>> ^alien_concept:

I have a question. What does the flashing colours actually mean??

I don't know either, so I did some googling. http://psychcentral.com/lib/2007/types-of-brain-imaging-techniques/ Thats as close as I came to answering the question. If the CAT scan tag is accurate then I've no idea how they image brain activity, so I'd guess it was of the other methods or a combination. Basically blood flow/oxygenation, electrical or magnetic fields from brain activity or positrons produced from radioactive decay from active parts of the brain.

What any of that means in terms of what is actually going on in the brain I've no idea. Ask a neurologist

No riskier than lethally high doses of gamma radiation or being bitten by radioactive spiders I suppose.
Walking through a rain storm covered in the stuff would be interesting, I could imagine a spray-on umbrella would be pretty cool.

If you get a geiger counter and hold it up to a box of cereal like Total or Cheerios, the radioactive potassium is high enough to get it to go off more than you would expect

Safe nuclear refers to many different new gen4 reactor units that rely on passive safety instead of engineered safety. The real difference comes with a slight bit of understanding of how nuclear tech works now, and why that isn't optimal.

Let us first consider this, even with current nuclear technology, the amount of people that have died as a direct and indirect result of nuclear is very low per unit energy produced. The only rival is big hydro, even wind and solar have a great deal of risk compared to nuclear as we do it and have done it for years. The main difference is when a nuclear plant fails, everyone hears about it...but when a oil pipeline explodes and kills dozens, or solar panel installers fall off a roof or get electrocuted and dies...it just isn't as interesting.

Pound per pound nuclear is already statistically very safe, but that isn't really what we are talking about, we are talking about what makes them more unsafe compared to new nuclear techs. Well, that has to do with how normal nukes work. So, firstly, normal reactor tech uses solid fuel rods. It isn't a "metal" either, it is uranium dioxide, has the same physical characteristics as ceramic pots you buy in a store. When the fuel fissions, the uranium is transmuted into other, lighter, elements some of which are gases. Over time, these non-fissile elements damage the fuel rod to the point where it can no longer sustain fission and need to be replaced. At this point, they have only burned about 4% of the uranium content, but they are all "used up". So while there are some highly radioactive fission products contained in the fuel rods, the vast majority is just normal uranium, and that isn't very radioactive (you could eat it and not really suffer any radiation effects, now chemical toxicity is a different matter). The vast majority of nuclear waste, as a result of this way of burning uranium, generates huge volumes of waste products that aren't really waste products, just normal uranium.

But this isn't what makes light water reactors unsafe compared to other designs. It is all about the water. Normal reactors use water to both cool the core, extract the heat, and moderate the neutrons to sustain the fission reaction. Water boils at 100c which is far to low a temperature to run a thermal reactor on, you need much higher temps to get power. As a result, nuclear reactors use highly pressurized water to keep it liquid. The pressure is an amazingly high 2200psi or so! This is where the real problem comes in. If pressure is lost catastrophically, the chance to release radioactivity into the environment increases. This is further complicated by the lack of water then cooling the core. Without water, the fission chain reaction that generates the main source of heat in the reactor shuts down, however, the radioactive fission products contained in the fuel rods are very unstable and generate lots of heat. So much heat over time, they end up causing the rods to melt if they aren't supplied with water. This is the "melt down" you always hear about. If you start then spraying water on them after they melt down, it caries away some of those highly radioactive fission products with the steam. This is what happened in Chernobyl, there was also a human element that overdid all their safety equipment, but that just goes to show you the worst case.

The same thing didn't happen in Fukushima. What happened in Fukushima is that coolant was lost to the core and they started to melt down. The tubes which contain the uranium are made from zirconium. At high temps, water and zirconium react to form hydrogen gas. Now modern reactor buildings are designed to trap gases, usually steam, in the event of a reactor breach. In the case of hydrogen, that gas builds up till a spark of some kind happens and causes an explosion. These are the explosions that occurred at Fukushima. Both of the major failures and dangers of current reactors deal with the high pressure water; but water isn't needed to make a reactor run, just this type of reactor.

The fact that reactors have radioactive materials in them isn't really unsafe itself. What is unsafe is reactor designs that create a pressure to push that radioactivity into other areas. A electroplating plant, for example, uses concentrated acids along with high voltage electricity in their fabrication processes. It "sounds" dangerous, and it is in a certain sense, but it is a manageable danger that will most likely only have very localized effects in the event of a catastrophic event. This is due mainly to the fact that there are no forces driving those toxic chemical elements into the surrounding areas...they are just acid baths. The same goes for nuclear materials, they aren't more or less dangerus than gasoline (gas go boom!), if handled properly.

