Is Safe, Green Thorium Power Finally Ready For Prime Time?

MrSeb writes "If you've not been tracking the thorium hype, you might be interested to learn that the benefits liquid fluoride thorium reactors (LFTRs) have over light water uranium reactors (LWRs) are compelling. Alvin Weinberg, who invented both, favored the LFTR for civilian power since its failures (when they happened) were considerably less dramatic — a catastrophic depressurization of radioactive steam, like occurred at Chernobyl in 1986, simply wouldn't be possible. Since the technical hurdles to building LFTRs and handling their byproducts are in theory no more challenging, one might ask — where are they? It turns out that a bunch of U.S. startups are investigating the modern-day viability of thorium power, and countries like India and China have serious, governmental efforts to use LFTRs. Is thorium power finally ready for prime time?"

Comments

NO

[mschiller]

Why?
NIMBY

Re:NO

[Captain Splendid]

Yeah, Global Warming and Peak Energy are going to fuck NIMBY in the ass soon.

You'd be surprised what people will put up with when basic survival is on the line.

Re:NO

[Russ1642]

I'd love one in my backyard. /until I go to sell the place

Re:NO

[roc97007]

You kidding? I'd have one in my basement if I could.

Re:NO

[preaction]

Unfortunately, by the time the evidence is clear enough for even the most ardent skeptic to take seriously, it will be too late to reverse the effects.

Re:NO

[mschiller]

I agree, but that doesn't change the fact that there is an awful lot of NIMBY going on. We could've and should've been building new reactors since the 70's, but instead the reactors that are online are mostly still the original first generation designs from the late 50's and early 60's. The same whack job environmentalists who should be all for this, are also typically the most adament against it. Yet watch them and their energy use isn't substantially different then any other American....

I suspect by the time we figure out that we can't put up with this NIMBY crap we will be OUT of oil OR have completely screwed up the environment once and for all...

I mean really this was the first new nuke plant licensed in 30 years:
http://money.cnn.com/2012/02/09/news/economy/nuclear_reactors/index.htm

And it's the AP1000. Still a Water based design and Generation 3.. Though from the look of it a lot safer than most of the reactors (Gen 2) in operation

Re:NO

[amorsen]

Uranium-233 is produced in LFTR's. It is perfectly suitable for bombs. The neat thing is that it is "easy" to separate since it is chemically different from the rest of the molten salt.

Admittedly nothing is ever easy around molten salts, especially not anything involving fluorine, but that kind of reprocessing is an integral part of how an LFTR will work. If you do not have equipment that could be repurposed to separate uranium-233, you probably do not have a commercially viable LFTR.

Re:NO

[ColdWetDog]

That's Ovaltine. Read the label.

Re:NO

[ApplePy]

What are you trying to say here? That we should quit wasting our breath arguing about AGW, and focus on the simple, easy ways we can clean up our environment? Concentrate on finding ways to use less coal and oil, instead of debating how many centimeters the sea level might or might not rise by 2100?

Whoa.

Re:NO

[MagusSlurpy]

You have to read the label, because they taste the same.

Re:NO

[terjeber]

That is, to a large degree the fault of the AGW lobby. For decades we have heard how important it is for us to go green, and the two main areas that has been focused on is getting us into electric cars and putting solar panels onto our roofs. The latter is slowly becoming possible as an energy source, but is still significantly more carbon intensive than most alternatives, and the former is just a retarded idea. Electrical cars have a carbon foot print that is at least as high as gas guzzlers, and in most cases significantly higher. In addition, the gas guzzlers are close to totally irrelevant as CO2 sources, so the Electrical Car is a terrible solution to a non-problem.

These things are easy to show, so the anti-AGW crowd has a field day with the morons in the AGW crowd. Irrespective of whether AGW is a real problem or not.

Re:NO

[Maury Markowitz]

"The latter is slowly becoming possible as an energy source, but is still significantly more carbon intensive than most alternatives"

Completely wrong. I'll quote figures from the most opposed source:

http://www.world-nuclear.org/education/comparativeco2.html

PV, wind and nuclear are all within a factor of 2. Hydro is half of any of those. All the others are at least one order of magnitude away, the best definition of "significantly" I can think of.

Re:NO

[Maury Markowitz]

"awful lot of NIMBY going on. We could've and should've been building new reactors since the 70"

The two are unrelated. As with all power sources, NIMBY is considerable and noisy, but has little real influence in the end.

What killed nukes was a combination of cash-flow, overbuilding, credit problems and double-digit inflation. Even today, getting funding for reactors is extremely difficult. That has nothing to do with NIMBY and a whole lot to do with NINJA loans five years ago.

