just so you people know, the reactor itself isn't glowing. the fission process is producing a form of radiation known as Cerenkov radiation. this causes the water to glow because Cerenkov radiation actually travels faster than light. i don't know the actual physics of it but thats what i know.
It would render the General and Special Theories of Relativity worthless, and all current Physics textbooks would be wildly incorrect if what you just said is true, because while it is possible to slow C down, in all sorts of special environments, it is not possible to exceed C, and it only becomes full C (186,000 mps) in a vacuum with no external action, e.g., a black hole. It is an irrefutable fact that nothing can or does exceed the speed of light. I don't know where you've heard differently.
@painxtreme If a charged particle (such as an electron) passing through a dielectric medium at a speed greater than the phase velocity of light in that medium, you'd be correct, but that means it is exceeding a light speed that has been very slowed by a medium... water slows light down by 25%, so the radiation exceeds the speed of that light in that medium, but nothing exceeds the speed of light in a vacuum, such as space (C -186,000mps) under any circumstances.
@painxtreme both of the above are addressed to GAMERFLY2552, forgive me for not hitting the reply button, but my 2 longer posts tells you the Physics.
@painxtreme Not a problem. I had said in my post, C can be slowed, but Gamerfly had asserted that Cerenkov Radiation travels faster than the speed of light, without qualification. Obviously if C is slowed, many things can exceed its speed, but that isnt exceeding C, it is exceeding photons traveling at less than C, that was my point, and to that end, it is not exceeding light speed. I can outrun a Bugatti Veyron in my powerchair, if the Veyron is towing 70 elephants, ok enough silliness, Cheers!
@David0Karesh Einstein's works clearly state that nothing exceeds C, period. If you are talking about slowing light down, it is no longer at "light speed" (186,000 mps), and is an entirely different matter, and it is not exceeding C.
@TheTechBite. That would not happen. Nothing would happen, as far as i know. The water, heavy water D2O. Is there to protect the viewers of the reactor. And you have to swim down to it in order for something to happen to you.
@BlueFoxTV Actually it is a mixture. On the one side of the reactor pool is a D2O pump, where as most of the water, more so toward the middle of the pool, is actually natural H2O. It was really cool watching this live during Nuc E 451 Lab on Thursday.
@9hello123 The way i see it, the wavelength decides both if we can see the color, and how radioactive it is.
radiation cant have any color witch we can see. because then it would not have been radioactive!
if we can see the light, it cant be radioactive. if we don't see light, it can be radioactive.
those rods of whatever material they use is radioactive, and emits light. but those light waves cant harm nobody. the waves that we don see on the other hand is in form of gamma.
@pinnegubbe In this case, it isn't the radioactivity however it is due to the radioactivity producing enough energy to make electrons go faster than the speed of light around it which causes the atoms around it to be excited and then de-excite emitting radiation.
In other cases radioactivity can cause any colour at all.
@9hello123 yes, but only outside of the spectrum we can see! you cant have radioactive red or blue light, because, for it to be radiation it must be gamma or near gamma.
please note that i have no whatsoever education on this, but have only read and watched documentaries about the subject. this is the way i have understood it, and i think it makes sense the way i see it :P
@pinnegubbe "where did i say that it has something to do with that?" You said it's only when gamma rays are emitted that it's radioactivity, gamma rays is just more energetic light and is emitted when a lot of energy is lost.
Radioactivity is purely if an unstable nucleus emits energy.
of course, it is not a whole lot slower. i saw in documentary once that they have slowed it, by like, 1% or something:P and that was through some kind of substance to make it slow down as much as possible.
@pinnegubbe you can get very close, but just as we cannot produce a perfect vacuum on earth, neither can we achieve absolute zed, just very close, and close enough to bring about super fluidity in some elements. Helium jumps to mind. Even though we cannot reach zed, we get close enough that some very counter-intuitive and amazing things occur.
@pinnegubbe I so love physics. I am formally trained as an Artist, which I then married with a degree in computer science, and became a Graphic Artist. Fast forward, Im almost 48, been disabled since 2005. I taught Art History at our local college, now Im an Emeritus with a very very limited role. My best friend there is the Chair of the Graduate Astrophysics Department. Sadly, he lost his wife 3 yrs ago, she was also an Artist, and Ron and I have always said the elegance of Physics is an Art
@painxtreme Part Deux: While teaching, I also owned a small Design company, which handled the creative work for Ad Agencies, and other sundry printed matter. Superfluidity is a captivating and mysterious discovery. Graphene is one of the latest amazing innovations. It's graphite sheets, one atom thick. Graphite dissipates heat much better than does silicon, so its likely that the future will bring us Graphene Intel Chips. It was, I think the 2010 Nobel for Physics. I wont even start with quantum
@painxtreme me too! im only 20, but i am already very much into physics.
Im norwegian, but quit school when i was 18. ohmaaan, you wont believe how much i regret that.. ever since then, i have been very keen on learning more.
i quit school because of one teacher. damn. i look back now an can only see myself as a fool for quiting.
@pinnegubbe Can you return, and continue your studies? I am ignorant of the Norwegian Education system, though im a quarter Norwegian, but that from generations back...Im not a fan of lutefisk like the Minnesotan Norwegians. A friend of mine has relatives in Norway, and he asked if they liked lutefisk, and he said "No, we ship it to Minnesotans" HAHA
Seriously, if there is a way to return, I can see in your words, you really need to. You may be depriving the world of a great mind if not.
@painxtreme Yeah, i'm going to in the spring! Just taking math to get an exam, and maybe some other classes.
Old Norwegians like lutefisk x) I don't at all! Have you heard of "pultost"? "Pult" means fucked, and "ost" means cheese. Old people go crazy over it! It smells like rotten dead sheep... seriously!
Thank you! Thats really nice to hear from an unknown!
You are an Emeritus? I don't know what that is in Norwegian. Still some kind of teacher or professor?
@painxtreme Yeah, i'm going to in the spring! Just taking math to get an exam, and maybe some other classes.
Old Norwegians like lutefisk x) I don't at all! Have you heard of "pultost"? "Pult" means fucked, and "ost" means cheese. Old people go crazy over it! It smells like rotten dead sheep... seriously!
Thank you! Thats really nice to hear from an unknown!
You are an Emeritus? I don't know what that is in Norwegian. Still some kind of teacher or professor?
@pinnegubbe Emeritus is a fancy title for a retired professor (or in my case, disabled), who still has priviliges, e.g. Fully Library use, Personal Office, and Art Studio. I give a few lectures a year, but that's about it. I do a little less each year. When I stop using it, my office and studio will become a small Art Library for the School, that will hold all of my collection of Art Books going back a few centuries, for students who desire further reference. It will be reference only library.
I don't think it's a negative void coefficient since no steam voids form in the water. The fuel is usually uranium hydride, with the hydrogen acting as moderator. It heats instantaneously when the reactor pulses, and the resulting Doppler broadening quickly un-moderates and stops the reaction.
Im a Navy nuke, so forgive me for being force fed ONLY what the Navy needs me to know about nuclear power. So how do you pulse a reactor, and what is the purpose of this?
@Blindauer717 I believe the main use for a short pulse like that is for neutron imaging and other experiments that require very high neutron flux. Basically it's like a camera flash but with a very powerful neutron beam instead of light. To create it, first you need a reactor with a negative void coefficient (to avoid a chernobyl). Then one of the control rods is popped out of the reactor with a pneumatic actuator. The reactor pulses and shuts down by itself due to the void coefficient.
