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The Soviets used robots in Chernobyl. The radiation was so intense that it makes the rubber tracks brittle and hard and it ceases to be rubber. Also, radiation fries electronics. The robots stopped working. Put a laptop near that reactor, and it'll soon BSOD. ;) Liquid Nitrogen can be used but the heat capacity of water would be greater and its in plentiful supply.... its just getting it to the cores.Quote:
Originally Posted by Glow9
Yep. The special thing about plutonium is that even if it wasn't radioactive, it is extremely poisonous.Quote:
Originally Posted by xVeinx
And lets all don't forget the people involved. Its very easy for us armchair experts to get stuck in minutae and bull:banana::banana::banana::banana:. Think about those 150 or so heroes that are holed up in that plant, knowing more then anyone else the risks they put themselves through. Knowing full well that they may not leave the same way the went in.... thinking about the invisible death that is trying to get its grips on them. From the details that are coming out it seems teams of them go into the reactor area for a few minutes, work the valves and pumps and then have to rush out again. Remember there is still a plant worker unaccounted for along with the other 11 or so injured. And form what I read, one of them had his two legs broken.
What about a lead enclose to protect the robot? Or can lead not stop that amount of radiation?
the radiation will go towards east. i think because the weather is moving from west to east for the north hemishpere.
in that manner the air can carry the radiation in a few days to all the north globe and god helps the "lucky" areas that will have rain in these days!
Gamma radiation will breeze through lead unless its seriously thick. You'd want a robot with a couple of metres of lead shielding to be secure for its electronics. Gamma radiation will flip bits like burgers at McDonalds. Or else use just a 'dumb' robot with wiring and all electronics cable attached with an operator offsite. You'd basically want a wire controlled version of a tank with a hydraulic acting arm I'd imagine :p: Even then I suspect high levels of radiation would screw something up like the oil.Quote:
Originally Posted by [XC] Oj101
My thought are with you my Japanese friends.... Take care and be well..
Radiation hardened electronics do exists:Quote:
Originally Posted by [XC] riptide
http://en.wikipedia.org/wiki/Radiation_hardening
How else could electronics survive in space?
Radiation hardened robots also exist, a quote from with Russias Emergencies Minister:
"As an emergency response force we built a large robotics center. We have big heavy robots that are able to clean up debris in high levels of radiation or when there is a chemical hazard."
(sourtce; http://rt.com/news/japan-nuclear-emergency-rescue/)
and I sure many other countries also have similar equipment.
To me it seem that the Japanese decion makers are dragging their feet and trying to do everything themselves despite that incapable of handling the situation. It was only today that they asked USA for help!
If they had asked Russia and USA for help with the nuclear situation last weeked when it looked like things where getting out of control they could have had those robots at the nuclear plant right now and the situation would likely have been better.
I don't have the link handy, but I read somewhere last night that engineers were laying a power cable to restore emergency power to the reactors - any news on this?
I know nothing about them but isn't that what they are? Last episode of IT Crowd in season four I think it is, where Moss and Roy bunk work and come across the bomb in the road with a robot defusing it - being controlled by a laptop a hundred meters away? No logic, completely remote controlled.:confused:Quote:
Originally Posted by [XC] riptide
Cables are stretched, they are now working on local power distribution (transformers, fuse panels etc) at the plant for connecting the cooling pumps of reactor 1 and 2, they hope to have power available at the site early Saturday morning (wich is in about 12 hours in Japan). They are still using water cannons on reactors 3 and 4 wich are emitting too much radiation to get close and connect power lines yet. Hopefully the pumps still work.Quote:
Originally Posted by cobra_kai
Quote:
Originally Posted by cobra_kai
Quote:
Originally Posted by Micutzu
well just heard on news, enginneer think maybe to cover the entire plants or last reactors with sand and concrete, like in Tchernobyl or Mary Island .... this don't look good, as this mean they are not sure to be able to power on the pumps... but again the informations are so badly given ... impossible to know if they just " think " to this possibility on last resort or if it's actuality. ( so many contradictory infos are given. )
Someone mentioned they got some pumps up and running again. And dont think they intended to restore power to anything else? If anything is still operational that is, after the fires, explosions and whatnot.Quote:
Originally Posted by cobra_kai
They are studying the construction of a sarcophagus as a last resort, if pumps at the site don't work:
http://www.reuters.com/article/2011/...72A0SS20110318
damn this picture isn't looking good!