"this was the first new nuke plant licensed in 30 years" [inserting missing statement] "in the US"

Quick math shows that the plant and associated wires comes to about $7.25 a watt in CAPEX. and minimum sizes are 1 GW. Onshore wind turbines are going in for $2 to $2.50 a watt, all in, and scale from a few hundred kilowatts up.

http://www.irena.org/DocumentDownloads/Publications/RE_Technologies_Cost_Analysis-WIND_POWER.pdf

So if you have to gather money for a power project, which do you think is going to take less than five years to arrange?

Stop looking for boogiemen. Follow the money.

Re:NO

[terjeber]

Completely wrong

It is? So electrical cars are less carbon intensive than gasoline cars?

http://www.world-nuclear.org/education/comparativeco2.html

Apparently not, you seemingly answered something completely different than I stated. OK.

Re:NO

[saihung]

Your blanket statement about EVs is not correct.

http://onlinelibrary.wiley.com/doi/10.1111/j.1530-9290.2012.00532.x/full

Re:NO

[Archangel Michael]

I'm saying that the problem isn't the deniers, it is the people actively blocking attempts to implement BIG GREEN energy, while saying they are "green". You know, like the Kennedy Opposition to Wind Farms off Nantucket ... because it ruins the view. Or Al Gore's huge energy sucking house (green offsets bought by him from his company, how convenient) They are green as long as it affects everyone else.

In other words, let me know when they start walking the walk. At least Ed Begley is not a hypocrite.

Green nuclear power.

[Hatta]

Isn't it usually blue?

Chernobyl was not a light-water reactor

[CajunArson]

Chernobyl was a graphite moderated water-cooled reactor. Any commercial nuclear plant in the U.S. is a water-moderated and water-cooled reactor.

  Despite the normal perception of the word, a "moderator" actually increases the nuclear activity in a fission plant since it slows-down ("moderates") neutrons and therefore increases the probability that the neutrons cause a fission event. In Chernobyl, the coolant (water) was blown away in the pressure explosion, but the moderator (graphite) remained in place which led to the runaway meltdown.

By contrast at Three Mile Island & Fukushima, the loss of coolant led to a meltdown (literally heat causing melting to occur), but since the water moderator was also missing, the accidents did not lead to a runaway that was anywhere near as severe as Chernobyl. If Fukushima had included a pressure vessel of the same caliber as the one used at TMI, then hardly any radioactivity would have been released during the Fukushima accident.

Re:Chernobyl was not a light-water reactor

[Fallen Kell]

Fukushima did have a pressure vessel. The problem was the pressure vessel was damaged by the earthquake. The other problem was the majority of the issues were from the spent fuel rod storage in which the pool lining was damaged by the earthquake leading to the loss of all the water in the spent fuel rod pools, which then lead to a partial meltdown of the spent fuel rods in the pool with the runoff radioactive materials leaking through the same cracks which allowed the water to escape and out into the environment.

Re:Chernobyl was not a light-water reactor

[nojayuk]

Wrong in all aspects.

The spent fuel pools at Fukushima were not compromised at all during the earthquake and the tsunami or indeed after the hydrogen explosions although it was suspected they had sustained some damage at the time of the accident. After engineers gained access to the top of the reactors a month or two after the accident cameras were lowered into the pools and the fuel rod bundles appeared to be totally undamaged. Two rod bundles were recently removed from reactor 4's pool for much closer examination (they were unused with no fission products and so could be handled without the shielding precautions exposed rods would need). Those rod bundles showed no noticeable damage or deformation and only a little surface corrosion from the use of seawater to top up the pool water levels just after the accident.

The explosions were caused by overheating of the fuel elements within the reactors themselves after cooling stopped resulting in a catalytic reaction that produced hydrogen and oxygen gas via disassociation of steam. Pressure relief valves released this gas mix plus significant amounts of volatile radioactive fission products such as I-131 and Cs-134 and Cs-137 into the upper parts of the reactor buildings where the explosions occurred. Continued heating from the uncovered fuel rods in the reactors compromised the bottom of the reactor pressure vessels and some melted fuel may have made its way down into the primary containments, mixed with water and contributed to the releases.

The spent fuel rods in the pools on the reactors and in the site central pool did not contribute at all to the contamination that resulted as far as anyone can tell. The site plan posted by TEPCO states they expect to empty reactor 4's spent fuel pool by the end of 2013 after building a weather shield and a crane system on top of the damaged reactor building, and then move on to deal with the spent fuel in the pools in the other reactor buildings in turn.

Hot, liquid fluorine is too corrosive

[bradleyjg]

Molten salt has a lot of advantages as a working fluid over water, unfortunately the major big disadvantage outweighs all the positives.

Viz. the conditions inside these reactors would be absurdly corrosive. F salts are chemically aggressive, and that aggressive increases with temperature. That is compounded by the fact that the reactor materials will also be bombarded with significant neutron fluxes, and by the presence of all dissolved decay products in the working fluid.

We simply don't have materials that can stand up for any length of time to that kind of abuse.