@80AFT They control rod(s) are removed and the reactor goes into a super critical state for barely a second. The control rods are made of boron, they absorb the neutrons and control the reaction. The blue light you see is Cherenkov radiation, this is when beta particles or electrons attempt to reach speeds faster than light but light travels slower in a medium. The water is the medium and you get the blue light photons produced in the process. You are seeing the true blue color.
@BWIENS789 Criticality actually lasts for much less than 1 second - otherwise there'd be an explosion. The blue glow is the Cerenkov radiation of the beta particles (electrons) emitted from the shortest lived (and thus most active) fission products that decay over several seconds after being almost instantly produced during the brief criticality.
@ApolloWasReal I've been reading your comments and felt they were more or less correct until this one. Can you please explain what you mean by "Criticality actually lasts for much less than 1 second - otherwise there'd be an explosion?" As we speak, my two reactors are critical at 100%.
@JustinHEMI05 Some of these pulsing videos give the reactivity insertion as considerably more than $1.00, confirming that they're taken prompt critical. Any prompt critical reactor has a period (power doubling time) of a few milliseconds, so unless the reaction stops quickly there'd be an explosion. Fortunately these reactors have very strong & quick negative feedback that stops the reaction when the core reaches a certain temperature, probably by Doppler broadening.
@ApolloWasReal Are you suggesting that prompt criticality = explosion? Or just in this reactor's case? If I took my reactor (Beaver Valley, Westinghouse 3 loop PWR), it would not explode. Now, admittedly, I am not versed on these test reactors which is why I am trying to understand what you are saying. What is your background if I may ask? I ask because I would like to know your basis for saying doppler broadening is the moderating effect, and not some other control device. Do you work here?
@JustinHEMI05 In many reactors, prompt criticality would produce an explosion, yes. Eg, Chernobyl #4 and SL-1. But these research reactors have strong, fast negative feedback that limits the energy release. It also makes them unsuitable for power production. The fuel is often uranium hydride. The hydrogen moderates, and the close U->H thermal coupling causes quick Doppler broadening that unmoderates the reaction.
I am NOT a nuclear engineer, just an EE who reads a lot.
@ApolloWasReal I am not trying to argue, but those weren't nuclear explosions, which is what I thought you meant. I did post the actual moderating mechanism below..., it isn't doppler broadening come to find out.
@JustinHEMI05 Well, you could think of these pulses as something like highly abbreviated nuclear explosions -- at first, the power level grows exponentially very quickly, albeit with thermal neutrons instead of fast neutrons, but a mechanism kicks in to keep it from growing too high. With SL-1 and Chernobyl #4, the power level grew much higher before other mechanisms (like physical disassembly of the reactor) stopped the reaction.
@ApolloWasReal Hehe well, like I said I am not trying to argue..., but they still weren't nuclear explosions. Even if I could make my reactor prompt critical, it still wouldn't be a nuclear explosion. Sure, fuel would melt and be destroyed, but that is vastly different than a nuclear explosion. I know some might say it is just "semantics," but in this case, it is not. It isn't correct to think of it as a nuclear explosion.
@JustinHEMI05 Well..I think it IS semantics. The difference is really a matter of degree -- how much of the fuel quickly fissions before the reaction stops. Even if, in a reactor it simply isn't possible for more than a tiny fraction of the fuel to quickly fission before multiple mechanisms stop the reaction.
I think we can agree this is not a discussion we should have with anyone who fears nuclear power and doesn't already know something about reactors.
@ApolloWasReal By the way, I have learned that it isn't doppler broadening that stops the reactor and is in fact, too slow. It uses the "warm neutron principle" that deals with the fact that the fuel is uranium zirconium hydride which gives the reactor a prompt negative coefficient of reactivity when at about 800c, the fuel "decomposes" into hydrogen gas and uranium metal. This causes a loss of neutron moderation and subsequently, the reaction is stopped. As temperature lowers...
@JustinHEMI05 I knew I read it somewhere, I just found a description of pulsing in a TRIGA zero-power reactor that says the negative fuel reactivity with temperature coefficient is due to "spectrum hardening" and the Doppler effect. Maybe the Penn State reactor works differently from a TRIGA.
@ApolloWasReal It is a Triga, it is even listed on their website. I agree with you in that I thought it had to be doppler as well, and I am sure it is to some effect. My source says there is a bigger effect however. Where are you reading?
@ApolloWasReal Thank you very much. It has been enjoyable talking with you, even if it has been via youtube comments. :) I will keep you posted on anything new I find out.
@ApolloWasReal Hey I heard from the director of the Triga facility at the University of Arizona. I provided him the link that you recommended I looked at for his evaluation. Here is what he said (I will break it up into two replies).
@JustinHEMI05 Ah, I see, very interesting. But how does the rise in fuel temperature increase the neutron temperature? Isn't that a Doppler effect? I.e., if you have a U atom moving toward you as it vibrates thermally, any neutrons it releases in your direction will be faster, i.e., hotter. Of course, if it's moving away as it fissions, any neutron it releases will be colder but the overall effect is probably to make the neutrons hotter.
@ApolloWasReal Well doppler is a property of the fuel, not the neutrons. Like he explained, the key is shifting the neutrons to the maxwell boltzmann range, which has to do with neutron diffusion through a gas. Thhe gas is the hydrogen, which is the moderator. This spectral shift causes the neutrons to not be "seen" by the uranium and they escape into the surrounding water instead of causing further fission.
@JustinHEMI05 I can see I'm going to have to read up on this. I know that fission cross sections depend on neutron energy, and that's the reason for moderation in thermal reactors, but I don't know the detailed physics of how moderators actually work.
@ApolloWasReal Yeah I was confused at first because I was trying to combine it with my knowledge of commercial nukes..., which simply doesn't work. The Triga is completely different since its moderator is mixed in the fuel and can't be compared to a reactor where the fuel and moderator is separate, like a commercial nuke. And being that it is a gas, that changes things as well. Interesting stuff!!! It is fun to learn new things. Half of me wants to work at one of these now. :D
@JustinHEMI05 So are you ex-Navy? I had heard that nearly all commercial reactor operators got their nuclear training in the Navy. As far as I know, they've never had an accident. I know of a company that thinks they can build turnkey modular reactors for commercial ships that need no refueling during their lifetimes, and cannot be damaged by any operator action or system malfunction. I wish them luck, they're gonna need it.
@ApolloWasReal Yep spend 9 year in, 4.5 on a fast attack submarine. So far they haven't had any major problems, but their plants are extremely forgiving and simple. They are fairly "sailor proof."
@JustinHEMI05 If you keep your reactor critical but not prompt critical, then the period will be fairly long and the power easily controlled. There's time for the coolant to remove the heat and keep the core temperature relatively low. The core stays critical and you can operate it indefinitely.
What are the power levels of your reactors? What are their core temperatures?
@ApolloWasReal ... the reaction starts and basically the reactor self regulates itself until the control rod is reinserted. It was really interesting. Google TRIGA reactor by general atomics and also google uranium zirconium hydride fuel. Fascinating stuff.
@JustinHEMI05 Interesting! Thanks. I know Doppler broadening is a regulation mechanism in at least some reactors, and I had thought I read it was the fast mechanism here. Question: how does the temporary UZrH decomposition actually result in demoderation? I don't think it could be physical expansion, that would seem too slow. The U also heats up too, of course; perhaps Doppler broadening reduces its effective cross section for neutrons of that energy. Maybe there are multiple mechanisms?
@ApolloWasReal I don't know that much detail..., yet. I am in contact with someone that works at the Penn State reactor and will get more technical details soon. You are correct, doppler is very important to traditional commercial reactors like the ones I operate. The effect is immediate when we raise fuel temperature, but from what I am reading, that this "decomposition" is even faster.I will let you know when I have more info.
@JustinHEMI05 Yes, more details would be interesting. Many thanks.