http://i.picasion.com/pic39/450ee43d...f7380249f4.gif
You can see a greenish/blue glow what means the core of the reactor is wide and open!
Here is a reference picture of a normal reactor in operation
http://i.picasion.com/pic39/5892d563...cb90f63d06.gif
It looks like power has been restored to the Fukushima Daiichi plants. Cooling won't restart until tomorrow (or a bit later, it's not clear), but it looks like a step in the right direction anyway.Quote:
Originally Posted by cobra_kai
Sorry but the link is in Japanese only
http://mainichi.jp/select/jiken/news...40083000c.html
No problem =)
http://translate.google.com/translat...40083000c.html
Good to hear that there are something that seemingly is going the right way.
uhmmm wouldnt it make sense MAYBE to buid one already? like right now?Quote:
Originally Posted by Micutzu
just in case? :D
actually im surprised they dont have pre-built parts already so IF something happens they can move all the parts to the place and put them together?
maybe they do... im sure they have all the parts like a big ikea set somwhere, ready to be shipped off just in case...
would be pretty irresponsible if they would have this prepared...
this isnt the reactor as far as i know, its the spent fuel rod pool...Quote:
Originally Posted by d33f
same for the second picture...
i think thats not the reactor... its the pool... but yeah, its open! :S
the blueish greenish light should indicate that there is still water in it though, as far as i know...
damn look at that damage though... those explosions didnt look all that powerful on tv and youtube, but thats cause it was taken from far away...
those structures are huge and made of reinforced concrete... look at all those steel rods folded down like wires... :S
has anybody looked at a pic of reactor3 and then at a pic of chernobyl recently? they look scarily alike...
and after reading about chernobyl, lets compare what happened, please correct me if im wrong!
chernobyl:
the fission spiked
water overheated and evaporated
lack of water increased radiation
increased radiation
increased fission reaction
water overheated and evaporated
->positive feedback loop
fukushima:
water overheated and evaporated
lack of water increased radiation
increased radiation
increased fission reaction
water overheated and evaporated
->positive feedback loop
this is what happened next at chernobyl:
the steam pressure popped the reactor core open by blowing off a 200ton(!) cover
after this increased temperatures caused a nuclear excursion, basically a small nuclear explosion, like a mini nuke... this blew parts of the rods all over the place and STOPPED the reaction... the real bad news was the graphite the rods were surrounded by caught fire and burned, which blew radioactive material way up into the atmosphere and it rained down over half of europe.
it burned for many hours, i think almost an entire day?
this is what COULD happen at fukushima: (?)
the steam pressure blows the pressure tank (might have happened for several reactors already)
increased temperatures cause an excurion, basically a small nuclear explosion, like a mini nuke...
this could damage or break other reactors which then blow as well
fuel inside the reactor will get blown all over the place
fuel inside the containment vessels will get blown all over the place
the radioactive reactions STOPS, all cools down
no graphite and no other fires = only small amounts of material get blown into the atmosphere
OR
water levels in spent fuel rod pools reach critical levels
fuel rods are cladded in zircaloy, which reacts with water/steam at high temperatures and creates hydrogen and oxygen, which causes a fire (sounds familiar?)
fire increases temperatures
increased temperatures reduce water level
no water causes the fire to stop, good
no water causes radiation to spike, not good
higher radiation results in even higher temperatures
fuel rods melt into a small pool of liquid metal, depending on how active the fuel still is, it COULD cause an excursion?