Re:Hot, liquid fluorine is too corrosive

[Anonymous Coward]

Weinbergs team at Oak Ridge managed to work with the Fluoride salts. They used high-nickel alloys (Hastelloy N) which were able to resist the F salts. Other manufacturers have alloys of similar make up - I believe a Czech group are developing their own at the moment due to difficulty of supply from Haynes - google MONICR. The problems are not trivial, but they are surmountable.

Re:Hot, liquid fluorine is too corrosive

[TehCable]

Prohibitive corrosion is a common misconception about this type of reactor. The U.S. built an experimental MSR in the 60's and ran it for 5 years. According to the results section of the wikipedia article about the experiment, the corrosion was negligible: http://en.wikipedia.org/wiki/Molten-Salt_Reactor_Experiment#Results

Re:Hot, liquid fluorine is too corrosive

[AmiMoJo]

Interesting article.

One unexpected finding was shallow, inter-granular cracking in all metal surfaces exposed to the fuel salt. The cause of the embrittlement was tellurium - a fission product generated in the fuel. This was first noted in the specimens that were removed from the core at intervals during the reactor operation. Post-operation examination of pieces of a control-rod thimble, heat-exchanger tubes, and pump bowl parts revealed the ubiquity of the cracking and emphasized its importance to the MSR concept. The crack growth was rapid enough to become a problem over the planned thirty-year life of a follow-on thorium breeder reactor.

So not quite as problem free and viable in the long term as you were hoping. Long term operation is in fact one of the biggest problems for thorium reactors. Even if the salt doesn't damage them the reactor vessel itself becomes highly radioactive and thus difficult to examine and maintain. Decommissioning is similarly problematic.

That's one reason no-one has built a commercial scale plant. It's a long term investment and there are many uncertainties about reliability over 40+ years, where as current designs are at least proven to mostly work at reasonable cost for that kind of lifetime.

Re:Hot, liquid fluorine is too corrosive

[Artifakt]

Weinberg and others as far back as the 1940s had to work with massive amounts of radioactive heavy metal-fluoride salts, as the gaseous diffusion process itself worked with Uranium Hexafluoride. The first US gasous diffusion plant was run from the early 40s to 1987, and employed over 12,000 people in a building of over 2,000,000 square feet, so it looks like the required safety protocols were very robust and should scale to any desireable degree for power plant use.
          John W. Campbell wrote an Astounding editorial in the early 50s listing over a dozen materials that had been determined to be safe ways to handle fluorine compounds and were publicly declassified by then, and mentioned the various Nickle alloys among them. Surprisingly, many concrete and cement formulas that use Calcium Carbonates as their base are common, easy to produce materials which are highly Fluorine resistant, and various substances already incorporating Fluorine, such as the Flurocarbons and related, including Teflon, give flexable sealants, gaskets, and liners for containment vessels. There's a lot of very tough problems in this area which have already been well solved, often for half a century or more.

Re:Hot, liquid fluorine is too corrosive

[Creepy]

Most of these issues are solved in the LFTR design, from what I recall. Some of the problems with long term storage after decommission are known only because they mothballed the MSRE. Mainly, they know radioactive fluoride gasses build up, and the cracking issues should be resolved with changes to the blanket.

Oh, and the only reason one hasn't been built is because Nixon killed the program (really, and pretty much exclusively because LWRs meant jobs in California and the MSRE threatened those jobs) and the nuclear industry prefers to stick with their patented designs, which bring more money to Westinghouse and the like. The exact dollar figure invested since Nixon killed the program: $0. Meanwhile, the US has tossed almost $750 billion into IFR with zero success (Russia has had success on a lesser investment). Congress tends to get in the way in the US.

Re:What's-his-name's Law

[olsmeister]

Betteridge.

nuclear > "green" energy

[Shakrai]

I have the misfortune of living at ground zero for an ongoing wind farm build. 24/7 truck traffic, massive clouds of dust, hour plus highway shutdowns while they move their superloads, obnoxious subcontractors that ignore traffic laws, etc, etc. Then there's the ecological impact -- acres upon acres of wooded hilltops have been deforested. I truly had no idea how obnoxious it was until Google Earth got updated images. Take a look at some before and after photos of a large wind farm and see for yourself how bad it is.

All of this might be worth it if wind energy scaled the same as nuclear, or could provide the same power density, but both of those are utterly impossible. You'll never match nuclear reactions for power density, and the footprint of a nuclear power plant is no larger than that of any other modern industrial concern.

Everything in life is a tradeoff, but having lived near Three Mile Island, and now living in the midst of a wind farm, I'd take the former any day of the week. You simply didn't know TMI was there, unless you happened to have cause to drive by it. Contrast that to dozens of wind turbines, visible for miles around, along with the obnoxiousness of their build process.

Nuclear and low impact hydro are the way to go for base load. Natural gas, along with wind, and solar for the peak load.

