10,000th cycle of the Annular Core Research Reactor

With a muffled "pop," a flash of blue light and a few ripples through 14,000 gallons of deionized water, Sandia National Laboratories' Annular Core Research Reactor (ACRR) recently conducted its 10,000th operation. During a maximum pulse, the ACRR generates a whopping 35,000 megawatts of power for seven milliseconds.
Read more at share.sandia.gov/news/resourc...
SAND 2011-7841P

[@Fordi]

God damn, but Cherenkov radiation is beautiful.

[@seanb3516]

+Bryan Elliott Electrons travelling faster than the speed of light. Gotta enjoy that!

[@seanb3516]

***** Yup...but don't spoil it for the braindead folks....

[@MistressGlowWorm]

Bryan Elliott ooooohhh yes it is. I could watch this a thousand times.

[@BM-yy8db]

There's something so enthralling about that single frame where it's just a white flash, the moment where it turns on

[@iamtenzin4409]

The strangest thing I thought about the whole process was that series of blue bars that appeared right before the flash. Possibly an effect of the camera?

[@jasonw.2232]

Most certainly.

[@10--50]

0.25x nerds, I love it! lol

[@InfiniteAmbient]

Tcherenkov effect.....the coolest glow ever. That would be a kucking badass pool

[@epasko5713]

@ do we have a problium? Mr. Weimium Sir :) Maybe, We name the next element after you, for sure if you are the one that finds it (Or, Makes it)

[@BarneyBarnett]

IT HEATS WATER, Let’s capitalise it as a water heater

[@TransTrump]

Higher rates of cancer around that water and a reactor but that's the price for 24 hour cable news!

[@pindropper100]

The blue light is from radiation being emitted at a speed greater than how fast light would travel in water normally. When you slow down electrons, a photon is emitted, and as the radiation travels through the water it moves the electrons a lot which emits light in a bunch of different colors, it just happens that the blue light is the brightest, so that's what you see. This effect is known as Cherenkov radiation if you'd like to read a little more about it.

[@parkerlamarbrook]

Pretty sure it has more to do with how water scatters different wavelengths of light and blue is what’s left after the other wavelengths are absorbed. Hence why the ocean is blue.

[@pindropper100]

@@parkerlamarbrook sorry no thats incorrect. That’s often what causes blue color in water but not what is happening in this specific case.

[@sjcb]

Both terrifying and beautiful to see that much power, so intense it emits shortwave blue light. Amazing

[@sjcb]

@Uncle Bremner wow ok 😅 hate to break it to you but short wave blue light is a thing, and refers to the blue light close to the UV frequency band, just as short wave UV is close to X-ray spectrum. Cherenkov radiation peaks at around 420nm and would definitely be classed as short wave blue light. Have a great day! 🤡

[@sorshamccarty3515]

Wow! One of the workers is actually talking with my class! Awesome!

[@pindropper100]

The whole reactor is submerged in water the whole time, you just can't see it in the beginning because the surface of the water is so smooth.

[@enthalpy]

supercritical does not necessarily mean explosion. When we start our BWR up, we actually pull it slightly supercritical. Supercritical just means you are producing more neutrons than you are losing. Critical means you break even, and subcritical means you lose more than you produce. It's a function of the core eigenvalue. Anytime you raise reactor power, you are temporarily making it supercritical, and natural effects such as boiling cause a decrease in reactivity which returns it to critical

[@LDAR1003]

Our reactors actually increase in reactivity in the event of boiling :)

[@thestormchasingconcorde6184]

@@LDAR1003 RBMK?

[@67noob1]

​@@thestormchasingconcorde6184BWR.

[@kickit246]

I would love to see that with an ultra slow motion camera. I wonder if it would be really interesting or just turn blue like it did here.

[@SpeedMjam]

SCRAM is one of my favorite words with one of the most interesting origins... :)

[@angusjoshi]

I crapped myself when it went on

[@dekal1]

Thanks a lot...