I think one of the best reactor designs in terms of both safety and efficiency are the molten salt reactors. They don't use water as a coolant, and as a result operate at normal preasures. The fuel and coolant is a liquid lithium, fluoride, and beryllium salt instead of water, and the initial fuel is thorium instead of uranium. Since it is a liquid instead of a solid, you can do all sorts of neat things with it, most notably, in case of an emergency, you can just dump all the fuel into a storage tank that is passively cooled then pump it back to the reactor once the issue is resolved. It is a safety feature that doesn't require much engineering, you are just using the ever constant force of gravity. This is what is known as passive safety, it isn't something you have to do, it is something that happens automatically. So in many cases, what they designed is a freeze plug that is being cooled. If that fails for any reason, and you desire a shutdown, the freeze plug melts and the entire contents of the reactor are drained into the tanks and fission stops (fission needs a certain geometry to happen).

So while the reactor will still be as dangerous as any other industrial machine would be...like a blast furnace, it wouldn't pose any threat to the surrounding area. This is boosted by the fact that even if you lost containment AND you had a ruptured emergency storage tank, these liquid salts solidify at temps below 400c, so while they are liquid in the reactor, they quickly solidify outside of it. And another great benefit is they are remarkably stable. Air and water don't really leach anything from them, fluoride and lithium are just so happy binding with things, they don't let go!

The fuel burn up is also really great. You burn up 90% of what you put in, and if you try hard, you can burn up to 99%. So, comparing them to "clean coal" doesn't really give new reactor tech its fair shake. The tech we use was actually sort of denounced by the person who made them, Alvin Weinberg, and he advocated the molten salt reactor instead. I could babble on about this for ages, but I think Kirk Sorensen explains that better than I could...hell most likely the bulk of what I said is said better by him



http://www.youtube.com/watch?v=N2vzotsvvkw

But the real question is why. Why use nuclear and not solar, for instance?

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

This is the answer. The power of the atom is a MILLION times more dense that fossil fuels...a million! It is a number that is beyond what we can normal grasp as people. Right now, current reactors harness less that 1% of that power because of their reactor design and fuel choice.

And unfortunately, renewables just cost to darn much for how much energy they contribute. In that, they also use WAY more resources to make per unit energy produced. So wind, for example, uses 10x more steal per unit energy contributed than other technologies. It is because renewables is more like energy farming.

http://videosift.com/video/TEDxWarwick-Physics-Constrain-Sustainable-Energy-Options


This is a really great video on that maths behind what makes renewables less than attractive for many countries. But to rap it up, finally, the real benefit is that cheap, clean power is what helps makes nations great. There is an inexorable link with access to energy and financial well being. Poor nations burn coal to try and bridge that gap, but that has a huge health toll. Renewables are way to costly for them per unit energy, they really need other answers. New nuclear could be just that, because it can be made nearly completely safe, very cheap to operate, and easier to manufacture (this means very cheap compared to today's reactors as they are basically huge pressure vessels). If you watch a couple of videos from Kirk and have more questions or problems, let me know, as you can see, I love talking about this stuff Sorry if I gabbed your ear off, but this is the stuff I am going back to school for because I do believe it will change the world. It is the closest thing to free energy we are going to get in the next 20 years.

In reply to this comment by ReverendTed:
Just stumbled onto your profile page and noticed an exchange you had with dag a few months back.
What constitutes "safe nuclear"? Is that a specific type or category of nuclear power?
Without context (which I'm sure I could obtain elsewise with a simple Google search, but I'd rather just ask), it sounds like "clean coal".

excatly... tobacco grown naturally is far less risky than a manufactured cigarette... the poison they put on the cigs during processing turns radioactive when combusted.

and as for this being an anti-pot argument? There are several smokeless methods, none of which affect the pulmonary system negatively. So, next argument.

What's that? illegaldrugsareallbadthinkofthechildren??

Oh, ok ill shut up. Good point.

Fucking Terrorist DEA

Cannabis has more tar than tobacco--but the cancer is caused by radioactive elements which tobacco concentrates in it's leaves--cannabis does not.

Bullshit is the correct call.

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!

>> ^TheSluiceGate:

They had something like this in the science museum in Barcelona - it detected these particles that were sleeting through the atmosphere at all times. Through your body too. It was kind of scary.


Due to radioactive carbon and potassium in your body, you have about 10 thousand of these kind of decays...per second! Radioactive world out there, your body is more than up to the task, though.

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.

