What does a nuclear meltdown look like?

[FishmanGeertz]

As far as we know, the buildings housing the reactors at the Fukashima nuclear power plant have exploded from hydrogen gas buildup. However, the reactor vessels themselves remain intact. A nuclear meltdown, also known as "the china syndrome" happens when all of the fuel inside of the reactor overheats and melts, then burns it's way through the bottom of the reactor vessel, through the floor of the containment building, through the ground beneath the plant, and into the water basin located directly underground. This creates a geothermal explosion causing giant geysers of radioactive steam shooting through the general area surrounding the plant.

I do not see this at the Fukashima NPP, meaning that a total meltdown has not yet occurred. All we are being told is that the buildings surrounding the reactors have exploded. If we see giant geysers of steam shooting up from out of the ground, is it safe to assume that one of the units went into total meltdown? Is this really what a meltdown looks like?

During the Chernobyl disaster, miners were sent to tunnel beneath the plant, and underneath the reactor to flood the area with concrete so the molten fuel still inside the shattered reactor wouldn't melt it's way through the floor of the plant and create an even bigger catastrophe. Many of these miners died from radiation sickness.

 

[misnderstudge]

em no i think it was divers who were sent to pump the water out and nothing was dug in the first 6 months as far as i know. this was to prevent a thermal explosion which is lucky because the reactor did fall through and the saved many many lives

 

[FishmanGeertz]

em no i think it was divers who were sent to pump the water out and nothing was dug in the first 6 months as far as i know. this was to prevent a thermal explosion which is lucky because the reactor did fall through and the saved many many lives

Some workers, or "liquidators" sent to clean up the Chernobyl disaster had to sometimes work in levels of radiation in excess of 1,000-15,000 Roentgens per hour! Almost all of them died within days, those who were exposed to lesser doses died of cancer years later. But their courageous sacrifices saved countless lives.

They flew helicopters directly over the reactor breach and dropped neutron-absorbing materials into the core. I believe that ALL of the workers in the helicopters died.

 

[misnderstudge]

Some workers, or "liquidators" sent to clean up the Chernobyl disaster had to sometimes work in levels of radiation in excess of 1,000-15,000 Roentgens per hour! Almost all of them died within days, those who were exposed to lesser doses died of cancer years later. But their courageous sacrifices saved countless lives.

They flew helicopters directly over the reactor breach and dropped neutron-absorbing materials into the core. I believe that ALL of the workers in the helicopters died.

yes that is right, but anyone who was on the diver team or that could see the reactor light died within days people that were further away die days or years later one person survived of the sanding team or cementing team. the worse part none have ever been recognised at all there is a video of them but it is hard to get and it was to say look i am alive the west is lying which is sad. i think there is a second video that was to say by to there family's nothing more on them is known

 

[Borek]

Some workers, or "liquidators" sent to clean up the Chernobyl disaster had to sometimes work in levels of radiation in excess of 1,000-15,000 Roentgens per hour! Almost all of them died within days, those who were exposed to lesser doses died of cancer years later. But their courageous sacrifices saved countless lives.

They flew helicopters directly over the reactor breach and dropped neutron-absorbing materials into the core. I believe that ALL of the workers in the helicopters died.

Do you have sources to confirm these claims? You know, "I believe" is not considered a proof.

 

[FishmanGeertz]

Do you have sources to confirm these claims? You know, "I believe" is not considered a proof.

http://www.youtube.com/watch?v=uoEgkGNO-sQ&feature=related

Watch all six parts.

Divers were sent into water-flooded basement areas directly beneath the burning Chernobyl reactor core to manually turn a valve and drain the water from that area. This room was then flooded with concrete so the molten fuel wouldn't cause a catastrophic geothermal explosion -- an explosion which allegedly would have been several megatons in power!

Both of the divers died from radiation within a few days. And they knew beforehand that they were going to die.

These heroes, as well as the liquidators, should have been given global recognition for their sacrifices.

 

[Borek]

http://www.youtube.com/watch?v=uoEgkGNO-sQ&feature=related

For the record - this video doesn't tell anything about rescue effots after explosion.

I am not telling you are wrong, but somehow - while I remember a lot about cleaning of the ground and the roof - I don't remember anything about underwater operation. Back in nineties I happened to work with Waldemar Siwiński, author of a book about the disaster (http://openlibrary.org/works/OL4496069W/Czernobyl). Book was probably censored, from what he told me it was pretty exact when it came to facts. But then I have read it 20 years ago and I can't find my copy after moving :grumpy:

 

[FishmanGeertz]

For the record - this video doesn't tell anything about rescue effots after explosion.

