[arriplify]

depends on the country in, but alot of the west state it was a steam explosion , whereas the east say it was a self contained nuclear explosion with nuclear fueled fire.... thoughts?

[etdgxcnc]

In short, steam explosion and graphite fire that released a fair bit of radioactive material, caused by errors when testing that overheated the core.
Been a few years, so if anyone has better info?

Should be copious amounts of info' and videos on the net, have a look around.
Also some good books about it, try your local library.

[phenterminediett]

In short, steam explosion and graphite fire that released a fair bit of radioactive material, caused by errors when testing that overheated the core.

This. I watched a history channel show, like Countdown to Destruction or something similar, that went through all the events of the day, pretty terrible especially for the people living nearby in Pripyat that came to watch the strange colored fire.

[arriplify]

as i said , the west say it was a steam explosion , whereas the east say otherwise.....

[phenterminediett]

as i said , the west say it was a steam explosion , whereas the east say otherwise.....

If you're talking about a nuclear explosion in the traditional sense, such as an atomic or nuclear bomb, I don't think that's even physically possible with a nuclear reactor. Perhaps someone like Neeyik can clarify, but the fissionable material used in reactors isn't weapons grade, and wouldn't be pure enough to cause a true nuclear explosion. It also wouldn't have the triggering mechanism, which would also be necessary I think.

[rushiddink]

Just ask Valve!

[arriplify]

you dont actually need `weapons grade` material for a fissile reaction - all `weapons grade` or enriched uranium does is reduce the amount of material needed for criticality. also heavy water reactors use `unrefined` uranium , literally dug out of the ground and shoveled in (well not quite but you get the idea)

[Zhgpavye]

They just noobed it when testing.

[Wachearex]

depends on the country in, but alot of the west state it was a steam explosion , whereas the east say it was a self contained nuclear explosion with nuclear fueled fire.... thoughts?

Everything you need to know is here:

http://www.iaea.org/NewsCenter/Focus/Chernobyl/#

It wasn't a nuclear explosion: civil reactor cores are designed to prevent this. Essentially the fuel rods are separated in such a way that a fission chain reaction is possible but not so much that it could go 'thermonuclear' on you. In the case of Chernobyl, the explosion was simply a gas pressure one - due to various reasons (some due to the architectural design of the RMBK but most were due to human error), the reactor core temperature to rise beyond the design limits. This caused a sequence of problems resulting in large portions of the coolant boiling away and ultimately rupturing the pressure vessel in the so-called 'steam explosion'. Further explosions were caused by the incoming air igniting the hot graphite moderator and a release of hydrogen due to the fuel rod walls reacting with the steam; the sheer temperature of the core and moderator ignited various other parts of the reactor infrastructure.

What source are using for the opinion of the "east"?

also heavy water reactors use `unrefined` uranium , literally dug out of the ground and shoveled in (well not quite but you get the idea) The uranium is heavily refined - it's just not enriched, as with the UK Magnox reactors.

[phenterminediett]

What source are using for the opinion of the "east"?

Akinkhoo?

[cmruloah]

Akinkhoo?

yeah, his dad told him the real truth, which obviously only china knows about [rofl]. Not our western lies... ya know, like Tienanmen Square.

[DailyRingtone]

From what I read about Chernobyl, they were pretty lucky to contain the damn thing.

From the second to tenth day after the accident, some 5000 tonnes of boron, dolomite, sand, clay and lead were dropped on to the burning core by helicopter in an effort to extinguish the blaze and limit the release of radioactive particles.
The core apparently was Molten liquid, they reckoned that if the core hadn't cooled it could have literally burned down through the earth's crust and carried on going down until it cooled off.

As you can imagine the helicopter pilots unknowingly were subject to masses amounts of radiation and died in the forthcoming weeks.

The only reason I researched about Chernobyl was because I played Stalker and wanted to know a little bit more on the background of the incident/accident.

And they say games can't teach you nothing.

[phenterminediett]

And they say games can't teach you nothing.

I hear if you get into the sarcophagus you get wishes. You should go see if it's true. [rofl]

[JOR4qxYH]

Something similar that almost happened to K-19.
Except they noticed that the core went critical and rigged a coolant line from the ships drinking water.

[etdgxcnc]

From what I read about Chernobyl, they were pretty lucky to contain the damn thing.

