and Caesium-137, but fissioning Uranium creates a large grab-bag of different fission products with very different half-lives and decay types.

Daniel_Newby2• 13 years ago

IIRC, the risks from Chernobyl were mainly from iodine-131, strontium-90, and cesium-137.

Iodine-131 has strong uptake into the body, concentrates in the thyroid gland, and is highly radioactive. It is bad news.

Strontium-90 is well absorbed by humans, becomes locked in the bones, and has a half-life of decades. It is a significant long term problem.

Cesium-137 also has a decade-ish half-life and some body uptake. The main issue with it is that reactors produce large amounts. If it was a trace product it could be ignored.

Tichy2• 13 years ago

How is wind power dangerous to people? Because the production of wind wheels pollutes the environment? Or it diverts thunderstorms? Maybe people die in the construction of the turbines? But then, wouldn't people die in mining Plutonium and constructing nuclear power plants? Somehow my faith into that kind of number juggling to make nuclear power look good has not yet been 100% established.

jws3• 13 years ago

Apparently about a dozen people a year are killed installing or maintaining wind turbines, however the post in question was referring to byproducts of refining the rare earths ultimately used for the magnets in the generators.

http://www.caithnesswindfarms.co.uk/accidents.pdf

(Solar is fairly deadly too. Mostly installers falling from roofs.)

mhartl• 13 years ago

This is an excellent and insightful comment. One quick note: it's and its are different words. I count ten occurrences of "it's", four of which should be "its":

    it's what you need           [correct in original]
    its half-life
    it's only mildly radioactive [correct in original]
    It's an alpha emitter        [correct in original]
    its oxides
    its lethality
    its *chemical toxicity*
    it's fine                    [correct in original]
    it's toxic, it's because     [correct in original]

ekianjo• 13 years ago

Btw, for people out there who know nothing apart from the media gibberish on nuclear energy, the ongoing nuclear energy course by Larry Foulke on Coursera is a good place to start to better under all aspects of nuclear reactors and radioactivity.

rorrr2• 13 years ago

Because it's half-life is so long, it's only mildly radioactive. It's an alpha emitter, so plutonium not in your body is not a risk to you

"if inhaled or digested, however, plutonium's effects due to radioactivity overwhelm the effects of plutonium's chemical interactions with the body, and the LD50 dose drops to the order of 5ug/kg"

That basically makes it one of the most toxic substances that we know of.

waps• 13 years ago

Where does this information come from ? Wikipedia has much lower toxicity figures :

Several populations of people who have been exposed to plutonium dust (e.g. people living down-wind of Nevada test sites, Nagasaki survivors, nuclear facility workers, and "terminally ill" patients injected with Pu in 1945–46 to study Pu metabolism) have been carefully followed and analyzed. These studies generally do not show especially high plutonium toxicity or plutonium-induced cancer results, such as Albert Stevens who survived into old age after being injected with plutonium.[91] "There were about 25 workers from Los Alamos National Laboratory who inhaled a considerable amount of plutonium dust during 1940s; according to the hot-particle theory, each of them has a 99.5% chance of being dead from lung cancer by now, but there has not been a single lung cancer among them."[96][97]

Source: http://en.wikipedia.org/wiki/Plutonium#Toxicity

Not that I expect wikipedia to be very trustworthy on contentious issues, but still, the references do seem to lead to relatively non-political websites.

rsync2• 13 years ago

"There is no-one in the world who has died of plutonium exposure who did not have it injected into his body"

False. The "demon core" killed two people in two separate incidents:

http://en.wikipedia.org/wiki/Demon_core

... and it was not injected, as you'll see.

swamp40• 13 years ago

It's also impossible to track all the exposures that lead to cancer that then killed the person. A "benign" form of radiation is a hard sell these days - I'm not buying it.

merraksh• 13 years ago

(And yes, just in case you were wondering, the element thorium really is named after Thor, the Norse god of thunder. And yes, Norse mythology originated from Norway, where Thor Energy is based. Coincidence, I think not!)

The first sample of Thorium was found in Norway:

https://en.wikipedia.org/wiki/Thorium#History

Morten Thrane Esmark found a black mineral on Løvøya island, Norway and gave a sample to his father Jens Esmark, a noted mineralogist. The elder Esmark was not able to identify it and sent a sample to Swedish chemist Jöns Jakob Berzelius for examination in 1828. Berzelius determined that it contained a new element, which he named thorium after Thor, the Norse god of thunder.[17] He published his findings in 1829.[50][51][52]

The fact that Thor Energy is Norwegian might just be due to the country being at the same time very wealthy and environment-minded. The Norwegian reserves of thorium are far smaller than those of other countries.

Dewie2• 13 years ago

The fact that Thor Energy is Norwegian might just be due to the country being at the same time very wealthy and environment-minded. The Norwegian reserves of thorium are far smaller than those of other countries.