I am not telling you are wrong, but somehow - while I remember a lot about cleaning of the ground and the roof - I don't remember anything about underwater operation. Back in nineties I happened to work with Waldemar Siwiński, author of a book about the disaster (http://openlibrary.org/works/OL4496069W/Czernobyl). Book was probably censored, from what he told me it was pretty exact when it came to facts. But then I have read it 20 years ago and I can't find my copy after moving :grumpy:

Parts of the reactor and reactor core including graphite and even pieces of raw plutonium and uranium were spat out of the reactor in the giant explosion, and scattered onto the roof and around the reactor block. "Liquidators" whom were wearing heavy lead tunics and respirators, were sent out onto the roof with shovels and told to throw all of the toxic debris into the blown-out roof of Chernobyl reactor block 4. These unfortunate "bio robots" were working in radiation levels in excess of 10,000+ RADS per hour! They could only work for about 45 seconds at a time.

They originally sent remote-controlled robots to perform this task, but the radiation levels were so high, their electronic circuits kept shorting out!

The entire roof of the reactor building was blown apart in the enormous steam and pressure explosion. The some 800-tonne lid or "upper biological shield" to the reactor was blown upwards and landed on it's side into the mouth of the RBMK-1000 reactor core. The burning fuel and graphite was exposed directly to the outside environment for several days! None of Chernobyl's four reactors had any containment structure like western reactors do. Keep in mind that this was the former USSR and many corners were cut during the design and construction of many of their nuclear power plants. Also, any information regarding the potential dangers of nuclear energy were kept highly classified.

Graphite is flammable, the moderator for the Chernobyl reactor was made of graphite. This is why the Chernobyl reactor core burned for such a long time.

 

[Borek]

Parts of the reactor and reactor core including graphite and even pieces of raw plutonium and uranium were spat out of the reactor in the giant explosion, and scattered onto the roof and around the reactor block. "Liquidators" whom were wearing heavy lead tunics and respirators, were sent out onto the roof with shovels and told to throw all of the toxic debris into the blown-out roof of Chernobyl reactor block 4. These unfortunate "bio robots" were working in radiation levels in excess of 10,000+ RADS per hour! They could only work for about 45 seconds at a time.

They originally sent remote-controlled robots to perform this task, but the radiation levels were so high, their electronic circuits kept shorting out!

The entire roof of the reactor building was blown apart in the enormous steam and pressure explosion. The some 800-tonne lid or "upper biological shield" to the reactor was blown upwards and landed on it's side into the mouth of the RBMK-1000 reactor core. The burning fuel and graphite was exposed directly to the outside environment for several days! None of Chernobyl's four reactors had any containment structure like western reactors do. Keep in mind that this was the former USSR and many corners were cut during the design and construction of many of their nuclear power plants. Also, any information regarding the potential dangers of nuclear energy were kept highly classified.

Graphite is flammable, the moderator for the Chernobyl reactor was made of graphite. This is why the Chernobyl reactor core burned for such a long time.

And that's precisely the part I remember.

 

[minerva]

A nuclear meltdown, also known as "the china syndrome" happens when all of the fuel inside of the reactor overheats and melts, then burns it's way through the bottom of the reactor vessel, through the floor of the containment building, through the ground beneath the plant, and into the water basin located directly underground. This creates a geothermal explosion causing giant geysers of radioactive steam shooting through the general area surrounding the plant.

I do not see this at the Fukashima NPP, meaning that a total meltdown has not yet occurred. All we are being told is that the buildings surrounding the reactors have exploded. If we see giant geysers of steam shooting up from out of the ground, is it safe to assume that one of the units went into total meltdown? Is this really what a meltdown looks like?

It's all about how you define "meltdown".

Have you ever noticed that "meltdown" is really never an actual technical, scientific word used by nuclear engineers, with any strict definition? It's a vague, non-scientific buzzword.

If you define "meltdown" to mean a severe, fuel melting, core damage accident, then we have certainly experienced LWR "meltdowns" on a couple of occasions, at Three Mile Island and at Fukushima.

But if that's your definition of meltdown, then a meltdown is highly unlikely to ever hurt or kill anybody.