this blows fuel all over the place and damages other reactors that might then blow as well
fuel is all over the place
the radioactive reactions STOPS, all cools down
no graphite and no other fires = only small amounts of material get blown into the atmosphere
please correct me if im wrong!
but it sounds like the worst case scenario is a chain reaction of reactors popping and blowing fuel all over the close vicinity of the reactor and possibly into the ocean. a significant amount of radioactive gases and material DOES enter the atmosphere, but not nearly as much as in chernobyl where the graphite fire was almost the perfect tool to spread the radioactive material for as far away as possible.
the reactor compound and a 10-20km radius will probably remain uninhabitable for a while to come and need to be cleaned up and sealed.
depending on the temperature and how concentrated the fuel is, excursions might never happen, i actually think its actually very unlikely right?
so then the worst case scenario would be the reactors popping blowing from steam pressure blowing SOME fuel into the ocean and near vicinity of the reactor
the reactor compound and a 10km radius will probably remain uninhabitable for a while to come and need to be cleaned up and sealed.
the next best scenario would be that the reactors pop, or already HAVE popped (very well possible) and the fuel rods have melted but they will just stay inside and boil, releasing gas and radioactive material into the atmosphere, if left unattended, maybe for weeks or even months...
not sure how much material this would be though...
the reactor compound and a 5km radius will probably remain uninhabitable for a while to come and need to be cleaned up and sealed.
the next better scenario would be that the pressure tanks are only damaged, cooling is restored or they are cooled well enough, leaks can be patched up, small amounts of radioactivity leak or none at all, but the reactors will have to be sealed off or taken apart anyways.
the reactor compound and a 5km radius will probably remain uninhabitable for a while to come and need to be cleaned up and sealed.
best case scenario, no pressure tank has been ruptured, cooling is fully restored, all is sealed and patched up, cleanup required at the plant and compound but people can probably return back to their homes even close to the reactor after a while, maybe a few years to make sure groundwater and soil isnt polluted...
so... i cant see this significantly affect other countries besides japan...
and even there, i only see it affect the near vicinity of the reactor compound... if radioactive material evaporates and burns it will get beyond both the 20 and 30km radius easily, but it will be temporary and SHOULD get dispersed... and SHOULD not be enough to contaminate any areas...
so... im relieved and can tell my girlfriend to cancel both our reservations on plane tickets to thailand on saturday and monday :D
too bad actually... was looking forward to visit zolkorn :D
That glow around the rods, what is it called? Cause I saw a program about nuclear disasters, how to prevent them and how they happened on our national tv station last night. The narrator called it "Tremco" effect or something, and he said the light was caused by something reaching speeds faster than the speed of light which I thought sounded really wrong!Quote:
Originally Posted by d33f
@saaya.
I'll take those tickets to thailand.
Yay party time lol...
Ehh, well...
That pic showing radiation blowing to the us it fake, it was a sim of sorts from random person online.
We'de need real readings.
I'll keep trying to find them even after this is over.
I'm a lazy person though, I understand the faster I find the data I'm looking for the better but again, I'm lazy lol.
I like looking at new bomb sites, waste or rod burial sites (area51 for example has a giant one...), and other nuke related things in google earth, would be nice to have radiation readings along side that.
Anyways the robot thing.
Noise level's would prevent radio controller stuff.
So you'de need to use a shielded cable (or shielded fiber) to control the robot.
At the very moment though, I think the only use you could get out of such a thing would be to show you what's going on inside the plant with a cam.
And that would be about it.
You might beable to design one to grab those spent fuel rods though and load it up, as long as you cleared a path for it.
But that's up to them to decide.
If it were using digital metal cable, I'de use a mimo config, one data chan, but using multible chan's to avg the data, and for error recovery.
Edit:
And if those rods in that sample pic are really lighting up like that it's due to the radiation they are spreading.
