What is particularly interesting, and new science to me is that the majority of the heat that keeps the core molten is just decay heat from Thorium, Uranium, and Potassium. Only 20% of the heat that drives the internal dynamo is believed to be primordial, most is from the decay of mainly these elements. This, coupled with our crust layer which forms a heat retaining blanket, has enabled the heat of our core to live much longer than otherwise. Predictions for core solidification without radioactive decay is on the order of a couple hundred million years. Every major thermodynamic system on the earth is powered via some form of nuclear; be it fission (well, decay, which isn't usually called fission) keeping the core molten, or fusion keeping the sun burning...we owe a lot to the strong and weak forces!

To continue this lesson, it is important to note that most bomb technology doesn't use enriched uranium alone. The other key material compound is plutonium. For all intents and purposes, all plutonium is man made (with only traces of 244 found in nature, of which is completely unsuitable for weapons..Pu244). Plutonium is usually needed in a bomb because of its much lower critical mass. This lower mass makes bomb fabrication easier, but that creation of plutonium is by no means trivial.

You need huge facilities, dedicated to the sole purpose of uranium exposure. Like the video mentions, normal uranium is mostly U238, this junk gains value in the creation of plutonium. Weapons grade plutonium is a special isotope of plutonium, Pu239. This need is very specific, the different isotopes of Pu can have so very serious implications for bombs. Lets go over them as we as we go over how uranium is exposed to make this very special isotope

First, we start off with U238...the fuel stock. This isotope is bombarded with neutrons. These neutrons are occasionally absorbed by the uranium, turning it into U239. U239 is highly unstable, and quickly decays (in 23.45 minutes) to neptunium 239. This will in turn, decay into Pu239 (in about 2.3 days). Sounds easy, right? Not exactly, neutron absorption isn't something you can control with ease. What I mean is, there is little to stop our Neptunium or Plutonium from absorbing neutrons any more or less than the Uranium (in fact, their absorption cross sections are typically much larger...they are more hungry of neutrons than uranium in other words). When this undesired absorption happens, the neptunium and plutonium eventually becomes Pu240...and that is a big problem.

Plutonium Pu240 is HIGHLY undesirable in a bomb. Pu240 is a medium lived isotope of Plutonium, meaning it decays pretty quick, but it is HOW it decays that is the problem. Pu240 often decays by spontaneous fission. Having spontaneous fission in your fission bomb is just as undesirable as it sounds. Firstly, all even number isotopes are poor fission candidates, so for every even number isotope in your bomb, that lowers the bombs over all yield (because they prefer to fission themselves, and for very little return energy). This is further complicated by high densities of Pu240 causing your bomb to prematurely detonate, ya...bad news. The levels of Pu240 represent yet another challenge in the level of heat they generate from their rather quick decay, though, considering the previous 2 issues, this one is less problematic, though still troublesome. And lastly, there is nothing stopping our Pu240 from absorbing yet another neutron causing yet another isotope of plutonium to arises, namely Pu241.

Pu241, being an odd numbered isotope heavier than lead makes it a rather good subject to undergo fission. It doesn't have the same set of problems as Pu241, but it rapidly decays (14 years) into Americium 241, which is not fissile, and has a halflife of 432 years. These factors add large amounts of heat to the bomb, and reduce overall yield, as well as detract from critical mass.

The solution for this is a very low tech, time consuming, laborious process with produces tons of waste and very little plutonium. One has to expose small blocks of uranium to neutrons under a very brief window. The brief window decreases the chances of undesired neutron absorption and negates much (but not all!) of the heavier forms of plutonium being created. After exposure, they are left to decay, then after a few months, are chemically processed to remove any plutonium and other undesirables (this is also very very hard, and I won't even go into how this is done), then re-exposed. This yields gram(s) at a time. To make a weapons, you need 10 killos, at least...for one bomb...if everything went great. This means you need HUGE facilities, HUGE staff, and HUGE uranium resources. Your facility would be obvious and serve no other purpose, use tons of energy, and pile up radioactive waste of the kind no one wants, heavier than uranium wastes...the worse of the worst. No such facility could exist alongside some traditional uranium facility and not be noticed, period, end of story, done.

We haven't even covered bomb making problems, of which killed some of our top minds in our own bomb program. A set of incidents revolving around a specific bomb type, after taking 2 lives, was dubbed the Demon core. These are the reasons over half the budget of the DOD gets soaked up in nuclear weapons, and we haven't even covered some of the more important aspects (like delivery systems, one simply doesn't walk into Mordor). Nuclear weapons are hugely expensive, hugely conspicuous, require massive facilities and require a level of sophistication that is completely absent from the training of reactor nuclear scientists.