In reply to this comment by GeeSussFreeK:
Oops, I wasn't being too haughty I hope :

I have a tendency to ramble on subjects that fascinate me, and sometimes it comes off bad.
In reply to this comment by deathcow:
>> ^GeeSussFreeK:

The actinides are, generally, "safe" to handle, .....


K K K K K Killer Post



I thought it was awesome.

>> ^GeeSussFreeK:

The actinides are, generally, "safe" to handle, .....


K K K K K Killer Post

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.

...this is so so wrong on so many levels. Cenk is generally a pretty good guy when it comes to actual issues....this is not one of those times.

One nuclear power plant is propped up so that 2-5 coal power plants dont have to be propped up.
Coal power produces more radioactive waste material than nuclear power plants.
More disease and death has been attributed to coal power plants and coal mining than that of nuclear plants and associated industries.

All this, despite the meltdown scenarios that are well known....nuclear is safer, and in the long term cheaper than coal.

...oh theres also this.

http://en.wikipedia.org/wiki/File:CO2%26NPPs.png


Nuclear plants are not evil, picking a few billion dollars a year when the defeceit is OVER 100$TRILLION including liabilities, is a JOKE, and a sick one at that.

Shutting down NPP research funding will potentially kill off the best chance humanity has of overcoming its thirst for energy - thorium salt reactor design / implementation.

Sorry Cenk...you are dead wrong on this one bud.

>> ^Skeeve:

The problem is that people do get treated unnecessarily.
The real problem, though, is that doctors do not have a reliable way to determine which of these very small cancers that are caught by a biopsy are potentially dangerous and which will never bother a man in his lifetime. (Indeed, autopsy studies show that more than half of men in their 50s and three quarters of men in their 80s in the U.S. had prostate cancer but died of something else.)[...]Such ambiguity would not be so bad if the treatments were virtually risk free.[...] Surgery (open radial prostatectomy) often results in urinary leakage [...] damage to the nearby muscle that controls urination may lead to incontinence. [...] Meanwhile, the nerves and blood vessels controlling erections may be severed during surgery, causing erectile dysfunction (impotence).[...] Radiation therapy of the prostate often ends up damaging the rectum and bladder because it is hard to avoid radiation scatter[...] Moreover, rectal bleeding and fecal soiling are frequent but commonly unreported side effects of both radiation therapy (including radioactive seed implants) and surgical approaches.

People do get treated unnecessarily. And those treatments have side effects that can be far worse than living with the cancer. Only 4 percent of prostate cancers spread to the bones or organs. Medical organizations now advise that asymptomatic men should not have routine screening unless they have a strong family history of prostate cancer.>> ^alien_concept:
@Yogi Perhaps because it's the most common form of cancer here in the UK and so many men remain undiagnosed because they're too scared to have it done and he though, fuck it. I dunno. Because it was funny and he knew it would be? I don't really understand what's dangerous about it @Skeeve? I can guarantee you that here they wouldn't treat anyone unnecessarily here on the NHS



I have no idea dude, whether it's the same here or not. Your post is very interesting. All I do know is my dad had prostate cancer after being checked and they caught it early enough for him to get away with a few weeks of radiation therapy, so maybe I'm biased

The problem is that people do get treated unnecessarily.

The real problem, though, is that doctors do not have a reliable way to determine which of these very small cancers that are caught by a biopsy are potentially dangerous and which will never bother a man in his lifetime. (Indeed, autopsy studies show that more than half of men in their 50s and three quarters of men in their 80s in the U.S. had prostate cancer but died of something else.)[...]Such ambiguity would not be so bad if the treatments were virtually risk free.[...] Surgery (open radial prostatectomy) often results in urinary leakage [...] damage to the nearby muscle that controls urination may lead to incontinence. [...] Meanwhile, the nerves and blood vessels controlling erections may be severed during surgery, causing erectile dysfunction (impotence).[...] Radiation therapy of the prostate often ends up damaging the rectum and bladder because it is hard to avoid radiation scatter[...] Moreover, rectal bleeding and fecal soiling are frequent but commonly unreported side effects of both radiation therapy (including radioactive seed implants) and surgical approaches.



People do get treated unnecessarily. And those treatments have side effects that can be far worse than living with the cancer. Only 4 percent of prostate cancers spread to the bones or organs. Medical organizations now advise that asymptomatic men should not have routine screening unless they have a strong family history of prostate cancer.>> ^alien_concept:

@Yogi Perhaps because it's the most common form of cancer here in the UK and so many men remain undiagnosed because they're too scared to have it done and he though, fuck it. I dunno. Because it was funny and he knew it would be? I don't really understand what's dangerous about it @Skeeve? I can guarantee you that here they wouldn't treat anyone unnecessarily here on the NHS