[@mattfuzzy]

dude... you just blew my mind... :)

[@pancakguy]

@MOLRobocop @ MOLRobocop: Three of the regulating rods are ejected (not all of them) and held up with compressed gas. After a time delay a computer system drops the designated rods and scrams the reactor to ensure it remains shut down. Doppler broadening shuts the chain reaction down much faster than the "SCRAM" action of the rods and turns power as temperature rises in the fuel. The reactor power levels rise and fall in 7ms, much faster than a typical operator can hit a scram button.

[@MOLRobocop]

@enthalpy So does this mean they removed all the control rods suddenly to suddenly start the reaction, and then put them back in when they hit a specific power-output or temperature? Hit the SCRAM button or something?

[@dekal1]

thanks.

[@MOLRobocop]

@pancakguy That is awesome and scary. Thank you for the explanation.

[@kasel1979krettnach]

Two questions: 1) how bright is it inside a running power reactor ? 2) Is there any cherenkov light inside a gas cooled reactor ?

[@TanyaSapienVintage]

well the speed of light in a liquid is slower than the speed of light in a vacuum. in specific environments, it's possible for a radioactive particle to go faster than light can go. in those cases, it glows blue.

[@Theineluctable_SOME_CANT]

That's a SERIOUS pulse...

[@CaptainWicket]

When I saw the light, all I could think of was Doctor Manhattan!

[@paulanderson79]

The noise is simply the control rod being lifted and dropped shortly afterwards. The reactor itself is very hushed indeed. These are neutron sources, research reactors for industrial and medical purposes. Nothing to fear from nuclear reactors.

[@stl1321]

So it's cool to swim in Fukushima reactor 2?

[@ronritekinamatigai]

Gorgeous sight. If you ever see this blue glow with your bare eyes, this would be the last thing you have ever seen and thought about.

[@moeburn]

Not true - they can see it through the water perfectly safely. It's when you see it in AIR that it's probably time to die.

[@orcstompa]

moeburn or become mr manhattan!

[@ennui2000]

I worked for years at a research reactor and saw it every day. My vision was as good when I retired as it was when I started. Cherenkov light is just visible light and so in itself is harmless. The mechanism that produces it can be harmful if not properly shielded, and water does a good job of shielding in this case.

[@JonathanSchattke]

Dmitry Shintyakov sorry? I've been in a reactor building while it was giving off Cherenkov radiation from the core. Harmless. The 10 meters of water was plenty of shield against neutrons and gammas.

[@a64738]

+Dmitry Shintyakov I guess with bare eyes you mean no water or any other shielding either. (cherenkov glow in free air)

[@KyleGotSkill]

@enthalpy thank you sir

[@TheGeekazoid]

can this type of reactor sustain a nuclear reaction to produce continual power via steam generation?

[@vortec2624]

prolly not a whole lot of power. A bigger core would.

[@bradcook8640]

Are those convection currents in the coolant? Does the water heat up that fast or is it just from movement of the core components?

[@SuperSerNiko97]

Maybe its the movement of the core. To produce this flash the control rods have to move very fast so probably they will move the whole core and the water

[@MonstertruckBadass]

That's awesome

[@paulcantshutup]

Oh, wow. I just realized this is the exact same shade of blue as Dr Manhattan glows.

[@Ben-uf3st]

What causes the water disturbance? Heat alone?

[@jamesxbondage]

Is that the blue light you see when plutonium goes super critical?

[@thelocal713]

Yes!

[@Cobns]

Where does all the energy go? I assume most converted to heat?

[@MrYoshicat]

forgive me for being a nuclear dummy , could someone please explain , is the fundamental basis of all this energy come from friction ? , i;e all these particles brushing past each other / ripping each other apart ? because before fusion you must have the heat to fuse right ? thx .

[@AluminumOxide]

0:24 the water down there is boiling! Lots of water vapor bubbles forming

[@seitengewehr98]

I noticed that the Cherenkov radiation seemed to consistently roll back in intensity after the first bright pulse, as if less and less neutrons were gradually striking the H2O. Anyone know why? Neutron poisons generated in the core that quickly? A function of the camera adjusting to the flash? The creation of gas bubbles reducing the amount of Cherenkov radiation created? Or were the control rods already being reintroduced into the core immediately following the initial excursion, but prior to a full shutdown? Something else? Just a layman so forgive my ignorance. Oh, and what is FOGBANK made of exactly, I seem to have misplaced my notes (tee hee)?