Reactor research and materials are orders of magnitude different from weapons grade materials and research. No bomb in history has EVER been made from reactor grade plutonium because the levels of Pu240 and Pu241 (and we haven't even covered Pu238!) are blisteringly high, way to high for weapons. Isotopic separation for Pu would be even more costly than uranium because of their mass similarities (compared to U235 and U238) and need a different set of enrichment facilities specially tailored to plutonium enrichment, of which all the people who knew something about that are Russian and American, and most likely dead or work classified to the highest degree.

The problem of nuclear weapons via reactor development is all a game to ratchet up the fear machine to get a particular end. It isn't a technical problem, it is a political problem. In the end, though, emerging technology could make enrichment easier anyway, so many of the issues I mentioned might eventually fall to the wayside (not within the next 10 years I imagine; for interested parties, google laser enrichment...coming to a world near you, but not exactly tomorrow, it's awesome stuff though). Eventually, the US is going to have to get used to the idea of more and more nations owning the bomb...but that issue is completely unrelated to reactor design and research. Reactors and nuclear weapons share about as much in common as cars and space shuttles...trying to link them as a dual proliferation argument is a political game and doesn't map on to them technologically.



I should note that I am not yet a nuclear engineer, but I did stay at a holiday inn express.

The actinides are, generally, "safe" to handle, like those Uranium Oxide pellets. You are more likely to damage the pellet with your nasty human oils than the uranium will you...unless you eat the whole thing, but its chemical toxicity will do you more harm that its radioactive toxicity. Uranium oxide just isn't that radioactive, that is why none of the containers or work areas were shielded in this lab.



Now, if they were dealing with a "hot" substance, one that has hard gammas (like when you do MOX fuel recycling), you have to take even greater precautions because then the radioactive problems really do start to show their heads. Not only will it damage your cells faster than they can repair, but it can start to take out unshielded electronics. This is generally only true for fission products, and a few actinides like protactinium which is highly radioactive AND chemically toxic, and generally only man-made (normal occurrences are less than a few parts per trillion in the crust).



These complications are pretty good generalization to why normal LWRs are not the best way to do nuclear, they just generate far to much waste compared to alternatives. You burn less than 1% of the mined uranium in current reactor tech and fuel cycle choices. With a thorium cycle in a molten salt reactor, you can burn greater than 90%, pushing up to 99% or higher if you try real hard. This means you generate an order(s) of magnitude less waste, and that waste generally is safe after about 300 years (radiation is about the same as naturally occurring radiation). There are also other alternates that use uranium in a faster spectrum that perform better than current tech.



A second age of the atom is fast approaching. Unfortunately, those great pioneers which made this industry in the shadow of "the bomb" failed to realize the full potential of e=mc^2. If nuclear power was developed along side the Apollo instead of the Manhattan project, we might already be in that future, alas...it was not to be.



Radiation is fascinating though! I used to believe what I read in the fear news about any radiation leading to death..turns out that isn't so true after all. The planet is a far more radioactive place then you normally consider, and FAR more radioactive when our primordial ancestors evolved. In fact, there are many people living today in what are dubbed High Background Radiation Areas that seem to suffer no ill effect, and some suggest, have lower rates of cancer than other groups. More studies need to be done, but initial findings fly in the face of the notion of radiation I grew up with (that it all is bad and it all kills you!) Some have even suggested that the creator of the entire model used for evaluating radiation risk knowingly lied about it. The entire basis for today's evaluation of radiological risk is evaluated by Muller's findings as supported by the National Academy of Sciences’ of the time. And in fact, might just be based in fear instead of evidence.



Perhaps ancient man went through the same struggles as he tried to adopt fire, some impassioned move against the dangers of fire prevented some groups from using fire and advancing their way of life. Fire, though, allowed the groups that adopted it to improve their life dramatically. The energy released from a fission event is over a million times more energy rich than any energy tech we currently use, imagine what that could mean for mankind. Fusion is over 4 times that of fission (but much harder), and antimatter over 2000x that of fission (and MUCH MUCH harder). Yes, the age of the atom has only just begun, and who knows were man will be a result? Don't settle for solar dandruff, the power of the atom will reign supreme.

Hey Cricket,

I just made an opinionated comment on your post and then realized it is posible that you may mis-interpret my contempt.
My umbridge is not with you or your post but with the News agencies that seek to exploit information and sensationalize the news.