Don't be ridiculous.

[Anonymous Coward]

Within microseconds of convincing any "environmentalist" that there is even the slightest possibility of a new class of reactor actually being built you will see the proponents vanish under thousands of lawsuits. Atomic energy is absolutely the only viable method of generating power without carbon emissions that we have, but it is not politically correct and a new reactor design not only won't change that, it will actually provoke a far more extreme response. Too much paranoia, too much stupidity, too much ignorance. It'll never happen, no matter how much it needs to. Americans can no longer deal with reality.

Re:Don't be ridiculous.

[AK Marc]

Atomic energy is absolutely the only viable method of generating power without carbon emissions that we have,

No matter how many times I see that lie, it's never going to become true. It's true if the question is: What's one and only one thing we can use to replace coal/gas/oil power generation, considering no other options?

But if you ask, can we stop burning all petrochemicals by the end of 2013, the answer is "yes" so long as you allow for a variety of options. Hydro can't do it alone, but hydro plus wind plus PV plus concentrated solar, plus geothermal would be able to for the vast majority of the planet, and for where those combinations won't work, energy can be imported, like North Africa imports its power now from Europe.

But, because no one of those can do it alone, and the better options are hard to control (distributed PV is one of the best options, and least politically popular because it directly attacks utility company business models). But distributed PV with some additional storage mechanisms would be more than enough to power the world, the others may be more efficient, so we should use them where practical.

Re:Don't be ridiculous.

[BeaverCleaver]

The nice thing about nuclear waste is that it's an "emission" that can be relatively easily collected, moved, and stored. Sure, it's radioactive, but it's a solid. You can put it in a truck, and store it somewhere safe.

Now try to do that with a few cubic miles of (also slightly radioactive, and quite high in heavy metals) coal power station exhaust.

Safety is relative

[Urban Garlic]

So there is a trope in the engineering world that the safest reactors are the ones that are confined to paper studies, or, to put it more timely, to PowerPoint slides.

It's true that the LFTR reactors don't have the same failure modes as the pressurized light-water reactors, but they still have the same basic issue, namely that there is a very large amount of power-generating capacity in a relatively small volume. Even pebble-bed reactors, similarly touted as "intrinsically safe" during their design phase, have had a radiation-release accident -- scroll down to "Criticisms of the design" on that Wikipedia page. The lesson (which I learned from Charles Perrow and Fukushima) is that complex systems with high power densities are intrinsically hazardous, because unexpected interactions (which arise from the complexity) tend to be highly destructive (because of the power density). LFTRs are less complex, and so less dangerous, than PLWRs, and that's good, but it doesn't make them safe.

The stupid cliche you hear over and over again is true -- safety is a process. You can design reactors so that the safety process is easier to implement, but what actually makes things safe is conservative management schemes that retain the redundancy and margin for error that the process demands, and not cutting them out because of the money, or, worse, because of complacency induced by faith in the design.

There's another industrial safety joke, particularly applicable to complex systems -- accident analysis consists of filling in X and Y in the phrase, "Nobody imagined X could happen whlie Y was true."

Re:Safety is relative

[Animats]

So there is a trope in the engineering world that the safest reactors are the ones that are confined to paper studies, or, to put it more timely, to PowerPoint slides.

Yes. Here's the original source of that, from Hyman Rickover, 1953:

"An academic reactor or reactor plant almost always has the following basic characteristics: (1) It is simple. (2) It is small. (3) It is cheap. (4) It is light. (5) It can be built very quickly. (6) It is very flexible in purpose. (7) Very little development will be required. It will use off-the-shelf components. (8) The reactor is in the study phase. It is not being built now."

"On the other hand a practical reactor can be distinguished by the following characteristics: (1) It is being built now. (2) It is behind schedule. (3) It requires an immense amount of development on apparently trivial items. (4) It is very expensive. (5) It takes a long time to build because of its engineering development problems. (6) It is large. (7) It is heavy. (8) It is complicated."

Looking at the history of reactors, almost everything other than water-cooled reactors has been an operational failure. Pebble-bed reactors have pebble jams. Helium-cooled reactors leak. Sodium-cooled reactors have fires. Boiling water reactors are basically simple devices, and even they have problems. Complexity in the radioactive side of a reactor system has not worked well in practice. The environment is hostile and the required lifetime without maintenance is decades long.

Re:Safety is relative

[nojayuk]

The British fleet of fourteen AGRs (Advanced Gas-cooled Reactors) have been running successfully for thirty years now and some of the fleet will probably operate for another ten to fifteen years with licence extensions. Based on the earlier Magnox design, they use carbon dioxide as coolant. They're a little bit more efficient than boiling-water or pressurised-water reactors since their cores run a bit hotter. The increased efficiency doesn't make up for the extra cost of construction though since the fuel costs are so low, and no-one else outside the UK licenced the design. The next generation of nuclear reactors built in the UK will be BWR or PWR designs.