Norway is also only nr. 22 when it comes to proven oil reserves :) (dunno about previous figures)

From the (few, probably inaccurate) estimates, Norway seems to have a sizeable enough amount of thorium for a country of its size and population.

vehementi• 13 years ago

What if you divide oil reserves per capita, or per area?

_delirium2• 13 years ago

Considering Norway is already a net exporter of both oil and hydroelectric power, if they add cutting-edge nuclear to the portfolio, they will really be all-around energy kingpins!

Incidentally, this is the project site, which the article irritatingly doesn't bother to link: http://www.thorenergy.no/en.aspx

blaabjerg• 13 years ago

Norway has a disproportional chunk of the world's known Thorium reserves as well. It seems Slartibartfast rigged the energy lottery in their favor.

iSnow• 13 years ago

Well, Germany got burned by Thorium reactors back in the 80s: https://en.wikipedia.org/wiki/THTR-300

Let's see if this performs any better.

GhotiFish• 13 years ago

a pebble bed reactor? It's like a nuclear gumball machine! Neat!

pjscott3• 13 years ago

The THTR-300 ran into trouble because of operational difficulties with its unconventional pebble-bed design. In contrast, this is a very conventional reactor design. The difference is that the fuel is initially made of about 90% ThO2 and 10% PuO2.

oal• 13 years ago

Here are some slides containing more details about the Norwegian thorium initiative and Thor Energy: http://www.statkraft.no/Images/Thorium%20power%20abundant%20...

andor• 13 years ago

The rod in the middle of the picture contains thorium-MOX pellets, and is being inserted into the reactor (which is underground).

So these guys are standing right next to a fuel rod radioactive enough to start a nuclear chain reaction? [0] Can anybody elaborate on how dangerous this is?

[0] only if close to lots of other fuel rods, I guess...

tarre• 13 years ago

Unused nuclear fuel has very low radioactivity. It is the fission products, which are the problem regarding radioactivity. Were it a used fuel bundle, they wouldn't be standing there.

jackfoxy• 13 years ago

Wait a minute...plutonium is a waste product? I thought the supply of plutonium (that is not used in weapons) was running so low there would not be enough to fuel deep space missions.

jpollock• 13 years ago

Plutonium is manufactured in a reactor, not processed from ore. The dominant source for plutonium for deep space missions was the US government, and they dominant reason for producing it was bombs.

However, the US govt. doesn't need to produce bombs anymore - they've done enough work to know how to extend the life of the bombs they do have, as well as how to go about reprocessing the plutonium in warheads that are too old into new ones (I think). They are reducing the number of warheads in service, so the US has shut down domestic production.

The Russians seem to have caught up to the US in the warhead lifespan tech and they seem to have shut down their breeders too?

http://en.wikipedia.org/wiki/Plutonium-238

pjscott3• 13 years ago

The isotope of plutonium that's used in radiothermal generators for space missions, Pu-238, is something you produce specially. Usually you get Np-237 from spent reactor fuel, and then bombard it with neutrons in a reactor designed for producing useful isotopes.

chii3• 13 years ago

where do these neutrons come from?

gweinberg• 13 years ago

At a test site in Norway, Thor Energy has successfully created a thorium nuclear reactor — but not in the sense that most people think of when they hear the word thorium. The Norwegians haven’t solved the energy crisis and global warming in one fell swoop — they haven’t created a cold fusion thorium reactor.

Who the hell thinks "cold fusion" when they hear thorium?

btilly• 13 years ago

The "not prone to nuclear weapons proliferation" bit is critical, and unfortunately wrong. As http://phys.org/news/2012-12-thorium-proliferation-nuclear-w... points out, thorium produces protactinium-233 which can be chemically separated out. In around a month that turns into uranium-233 at sufficient purity to make nuclear bombs.

This process is much easier to do in secret than the centrifuges that are required to separate isotopes of uranium. Thus thorium is worse for proliferation, not better.

DennisP4• 13 years ago

Yes, but you have to separate the protactinium shortly after it's created, or you end up with enough U232 to make a bomb impractical. And in a solid-fuel reactor, what are you going to do, shut down the reactor every day so you can melt the fuel rods, pull out the protactinium, and refabricate them?

A liquid-fueled reactor could be another matter, and we'd want to keep an eye on them in non-nuclear states. But another factor is the breeding ratio, which is barely over one for thermal thorium. If someone were to pull out much fissile, the reactor would shut down, and they'd have to go begging for more fissile to start it up again.

Another advantage for liquid fuel is very high burnup, so pretty much all you're taking out of the reactor is fission products, not leftover fissile that could theoretically be reprocessed.

Expez• 13 years ago

The key thing here is that these pellets are designed to work with existing reactors. If you want to start using thorium it is a very hard sell (given the popularity of nuclear power atm) to build new reactors/plants, but changing the fuel in existing plants to something that can be said to be 'cleaner' or 'safer' might be doable.

Thorium nuclear reactor trial begins in Norway

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