An opinion that got away from me

Cheers



In reply to this comment by Sagemind:
I was just reading a huge article yesterday on what a bullshit story this is.
The uranium wasn't weapons grade and these reactors are common to research facilities such as large companies (as mentioned) and universities. The idea that this was top secret is also untrue as it was common knowledge back in the seventies while it was in use - they just haven't used it in such a long time, people just forgot about it.

I wish I could find the article and comments again but the truth is, I don't remember how I came across it in the first place.

Now the news outlets are picking up the story and sensationalizing the crap out of it - as they always do. "Breaking Story - This just in!!!" - who cares - not me. Inform us with some real news instead of misdirecting us with the bullshit stories.

I was just reading a huge article yesterday on what a bullshit story this is.
The uranium wasn't weapons grade and these reactors are common to research facilities such as large companies (as mentioned) and universities. The idea that this was top secret is also untrue as it was common knowledge back in the seventies while it was in use - they just haven't used it in such a long time, people just forgot about it.

I wish I could find the article and comments again but the truth is, I don't remember how I came across it in the first place.

Now the news outlets are picking up the story and sensationalizing the crap out of it - as they always do. "Breaking Story - This just in!!!" - who cares - not me. Inform us with some real news instead of misdirecting us with the bullshit stories.

Tags for this video have been changed from 'TSR, Uranium, Sodium, Terrapower, Bill Gates, Nuclear, New Nuclear' to 'TSR, Uranium, Sodium, Terrapower, Bill Gates, Nuclear, New Nuclear, ted' - edited by xxovercastxx

>> ^marinara:

if I dont have a $50 dollar electric bill, and a $50 dollar a tank of gas, what will i spend my money on?


Conversely, what would you do if your energy bills amounted to a thousand dollars?

>> ^ghark:
a regular chest xray would expose you to 0.06 mSv while a helical CT scan of the chest would expose you to 8 mSV - thirten hundred and thirty three times as much radiation (although the effective dose only ends up being about one hundred times as much).
If you mean the same thing with "mSv" both times (and not jumping between milli and micro or anything like that), then you're off by a factor of 10. 8 / 0.06 = 133.333333, not 1333 like you said. And if the effective dose follows the same pattern, then the CT scan would be about 10 times as much as the x-ray, though I don't know anything about that part.

I might be wrong but it wouldn't surprise me to find out that they are pretty much normal.

[edited to add:] Not that I'm trying to say that radiation's not dangerous or anything like that. I left my tinfoil hat in the closet where it belongs.

>> ^Jinx:

Is either model even relavent? aplha radiation has a hard time passing through a single sheet of paper or just several metres of air never mind layers of skin. I'm not sure how much beta or even gamma radiation you might be getting from the decay products though. I definitely wouldn't want to eat off it.
Part of the UK have sufficiently high radiation from radon gas that nuclear sites cannot be opened there because they'd already exceed legal radiation limits. I'd like to know what the cancer rates are like in those areas.

>> ^GeeSussFreeK:

>> ^ghark:
It's not made that clear in the video, but the reason he says that the plate is safe to store and handle, but not eat off is because Uranium 238 is usually an alpha emitter. Alpha radiation doesn't penetrate skin that well, but it is very dangerous when ingested and the soft tissues become exposed to it. Please correct me if I'm wrong there.

Depends on if you believe in radiation hormesis or linear no-threshold model . Most likely the truth is somewhere in-between (which by default makes hormesis "more" accurate). In the end, though, it is always best to avoid ingesting heavy metals, radioactive or not.
Learning lots about radiation as of late. There is a lot of fear factor behind it, even though our daily lives are pretty much consumed with radiation...NEATO! Bones full of radioactive carbon, potassium, you name it, you most likely have lots of radioactive isotopes of it Once again, truth stranger than fiction


I find the argument between those two models quite fascinating, they both make sense TBH. One interesting thing I found out recently was the enormous difference in radiation exposure between regular x-ray's and CT scans when visiting the doctor. It makes sense that CT scans expose you to more radiation because they make multiple passes to get a better image - however the difference astonished me - a regular chest xray would expose you to 0.06 mSv while a helical CT scan of the chest would expose you to 8 mSV - thirten hundred and thirty three times as much radiation (although the effective dose only ends up being about one hundred times as much). As a comparison point, the typical human is exposed to 2-3 mSv per year, so with a helical chest CT you're getting 3 years worth of radiation in a few seconds.