[@decimations7224]

The pulse is only 7 ms long I stood over one right on that bridge awesome to see. 7 ms is the time it takes to snap your fingers if you're wondering very fast. Doppler feedback, fuel heating up, terminates the excursion for the most part. Also the bubbles are actually fission products and radiolosis of water not boiling as others have incorrectly stated btw. I have a PhD in Nuclear engineering plus more helpfully the people explained it to me before and after if you're wondering how I know this.

[@hs_fassih]

Looks like they've found the "Tesseract"

[@MsShipbuilder]

I have a question. After the pulse of the reactor core rise the gas bubbles. What kind of gas? These are the products of radiolysis of water? Or is it just water vapor?

[@decimations7224]

Correct radiolosis of water yes

[@enthalpy]

@KyleGotSkill They brought the reactor from subcritical (offline) to supercritical. This is the same mode that nuclear bombs operate in during the fraction of a second between releasing energy and exploding. Research reactors are designed to do the same thing w/out blowing up for test purposes.

[@dekal1]

Here's another noob question. Any paticular reason for the bright blue light?

[@vacuumboy6.0]

wow it looked like the water was boiling for a second

[@KennyTheB]

A CMOS/CCD isn't designed to image gamma radiation. You need special equipment to detect things like x-rays and gamma rays. This is similar in context as to why radiowaves don't blow out your photos. Beyond the visible spectrum, they only lightly touch into the infrared and ultraviolet. The effect you're thinking about is only seen in photographic film. Even then, the film has to be of a particular sensitivity.

[@alexverapons537]

Me gustan las sandias

[@Minato_Namikaze]

Si a mi también me dieron ganas de comer sandia

[@H8edsinclair]

There has been at least one nuclear inspector that fell into a pool but he was ok just wet I don't know if the reactor was on.

[@n0neCheaper]

That water looks delicious.

[@ShindenZero]

Are those bubbles helium?

[@moeburn]

Why did the water suddenly start bubbling and rolling? Was it a result of the radiation, or something mechanical disturbing the water?

[@PauloHenriquewf]

is the result of temperature increase

[@PauloHenriquewf]

the effect of Cherenkov radiantion is the blue light!

[@moeburn]

Paulo Henrique No I know Cherenkov radiation causes blue light, that's how I ended up on this video. But I've never seen a reactor cause all that water it's submerged in to suddenly boil. I don't know that much about reactors - Is that how they normally operate, or was it a rare occurrence because of this test?

[@PauloHenriquewf]

moeburn Nuclear reactors produce heat splitting atoms, so the appearance of bubbles in water occurs, it is boiling! Probably this is a BWR(Boiling Water Reactor).

[@--Valek--]

it was pulsed at full power......I assume they had done things with the water or put/transfer equipment around in the water and air bubbles became trapped while doing or after. The sudden jolt when energized was enough to free the bubble from under need flat part of the submerged equipment.

[@rhino2960]

so the color of death is in fact...blue

[@olivrob2535]

+rhino2960 je suis d'accord avec vous le bleu n'est pas la couleur de l’espérance mais celle de la mort !!

[@Elian504]

+oliv rob english ...

[@rhino2960]

+Elian Bollue (fireclaw20) he said he agrees with me, and that blue is not the color of hope, but the color of death.

[@Elian504]

+rhino2960 yes I know but when you reply on an English command it would be the most logical to reply in English, it would be weird if I started talking Dutch now. EEY jonguus laten we biertje gaan drinken in die tent daar in Leuven ja hoor!

[@alekseikirillov8507]

+Elian Bollue (fireclaw20) Согласен. :)

[@kkman5050]

Wow…

[@Brendedn]

That was beautiful and all but my ears are bleeding. I wasn't expecting it to be so loud in my earbuds. I learned something new. Nuclear reactors are loud.

[@paulanderson79]

Cans can exaggerate such things,

[@liuwenjie9105]

Damn,it scared the shit outta me,thought it was quiet...!!!

[@scottanderson2879]

Yup, 😳

[@qwe2433]

Big metal rods make a loud noise when they move that fast. ^^

[@iNotFound]

Where does the sound come from?