The difference between critical and prompt critical seems so small that it's really nice to know that so many regulatory mechanisms can control reactor power -- IF the reactor is properly designed, that is (not the RBMKs at Chernobyl).
@ApolloWasReal I couldn't agree more, RBMK was such a piss poor design. The Russians had many many objectors to the design, but they were fired or otherwise silenced and the state went ahead with building them anyway.
@JustinHEMI05 The RBMK designers weren't stupid, they certainly knew the vulnerabilities and carefully documented them in the manuals. But the operators were idiots. They came from coal plants. They weren't trained; their knowledge of nuclear reactors was limited to "control rods out, power up. Control rods in, power down". Nobody told them about xenon poisoning so they had no idea why the power kept going down even when they pulled all the rods out...
@ApolloWasReal Agreed, the operators were stupid, but it was a piss poor design with many objectors. There were a lot of failures in that program, the operators being the culmination of all of them.
@JustinHEMI05 Yes. It was the sum of **so** many things -- a nonexistent Russian safety culture, a requirement to breed Pu for weapons, a lack of containment, poor/no operator training, you name it. It certainly demonstrates the importance of defense in depth. And it makes me so angry because so many people now see it as symbolic of nuclear power, something we really need now along with every other form of energy that doesn't produce CO2.
@ApolloWasReal Yeah the same things make me angry. I am constantly trying to educate people on the US nuclear program and how good we really are. Did we have our wake up call with TMI? Sure, but it did wake us up. The robustness of our plants, our operator training programs, and regulatory oversight should make people sleep soundly at night, but they often still hold irrational fear based simply in ignorance. So I cheerfully try to bring them into the light!
@JustinHEMI05 TMI was an economic disaster (the plant was still pretty new) but not a single person died. Nor did a single person get a dangerous radiation dose. I think a lot of the problem is, ironically, the safety precautions. The public just doesn't understand ALARA. E.g., the X-ray tech doesn't leave the room because radiation is horribly dangerous, they leave because it's so easy to do so, so why not? The linear no-threshold is clearly wrong, but people still live in fear of tiny doses.
@JustinHEMI05 I have been saying that the strong negative feedback mechanisms in these hydride fuels makes them useless in power reactors, but now I'm remembering a company trying to overcome that problem. I think they were looking at power levels in the tens of MW, well below most power reactors, and intended for turnkey operation. Like TRIGA, it would simply be impossible to damage the fuel by any operator action or inaction or power failure. Sounds good to me.
@ApolloWasReal Yeah I came across a bit of that as well. It seems they would have to be smaller scale "local" power plants unlike the behemoth commercial plants of today. I would support that. :)
@BWIENS789 Boron, isn't that like Silver? since in sweden @Ringhals nuclear power plant we use silver, atleast thats what they say in the control room, i work in the water cleaning haha :)
@mattias990 Boron is nothing like sliver. Boron (B), the element is a non-metal, whereas Silver (Ag) is a transition metal on the Periodic table. They are no more alike than Sulfur (S) and Lead (Pb). No idea why they use that phrase, sorry.
@EnigmaNZ1 Its Latin name is derived from the use of lead water pipes in the cities of Rome, hence plumbing. No question about that, I was saying I have no Idea why the people in that guy's power plant seem to use the element names Boron and Silver interchangeably. Boron is used as the control rods in many facilities, but silver would be disastrous. I do believe some did, and maybe some still do use Cadmium Control Rods, but the toxicity of Cadmium among other stuff make Boron a better choice
@sirdude456 nothing can go faster than the speed of light.It defies the laws of physics.To prove my point Steven hawking's theory is if you accelerate a train to the speed of light it will slow down time inside the train to avoid breaking light speed.This means in one week to the passengers 100 years will have past outside the train so it's time travel so your comment is wrong
@TynchySniper1 You're right, nothing can go FASTER than the speed of light, IN A VACUUM. But light travels more slowly in dense matter, like WATER. Try to move a particle at a speed FASTER than light can move IN WATER, and you get the "Blue Light", a photon that represents the difference in energy levels.
Call your buddy Hawking, I'm sure he can explain it better . . .
@firedogbme It's called Cherenkov radiation, molecules moving through the water at the speed of light. It excites the water, when it quicky returns to it's un-excited state it glows blue.
There's no lights in there, it's caused by super fast radiation.
@TynchySniper1 Oh btw, that was Einstein who came up with time dilation in his theories of relativity (special and general), not Hawking. However, Hawking has used that knowledge to describe black holes, etc, to make other theories.
the blue glow you see is cherenkov radiation, it is given off when anything goes faster than the speed of light in that medium. The medium in this case is water
@migkillertwo "what would happen if someone tossed a penny in there" Basically nothing. Of course they'd make you swim down to get it, so you might puke up your own liver.
ZOMG Im a fearful ignorant and I just realized that we had reactors since the 50s!!! Time to panic and make lame comments on how every single reactor will fail in a near future!
@silvawtf69 That's just what they're doing: pulling out the rods very quickly so the reactor goes into a supercritical state. Power increases exponentially, doubling every few milliseconds. But this reactor is designed so that when the power reaches a certain point, the reaction automatically stops, thus making a chernobyl impossible. It also makes this kind of reactor unsuitable for producing power. It's used for teaching, research and isotope production.
@EupFilmStudent2012 no, this really is a fission reactor, its called a PULSTAR reactor, NC State has had the same type of reactor on campus since 1972 and these reactors do in fact use uranium oxide fuel pellets for their fission reaction, the difference is that a university doesn't exactly swap out he fuel rods every 18months like a normal power plant does, the handful of universities that have reactors use their fuel for many many years
@SAOrules few seconds is too short to do any experiments but they usually line up experiments and then have it running for a few days at a time, but the downtime is longer especially if there are no experiments or classes going
@ggilley71 yes and the reason for this is the same reason why all U.S. submarines go quite a while before changing theirs out as well, civilian plants operate at 100% power all the time so they burn much more fuel than say a college reactor that only operates at 20% power for experiments and classes only on certain days.
@ApolloWasReal kind of, they mainly used highly enriched uranium because they need to be able to have the same high power output with a much smaller reactor. They also design them to last a very long time but civilian plants do as well. We are getting much better at it as well, the new submarines that are coming out can last much much longer on almost the same amount of fuel just because of the new technology and methods we are coming up with at power generation,
@EupFilmStudent2012 These reactors operate at such low average power that I think the fuel lasts the lifetime of the reactor. There's no need for refueling, so there's no need to store spent fuel. When the reactor is eventually decommissioned the core can be taken away for reprocessing (in countries that do that) or join the rest of the spent nuclear fuel waiting for the politicians to stop posturing and pick a permanent burial site.
@JustinHEMI05 I stand corrected, thanks for the info. I had heard that at least most of these "swimming pool" reactors were designed for a single fueling. I also heard that there was a NRC campaign to reduce the enrichment level of the fuel below 20%. Maybe that shortened the fuel lifetime to the point that refueling was required. Is that the case?
@ApolloWasReal Yeah I would imagine so. I learned this by reading the FAQ on penn states reactor website. Since seeing this video, I have been reading all I can get my hands on about this reactor.
@JustinHEMI05 I have now seen other research reactors with spent fuel pools. It may be because of a US nonproliferation program to reduce fuel enrichment in research reactors to less than 20%, presumably to decrease the attractiveness of the fuel to someone who might want to build a weapon. HEU can last a long time, but LEU has a shorter life and the reactors may require refueling depending on how much they're run.
@EupFilmStudent2012 Actually quite a few colleges and universities have had these low power research reactors for many years. Cornell had one in the 70s when I was there. Many have since been shut down or removed because of the political unpopularity of nuclear technology, not because of any actual safety hazard. These particular reactors are extremely safe; they have such strong inherent negative feedback that they are useless for producing significant power.
