How did this worker approach this fuel mass at Chernobyl?

[Kutt]

I accidentally happened upon this photo while researching some things about the 1986 Chernobyl nuclear disaster and I freaked out! How did this worker get so close to this mass of melted nuclear fuel in the basement of Chernobyl without receiving several lethal doses of radiation?

This mass of corium located in the basement directly beneath the Chernobyl reactor is known as "the elephants foot" and it emits radiation at levels in excess of 10,000 roentgens per hour.

Approaching it would mean certain death. The individual shown in the below image is either completely insane or outright suicidal.

I am quite certain that this worker, as well as the person who took the photograph, are now both deceased. Probably from either cancer or acute radiation sickness.

 

[micromass]

I don't think that the Soviet government really told those people about the dangers.

 

[Kutt]

I don't think that the Soviet government really told those people about the dangers.

I think that photo was taken in the 1990's, after the collapse of the USSR.

 

[Kutt]

Here is another photo of the "elephant's foot." You can see distortions and abnormalities in the photograph caused by EXTREME levels of radiation. This radiation (thousands of rads per hour) actually caused the lower half of the worker to appear transparent.

Crazy... absolutely crazy...

 

[I like Serena]

Just making a couple of calculations...

This elephant's foot gives off 10000 R per hour at its surface.
According to wiki 500 R during 5 hours is considered lethal.
That is equivalent at sitting at a distance of 1.5 m for 5 hours.
... which appears to be what this guy is doing!
Presumably doable with protective clothing but it does not look smart.

 

[QuantumPion]

10,000 R/hr is 2.8 R/second. Assuming the guy just ran up, took the picture, and then ran back, his dose would not be too extreme. More than I would volunteer to receive though.

 

[Kutt]

10,000 R/hr is 2.8 R/second. Assuming the guy just ran up, took the picture, and then ran back, his dose would not be too extreme. More than I would volunteer to receive though.

Yes, but enough to make you very ill and dramatically increase your risk of cancer and many other health ailments.

Approaching a mass of corium is crazy regardless of the circumstances. This should have been done with robots and not people.

Off-topic, but how do roentgens convert to rads? Which unit is greater? Why isn't this unit of measurement used in the United States?

 

[QuantumPion]

Yes, but enough to make you very ill and dramatically increase your risk of cancer and many other health ailments.

Not for 10-20 R. You don't start to see acute symptoms until around 100 R. As for increase risk of cancer, there is no way to know if there are long term risks associated with low exposure doses.

Approaching a mass of corium is crazy regardless of the circumstances. This should have been done with robots and not people.

Not as crazy as smoking, being overweight, or texting while driving.

Off-topic, but how do roentgens convert to rads? Which unit is greater? Why isn't this unit of measurement used in the United States?

From: http://www.osha.gov/SLTC/radiationionizing/introtoionizing/ionizinghandout.html

Quantifying Exposure and Dose

Exposure: Roentgen

1 Roentgen (R) = amount of X or gamma radiation that produces ionization resulting in 1 electrostatic unit (esu) of charge in 1 cm3 of dry air at STP. Instruments often measure exposure rate in mR/hr.

Absorbed Dose: rad

1 rad (Roentgen absorbed dose) = absorption of 100 ergs of energy from any radiation in 1 gram of any material; 1 Gray (Gy) = 100 rads = 1 Joule/kg; Exposure to 1 Roentgen approximates 0.9 rad in air.

Dose (in rads) = 0.869(f)(Roentgens) where the f-factor is the ratio of mass energy-absorption coefficient of medium, such as bone, compared to air.

Biologically Equivalent Dose: rem

Rem (Roentgen equivalent man) = dose in rads x QF, where QF = quality factor. 1 Sievert (Sv) = 100 rems.

 

[jim hardy]

The elephant's foot is largely silica glass from the sand that surrounded the vessel.
While it contains fuel fragments, it's not like it was pure corium. It's a few percent uranium.