[@SuperSerNiko97]

From a pneumatic mechanism that move the control rods very fast, I suppose

[@corallall]

Why are they in water?

[@MatthewBallinger]

It's called Cherenkov radiation and it is visible. With 20 or 30 feet of water shielding the gamma radiation is minimal.

[@derekwall200]

that blue glow or Cherenkov radiation, wont it cause radiation poisoning if you were swimming next to the pile?

[@ClariNerd]

Derek Wall no, water is such a good radiation shield that you would have to be physically touching the pile to receive a dose. Of course, this is assuming you weren't killed by bullets from security as you were jumping in.

[@qwe2433]

I figure they'd taze or tranq you and pull you out before having you arrested. Less blood in the water to lower what I presume to be a certain purity of water that they aim for.

[@JimGriffOne]

Is this a giant kettle to heat water so people can make more cups of tea at a quicker rate? I don't get it.

[@JimGriffOne]

+crobc1 Well, it kinda looks like a kettle with the metal elements in there. And yes, I'm British heh.

[@tvmalk]

Are all reactions at power plants this fast?

[@decimations7224]

No absolutely not. This is not anything like a power reactor.

[@garyvale8347]

Could someone explain, in the simplest way...what just happened.... I' am asking, flip a switch for the 10,000th time controlling what...why are 14,000 gallons of de-ionized water pulsed.....and pulsed with what.....thanks

[@Thedutchjelle]

Gary Vale I'm not a nuclear scientist so I could be wrong in a bunch of things but: This is a research reactor, so I'm guessing they're either using the nuclear reactor to create radioactive compounds for study/medicine, or to test nuclear science. They can just switch it on for a few moments (the pulse?). The water is there to shield people from radiation and to keep the reactor cooled. The blue light you can see is Cherenkov Radiation.

[@garyvale8347]

yes....that makes a lot of sense...thanks much..

[@ApolloWasReal]

Gary Vale This is a special research reactor. It is pulsed by quickly yanking out the control rods to induce prompt criticality, i.e., a very rapidly growing nuclear chain reaction. Ordinarily you *really* don't want to do this with a reactor (think Chernobyl) but this one has such strong negative feedback that even without the control rods it automatically stops very quickly before a dangerous amount of energy can be released. Some time later, the control rods are lowered back into the reactor. And you see a "bubble" of warm water ripple up to the surface. The blue glow is Cerenkov radiation in the water from the energetic beta particles (electrons) emitted by the radioactive fission products produced by the nuclear reaction. The nuclear reaction itself is over in an instant (7 ms) but the fission products take longer to decay: a lot with half lives in milliseonds or seconds, some in minutes, somewhat less in hours and so on up to a *very* small fraction in hundreds of thousands of years. That's why the blue light steadily dims after the pulse. This reactor cannot produce significant power because it shuts itself down so quickly; that's how it can sit safely in an open pool of water. Power reactors are designed very differently and require significantly more complex safety systems.

[@JonathanSchattke]

Gary Vale its a fission reactor; they generate 245 MJ of energy (about 7.6e18 fissions) in about 1/60th of a second, before the feedback effects shut off the reaction. This high flux (100x that in a PWR) can be used to study the effects on materials of intense neutron bombardment.

[@ApolloWasReal]

Jonathan Schattke I assume that one of the advantages of such a high peak power is that neutron-activated radionucleotides with very short half lives can still be detected?

[@ktx49]

If you pause this video at exactly the right moment before it reaches its brightest point, you can see what appears to be an interference pattern from the radiation....what is that exactly & how did it form?

[@GOLTURBO555]

From the neutron source... the BANG is the HUGE energy of the uranium dioxide being "pissed off" relationship, with the initiator...

[@mscheese000]

GOLTURBO555 No, the bang is the control rod being ejected rapidly by pneumatics. They do this to start the pulse.

[@GOLTURBO555]

James Amril-Kesh With fresh fuel, they can not start the reaction like this.

[@mscheese000]

I don't know enough to know if that's true or not. I kind of doubt it. Regardless, that's not the point, and it's not the cause of the bang.