The "Blue" you see is actually Cerenkov radiation. It happens when an charged particle (in this case an electron) travels faster then the phase velocity,(or speed of light) through a dielectric medium.
c / n < vp < c where "c" is the speed of light in a vacuum and "n" is the refractive index of the medium. Dont know much about reactors but i guess the medium here is de-mineralized water?
@theleadprogrammer The blue glow is indeed Cerenkov radiation from the beta particles (electrons) emitted by the fission products of the nuclear reaction. Reactor criticality actually lasts only a fraction of a second but the shorter-lived (and more active) fission products decay over several seconds after the reaction stops. Think of it as a nuclear explosion aborted at its very early stages by the design of the core and its fuel.
Very interesting ...
Jochen754 1 month ago
uh was that actually the rod glowing?
boots992134 3 months ago
I look forward to seeing the pulse at Breazeale at the end of the semester myself =)
ubuntuibex 3 months ago
just so you people know, the reactor itself isn't glowing. the fission process is producing a form of radiation known as Cerenkov radiation. this causes the water to glow because Cerenkov radiation actually travels faster than light. i don't know the actual physics of it but thats what i know.
GAMERFLY2552 4 months ago
It would render the General and Special Theories of Relativity worthless, and all current Physics textbooks would be wildly incorrect if what you just said is true, because while it is possible to slow C down, in all sorts of special environments, it is not possible to exceed C, and it only becomes full C (186,000 mps) in a vacuum with no external action, e.g., a black hole. It is an irrefutable fact that nothing can or does exceed the speed of light. I don't know where you've heard differently.
painxtreme 3 months ago
@painxtreme If a charged particle (such as an electron) passing through a dielectric medium at a speed greater than the phase velocity of light in that medium, you'd be correct, but that means it is exceeding a light speed that has been very slowed by a medium... water slows light down by 25%, so the radiation exceeds the speed of that light in that medium, but nothing exceeds the speed of light in a vacuum, such as space (C -186,000mps) under any circumstances.
painxtreme 3 months ago
@painxtreme both of the above are addressed to GAMERFLY2552, forgive me for not hitting the reply button, but my 2 longer posts tells you the Physics.
painxtreme 3 months ago
@painxtreme what about this kid....
liveleak.com/view?i=63d_1301350978
NikoVlogsGud 2 months ago
@painxtreme Not a problem. I had said in my post, C can be slowed, but Gamerfly had asserted that Cerenkov Radiation travels faster than the speed of light, without qualification. Obviously if C is slowed, many things can exceed its speed, but that isnt exceeding C, it is exceeding photons traveling at less than C, that was my point, and to that end, it is not exceeding light speed. I can outrun a Bugatti Veyron in my powerchair, if the Veyron is towing 70 elephants, ok enough silliness, Cheers!
painxtreme 2 months ago
@painxtreme
Tell that to Pavel Alekseyevich Cherenkov so then maybe Aether is real and Einstein was a crack pot
David0Karesh 2 months ago
@David0Karesh Einstein's works clearly state that nothing exceeds C, period. If you are talking about slowing light down, it is no longer at "light speed" (186,000 mps), and is an entirely different matter, and it is not exceeding C.
painxtreme 2 months ago
By the way, that was only one rod.
shadyman2000 4 months ago 9
Soooo preeetty
User1127531 4 months ago
quick someone jump in and gain super powers
TheTechBite 5 months ago 26
@TheTechBite Actually, you'd more likely die if you jumped in.
Mrtheunnameable 3 months ago
@TheTechBite Are you a dumbass or what?
TheReviewteam5 2 months ago
@TheReviewteam5 Whats going on spook? cool story, bro.
TheTechBite 2 months ago
@TheTechBite. That would not happen. Nothing would happen, as far as i know. The water, heavy water D2O. Is there to protect the viewers of the reactor. And you have to swim down to it in order for something to happen to you.
BlueFoxTV 1 month ago
@BlueFoxTV Do you not understand the concept of a simple joke? Man people can be so dull sometimes.
TheTechBite 1 month ago
@BlueFoxTV Actually it is a mixture. On the one side of the reactor pool is a D2O pump, where as most of the water, more so toward the middle of the pool, is actually natural H2O. It was really cool watching this live during Nuc E 451 Lab on Thursday.
klajcollege 1 month ago
Fusion ... NOT FISSION is the way to go ... NO MELTDOWN or RUN_AWAY_ REACTION is possible with fusion.
Visit Fusion Power Corporation's web site and see the video "StarPower for Tomorrow" on YouTube for a real education.
hhelsley 5 months ago
@hhelsley you have made fusion give more energy then it takes to fuze? bravo!
sk8er4ever0101 4 months ago
@BENBOOST9 you cant see radioactivity.
pinnegubbe 6 months ago
@pinnegubbe You realise that every form of radioactivity emits light?
9hello123 6 months ago
@9hello123 Yes, but the RADIOACTIVITY is gamma-rays.
You cant see the gamma-rays, but you see the light with a wavelength in the part of the specter of lightwaves we see.
Gamma passes right through our eyes.
pinnegubbe 6 months ago
@pinnegubbe "Yes, but the RADIOACTIVITY is gamma-rays." In most cases. However it can be absolutely any colour.
9hello123 6 months ago
@9hello123 The way i see it, the wavelength decides both if we can see the color, and how radioactive it is.
radiation cant have any color witch we can see. because then it would not have been radioactive!
if we can see the light, it cant be radioactive. if we don't see light, it can be radioactive.
those rods of whatever material they use is radioactive, and emits light. but those light waves cant harm nobody. the waves that we don see on the other hand is in form of gamma.
pinnegubbe 6 months ago
@pinnegubbe
Radioactivity is when energy is emitted from the nucleus of an atom. It has absolutely nothing to do with whether or not it is harmful to you.
9hello123 6 months ago
This has been flagged as spam show
@9hello123 i did not say it did.
pinnegubbe 6 months ago
@pinnegubbe In this case, it isn't the radioactivity however it is due to the radioactivity producing enough energy to make electrons go faster than the speed of light around it which causes the atoms around it to be excited and then de-excite emitting radiation.
In other cases radioactivity can cause any colour at all.
9hello123 6 months ago
@9hello123 yes, but only outside of the spectrum we can see! you cant have radioactive red or blue light, because, for it to be radiation it must be gamma or near gamma.
please note that i have no whatsoever education on this, but have only read and watched documentaries about the subject. this is the way i have understood it, and i think it makes sense the way i see it :P
pinnegubbe 6 months ago
@pinnegubbe radioactivity is just if a nucleus loses energy. It has nothing to do with how much energy it has lost.
9hello123 6 months ago
@9hello123 where did i say that it has something to do with that?
but as i understand it has something to do with how fast they loose the energy? im not sure. u tell me : )
pinnegubbe 6 months ago
This has been flagged as spam show
@pinnegubbe "where did i say that it has something to do with that?" You said it's only when gamma rays are emitted that it's radioactivity, gamma rays is just more energetic light and is emitted when a lot of energy is lost.
Radioactivity is purely if an unstable nucleus emits energy.
9hello123 6 months ago
of course, it is not a whole lot slower. i saw in documentary once that they have slowed it, by like, 1% or something:P and that was through some kind of substance to make it slow down as much as possible.
pinnegubbe 6 months ago
@pinnegubbe Actually, they slowest they've gotten light is to just under 40 miles per hour. Look up "slow light" on google.