Re:Safety is relative

[bill_mcgonigle]

complex systems with high power densities are intrinsically hazardous

Can we just generalize that to say that producing and distributing energy has inherent risks? IIRC about 30 people have been killed installing and maintaining wind turbines in the US so far. When those big hydro plants were being built by the WPA, lots of people fell, sometimes into an active concrete pour. When solar goes massive, there will be big factories and some people will die in manufacturing, and probably people have fallen from roofs installing solar panels, and we can probably figure in many deaths in China from the areas where the rare earths are mined. There are numbers on the exhaust from coal plants, and of course coal mining is incredibly dangerous (not like fisherman-dangerous, but still high). Even US nuclear, which hasn't had any fatalities at the civillian plants, depends on people driving to and from work. I have to imagine some of them have been killed en route.

Re:What's-his-name's Law

[Jeng]

The title of your post asks a question, that question is What's-his-name law.

Since the law in question is "If the title asks a question, then the answer is no."

Therefor it is No's Law.

Re:nuclear "green" energy

[Waffle Iron]

Indeed, another great advantage of nuclear power is that whenever there's a catastrophic meltdown, we get hundreds of square kilometers of new wooded nature preserve.

Technolopgy is not the problem.

[Required Snark]

There is no "technological fix" that will make nuclear power safe. All the bad outcomes at nuclear power plants are due to organizational failures. TMI, Chernobyl and Fukushima all resulted from bad decisions, both short term and long term.

One of the units at San Onofre is indefinitely off line because an upgraded heat exchange system was designed incorrectly. This is not exactly new technology, but somehow a flawed design made it through all the review processes. This is ultimately a organizational failure, not a technical failure.

Going from uranium to thorium will not make any difference in the long term. Serious nuclear accidents are low probability events will hugely destructive outcomes. Any claims that a technology change will result in a safe system is dangerously naive thinking.

Re:Technolopgy is not the problem.

[abies]

Technology CAN help. Problem with current reactors is that that when mismanaged or left alone when problems happen, they go hotter and hotter. Some of proposed reactor designs are opposite of that - if system breaks, they will calm down.
http://en.wikipedia.org/wiki/Passive_nuclear_safety

If we ever plan to have sustainable civilisation, we need 4th+ generation atomic power AND reduce the population. Only then we can think about civilization surving and expanding for next thousand of years. Without reducing population, nothing will save us. Without proper atomic power, we will be energy starved and damage environment even more.

Re:Technolopgy is not the problem.

[amorsen]

LFTR accidents are more likely to be similar to industrial chemical plant accidents than to TMI or Fukushima. Of course that is little comfort to those who know about chemical plant accidents, but society is much more accepting of chemical plant accidents than of nuclear accidents.

LFTR is a potential game changer when it comes to risk perception.

Re:nuclear "green" energy

[Anonymous Coward]

So, what you're saying is, you don't like living next to a building site? What makes you think that subcontractors on wind farms are any worse in traffic than subcontractors on any other building site?

#shakes head#

Re:nuclear "green" energy

[AmiMoJo]

I have the misfortune of living at ground zero for an ongoing wind farm build. 24/7 truck traffic, massive clouds of dust, hour plus highway shutdowns while they move their superloads, obnoxious subcontractors that ignore traffic laws, etc, etc. Then there's the ecological impact -- acres upon acres of wooded hilltops have been deforested. I truly had no idea how obnoxious it was until Google Earth got updated images. Take a look at some before and after photos of a large wind farm and see for yourself how bad it is.

Where is this exactly? Come on, don't just give us an unverifiable anecdote, give us hard facts that can be verified.

A properly designed wind farm shouldn't require mass deforestation or environmental damage.

Where have I heard this before?

[wisnoskij]

It is unsinkable.

Article wrong on sodium-cooled reactors

[Animats]

The article indicates that Adm. Rickover didn't like molten salt / sodium cooled reactors because the "Navy knew how to handle water". In reality, Rickover's nuclear program tried both approaches. The Nautilus (SSN-571) used a boiling water reactor, and the Seawolf (SSN-575) used a sodium cooled reactor. Both were built, both went to sea, and both performed reasonably well. But the sodium-cooled reactor turned out to be harder to maintain than the boiling water reactor, and couldn't be run at full capacity because of some design problems. so after a year, Seawolf was returned to the yards and converted to a boiling water reactor.

That was very typical of the military approach of the period - fully develop several alternatives, operate them, then dump the losers. The history of 1950s jet fighters is a striking example.

Re:nuclear "green" energy

[amorsen]

It's amazing what scores "informative". Why did they clear the forest? Is there really no farmland nearby which could have been used instead?

Also, modern turbine towers can be built tall enough that trees are less of a concern, although that obviously does not work if we are talking redwoods. Some power will be lost and the towers will be more expensive, but that seems like a reasonable trade off if the forest is not just a tree farm with pines in neat rows.