>> ^ghark:

It's not made that clear in the video, but the reason he says that the plate is safe to store and handle, but not eat off is because Uranium 238 is usually an alpha emitter. Alpha radiation doesn't penetrate skin that well, but it is very dangerous when ingested and the soft tissues become exposed to it. Please correct me if I'm wrong there.


Depends on if you believe in radiation hormesis or linear no-threshold model . Most likely the truth is somewhere in-between (which by default makes hormesis "more" accurate). In the end, though, it is always best to avoid ingesting heavy metals, radioactive or not.

Learning lots about radiation as of late. There is a lot of fear factor behind it, even though our daily lives are pretty much consumed with radiation...NEATO! Bones full of radioactive carbon, potassium, you name it, you most likely have lots of radioactive isotopes of it Once again, truth stranger than fiction

It's not made that clear in the video, but the reason he says that the plate is safe to store and handle, but not eat off is because Uranium 238 is usually an alpha emitter. Alpha radiation doesn't penetrate skin that well, but it is very dangerous when ingested and the soft tissues become exposed to it. Please correct me if I'm wrong there.

@Spacedog79

Indeed, this takes a different approach than a LFTR, I wasn't meaning to suggest this would solve a parallel set of problems. And I don't know if the complexity of it should be a deal breaker right away, look at combustion engines, Diesel is by far simpler than Gasoline engines, however both have their uses; complexity alone can't be the deciding factor.

Also, from my understanding...and let me point out again that I am no expert, but it seemed that while they are indeed firing protons, they are firing them at a heavy metal, and through the spallation effect, producing a beam of neutrons (or that is the plan, they currently are just beaming electrons I believe). Either way, it is a complex way to go about fission; but very much like Gas Vs Diesel with the lack of a perfectly sustained reactor (Uranium or Thorium) of perfect ability, research in this quasi-dieselesk solution might not be a terrible waste of time and money.

There is also a "problem" of using the fissile we have today, as far as I understand it. As they are mixed with many other undesirable fissile and non-fissile fission products in a chemical stew. So to use that, you would need a secure, safe, and practical way to go about reconditioning and reconstituting it in a form you could use. Once again, not a deal breaker for that to happen either, but you have to keep your mind and options open for good technologies that offer a different game plan. Ultimately, I think a critical reactor is the way you want to go if you can get the engineering and physics behind you, if not, or in certain situations, perhaps sub-critical will offer some unique solutions.

Thanks for the well wishes, apparently, one of the better nuclear schools is in my state...score! And one of the others is near my family...double score!

>> ^GeeSussFreeK:

I have been considering heading back to school for nuclear engineering for said thorium, @Spacedog79. Problem is, schooling for it is all actually for the uranium stuff, and they mock thorium based reactors. I have a friend whom is a freshman in nuclear engineering and he already discounts it at the direction of his teachers. I think I am going to drop Kirk Sorensen an email and ask what should my course be, I know he just (last year) started the Flibe energy company to develop the LFTR, I want to try and be involved with that in whatever way is the smartest for me. Even so, like this video points out, growth makes it so that even thorium, anything that is consumed is limited. The energy advancement we make will make future generations even more dependent on even further advancements. The failing of that will result in more massive suffering than if no advancement was ever made, or at least that is a risk (one of many). Either way, thorium seems like a good solution in the interim. I'll let you know what I hear, if I hear, from Kirk.


awesome. dig it.

Myself and a few friends are very serious about buying some land and building a sustainable teaching farm in the next few years. aquaponics, etc.

We certainly can't wait for politicians to lead.

I wish more peeps would upvote this vid. sucky title but a very comprehensive summary of the world.

I have been considering heading back to school for nuclear engineering for said thorium, @Spacedog79. Problem is, schooling for it is all actually for the uranium stuff, and they mock thorium based reactors. I have a friend whom is a freshman in nuclear engineering and he already discounts it at the direction of his teachers. I think I am going to drop Kirk Sorensen an email and ask what should my course be, I know he just (last year) started the Flibe energy company to develop the LFTR, I want to try and be involved with that in whatever way is the smartest for me. Even so, like this video points out, growth makes it so that even thorium, anything that is consumed is limited. The energy advancement we make will make future generations even more dependent on even further advancements. The failing of that will result in more massive suffering than if no advancement was ever made, or at least that is a risk (one of many). Either way, thorium seems like a good solution in the interim. I'll let you know what I hear, if I hear, from Kirk.