Colour photo of the exterior of the Chernobyl power plant shortly after the explosion, just outside the Russian town of Pripyat. How shortly is unknown.
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From: jason
(Wed Jan 19 10:23:50 2005)
that looks like crap, that must have been a very big explosian
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From: person
(Sat Mar 26 15:03:52 2005)
it was actually 2 explosions and a bunch of fires.
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From: person
(Tue Apr 5 17:58:00 2005)
that game looks amazing. i dont have a good enough come to run it! :'(
read my post in the other explosion picture. it tells about what happened.
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From: Walks_with_chairs
(Sat Apr 16 09:48:04 2005)
Well folks, this just goes to show that we need to be careful with Nuclear Power in all its forms, and especially Nuclear Radiation. What happened here is kind of creepy to look at though, it looks like a ghost town, thats strange
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From: Alien_God
(Thu Apr 21 05:37:01 2005)
It also shows you what happens when safety measures aren't taken, ignorance of certain dangerous technology is just absolutely unacceptable and the U.S. is lucky the same didn't happen at 3 mile island.
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From: John
(Wed Apr 27 21:10:12 2005)
that wouldnt have happened at TMI, the reason you see their containment building blown apart like that is because.. well... if was basically housed in a tin box, and we do not use graphite monitored reactors, and we have licensed trained control room operators
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From: lkarlov
(Sat Apr 30 07:32:10 2005)
I am interested...
Is this building next to reactor 4 building (very close on the left) reactor 3 building?
How could they run this reactor until 2000???
Who wanted at all to work in a place like this?
How severe is radiaton dose received by these workers who worked there until 2000?
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From: person
(Mon May 2 19:06:25 2005)
Yes, that is the reactor three building. during the explosion and fires the personel running the other reactors had to stay at their posts and keep the other reactors running saftly. it didn't keep running till 2000, more like early '90's, (about 1992 i think the scram button was pushed in a ceramony) i am not certain how much radiation they got, but i do know i wouldn't want to be working there! a 30 km 'zone of exclusion' is permatnantly around the reactor, where no one can live. it is realitivly safe from the road, but it is highly dangerous if you step off (concrete doesn't absorb radiation, but the ground and trees do)
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From: lkarlov
(Tue May 3 03:43:04 2005)
I'm sure, reactor 3 was shutdown at 2000, in a ceremony, as you said.
Reactors 1 and 2 were shutdown earlier.
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From: person
(Wed May 4 21:14:06 2005)
your right, sory!
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From: lkarlov
(Thu May 5 13:06:52 2005)
I can't imagine how could they work there. If an area of radius of 80km is mostly deserted, how could they work in the center of a such disaster? What will happen to their health?
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From: Titanium
(Thu May 5 22:02:11 2005)
Something like this could never happen in the USA. The United States only has Positive Void Coefficient reactors of the PWR and BWR types. Chernobyl was a RMBK type reactor which has a Negative Void Coefficient. In a Negative Void Coefficent reactor the Water acts as a Moderator controlling the reaction and draining the reactor of that water speeds up the reaction causing a meltdown. In a Positive Void Coefficient Reactor the water in the reactor speeds up the reaction and they use Boron rods as a moderator to keep the reaction under control. This means if the water is drained the reaction stops. The technicians at TMI overcompensated when the coolant level dropped and flooded the reactor with water way to fast which caused a large amount of radiation to be released from the containment building. A full nuclear meltdown could have never occured at TMI and can never occur at any USA reactor.
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From: person
(Thu May 5 22:45:18 2005)
titanium, you have it reversed. our reactors have negative void coeficient. rbmk's have positive. also, pwr dont really have any void coeficient, because the water is kept at hight pressure, so it isn't allowed to boil, but if it was it would have negative void coeficient. what this means is that when teh coolent starts to boil voids are formed. depending on how the moderator works, this eitehr leads to an increase in teh reactoin or a decrease. since light water is the only moderator in us's reactors, when it starts to boil it looses its moderating effect, decreasing the reaction. but with the rbmk reactors the control rods were heavy moderators, not absorbers, so when they were inserted they heavaly moderated the nutrons, then the nutrons were stoped by the coolant. but if the coolant turned to steam, UH-OH! the control rods are now moderating the reaction, making the reactoin grow at an expodental rate! as an added con, since the rods were such good moderators, that ment as the reaction increased it was able to handel the nutrons very well, so it gets caught in a posotive feed back loop! the increase in the reactoin let to a ferther increase in the reaction!!! and a full nuclear meltdown can occur in the us, and almost ocured in three mile island. with three mile island, a big hydrogen bouble formed at the top of the reactor, which prevented the coolant from cooling this area well. they got lucky that the bouble got smaller, otherwise it could have been alot worse.