Re:Never? Well, hardly ever [Re:NO]

[Anonymous Coward]

Oh no. Nation states might do bad things using their custom designed expensive reactors.

In the production of U233 from thorium-232, it is unavoidable that one will invariably produce small amounts of uranium-232 as an impurity, because of parasitic (n,2n) reactions on uranium-233 itself, or on protactinium-233. Uranium 232 is really, really bad stuff.

The decay chain of U232 quickly yields a number of different strong gamma radiation emitters, which makes manual handling in a glove box with only light shielding (as commonly done with plutonium) too hazardous. Not only will it kill you dead, its presence will also poison your weapon yield, and it will alert anyone who cares to look exactly where your weapon site is.

The thing is, any nation (or terrorist group?) with the money and the resources needed could produce weapons more cheaply and with less risk to their workers by enriching U238 into Plutonium 239, which is much better for making weapons anyway.

I think the article is fear mongering at best. Is their a proliferation risk? Sure. An exceedingly impractical risk imho.

According to wikipedia:
Quote:
The United States detonated an experimental device in the 1955 Operation Teapot "MET" test which used a plutonium/U-233 composite pit; this was based on the plutonium/U-235 pit from the TX-7E, a prototype Mark 7 nuclear bomb design used in the 1951 Operation Buster-Jangle "Easy" test. Although not an outright fizzle, MET's actual yield of 22 kilotons was significantly enough below the predicted 33 that the information gathered was of limited value. In 1998, as part of its Pokhran-II tests, India detonated an experimental U-233 device of low-yield (0.2 kt) called Shakti V.

So it has been attempted, and seems to have badly fizzled with both efforts. The bomb makers with deep pockets have quite rightly given up in disgust. If some well funded terrorist group or nation state is going to bother with trying to make a bomb, they are going to buy or steal U239 or they will build themselves a uranium reactor, then frequently load and unload fresh fuel rods so they can extract plutonium. Nobody is likely to ever again give bomb making with U233 much additional effort.

Anybody trying to extract the Protactinium from a LFTR in the hope of making U233 will find the neutron economy is such that they simply have to load all that U233 right back into the reactor or the thing will shut down.

Only if you can separate it from the U-232

[meldroc]

U-232 is also produced in LFTR reactors, and is HELLACIOUSLY radioactive. You can't work around U-232 with just a glove-box - you're gonna get a tan that way. It also poisons the reaction of a U-233 bomb, so you've got to separate it out, so you're back to centrifuges and the like, and you're gonna have to throw out the contaminated and radioactive centrifuges when you're done as well.

Re:Only if you can separate it from the U-232

[letherial]

so your saying that not only can we have power, but we can get a tan at the plant as well

thats a win win if i ever heard one.

Re:Only if you can separate it from the U-232

[Michael Hunt]

Not only that, but 232U and 233U are far more difficult to separate in a centrifuge than 235U and 238U are, by virtue of being far closer together in mass.

Besides, given how much hard radiation 232U kicks out, i'd be surprised if your average centrifuge could use it as an input without premature, costly failures. 235U isn't a particularly hard emitter of anything, it's just fissile. 232U is fucking nasty.

Re:Only if you can separate it from the U-232

[MachineShedFred]

Yeah, let's see. We can have a centrifuge cascade and work with somewhat commonly available yellowcake Uranium, or we can build the same centrifuge cascade with an input that is non-naturally occurring material that will kill you (reactor waste), and the output of the cascade has to be handled in a robotic trench due to massively radioactive daughter products that have half-lives measured in minutes and seconds, and emits gamma radiation as it fissions.

I think I know which I'd pick.

Re:Only if you can separate it from the U-232

[Creepy]

Actually, it is fairly trivial, but not straightforward. The "easy' way is to separate out the Protactinium-233 and ignore U233 (what you want) and U232, which can't easily be separated. Protactinium-233 naturally decays into U-233, however, producing protactinium-233 is undesirable (because it sucks up scarce neutrons - a LFTR produces about 1.07 for every 1) in a LFTR and can be limited or (practically) eliminated by increasing the size of the blanket. Of course, if you WANTED protactinium, you could design your blanket accordingly and separate them, but you need to siphon it off carefully or the reaction will stop and you will need to inject more U233. Obviously leaving the Protactinium in the reactor is fine, as after it decays to U233 it is fuel.

The nice thing about either LFTR or IFR (4th generation reactors) is they burn the actinides off, so the dangerous waste only lasts about 300 years. The US has dumped billions into IFR (about 3/4 of a trillion last I checked, and incidentally, nothing into LFTR) and has zero working reactors. Russia spent far less and has two and is building a third.