From the second to tenth day after the accident, some 5000 tonnes of boron, dolomite, sand, clay and lead were dropped on to the burning core by helicopter in an effort to extinguish the blaze and limit the release of radioactive particles.
The core apparently was Molten liquid, they reckoned that if the core hadn't cooled it could have literally burned down through the earth's crust and carried on going down until it cooled off.

As you can imagine the helicopter pilots unknowingly were subject to masses amounts of radiation and died in the forthcoming weeks.

The only reason I researched about Chernobyl was because I played Stalker and wanted to know a little bit more on the background of the incident/accident.

And they say games can't teach you nothing.

Relatively few of the pilots died, biggest casualties were from those on the ground.
You're thinking of the "China Syndrome", when the hot material was said to melt it's way to China, in truth the probably result of the containment vessel being ruptured would be a large steam explosion as it hit the groundwater with the material being spread over a much greater area and that was one of their big concerns - if it was a simple case of menting it's way though the ground, I expect they'd've welcomed it.

[Wachearex]

The core apparently was Molten liquid, they reckoned that if the core hadn't cooled it could have literally burned down through the earth's crust and carried on going down until it cooled off.

The entire core was well short of being liquid given the melting points of graphite and uranium oxide are in excess of 2000 K, but they were parts of it that had become molten. The real reason why they dumped so many materials on to it was to extinguish the different sources of ignition (such as the oxidation of graphite, the reaction between steam and the fuel rods and the chain reaction of the fuel) and to prevent the core from reaching deeper into the building sub-structure.

if it was a simple case of menting it's way though the ground, I expect they'd've welcomed it.

Actually they worried about that happening because it could create further explosions if it came into contact with the water table and it would contaminate further areas of land. Ideally they wanted it contained with the reactor building so that they could (eventually) encase of the whole structure.

As you can imagine the helicopter pilots unknowingly were subject to masses amounts of radiation and died in the forthcoming weeks. Hundreds of people at the accident were exposed to far higher doses than the helicopter pilots but the total death toll after several weeks was around 30 - none of which were the pilots: they were actually safer than the ground workers once they stopped direct dumping. Of the people who died in later years, it's not possible to say with absolute certainty that the severe acute dose they received was responsible for their deaths.

[etdgxcnc]

Neeyik, I know that, didn't you read the bit about the section quoted? [rolleyes]

[Wachearex]

Apologies - I had skimmed the sentence immediately preceding the one I quoted, although it does contradict what you'd said. They wouldn't have welcomed it melting through the ground (just melting or otherwise) for the very reasons given by yourself.

There was no need for the rolling eyes smilie though. Why is everybody becoming so aggressive on this forum these days? Everybody seems to take offence at the slightest remark or be incapable of holding any kind of conversation without being prickly.

[BundEnhamma]

A documentary I watched made it sound like more people died, and virtually all pilots were included in that.

[arriplify]

good morning neeyik ;


the sourse(s) i had were from a number of years ago - they simply said that (when translated from russian) the explosion was nuclear in nature , and it was the americans who were saying it was a steam explosion - the conditions within the core caused the overheat and poorly regulated nuclear reaction `ran away` causing a lowl level nuclear explosion.

this is supported in the details - the RBMK design is a light water design (with a huge positive void co-efficient) using U 235/U238 natural mix ,as we know U238 which is a fertile material for production of plutonium , of which russia is the only country to use breeder reactors for producing power - intersting thought that one..... but U 238 can also be fissile with high energy neutrons;


so we have a positive void design , graphite tipped control rods and a low power setting at the time (un authorised test) and a shift change without the new shift being prepared for the test...


the core goes down to ultra low power , they remove the control rods to bring the power up , the switched off water pumps lower water pressure coupled with the increased nuclear reaction from removing the control rods boils more water quicker.The void co-efficient comes into effect and the reaction runs out of control , in 40 seconds iirc the plant ramps up to 3000MW or something high , the scram is pressed but since the control rods are graphite tipped they actually displace coolant and make it worse (and are motor lowered taking 20 seconds to fully lower) ; with the the void co-efficient effects we now have high energy neutrons effecting the usually fertile U238 , combined with the now high temp and pressure (and U239 pressence) we now have an uncontolled criticality core - and the effects are known.

so why no mushroom etc? different parts of the core would have been at different temps and pressures (ala windscale) so the explosion was part of the core and contained - the fuel fire after resulted in the disharge of the radioactive elements.


btw seen a great video of 2 australians going round prypiat - the detection equipment they used was on max when they went to the dogem cars