Freeflyer91 6 months ago
@Freeflyer91 yeah you are right! wow, that was interesting! cool, man.
but it says it is a special light. so the light as you and me think of. is not the light they use for the experiment.
pinnegubbe 6 months ago
@Freeflyer91 and it says that they had the substance cooled to 0 Kelvin. which is theoretically impossible. quite weird they say that...
pinnegubbe 6 months ago
@pinnegubbe you can get very close, but just as we cannot produce a perfect vacuum on earth, neither can we achieve absolute zed, just very close, and close enough to bring about super fluidity in some elements. Helium jumps to mind. Even though we cannot reach zed, we get close enough that some very counter-intuitive and amazing things occur.
painxtreme 2 months ago
@painxtreme yeah i watched a docu about superfluidity and helium about the time i watched this film.
Very interesting!
Also, I have come to a deeper understanding of kelvin and absolute zero now ; )
pinnegubbe 2 months ago
@pinnegubbe I so love physics. I am formally trained as an Artist, which I then married with a degree in computer science, and became a Graphic Artist. Fast forward, Im almost 48, been disabled since 2005. I taught Art History at our local college, now Im an Emeritus with a very very limited role. My best friend there is the Chair of the Graduate Astrophysics Department. Sadly, he lost his wife 3 yrs ago, she was also an Artist, and Ron and I have always said the elegance of Physics is an Art
painxtreme 2 months ago
@painxtreme Part Deux: While teaching, I also owned a small Design company, which handled the creative work for Ad Agencies, and other sundry printed matter. Superfluidity is a captivating and mysterious discovery. Graphene is one of the latest amazing innovations. It's graphite sheets, one atom thick. Graphite dissipates heat much better than does silicon, so its likely that the future will bring us Graphene Intel Chips. It was, I think the 2010 Nobel for Physics. I wont even start with quantum
painxtreme 2 months ago
@painxtreme me too! im only 20, but i am already very much into physics.
Im norwegian, but quit school when i was 18. ohmaaan, you wont believe how much i regret that.. ever since then, i have been very keen on learning more.
i quit school because of one teacher. damn. i look back now an can only see myself as a fool for quiting.
pinnegubbe 2 months ago
@pinnegubbe Can you return, and continue your studies? I am ignorant of the Norwegian Education system, though im a quarter Norwegian, but that from generations back...Im not a fan of lutefisk like the Minnesotan Norwegians. A friend of mine has relatives in Norway, and he asked if they liked lutefisk, and he said "No, we ship it to Minnesotans" HAHA
Seriously, if there is a way to return, I can see in your words, you really need to. You may be depriving the world of a great mind if not.
painxtreme 2 months ago
@painxtreme Yeah, i'm going to in the spring! Just taking math to get an exam, and maybe some other classes.
Old Norwegians like lutefisk x) I don't at all! Have you heard of "pultost"? "Pult" means fucked, and "ost" means cheese. Old people go crazy over it! It smells like rotten dead sheep... seriously!
Thank you! Thats really nice to hear from an unknown!
You are an Emeritus? I don't know what that is in Norwegian. Still some kind of teacher or professor?
pinnegubbe 2 months ago
@painxtreme Yeah, i'm going to in the spring! Just taking math to get an exam, and maybe some other classes.
Old Norwegians like lutefisk x) I don't at all! Have you heard of "pultost"? "Pult" means fucked, and "ost" means cheese. Old people go crazy over it! It smells like rotten dead sheep... seriously!
Thank you! Thats really nice to hear from an unknown!
You are an Emeritus? I don't know what that is in Norwegian. Still some kind of teacher or professor?
pinnegubbe 2 months ago
@pinnegubbe Emeritus is a fancy title for a retired professor (or in my case, disabled), who still has priviliges, e.g. Fully Library use, Personal Office, and Art Studio. I give a few lectures a year, but that's about it. I do a little less each year. When I stop using it, my office and studio will become a small Art Library for the School, that will hold all of my collection of Art Books going back a few centuries, for students who desire further reference. It will be reference only library.
painxtreme 2 months ago
@WeedChat the speed of light isnt constant. it is about 300000 km/s in a vacuum. so through the air around you, it is actually a bit slower.
pinnegubbe 6 months ago
Man I'm just thinking on how much I could save on my electrical bill with this....damn!
midnull 7 months ago
@midnull They can't generate electricity. They can generate hot water, so I suppose you could save on your natural gas bills.
ApolloWasReal 7 months ago
would u die if u dived in a swam down there to get a really nice picture =P
Ptro001 8 months ago
@Ptro001 No, they do scuba lessons on saturdays
MrFreddyFeatures 8 months ago 18
I don't think it's a negative void coefficient since no steam voids form in the water. The fuel is usually uranium hydride, with the hydrogen acting as moderator. It heats instantaneously when the reactor pulses, and the resulting Doppler broadening quickly un-moderates and stops the reaction.
ApolloWasReal 8 months ago
Im a Navy nuke, so forgive me for being force fed ONLY what the Navy needs me to know about nuclear power. So how do you pulse a reactor, and what is the purpose of this?
Blindauer717 8 months ago
@Blindauer717 I believe the main use for a short pulse like that is for neutron imaging and other experiments that require very high neutron flux. Basically it's like a camera flash but with a very powerful neutron beam instead of light. To create it, first you need a reactor with a negative void coefficient (to avoid a chernobyl). Then one of the control rods is popped out of the reactor with a pneumatic actuator. The reactor pulses and shuts down by itself due to the void coefficient.
aforencich 8 months ago
whats the pulsing power of the reactor there?
bloodasp90 8 months ago
I want one of those
1988tq 8 months ago
Okay :) alot of power
80AFT 8 months ago
Dayumm!
NFLization 8 months ago
what happens when the reactor is pulsing?
80AFT 9 months ago
@80AFT They control rod(s) are removed and the reactor goes into a super critical state for barely a second. The control rods are made of boron, they absorb the neutrons and control the reaction. The blue light you see is Cherenkov radiation, this is when beta particles or electrons attempt to reach speeds faster than light but light travels slower in a medium. The water is the medium and you get the blue light photons produced in the process. You are seeing the true blue color.
BWIENS789 8 months ago 13
@BWIENS789 Criticality actually lasts for much less than 1 second - otherwise there'd be an explosion. The blue glow is the Cerenkov radiation of the beta particles (electrons) emitted from the shortest lived (and thus most active) fission products that decay over several seconds after being almost instantly produced during the brief criticality.
ApolloWasReal 8 months ago
@ApolloWasReal I've been reading your comments and felt they were more or less correct until this one. Can you please explain what you mean by "Criticality actually lasts for much less than 1 second - otherwise there'd be an explosion?" As we speak, my two reactors are critical at 100%.
JustinHEMI05 7 months ago
@JustinHEMI05 Some of these pulsing videos give the reactivity insertion as considerably more than $1.00, confirming that they're taken prompt critical. Any prompt critical reactor has a period (power doubling time) of a few milliseconds, so unless the reaction stops quickly there'd be an explosion. Fortunately these reactors have very strong & quick negative feedback that stops the reaction when the core reaches a certain temperature, probably by Doppler broadening.
ApolloWasReal 7 months ago
@ApolloWasReal Are you suggesting that prompt criticality = explosion? Or just in this reactor's case? If I took my reactor (Beaver Valley, Westinghouse 3 loop PWR), it would not explode. Now, admittedly, I am not versed on these test reactors which is why I am trying to understand what you are saying. What is your background if I may ask? I ask because I would like to know your basis for saying doppler broadening is the moderating effect, and not some other control device. Do you work here?