Re:Only if you can separate it from the U-232

[qeveren]

Well, only if you're being really slow about it. Its half-life is like, 68 years. Which is still very short and does count as 'hellaciously radioactive', particularly considering the decay products and what they decay into.

Re:What's-his-name's Law

[jfengel]

In this case, Dr. No is Ian Betteridge, who coined Betteridge's Law (though obviously the idea has been around long before him).

Re:Technolopgy (sic) is not the problem.

[lbates_35476]

There's also "no technological fix" that will make driving an automobile safe, but we do it every day and have learned to live with the risk. I guess we could make everyone drive 10mph, but choose not to. According to wikipedia (http://en.wikipedia.org/wiki/List_of_motor_vehicle_deaths_in_U.S._by_year) there were 32,367 automobile deaths in 2011. There have NEVER been anything like that number of deaths in a year from a nuclear reactor. Chernobyl had approximately 4000 deaths and the entire list on wikipedia for deaths due to nuclear and radiation accidents doesn't adds up to around 4,066 (http://en.wikipedia.org/wiki/Nuclear_and_radiation_accidents). These numbers might not be entirely accurate, but I'm guessing that all the deaths due to nuclear accidents amount to less than 2 months deaths due to automobile accidents in the US alone.

We have got to start thinking about this like we think about automobile accidents. Tragic, but unless are willing to make a drastic lifestyle change, they are necessary and we just live with them. We don't agonize over getting in our car and driving even though it is statistically WAY more dangerous than any nuclear plant.

Decentralise energy production

[Nefarious Wheel]

Still talking about large centralised power plants, are we?

I'll put my money behind decentralised power. In fact, I already have ... 3.5kw PV system just installed on the roof.

Cogeneration units for at-home are also gaining popularity, particularly in Germany and Spain. Whispergen.

What a LFTR really means

[mbkennel]

You have a very caustic liquid at hundreds of degrees which is infused with very large amounts of high level radioactive waste. Fission daughter products which in a regular reactor are solid and encased in zirconium steel and treated with utmost care are now free floating in something very hot, flowing and caustic. What if if there's an accident and it rains. Or a flood. The fission products are very water soluble.

Every power plant also has to be a very nasty chemical separation and reprocessing plant. Consider the contamination just in "normal" operation. And consider the people running them.

What happens if it cools off and solidifies? You've frozen radioactive waste in the pipes a multi-billion dollar plant, and you can't go in there for decades.

There aren't some failure modes of existing reactors, but there are other failure modes and problems.

It might be a good idea to have one or two, very highly regulated and operated with the utmost skill (i.e. not for profit) used to burn up actinides wastes from other reactors.

Re:What a LFTR really means

[dbIII]

The fission products are very water soluble.

Even worse, some of the devil's brew of molten salts catches fire when you get it wet. It adds an extra level of paranoia required in design since you need to site big reactors near a lot of water (the entire point of nuclear reactors is big temperature differences that you can't easily get with coal or oil, and that means vast amounts of cooling water).
Of course the first reaction of any chemist, engineer or a pile of other professions when hearing about such a radioactive devil's brew (which would be horrific enough before it gets radioactive) is extreme paranoia so you can be sure that most of a design would be about keeping such a nightmare substance from getting out.

Re:What a LFTR really means

[Creepy]

LFTR uses liquid Fluoride, not liquid Sodium. More than likely, the water would vaporize due to the extreme heat. If you want to be paranoid about liquid sodium, take a look at the US government and nuclear industry's preferred reactor type, the IFR (integral fast reactor) which uses both high pressure and liquid sodium.

Re:What a LFTR really means

[Kaitiff]

Wow man, chicken little much? Yes a liquid sodium reactor would react in a very violent way to a water intrusion... but the whole system isn't PRESSURIZED. The byproducts of a LFTR reactor are orders of magnitude LESS radioactive than the byproducts of a LWR, and ALL the fuel is used. None of it is left to lanquish in your vaunted zirconium steel (which by the way, are cracked and fissured by end of life due to the temp and flux in the core). The whole concept of the LFTR is it's 'safe mode' is to freeze like you intimate. You simply heat it back up to unplug the channels. The chemical separation portion of the reactor is a fairly simple and non-complex affair, unlike the current enrichment facilities for uranium processing and could easily be managed by a small group of chemists at about the level of complexity used to make freaking beer. There's also NO possibility of a 'china syndrome', and it can't go BOOM no matter what you do. If Fukishima had been an LFTR reactor we would never have even heard about it, because when the power went out, the freeze plug would melt and the entire contents of the core would have drained into the safety tank and cooled into a solid. When they were ready, you just heat it back up and start pumping again. Hell, even the quantity of reactants in the core at any one time is miniscule compared to a LWR, so even if there WERE a catastrophic event and the fissionables were released they effect would be marginal compared to the radioactive MESS you have with a plant like Fukishima. Bottom line man.. they freaking guy that owned the patent (read that as the acclaimed inventor of) nuclear power said LFTR was far better, both in efficiency and safety. And that was with 1950's tech. I imagine we could do a bit better now.