Lots of things are radiation, the light from your light bulb is a type radiation.
It's all about the wave length, we can see some waves, hear others, etc etc.
That looks uv like, in the lower nm range.
The cam probably wouldn't pick that up though, but then again maybe they don't filter uv like some of them filter ir...
Add some some red's and we might beable to have some hydroponics down in there :P.
i read that on wikipedia as well... weird huh? :confused:Quote:
Originally Posted by Kallenator
they mentioned there are 2 sources for this electric blue light
1. the effect you mentioned
2. ionized atoms/molecules that get their outer electrons "charged" by radiation, they then fall back to resting states emitting light. some is UV, some is IR and the visible part is predominantly blue apparently...
and its apparently the same effekt that causes electric sparks to look blue as well...
anyhow...
after watching the damage to reactor3... and this video... where you can see how the massive concrete roof gets blown up to a HUGE altitude...
http://www.youtube.com/watch?feature...&v=T_N-wNFSGyQ
i honestly have my doubts over what exactly happened at reactor3...
is it possible that a nuclear excursion happened at reactor3?
the rods melted, formed a pool of highly radioactive fuel, radiation spiked and it caused an excursion, the whole reactor blew up...
im actually surprised to see the spent fuel rod pool still standing after this, and still having water in it! :eek:
i mean... the explosion happened in the center of the reactor building and went straight up, shooting a huge column of smoke straight up...
if it would have been a hydrogen explosion, then wouldnt it have gone in all directions and thats it?
the other reactor explosions were like that... it just blew off the top of the reactors in all directions, but the main reactor structure remained in tact...
also, the other explosions showed no visible fire or glow, right?
the reactor3 explosion shows a deep red explosion after the roof popped off...
hmmmmm
actually... couldnt it be that the other explosions were all steam explosions?
of the pressure vessels blowing up?
the reactors could still be in tact, and they could still pump water through the pressure vessels...
honestly, i cant wait to see all the details about what REALLY happened when this is over... and im pretty sure this will have a notable effect in the japanese political environment as well, with people bsing the press and people apologizing and resigning...
and i really hope kan keeps his promise and dismantels tepco...
they apparently have a long standing history of faking reports, not fixing problems, undermining security standards and lying to the public and officials...
It's called Cherenkov radiationQuote:
Originally Posted by Kallenator
http://en.wikipedia.org/wiki/Cherenkov%20radiation
Thanks for link! =)
does anybody know how tall those white cooling(?) towers at fukushima are?
the concrete roof gets blown up to almost 3x the altitude of those towers... i wonder how many meters that is...
EDIT: urgh...
Quote:
Thierry Charles, a safety official at France's Institute for Radiological Protection and Nuclear Safety (IRSN), said: "The next 48 hours will be decisive. I am pessimistic because, since Sunday, I have seen that almost none of the solutions has worked." He described the situation as "a major risk", but added: "All is not lost."
Asked about the maximum possible amount of radioactive release, he said "it would be in the same range as Chernobyl".
Based on this information I would say the complete structure which got it's roof blown of is around 160 feet / 50 meter.
http://www.beyondnuclear.org/home/20...schematic.htmlQuote:
The actual "pressure suppression system" structures credited for containment sit below this structure inside the concrete reactor building, namely the drywell and wetwell or "torus." The drywell is the large inverted lightbulb steel structure which is 100 feet tall and a nominal wall thickness of 1.5 inches.
thanks, found some nice pics:
http://img841.imageshack.us/img841/6681/mark1y.jpg
http://img715.imageshack.us/img715/892/mark12.jpg
so there is a thick concrete base with a pool that would catch the molten rods if they would melt through the reactor vessel... what i dont like is that its walled with graphite? 0_o isnt that what chernobyls worst design flaw was? to use graphite that can ignite and burn under high temperatures, blowing radioactive material high into the atmosphere? :S