JustinHEMI05 7 months ago
@JustinHEMI05 In many reactors, prompt criticality would produce an explosion, yes. Eg, Chernobyl #4 and SL-1. But these research reactors have strong, fast negative feedback that limits the energy release. It also makes them unsuitable for power production. The fuel is often uranium hydride. The hydrogen moderates, and the close U->H thermal coupling causes quick Doppler broadening that unmoderates the reaction.
I am NOT a nuclear engineer, just an EE who reads a lot.
ApolloWasReal 7 months ago
@ApolloWasReal I am not trying to argue, but those weren't nuclear explosions, which is what I thought you meant. I did post the actual moderating mechanism below..., it isn't doppler broadening come to find out.
JustinHEMI05 7 months ago
@JustinHEMI05 Well, you could think of these pulses as something like highly abbreviated nuclear explosions -- at first, the power level grows exponentially very quickly, albeit with thermal neutrons instead of fast neutrons, but a mechanism kicks in to keep it from growing too high. With SL-1 and Chernobyl #4, the power level grew much higher before other mechanisms (like physical disassembly of the reactor) stopped the reaction.
ApolloWasReal 7 months ago
@ApolloWasReal Hehe well, like I said I am not trying to argue..., but they still weren't nuclear explosions. Even if I could make my reactor prompt critical, it still wouldn't be a nuclear explosion. Sure, fuel would melt and be destroyed, but that is vastly different than a nuclear explosion. I know some might say it is just "semantics," but in this case, it is not. It isn't correct to think of it as a nuclear explosion.
JustinHEMI05 7 months ago
@JustinHEMI05 Well..I think it IS semantics. The difference is really a matter of degree -- how much of the fuel quickly fissions before the reaction stops. Even if, in a reactor it simply isn't possible for more than a tiny fraction of the fuel to quickly fission before multiple mechanisms stop the reaction.
I think we can agree this is not a discussion we should have with anyone who fears nuclear power and doesn't already know something about reactors.
ApolloWasReal 7 months ago
@ApolloWasReal Agreed, we'll let this one go. :)
JustinHEMI05 7 months ago
@ApolloWasReal By the way, I have learned that it isn't doppler broadening that stops the reactor and is in fact, too slow. It uses the "warm neutron principle" that deals with the fact that the fuel is uranium zirconium hydride which gives the reactor a prompt negative coefficient of reactivity when at about 800c, the fuel "decomposes" into hydrogen gas and uranium metal. This causes a loss of neutron moderation and subsequently, the reaction is stopped. As temperature lowers...
JustinHEMI05 7 months ago
@JustinHEMI05 I knew I read it somewhere, I just found a description of pulsing in a TRIGA zero-power reactor that says the negative fuel reactivity with temperature coefficient is due to "spectrum hardening" and the Doppler effect. Maybe the Penn State reactor works differently from a TRIGA.
ApolloWasReal 7 months ago
@ApolloWasReal It is a Triga, it is even listed on their website. I agree with you in that I thought it had to be doppler as well, and I am sure it is to some effect. My source says there is a bigger effect however. Where are you reading?
JustinHEMI05 7 months ago
@JustinHEMI05 Problem is, YT censors URLs. Try googling for Reactor Physics of Pulsing:
Fuchs - Hansen Adiabatic Model M. Ravnik and see if that finds it.
ApolloWasReal 7 months ago
@ApolloWasReal Thank you very much. It has been enjoyable talking with you, even if it has been via youtube comments. :) I will keep you posted on anything new I find out.
JustinHEMI05 7 months ago
@JustinHEMI05 You're welcome. It's quite unusual to have a productive, informative exchange on YT, I can tell you that...
ApolloWasReal 7 months ago
@ApolloWasReal Hey I heard from the director of the Triga facility at the University of Arizona. I provided him the link that you recommended I looked at for his evaluation. Here is what he said (I will break it up into two replies).
JustinHEMI05 7 months ago
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JustinHEMI05 7 months ago
@ApolloWasReal PART 1; "The information in the link you sent is reliable, though the model he
describes is known to me as the Fuchs-Nordheim model, not Fuchs-Hanson.
There is a small Doppler broadening effect in TRIGAs, the reduces the
resonance escape probability as in other thermal reactors, but that is not the main
contribution to the negative temparature coefficient. The main contribution
comes from a spectral shift of the thermal neutrons. "
JustinHEMI05 7 months ago
PART 2: Because most of the
moderator is homogeneously mixed in the fuel, its temperature is the same as
the fuel temperature. Therefore a rise in fuel temperature increases the
neutron temperature of the Maxwellian part of the spectrum. Because the
fission cross section in uranium is approximately inversely proportional to neutron
speed, the higher the neutron temperature, the less the effective
fission cross section.
JustinHEMI05 7 months ago
PART3: Sorry, didn't fit in 2 parts. :) "This reduces the thermal utilization, eta, and hence reduces keff.
There is no comparable effect in reactors with the moderator separate from the
fuel."
So, doppler is a small effect. Makes much better sense now.
JustinHEMI05 7 months ago
@JustinHEMI05 Ah, I see, very interesting. But how does the rise in fuel temperature increase the neutron temperature? Isn't that a Doppler effect? I.e., if you have a U atom moving toward you as it vibrates thermally, any neutrons it releases in your direction will be faster, i.e., hotter. Of course, if it's moving away as it fissions, any neutron it releases will be colder but the overall effect is probably to make the neutrons hotter.
ApolloWasReal 7 months ago
@ApolloWasReal Well doppler is a property of the fuel, not the neutrons. Like he explained, the key is shifting the neutrons to the maxwell boltzmann range, which has to do with neutron diffusion through a gas. Thhe gas is the hydrogen, which is the moderator. This spectral shift causes the neutrons to not be "seen" by the uranium and they escape into the surrounding water instead of causing further fission.
JustinHEMI05 7 months ago
@JustinHEMI05 I can see I'm going to have to read up on this. I know that fission cross sections depend on neutron energy, and that's the reason for moderation in thermal reactors, but I don't know the detailed physics of how moderators actually work.
ApolloWasReal 7 months ago
@ApolloWasReal Yeah I was confused at first because I was trying to combine it with my knowledge of commercial nukes..., which simply doesn't work. The Triga is completely different since its moderator is mixed in the fuel and can't be compared to a reactor where the fuel and moderator is separate, like a commercial nuke. And being that it is a gas, that changes things as well. Interesting stuff!!! It is fun to learn new things. Half of me wants to work at one of these now. :D
JustinHEMI05 7 months ago
@JustinHEMI05 So are you ex-Navy? I had heard that nearly all commercial reactor operators got their nuclear training in the Navy. As far as I know, they've never had an accident. I know of a company that thinks they can build turnkey modular reactors for commercial ships that need no refueling during their lifetimes, and cannot be damaged by any operator action or system malfunction. I wish them luck, they're gonna need it.
ApolloWasReal 7 months ago
@ApolloWasReal Yep spend 9 year in, 4.5 on a fast attack submarine. So far they haven't had any major problems, but their plants are extremely forgiving and simple. They are fairly "sailor proof."
JustinHEMI05 7 months ago
@JustinHEMI05 Oh, BTW, I think the Fuchs in that paper is none other than Klaus Fuchs, the atomic spy. Just an interesting historical tidbit.
ApolloWasReal 7 months ago
@JustinHEMI05 If you keep your reactor critical but not prompt critical, then the period will be fairly long and the power easily controlled. There's time for the coolant to remove the heat and keep the core temperature relatively low. The core stays critical and you can operate it indefinitely.
What are the power levels of your reactors? What are their core temperatures?
ApolloWasReal 7 months ago
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JustinHEMI05 7 months ago
@ApolloWasReal ... the reaction starts and basically the reactor self regulates itself until the control rod is reinserted. It was really interesting. Google TRIGA reactor by general atomics and also google uranium zirconium hydride fuel. Fascinating stuff.