[@GOLTURBO555]

James Amril-Kesh ur are right, but the rods are pneumatic, the bang is a close call... this reactor, are refueled, fresh fuel, no neutron source, they inserted Californium, then "started" it... Its a mix of Polonium and Californium, as neutron source... A couple of hiroshimas in a matter of miliseconds...

[@rtensor]

Anybody know what the sizzling sound is? (Matt Damon getting irradiated?)

[@Unrealer1986]

The bubbles are created from boiling of water surrounding the fuel rods, and this is caused due to the intense heat from the sudden increase in reactivity.

[@decimations7224]

This is wrong bubbles are from radiolosis of water and resulting activation there is no boiling they don't even have the pumps on during these. Water has a surprisingly high heat capacity.

[@Komkanit]

I would like to know how to start and stop nuclear reaction. thanks

[@RobinCernyMitSuffix]

Control rod out, neutrons can fly freely and hit other atoms, these atoms split and produce heat and other neutrons, these neutrons also hit other atoms, etc. Control rod in, the neutrons got absorbed by the control rods which slows down and/or stops the reaction.

[@thisisthenameofmychannelig6037]

Why do you need to know?

[@dekal1]

Now for the fun stuff =) What would happen if someone were in that water while that turned on.

[@valeriylegasov8936]

dekal1 they’d survive by the amount of water was blocking radiation, if it was sealed, they’d drown.

[@swellkill1]

that fucking scared the shit out of me wacthing at 11:30pm

[@heisenberg3099]

woah

[@noahw808]

Because of Cherenkov radiation?

[@nukeboy27]

Led protecting

[@user-dk9wv3oy5f]

Быстро отшипелся)

[@MysticalDork]

@lukealization No, mostly neutrons and electrons.... you are thinking of an atomic bomb producing hard x-rays, but that only happens at stupid-high temperatures and energy densities.

[@anton_c8gur]

damnn my ears got radioactive

[@KyleGotSkill]

what just happend?

[@ximowilson]

Why is it surrounded by water? I'm sure there's an obvious reason but i'm too dumb to figure it out.

[@alecdacyczyn]

Joaquin Wilson Water makes cheap and effective radiation shielding. It's also likely a functional component, acting as a neutron moderator, to facilitate the actual reaction.

[@philkarn5661]

+Joaquin Wilson Yes, water is an excellent radiation shield. Even gamma radiation, one of the most penetrating kinds, is halved by just 7 cm of water, and beta particles (which produce the harmless blue glow seen here) are absorbed even more rapidly. Water is also cheap, nontoxic, transparent, and easy to store and transfer. It has a very high heat capacity useful in reactor cooling. Water is somewhat chemically reactive, but that problem can usually be avoided.

[@ximowilson]

Thanks for the info guys!

[@Elian504]

+Joaquin Wilson and so the whole thing doesn't overheat and explode .... Why did nobody mention that?

[@philkarn5661]

Elian Bollue It doesn't overheat and explode because it's not designed as a power reactor. The fuel (usually uranium zirconium hydride) has a very large negative temperature coefficient of reactivity such that when it heats up, the chain reaction automatically slows down very quickly. This makes it safe to rapidly yank out the control rods to "pulse" the reactor. It's essentially meltdown-proof because it's simply incapable of operating at high power for more than a few milliseconds. Yanking out the control rods like this could be very dangerous in a power reactor where the fuel must be designed to keep reacting at the high temperatures needed to produce steam.

[@mustafacaglarr]

why and how the iron makes the pool blue?

[@ender25ish]

mustafa çağlar its Cherenkov radiation

[@Xander1234567891]

mustafa çağlar inside the reactor core and around it the radiation is so high, that it travels faster than light in water, so it emits this blue light

[@JonathanSchattke]

mustafa çağlar its not the iron - there likely is no iron in the whole area. it's the nuclear reactor, giving off high energy particles, that have so much energy they are going faster than light in the water, and like a sonic boom in air, they give off energy as light.

[@alpereninan9500]

iron? seriously???

[@heylookacar]

Is that the same blue flash that would have been seen in criticality accidents?

[@AlexBesogonov]

+heylookacar Nope. The blue flash in criticality accidents is caused by recombining ionized oxygen. And this glow is straightforward Chernkov radiation that can't really happen in the air (since the speed of light in the air is just slightly less than in a vacuum). Amazingly enough, both phenomena produce very similar color even though they are completely dissimilar.