But some people think that "meltdown" equals some kind of horrible apocalyptic catastrophe, with heaps of radioactivity everywhere in the environment, everybody getting sick and dying, all the radioactivity within the reactor splashed around the environment, etc.

So if that's the definition that they believe, you can see how people get extremely confused when they see that there has been a meltdown at Fukushima or at Three Mile Island, but nobody has been hurt.

It's basically just misunderstanding, misconception and mis-prediction of what could happen, based on inappropriate definitions of this unscientific word.

Does "meltdown" mean the fuel melts down through the core of the Earth and pops up in China? Of course that's a completely absurd fantasy, it does not and will not ever happen.

an explosion which allegedly would have been several megatons in power!

That's absolutely absurd. Extraordinary claims require extraordinary evidence.

There is no force on earth, other than an extremely severe explosive volcanic event or extremely severe earthquake, or a thermonuclear weapon, that can release that much energy that quickly.

 

[nikkkom]

Some workers, or "liquidators" sent to clean up the Chernobyl disaster had to sometimes work in levels of radiation in excess of 1,000-15,000 Roentgens per hour! Almost all of them died within days,

Wrong. Only 3 people died "within days" (in, say, less than 10 days):

Valery Khodemchuk: buried in rubble when reactor blew up, likely died at once.

Vladimir Shashenok: received massive thermal (and probably radiation) burns during accident, died after ~5 hours.

Alexander Lelechenko: after receiving high dose, was treated by local medics, then ran away from them, returned to station and continued working for a few more hours, allegedly in order to save younger workers from the necessity to go into high radiation fields. Died in Kiev on May 7.

During 1986, only 28 people died from acute radiation sickness. Even people with undoubtedly lethal doses took weeks or months to die (one of the more horrible sides of death from radiation).

If you know someone else who "died within days", please tell me who exactly.

 

[Danuta]

hai,

Lt. Pravik on May 9th. Does he count? 13 days.

 

[SteveElbows]

I only just got round to reading this very interesting study about containment failure, which other people found and posted about previously on the main Fukushima thread:

http://www.osti.gov/bridge/servlets/purl/5835351-nR29Hq/5835351.pdf

The idea of blowdown into the torus room is interesting.

 

[nikkkom]

For the record: I'm not saying that not that many liquidators died. I merely say that most liquidators who died did so sometime later.

In many cases, their deaths were not documented as the result of them working in Chernobyl. It was in the interest of both Soviet government and nuclear industry to minimize official death count. Even today I often see more extremist faction of pro-nuclear crowd to claim than "only 30 people died in Chernobyl".

 

[clancy688]

If you define "meltdown" to mean a severe, fuel melting, core damage accident, then we have certainly experienced LWR "meltdowns" on a couple of occasions, at Three Mile Island and at Fukushima.

How would you define a "meltdown"? If an accident where molten Corium penetrates the containments and releases great amounts of radioactivity (didn't happen at TMI, did happen at Fukushima) isn't a meltdown, then what is?

Personally I'd say a meltdown is an accident where nearly all of the core relocates to the lower RPV cavity and maybe anything below.

But some people think that "meltdown" equals some kind of horrible apocalyptic catastrophe, with heaps of radioactivity everywhere in the environment, everybody getting sick and dying, all the radioactivity within the reactor splashed around the environment, etc.

[...]

So if that's the definition that they believe, you can see how people get extremely confused when they see that there has been a meltdown at Fukushima or at Three Mile Island, but nobody has been hurt.

Wait, what? Nobody has been hurt at Fukushima? Are you kidding? Do you only consider people being hurt when they bleed? There are dozens of workers with radiation doses well over 100 mSv, doesn't that count as "hurt"? What's with those unlucky guys who got beta-burns at their feet?
What's with all those thousands of psychologically hurt people people because of their forced relocation? As swr quoted, that already cost dozens their life.

Oh yes, Fukushima did hurt people. And it did hurt an immensely big amount of people. It hurt them where it doesn't bleed. But it hurt them, nonetheless.

 

[swl]

Revised Post

Reason: Original post deleted.

Sincere thanks to Moderator Borek for offering unsolicited guidence in this matter.

Please note: I include no mention of any incidents of radiation sickness in this post.

Revised Post:

If you define "meltdown" to mean a severe, fuel melting, core damage accident, then we have certainly experienced LWR "meltdowns" on a couple of occasions, at Three Mile Island and at Fukushima.