JustinHEMI05 7 months ago
@JustinHEMI05 Interesting! Thanks. I know Doppler broadening is a regulation mechanism in at least some reactors, and I had thought I read it was the fast mechanism here. Question: how does the temporary UZrH decomposition actually result in demoderation? I don't think it could be physical expansion, that would seem too slow. The U also heats up too, of course; perhaps Doppler broadening reduces its effective cross section for neutrons of that energy. Maybe there are multiple mechanisms?
ApolloWasReal 7 months ago
@ApolloWasReal I don't know that much detail..., yet. I am in contact with someone that works at the Penn State reactor and will get more technical details soon. You are correct, doppler is very important to traditional commercial reactors like the ones I operate. The effect is immediate when we raise fuel temperature, but from what I am reading, that this "decomposition" is even faster.I will let you know when I have more info.
JustinHEMI05 7 months ago
@JustinHEMI05 Yes, more details would be interesting. Many thanks.
The difference between critical and prompt critical seems so small that it's really nice to know that so many regulatory mechanisms can control reactor power -- IF the reactor is properly designed, that is (not the RBMKs at Chernobyl).
ApolloWasReal 7 months ago
@ApolloWasReal I couldn't agree more, RBMK was such a piss poor design. The Russians had many many objectors to the design, but they were fired or otherwise silenced and the state went ahead with building them anyway.
JustinHEMI05 7 months ago
@JustinHEMI05 The RBMK designers weren't stupid, they certainly knew the vulnerabilities and carefully documented them in the manuals. But the operators were idiots. They came from coal plants. They weren't trained; their knowledge of nuclear reactors was limited to "control rods out, power up. Control rods in, power down". Nobody told them about xenon poisoning so they had no idea why the power kept going down even when they pulled all the rods out...
ApolloWasReal 7 months ago
@ApolloWasReal Agreed, the operators were stupid, but it was a piss poor design with many objectors. There were a lot of failures in that program, the operators being the culmination of all of them.
JustinHEMI05 7 months ago
@JustinHEMI05 Yes. It was the sum of **so** many things -- a nonexistent Russian safety culture, a requirement to breed Pu for weapons, a lack of containment, poor/no operator training, you name it. It certainly demonstrates the importance of defense in depth. And it makes me so angry because so many people now see it as symbolic of nuclear power, something we really need now along with every other form of energy that doesn't produce CO2.
ApolloWasReal 7 months ago
@ApolloWasReal Yeah the same things make me angry. I am constantly trying to educate people on the US nuclear program and how good we really are. Did we have our wake up call with TMI? Sure, but it did wake us up. The robustness of our plants, our operator training programs, and regulatory oversight should make people sleep soundly at night, but they often still hold irrational fear based simply in ignorance. So I cheerfully try to bring them into the light!
JustinHEMI05 7 months ago
@JustinHEMI05 TMI was an economic disaster (the plant was still pretty new) but not a single person died. Nor did a single person get a dangerous radiation dose. I think a lot of the problem is, ironically, the safety precautions. The public just doesn't understand ALARA. E.g., the X-ray tech doesn't leave the room because radiation is horribly dangerous, they leave because it's so easy to do so, so why not? The linear no-threshold is clearly wrong, but people still live in fear of tiny doses.
ApolloWasReal 7 months ago
@JustinHEMI05 I have been saying that the strong negative feedback mechanisms in these hydride fuels makes them useless in power reactors, but now I'm remembering a company trying to overcome that problem. I think they were looking at power levels in the tens of MW, well below most power reactors, and intended for turnkey operation. Like TRIGA, it would simply be impossible to damage the fuel by any operator action or inaction or power failure. Sounds good to me.
ApolloWasReal 7 months ago
@ApolloWasReal Yeah I came across a bit of that as well. It seems they would have to be smaller scale "local" power plants unlike the behemoth commercial plants of today. I would support that. :)
JustinHEMI05 7 months ago
@BWIENS789 Boron, isn't that like Silver? since in sweden @Ringhals nuclear power plant we use silver, atleast thats what they say in the control room, i work in the water cleaning haha :)
mattias990 3 months ago
@mattias990 Boron is nothing like sliver. Boron (B), the element is a non-metal, whereas Silver (Ag) is a transition metal on the Periodic table. They are no more alike than Sulfur (S) and Lead (Pb). No idea why they use that phrase, sorry.
painxtreme 3 months ago
@painxtreme Lead's symbol Pb is an abbreviation of its Latin name plumbum
EnigmaNZ1 2 months ago
@EnigmaNZ1 Its Latin name is derived from the use of lead water pipes in the cities of Rome, hence plumbing. No question about that, I was saying I have no Idea why the people in that guy's power plant seem to use the element names Boron and Silver interchangeably. Boron is used as the control rods in many facilities, but silver would be disastrous. I do believe some did, and maybe some still do use Cadmium Control Rods, but the toxicity of Cadmium among other stuff make Boron a better choice
painxtreme 2 months ago
すごく不思議な光ですね。
きれいんだけどライトなんかの光とは少し違うような・・・
ronronmm 9 months ago
yes i seen the rods go down
sertox12345 9 months ago
i saw the control rod move
tigermki 9 months ago
@sirdude456 nothing can go faster than the speed of light.It defies the laws of physics.To prove my point Steven hawking's theory is if you accelerate a train to the speed of light it will slow down time inside the train to avoid breaking light speed.This means in one week to the passengers 100 years will have past outside the train so it's time travel so your comment is wrong
TynchySniper1 9 months ago
@TynchySniper1 You're right, nothing can go FASTER than the speed of light, IN A VACUUM. But light travels more slowly in dense matter, like WATER. Try to move a particle at a speed FASTER than light can move IN WATER, and you get the "Blue Light", a photon that represents the difference in energy levels.
Call your buddy Hawking, I'm sure he can explain it better . . .
firedogbme 9 months ago 17
@firedogbme good point!! :)
xeroxusify 9 months ago
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@firedogbme It's called Cherenkov radiation, molecules moving through the water at the speed of light. It excites the water, when it quicky returns to it's un-excited state it glows blue.
There's no lights in there, it's caused by super fast radiation.
sterben360z 6 months ago
@TynchySniper1 Oh btw, that was Einstein who came up with time dilation in his theories of relativity (special and general), not Hawking. However, Hawking has used that knowledge to describe black holes, etc, to make other theories.
MrLolman666 7 months ago
the blue glow you see is cherenkov radiation, it is given off when anything goes faster than the speed of light in that medium. The medium in this case is water
SirDude456 9 months ago
Luuuuv that, have seen such a pulse in real life at the experimental reactor of the nuclear research facility in vienna <3.
School- class was standing on top of the reactor, looking right down into the reactor core, and flaaash.
WOnt forget this^^
H0R53FR34K 9 months ago
what would happen if someone tossed a penny in there?
migkillertwo 10 months ago
@migkillertwo They would have to pay to replace all that heavy water.
GIRLIKESTACOS 10 months ago
@GIRLIKESTACOS The penn state breazeale reactor is light water cooled and moderated.
soylentgreenb 10 months ago
@soylentgreenb they would still have to pay for new water.
GIRLIKESTACOS 10 months ago
@GIRLIKESTACOS Heavy water is much more expensive, even requiring that the light water be very clean.
soylentgreenb 9 months ago
@soylentgreenb my b they have 1 price all the time dont matter how much they use lol
sertox12345 9 months ago
This has been flagged as spam show
@migkillertwo "what would happen if someone tossed a penny in there" Basically nothing. Of course they'd make you swim down to get it, so you might puke up your own liver.