[@heylookacar]

Good answer! Thanks.

[@SN2D]

Cherenkov Radiation can only be observed in water, it is also used to detect neutrinos.

[@sloth0jr]

Actually, I've heard some supposition that the blue flash IS actually Cherenkov radiation, as seen in the fluid of the eye.

[@fratermus5502]

Could Chernkov radiation happen fluid of the eyeball in criticality events?

[@CodyShell]

RIP ears

[@magicstix0r]

Well yeah, the compressed air they use to shoot the control rods out of the core is pretty loud...

[@pancakguy]

it goes from 20C to 22 or 23C during a max pulse, not very hot.

[@compwiz00]

See all that water? It blocked most of the radiation.

[@vladabuba]

Great video. And I have to say I'm sorry but I need to say this... 3.6. not great, not terrible.

[@anthonybush3134]

ITS OVER NINE THOUSAAAAND

[@ScottKathrein]

yes. google this: 35000 megawatts * 7 milliseconds in kilowatt hours

[@nfsmohpsp]

it would have gone through the lens

[@AstroAvenger]

3.6 roentgen, not great, not terrible.

[@TanyaSapienVintage]

yes, supercritical fuel rods can flash-boil water they're in contact with.

[@Mattyew]

Does this water become radioactive and if not, why not?

[@Naychzu]

It does not become radioactive. Only certain elements are radioactive. Matter does not magically become radioactive because there is radioactive material next to it.

[@paul9813]

Naychzu what about neutron bombardment? you shouldn't answer questions to which you don't know yourself. short answer, yes it does

[@ObsidianJunkie]

Paul smith Source?

[@paul9813]

***** I work at a nuclear power plant. also en.wikipedia.org/wiki/Neutron_radiation

[@ObsidianJunkie]

Paul smith Aahhh, the classic "I work at ... *insert relevant job here* ".

[@scienceehal2596]

核分裂原子炉の始動の瞬間。 如何に核分裂をお越し易いかが見て取れますね。 つまり止めにくいと。

[@scienceehal2596]

***** ですね。 止められない止まらない。 運転止めても止まった事にはならない。

[@scienceehal2596]

***** 繋ぎで動かすべきですね。

[@Merchant_Admiral]

Hello there

[@user-bo3gh5ko1r]

SCIENCEe HAL 核融合炉にさ、飛び込んでみたら！ 真っ青な光、包まれて綺麗！

[@IgorFrost]

Я подпрыгнул!

[@cjob-ross]

0:10 pierwsze chwile na tronie po nocnym kebsie z baletoOFF

[@dekal1]

Was the water already there or did it fill up that fast? I don't get it!

[@pindropper100]

Haha if you were in the top of the pool, nothing! :) It's a pretty deep pool and they put it under all that water to moderate the radiation coming out. The blue light itself hitting you wouldn't hurt you, it's the invisible radiation causing the blue light that could damage you. The closer you swim to the blue light, the greater your radiation exposure. If you were within a foot or so of where the light is really bright, you'd probably get acute radiation sickness which can kill you.

[@ediakaran]

It takes just $2 to do this. ;-)

[@snanon]

Like a metal Gear Solid 2 place

[@AlexForencich]

They would get very, very, very wet.

[@AlexReynard]

The X-Men would get a new member.

[@MrYoshicat]

"SIMPSON " what have you done !

[@sompka1]

its probably lead'ed glass

[@vacuumboy6.0]

wow i thought you coud not swim in it cause its so hot

[@suicune690]

The lab where Mewtwo was born.

[@Avetarx]

Nuclear power is a hell of a way to boil water.

[@Merchant_Admiral]

Also good for making coffee and tea!

[@trustthewater]

I think that if I had been working there I would have had 9,999 minor heart attacks prior to this event. Amazing work, but with all the bogey-man hype around nuclear technology I would have wet my pants even if I knew it was constructed by some of the brightest minds in the world.

[@ImaFnT-Rex]

it's not 3 roentgen

[@RetiredNihilist]

Теперь я понял зачем ученым сменные белые штаны.