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From: lkarlov
(Fri May 6 02:25:50 2005)
person, I've found this diagram:
http://world-nuclear.org/info/chernobyl/chornobyl.gif
From in I concluded that these graphite blocks were used as moderators, and control rods were used as absorbers.
So, when rods are down, they absorbe neutrons, and fission is stopped.
When rods are up, fission is in progress, and graphite blocks moderate neutrons.
You basically said that control rods were graphite, and that when they were down, they moderated, not absorbed, so in order to shut down fission, the rods would have to be up.
Which one of our stories is correct? Do you have some more precise schematic of RBMK?
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From: lkarlov
(Fri May 6 02:51:06 2005)
What about this: http://www.npp.hu/tortenelem/kepek/csernokep-e.jpg
It seems from this that control rods had absorber section and moderator section?
But here I don't get why should this first (left) situation be dangerous? There is (almost) no moderator section between fuel! (rods pulled too high). I see how rod insertation can be dangerous from this left situation, because when rods lowered, in order to get to absorber section, moderation section is lowered first.
And also, Is there a way to get official schematic of RBMK-1000? I can go to 10 different sites, and find 10 different schematics that do not match with each other...
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From: person
(Fri May 6 19:52:46 2005)
yes the control rods are moderators. they are put in so they can heavaly moderate the nutrons, but remember that the coolent is also a moderator. the theory was that after the nutrons hit the control rods the coolent would take care of most of the rest of the job, what was left could help continue the reaction. if you take the coolent out of the equation, the control rods are now moderating and the reaction goes up at an exponetial rate. you may point out that if the coolant was completly gone, pulling the control rods out would stop the reactoin, which is true, but the fule creates so much heat from its own decay (not fission) that in a us PWR the core would melt in 1 hour if all coolent was stoped. so you always have to have coolent, which is why the rods are never taken out to stop the reaction. the RBMK's were unstable at low power because of the positive void coeficeint, and because of a flaw in the control rod design. the tips of the rods were hollow, so when they are inserted the water level in the reactor goes up, since water is a moderator, when the water level went up the reaction increased. since the rbmk's are overmoderated, (with the control rods ect.) it often got stuck in a posotive feedback loop. (the increase in the reactoin leads to a ferther increase in the reaction and so on.) i recomend going to this page http://en.wikipedia.org/wiki/RBMK it has lots of info, click on each of the blue words to go to another page that will teach you more about the consept/word. also, you should check out the chernobyl page on that same site, http://en.wikipedia.org/wiki/Chernobyl_accident
i didn't sugest this site before because you need some backround information, but it is obyous now that you have it.
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From: guest21
(Mon May 30 05:45:45 2005)
actually Pripyat is in Ukraine, not Russia
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From: coolbest _at_ paradise . net . nz
(Sun Jul 10 04:14:40 2005)
Actually, this photo was not taken "shortly after" the axplosion. As it is clearly visible from the photo - the snow can definatly be seen. In that area of Ukraine the it starts to snow from mid october - mid november. So, the photo taken at least 5 months after the explosion (more realistically, Jan - Feb 1987 due to the ammount of snow)
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From: Arun
(Mon Aug 22 05:26:10 2005)
Mr coolbest where can u see the snow it looks more like sand or somethin and if u look carefully on the right top far away u can see all green land..really i can see no snow anywhere it does look like a picture which was taken soon after the disaster
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From: andre_s
(Fri Dec 16 11:15:36 2005)
there can be no snow in that picture as there is no sarcophagus present. THe sarcophagus was built several months after the explosion, and that would put it summer (or early autumn at the very latest!) and it doesnt snow till late autumn.
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From: dert@hotmail.com
(Wed Apr 26 03:09:16 2006)
chernobyll was one of the worst ever tragedies i have ever seen.if only we knew who the person who ade that terrible mistake,will live to regret it.honesty,i rekon the amount of reactors playing up is showing us a sign,we should really take care,or these sort of accident will happen again.
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From: lk
(Wed Apr 26 11:21:49 2006)
the question of guilt in this case is not so simple.
You cannot point finger at one person (operator) and say: he is guilty for this.