ImMichaelTaylor 10 months ago
LOOKs like same one from DR NO, first 007, Jame bond movie 1961..
4624tone 10 months ago
I'm sorry....The Ad Smothers the Nuclear Reaction! i Couldn't See...That Really Sucks and is Souless!..
BarryPuppetSoetoro61 10 months ago
if you fall in that you will turn into a centauer
cicadafan 10 months ago
i like the lighting in that swimming pool
wookieinheat 10 months ago
The Cherenkov effect is wonderful...
MelstarfireGrayson 10 months ago 2
ZOMG Im a fearful ignorant and I just realized that we had reactors since the 50s!!! Time to panic and make lame comments on how every single reactor will fail in a near future!
tommysch 10 months ago
@tommysch Tell me about it. People are so ignorant.
N33DL3R 10 months ago
Do a little research on LFTR's you might well uncover some surprising facts.
awakeamericanow 10 months ago
oOOOOooo pretty
Icandrum2 10 months ago
so since there are a number of control rods what would happen if all the rods are ejected out of the reactor at same time
silvawtf69 10 months ago
@silvawtf69 CHERNOBYL...THAT'S WHAT
seatboi 10 months ago
@seatboi ahaha ok.thanks for the reply
silvawtf69 10 months ago
@silvawtf69 That's just what they're doing: pulling out the rods very quickly so the reactor goes into a supercritical state. Power increases exponentially, doubling every few milliseconds. But this reactor is designed so that when the power reaches a certain point, the reaction automatically stops, thus making a chernobyl impossible. It also makes this kind of reactor unsuitable for producing power. It's used for teaching, research and isotope production.
ApolloWasReal 8 months ago
@ApolloWasReal thanks for the info man...
silvawtf69 8 months ago
isnt it really a fusion reactor? the last time i checked, they wouldnt be passing out reactor grade uranium to a state college.
EupFilmStudent2012 10 months ago
@EupFilmStudent2012 no, this really is a fission reactor, its called a PULSTAR reactor, NC State has had the same type of reactor on campus since 1972 and these reactors do in fact use uranium oxide fuel pellets for their fission reaction, the difference is that a university doesn't exactly swap out he fuel rods every 18months like a normal power plant does, the handful of universities that have reactors use their fuel for many many years
ggilley71 10 months ago
@ggilley71 Right, because they only turn their reactors on for a few seconds at a time right?
SAOrules 10 months ago
@SAOrules few seconds is too short to do any experiments but they usually line up experiments and then have it running for a few days at a time, but the downtime is longer especially if there are no experiments or classes going
ggilley71 10 months ago
@ggilley71 yes and the reason for this is the same reason why all U.S. submarines go quite a while before changing theirs out as well, civilian plants operate at 100% power all the time so they burn much more fuel than say a college reactor that only operates at 20% power for experiments and classes only on certain days.
EugeneLancelot 9 months ago
@EugeneLancelot Don't submarines use fairly highly enriched uranium so they can last the lifetime of the submarine without refueling?
ApolloWasReal 7 months ago
@ApolloWasReal This is the case on new class submarines. However, on older boats, like my old ship, still need refueling after a period of time.
JustinHEMI05 7 months ago
@ApolloWasReal kind of, they mainly used highly enriched uranium because they need to be able to have the same high power output with a much smaller reactor. They also design them to last a very long time but civilian plants do as well. We are getting much better at it as well, the new submarines that are coming out can last much much longer on almost the same amount of fuel just because of the new technology and methods we are coming up with at power generation,
EugeneLancelot 7 months ago
@EupFilmStudent2012 no shit, what do you do with spent rods after they are used up? is there a fuel pool or containment facility on campus?
EupFilmStudent2012 10 months ago
@EupFilmStudent2012 These reactors operate at such low average power that I think the fuel lasts the lifetime of the reactor. There's no need for refueling, so there's no need to store spent fuel. When the reactor is eventually decommissioned the core can be taken away for reprocessing (in countries that do that) or join the rest of the spent nuclear fuel waiting for the politicians to stop posturing and pick a permanent burial site.
ApolloWasReal 7 months ago
@ApolloWasReal This isn't true. The Penn State reactor does have spent fuel that is stored at the edges of the pool that contains the reactor.
JustinHEMI05 7 months ago
@JustinHEMI05 I stand corrected, thanks for the info. I had heard that at least most of these "swimming pool" reactors were designed for a single fueling. I also heard that there was a NRC campaign to reduce the enrichment level of the fuel below 20%. Maybe that shortened the fuel lifetime to the point that refueling was required. Is that the case?
ApolloWasReal 7 months ago
@ApolloWasReal Yeah I would imagine so. I learned this by reading the FAQ on penn states reactor website. Since seeing this video, I have been reading all I can get my hands on about this reactor.
JustinHEMI05 7 months ago
@JustinHEMI05 I have now seen other research reactors with spent fuel pools. It may be because of a US nonproliferation program to reduce fuel enrichment in research reactors to less than 20%, presumably to decrease the attractiveness of the fuel to someone who might want to build a weapon. HEU can last a long time, but LEU has a shorter life and the reactors may require refueling depending on how much they're run.
ApolloWasReal 7 months ago
@EupFilmStudent2012 Actually quite a few colleges and universities have had these low power research reactors for many years. Cornell had one in the 70s when I was there. Many have since been shut down or removed because of the political unpopularity of nuclear technology, not because of any actual safety hazard. These particular reactors are extremely safe; they have such strong inherent negative feedback that they are useless for producing significant power.
ApolloWasReal 8 months ago
BORING
CrotchPipe 10 months ago
How many coffees can it make?
zugurudumba 10 months ago 3
So thats how nuca-cola quantum is made :D
XTwina 10 months ago 95
@XTwina YES!!
EG33SVXLSi 10 months ago
@XTwina lol next thing we know, a nukalurk jumps outta the water
AHTSvideo 10 months ago
@XTwina haha
rTZink124 9 months ago
@XTwina :-D good stuff.
JonnyTommyGuns 8 months ago
Penn state has a nuclear reactor on campus? WHAT THE F*CK?
kikicreamify 10 months ago 5
@kikicreamify McMaster has one here in Canada, lol. My friends go to McMaster XD, i dont -_-
iHacksorzz 10 months ago
sweet :D
doom705 11 months ago
does it make 1.21 gigawatts?
HedgehogStudios1 11 months ago
@ MonsieurSinan the blue is the heat produced from the Fission
jnm144 11 months ago
@jnm144
The "Blue" you see is actually Cerenkov radiation. It happens when an charged particle (in this case an electron) travels faster then the phase velocity,(or speed of light) through a dielectric medium.
c / n < vp < c where "c" is the speed of light in a vacuum and "n" is the refractive index of the medium. Dont know much about reactors but i guess the medium here is de-mineralized water?
theleadprogrammer 11 months ago
@theleadprogrammer The blue glow is indeed Cerenkov radiation from the beta particles (electrons) emitted by the fission products of the nuclear reaction. Reactor criticality actually lasts only a fraction of a second but the shorter-lived (and more active) fission products decay over several seconds after the reaction stops. Think of it as a nuclear explosion aborted at its very early stages by the design of the core and its fuel.
ApolloWasReal 8 months ago
"the pool is closed due to FAIL and AIDS"
AceSpade09 11 months ago
This blue colors is too mysterious
Yes 3... 2.... 1... B O O O M
MonsieurSinan 1 year ago
3...2...1...BOOM
TheMaccyT 1 year ago
I'm assuming that what happens at 0:09 is the control rod being inserted?
Andyman3k 1 year ago
@Andyman3k thats correct as incase of an accident the control rod is dropped under its own weight.
anikidwolfy 1 year ago