But if that's your definition of meltdown, then a meltdown is highly unlikely to ever hurt or kill anybody.

Thank you for your considered insights, Minerva.

Only around http://www.yomiuri.co.jp/dy/national/T110702002582.htm" that I can think of at the moment, from the evacuation necessitated by radiation (as before, no mention of radiation sickness). Of course you know, as the industry knows, that death from radiation is most often a slow (years or decades) and painful process. A process so slow, that when combined with evacuations, sometimes it can be difficult to establish a cause and effect relationship. It is convenient that the industry and it's supporters can sit back and say 'prove radiation caused it' anytime there is claim regarding exposure to radiation.

As for injury, how should we consider the injury to http://www.asahi.com/english/TKY201106240204.html" people evacuated due to radiation released from the meltdown at Fukushima? People who have lost their lifelong belongings, their jobs, and schools. Now they have a new public home in the gymnasium of some distant elementary school. A home without privacy, without heating in the cold and without air conditioning in the hot humid summer that is just starting.

If you define "meltdown" to mean a severe, fuel melting, core damage accident, then we have certainly experienced LWR "meltdowns" on a couple of occasions, at Three Mile Island and at Fukushima.

But some people think that "meltdown" equals some kind of horrible apocalyptic catastrophe, with heaps of radioactivity everywhere in the environment, everybody getting sick and dying, all the radioactivity within the reactor splashed around the environment, etc.

In Fukushima there has been a huge and horrible release of radioactivity into the environment, and more than three months into the accident there is ongoing contamination of land, sea and air.

It is my understanding that an area exceeding 1250km^2 is closed to habitation, agriculture, business, or harvest due to this massive radioactive release. I have heard that many parents in the Fukushima area feel the evacuation area should be larger, but the nuclear industry and government will only compensate those in the mandatory evacuation [STRIKE]circle[/STRIKE] area.

This accident continues to be a fantastic example of the dangers of nuclear power. Failure to recognize these dangers could be an indicator...

I sincerely apologize to any forum members I may have offended with my previous post, and I thank the Admin team for their understanding and guidance. It has been very frightening living in Japan during this nuclear crisis, and the information from this forum has been helpful.

 

[Borek]

Only around http://www.yomiuri.co.jp/dy/national/T110702002582.htm" that I can think of at the moment from the Fukushima radiation

This can be a language thing, but as I explained to you earlier this statement is incorrect, as it suggest they died because of radiation. They didn't - they died because of the evacuation. Yes, this is accident related, no it is not radiation related.

 

[swl]

Sorry I used the wrong language again. I edited the post. Please let me know if other changes are required.

This can be a language thing, but as I explained to you earlier this statement is incorrect, as it suggest they died because of radiation. They didn't - they died because of the evacuation. Yes, this is accident related, no it is not radiation related.

I suggest that they died of radiation because, I believe radiation is the root cause that forced their evacuation. Please let me know if I'm mistaken.

It is my understanding that neither TEPCO, nor that government have acknowledged any deaths due to radiation sickness.

 

[Borek]

The way it is worded now is OK to me. "Died of radiation" implied radiation sickness, and was misleading.

This is not to downplay the problem, just to clarify the situation.

 

[QuantumPion]

Sorry I used the wrong language again. I edited the post. Please let me know if other changes are required.



I suggest that they died of radiation because, I believe radiation is the root cause that forced their evacuation. Please let me know if I'm mistaken.

It is my understanding that neither TEPCO, nor that government have acknowledged any deaths due to radiation sickness.

If you want to play that game than the root cause of the evacuation was the earthquake and tsunami.

 

[Caniche]

If you want to play that game than the root cause of the evacuation was the earthquake and tsunami.

I think he's talking about folks who died as a direct result of the radiation contamination. Don't think he's "playing a game"more like alluding to the fact that carers fled days after the tsunami cos they were quite attached to their existing genetic configuration

 

[swl]

If you want to play that game than the root cause of the evacuation was the earthquake and tsunami.

I understand your interesting point, and of course I am aware of the position of the earthquake in the chain of events. As I'm sure you understand, an earthquake is not an event that the nuclear industry has any control over. As such, the earthquake can not be the root cause. If you like, I suppose you could push the cause back to defects in the design or construction of the plant, or maybe the decision to utilize nuclear power.

I suppose I should have avoided the term 'root cause' so as to reduce obfuscation.