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From: sarah
(Fri Apr 28 06:42:53 2006)
ok i going to sound stupid asking this but what is positive void coeficeint.
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From: Constantin
(Sat Apr 29 17:50:55 2006)
I wonder where the control room is and is still almost intact. I heard on tv that the reactor no2 become unstable because of the explosion of no4 and almost to blow up, is it true?
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From: james@tripwire.net.nz
(Mon May 1 01:56:39 2006)
They say that Chernobyl wont be safe for at least 1000 years... - That's what confirms for me that we shouldn't be playing around with nuclear technology.
And all that USA being so great - where does all the nuclear waste from the plants go? Some of the high level nuclear waste has half-lives of longer than 100,000 years - though most is more like 10,000 years.
It has only been 3000 years scince the Egyptian Empire, how on earth is it going to get stored securely for that ammount of time, when the "modern world" will likely fall and be replaced many times over.
Thank goodness NZ is Nuclear Free.
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From: James
(Mon May 1 01:57:46 2006)
Oh and yes the control room is still in tact, although you are only allowed in there for several minutes at a time.
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From: lk
(Tue May 2 15:32:43 2006)
@sarah
positive void coeficeint is a positive feedback loop. Power increase leads to another power increase, and so it goes on in a loop...
Remember: in this reactor type, moderator is graphite core, so if water from the core is lost, moderation (required for the fission) isn't really affected. reaction doesn't stop like in other water-moderated reactors.
Let's get back to the point: positive void coefficient.
It means, if power (temperature) in reactor increases, more water will be lost (converted to steam), and because this lack of water in the core, cooling and neutron absorption is decreased, which means higher fission rate, which means addidional power (temperature) increase, which means additional water will be lost, which means additional decrement of cooling and absorption, which means additional fission rate increment... AS YOU CAN SEE, it is a very bad unstable reactor condition (loop) which can lead to overheating in very short time interval.
@Constantin
The control room is intact.
Most NPP's I've seen have control room between reactor building and turbine building.
At RBMK-1000 design, control room is located maybe 150-200 m from the reactor.
It is located near the turbine hall, between reactor building and turbine compartment, maybe a bit on the right looking from this location, in this lower long building that isn't on this current picture.
Reactor no2 was shut down due to fire in turbine hall in 1992 I think, not due to instability because 4th react explosion. Fire damage on unit 2 was never repaired, so it stayed offline.
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From: Juan
(Wed May 3 11:09:23 2006)
all you know that only about 3% of that radiation was released! The reading was at over 13000 in the area with 10-20 being normal! If that other 97% were to be released, especially with the wind drafts leading our way (toward USA)..... god forbid......
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From: vampiricon@abv.bg
(Fri May 5 01:30:02 2006)
I wish It would have been just a scilence - fiction book or movie! I begin to wander how The Strugarcki Brothers suceeded to describe "a zone", like the hell you see at the moment?...
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From: anton_92_apa@hotmail.com
(Sat May 6 09:34:55 2006)
the same question is bothering me like it bothers ''Ikarlov''..... Who worked at the plant until 2000??? How did they work there, didnt the radiation kill them?
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From: Andrew
(Sun May 7 22:38:44 2006)
anyone who uses nuclear power or wants it is incredibly stupid why use it when you have so many alternatives neclear power KILLS... i hate it go NEW ZEALAND
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From: n00bMonkel
(Thu May 11 23:40:37 2006)
Andrew, I don't think there are many alternatives to nuclear powerplants. Other sources of power are just too inefficent to meet the demands of modern needs.
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From: LaTeisha_69@hotmail.com
(Fri May 12 06:07:05 2006)
the reason the picture looks snowy is because the radiation got to the film and damaged it.
did they really work in it until rather recently. if no one is allowed to live with in 70km i wouldnt have thought they would be allowed to spend long hours working right in the middle of it all.
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From: emis
(Sun May 21 03:57:57 2006)
Actually this phtoto is taken when russian build the sarcofag
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From: shamoo
(Sun May 21 11:28:05 2006)
The nuclear reactor had a problem, when the control rods were inserted the reaction sped up then slowed this was the main problem because a scram all the rods were put in at once and since it was already starting to melt the channels that the rods that go into the reactor became deformed, after that the rods got stuck and the reactor built up pressure. Then it blew.
Also in 1991 one of the reactors turbine halls caught fire. The closed that reactor down I think it was the number 1 but dont hold me to that.