Re:What a LFTR really means

[Kaitiff]

Umm, wrong there skippy. You do NOT need huge amounts of water cooling. No cooling towers needed at all. The whole system runs at a much higher temp altogether, that's part of the design issues we have to address when building a LFTR. Current steam generators use a very 'low quality' steam to extract energy to convert to electricity. A LFTR runs bets several times hotter than a LWR. The turbines for a LFTR would be immensely smaller and more efficient than the ones used in current reactor generators and you don't have the need to use that water as cooling for the core. One of the primary advantages of a LFTR is the efficiency of the design and the extreme hot temps it runs at. A 'byproduct' of LFTR would be the ability to use all that heat to do interesting things like make clean water from salt water, making fuel from captured CO2 in the air etc etc. A LFTR plant could at one location make electricity, butanol (for cars) and a methanol alternative for diesel vehicles (both of which are practically drop in replacements for gasoline and diesel btw, no blending or other issues like alcohol) AND make clean water.

Re:What a LFTR really means

[dbIII]

Where did this one come from and what cornflake packet is he quoting?
Look kid, it's not really a disadvantage, just a thing that defines where you site the power plant. The majority of the cooling water is to do a heat exchange with the steam in the turbine loop anyway and is effectively the same as you'd have in a coal fired plant of the same capacity if they came in that size. All you need is a big lake, river or a seaside location and just keep on looping it through, with effectively zero impact on the body of water if you have cooling towers and multiple small outlets.

It's depressing, mention some minor constraint imposed by reality and some cargo cult nuclear fanboy that loves finished technology but hates any mention of the science behind it takes it as an insult to their beloved technology, calls you names then gets everything backwards - seems to happen a lot in this place and sadly something like that killed the thorium project out in the political world when some idiot thought a mention of thorium reactors improved safety was an insult to "perfect" uranium reactors.

It should be obvious - the higher the temperature difference the greater the cooling required to do it. For more detail look at the rankine cycle, it may not be taught in high school but it's simple enough that it could be. Don't take my word for this, look it up kids and avoid the embarassment of looking like idiots to anyone with a clue about very simple thermodynamics in the future. Become informed advocates of a technology you like instead of clueless fanboys that take offence whenever somebody discusses things that reality brings to the mix.

Re:What a LFTR really means

[bojanb]

Fluoride salt used in the LFTR is not caustic. It is in fact chemically very inert. Fission products dissolved in the salt are not water soluble either.

If it cools off and solidifies, you just heat up the salt again (e.g. using electric heaters) and continue operating the reactor. Oh, and if the solidified salt comes into contact with water, nothing will happen (as it is not water soluble).

Flibe Energy is working with the U.S. military on making a small reactor that can be deployed at Forward Operating Bases during war. You don't think they would be doing that unless the reactor design is fairly resilient?

Re:Never? Well, hardly ever [Re:NO]

[ThePeices]

Not only will it kill you dead

kill me dead..... erm...isn't "it will kill you" enough? the added "you dead" seems utterly extraneous

Greetings Pedant!

Welcome to Slashdot. You will fit in here quite nicely!

Enjoy your prolonged stay.

Re:nuclear "green" energy

[fgouget]

I have the misfortune of living at ground zero for an ongoing wind farm build. 24/7 truck traffic, massive clouds of dust, hour plus highway shutdowns while they move their superloads, obnoxious subcontractors that ignore traffic laws, etc, etc. Then there's the ecological impact -- acres upon acres of wooded hilltops have been deforested.

I have family who live within a mile of a wind farm. They never mentioned the contractors being obnoxious, clouds of dust, or the roads being shut down for extensive periods during the construction, and not a single tree was felled. I think someone just made a mess of things in the planning and implementation stages of your wind farm.

No design there - just powder

[dbIII]

Some years ago an old Polish mechanical engineering lecturer (with a small bit of English as about his sixth language) said this to me when I was sketching up a design on a drawing board as a student: "your design is powder."
Impressive parts are a start, but they have to work together before you have a final design. That's why there's still a lot of R&D before the first modern Thorium reactor let along a good one worth producing by the dozen. Luckily India is still doing some of that Thorium reactor R&D.

Re:nuclear "green" energy

[sjames]

Coal power has rendered a good sized area including a whole town uninhabitable for the foreseeable future. A fire started in a coal seam and just won't go out. The CO levels in the town range from harmful to deadly depending on the wind at the time. Eventually, it will all fall into a sinkhole and burn.

Re:nuclear "green" energy

[ultranova]

Their POTENTIAL deaths is massively higher than anything else.

No, hydro has them beat: a dam breaking will kill everyone downstream. And of course coal's actual annual death toll beats nuclear's potential one hands down.