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From: Phil
(Sat May 27 22:26:50 2006)
A few corrections. In the Chernobyl reactor design, graphite blocks were the primary moderator. The control rods are meant to be neutron *absorbers*. Unfortunately, for some inexplicable reason, the tips of these rods were graphite. That meant that as the rods were inserted, the reaction rate increased before it would have decreased (if not for the explosion).
As for nuclear power in general, I don't think we have a choice. We need it. We've already seen the worst credible accident in a US-style power plant (TMI), and while it was an economic disaster for the utility *no one* was killed. Compare that to those killed in coal mining accidents. And then there's global warming.
Solar is a good idea too, but we can't bet on it scaling to all our needs anytime soon. Nuclear is the most practical, most environmentally friendly alternative we have.
And no, waste disposal is not a problem, at least not a technical one. It's purely a political problem, based on ignorant hysteria.
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From: sarah
(Tue Jun 13 21:21:37 2006)
thankyou lk for explaning what positive void coeficeint is. i still dont quite understand but ill get my dad or one of his friends to explain it to me again. and phil i dont want to start a fight or anything but i dissagree with you on that we need neuclear power, thats just my oppion though.
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From: Sonny
(Mon Nov 6 21:43:23 2006)
We must maintain faith in our education of the good and bad in nuclear power. The ignorant hysteria started when the power companies in these united states did not inform the public correctly about nuclear power and so valuable important time of research and development in nuclear power were lost. This country turns out some of the best engineering students that can solve the most adverse nuclear questions, I know I have had the pleasure to work with some. Our society needs to question their wants before they condemn our progressive inherited ability to move forward in any endevor. Hysteria stands all things in time, it's movement in nowhere!
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From: Sonny
(Thu Nov 16 22:07:36 2006)
To James at Trip wire. net Nz
I think you better realize you don't live in a Nuclear free Zone. as exsample do you have doctors and hospitols where you live? ,do you have dentist , do you have heavy industry. I believe you do have a military(GEE)! now what makes you think your country will not produce radiation waste oops!
Where does all your radwaste go to ? too what country do you have it sent to be buried OOps, I forgot your nuclear free. Period...
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From: Daniel
(Tue Jan 9 18:11:30 2007)
There is a very good reason why New Zealand doesn't need nuclear power, that's because it only has 3 million people, compared with over 250 million in the United States and 80 million in Great Britain.
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From: Brad
(Sat Jan 27 14:27:27 2007)
just a little taste of whats coming sooner than you think
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From: Zappa
(Mon Mar 5 16:46:17 2007)
That's probably not snow. Its probably some of the 2,000+ tons of sand and dolomite (ground limestone) dumped on the site to put out the fires. Its also difficult to determine how long after the dumping occurred that the picture was taken, since I doubt anyone stuck around to sweep up the mess.
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From: Zappa
(Mon Mar 5 17:01:25 2007)
Nuclear power will eventually either save us or destroy us.. there's really no middle ground. Its an issue that must be dealt with. As we use up all the fossil fuels and burn all the trees, we'll have to get power from somewhere.
The shame of it is, if you look at the US nuclear weapon stockpiles, there has never been an accidental detonation of a weapon, even though almost all of the weapons were built hastily with little testing. The reason is that no expense was spared when it came to safety. Nuclear weapons are hugely expensive not only to design and build, but copious amounts of money is spent yearly to perform maintenance, house, upgrade, decommission, etc. They take it seriously, and it has worked well. Even planes that have crashed and burned with live weapons onboard still did not detonate. They have safety features, and even more safety features as backups.
When you get into the power sector however, its too easy to create these Chernobyl scenarios. Privatization of nuclear power is the problem. Look at the Union Carbide "accident" in Bophal, India sometime. They did everything half-assed, as cheaply as possible, all for the sake of more profits. They built the factory in a residential area and maintained it irresponsibly. As a result, thousands of people got hurt. In the Chernobyl scenario, the Russian government was idiotic in running a state business in such a shoddy manner. The weak containment building, cheap design, cheap construction, lack of training, etc. One thing you can give them credit for is that they didn't make the mistake again.
The truth is, until nuclear power is taken seriously and managed based on safety rather than profit, there is no way it will ever be safe.
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From: Jason
(Thu Sep 13 21:35:09 2007)
Noone can ever explain what happens to all the nuclear waste that is piling up, I wonder why that is!? And all you people with bad grammar should go back to school, it' frigging annoying.
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From: wildespace
(Sun Sep 16 09:52:08 2007)
The control rods (which absorb, NOT moderate the reaction) had graphite end tips because when the rods are removed to increase the power, the coolant would normally take their place in the rod channels. So those graphite tips were there to prevent the coolant from coming in.
The actual design flaw was that, with the rods fully taken out, the graphite tips didn't cover the whole length of the channel - there was still a bit of coolant at the bottom. So when the rods started going in, that coolant was pushed out, increasing the power briefly before the rods themselves could do their job.
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From: Timi
(Wed May 14 16:47:49 2008)
shut up jason and you to wild space you booth no nothing my father was a freakin worker there and youve all got it wrong it was purposely done my the governmeant to see how they would cope in a nuclear war
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From: mhajda@hotmail.com
(Mon Jun 2 10:12:05 2008)
People that are anti nuclear just dont understand the facts. Its that simple.
I dont mean to call anyone stupid. Maybe uneducated about nuclear physics and science is more appropriate. Greenpeace and sierra, twist facts, fear monger and do what ever they can to get people to hate and fear nuclear power.
Nuclear power if handled incorrectly can be very dangerous. But the design of the reactor, and the training of the operators can make a nuclear reactor 100% safe.
The rest of the world build nuclear reactors with containment buildings and two layers of safety. Any explosions a reactor can dish out will be handled by these containment buildings. Also any terrorist that thinks he can fly a plane thru a containment building will have a rude awakining when his plane vaporised as it comes incontact with 2 meter think super dence reinforced concrete.
Secondly these containment buildings probably would never have to be used because the design of the reactor is now one where a steam explosion is impossible. Also graphite moderators are no longer allowed. Now if water level drops due to operator error or equipment failure (there is also back ups) the reaction would stop because the water acts as the moderator. So the worst case senario is that the reactor material gets so hot that it melts into a blob that collects at the bottom of its containment area. It would destroy the reactor (probably forever) but there would be zero contamination to the enviroment.
Learn the facts. Know that a coal plant put more radiation into the enviroment then any nuclear plant. Know that you would take in more radiation standing infront of the capital building then you would eating lunch next to a nuclear power plant.
And also dont compair a nuclear power plant to a nuclear bomb. A nuclear bomb needs to be made of 100% uranium 235 inorder to explode. Powerplants use uranium 238. It would be impossible to make a bomb or have any explosion using 238. The only reason 238 even has a reaction is by using a moderator and even then with a moderator the worst that could happen is it over heats and melts..
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From: bsimic@fesb.hr
(Tue Aug 12 16:08:49 2008)
mhajda, I must underline some facts you have mentioned in your post. Do not understand me wrong, but I'm in favor of NPP's. There's no reactor which is 100% safe! You may make it 99.9999% safe, but there's always a chance... There is also a possibility that you fall down in your bath tub and break your neck. The NPP manufacturers do their best to minimize the possibility, so I think the Chernobyl type of accident is ALMOST impossible, and the advantages of the NPP's make that risk acceptable.
About the plane crash: Germans did some testing after 9/11. The old German NPP's have their containment buildings made and tested to withstand the fighter plane crush (such as F-14 Tomcat), but NOT for jumbo jet airliner (like Boeing 747). All new NPP's containment buildings projects after 9/11 are designed to withstand jumbo jet crash, but no reinforcement was made to any old NPP (due to high cost), so there's still a risk of containment building breach by terrorist attack. They hope, I hope, and everybody else hopes that the terrorists do not have the balls to do it.
The reactor may explode, but it is not the uranium fuel that explodes (as in bomb), it is the coolant that boils into steam, the pressure incerases and the reactor vessel actually explodes due to steam buildup. Actual design of EVERY reactor vessel has the relief valves to reduce the pressure, but the there was too much steam created in the 4th reactor in Chernobyl at the momenth of accident. It still puzzels me, and I didn't read/heard/saw it anywhere, whether the reactor lid blew up due to the excess steam or due to the fuel channels meltdown and rupture due to the lack of coolant. THE FACT: as long as there is liquid water (coolant) inside the fuel channel, there is no way the channel may get so hot to meltdown, only if all the liquid water had vaporized. The reactor was running at very low power (less than 10% of nominal) just seconds before the accident, and the operators were trying to keep it this low. The pressure relief valves were designed to relief all the excess steam at least in case of full power operation, and probably a lot more. Now, do you trully believe that the reactor power spiked to 10 times nominal BEFORE the top lid actually blew up, or was it simply the poor coolant flow through the reactor core?
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