Lava-Like Fuel-Containing Materials. The high temperatures associated with the accident melted the zirconium fuel cladding and led to an interaction between the molten zirconium and the uranium dioxide, resulting in a uranium-zirconium-oxygen phase. When this phase interacted with structural materials (serpentine, concrete and sand) as well as air, lava-like fuel-containing materials were formed.

Researchers working at Chernobyl NPP Unit 4 encountered this lava-like fuel-containing material for the first time in the fall of 1986. Subreactor location 217/2 was found to contain a large solidified mass, approximately 1 m wide that came to be called the Elephant’s Foot (Figure 2.2-1). Analysis of the Elephant’s Foot revealed that it consists primarily of silicon dioxide with other compounds as impurities, including uranium compounds. The mixture of radionuclides found in samples of the Elephant’s Foot match those found in the irradiated nuclear fuel with an average burnup for Unit 4.

http://www.tesec-int.org/chernobyl/Radioactive waste in the Sarcophagus.htm

Not to minimize the danger at all.
As somebody else pointed out - in a 10,000 R field one could have a few second stay time.
I'd wager the field there was on order of a few hundred R. But that's just a guess. Lack of fogging on the film supports it...

 

[a.ua.]

At the time when they made this picture there were already 100 - 700 Roentgen

 

[Kutt]

So the "elephants foot" was only a few % uranium and was made largely of sand/concrete/zirconium and other materials which the molten corium mixed in with after melting?

 

[Hiddencamper]

What we don't know, was the mass 10000R/hr on contact or at some distance away?

Typically dose rates are reported as on contact and at 3 feet. 10000R/hr on contact means less a few feet away, which gives him just enough time to safely get in and take a picture. Or he could have just not cared.

Because there was other materials in the mass, it's likely the dose rates were only internal or on contact to the mass. The other materials mixed in the glass type mass would also provide some level of shielding.

 

[nikkkom]

So the "elephants foot" was only a few % uranium and was made largely of sand/concrete/zirconium and other materials which the molten corium mixed in with after melting?

BTW, uranium per se is _not_ a significant source of radiation here. Fission products are.

The worker in this photo is reckless, but not too much.

You know, some people in fact had to *collect* material with comparable levels of radiation in the first weeks and months after accident, when chunks of fuel and graphite from reactor were lying bare of the ground around the destroyed Unit 4 and were making any sort of accident response very dangerous. THAT was crazy.

 

[I like Serena]

You know, some people in fact had to *collect* material with comparable levels of radiation in the first weeks and months after accident, when chunks of fuel and graphite from reactor were lying bare of the ground around the destroyed Unit 4 and were making any sort of accident response very dangerous. THAT was crazy.

If I were say 70 years old and had kids and grand kids living nearby, I'd be motivated not to wait for the proper equipment.

 

[nikkkom]

If I were say 70 years old and had kids and grand kids living nearby, I'd be motivated not to wait for the proper equipment.

In this particular situation "kids and grand kids" already got their dose of Iodine-131 etc from the aerosols in the air.

The cold debris around reactor was not producing much of a contamination any more - at least compared to still burning open-air graphite fire in the ruined reactor core it is miniscule.

Yes, debris was very radioactive per se, but IIRC gammas are attenuated in half by ~150 meters of air. Nearest housing is no closer than 3 kilometers - attenuation of gammas by 2^20 = ~million times, even discounting attenuation due to inverse square law.

Clean-up was necessary because otherwise it was impossible to approach the Unit 4 building and do anything. Thousands of R/h.

 

[jim hardy]

There are motion pictures from days after the accident of people atop the building tossing pieces of reactor back down into the pit. They'd get a very high dose in just one few second run.

That was self sacrifice.

 

[Color_of_Cyan]

Is that the actual elephants foot? I don't think so that kind of looks like it might be a turbine or something, and I thought no one EVER got that close to the "elephants foot" in person... I thought the only photo(s) they got of it was with a robot.

 

[Kutt]

ONLY robots should be used to approach areas of the Chernobyl reactor that are too radioactive for people.

The workers who entered areas of the reactor where there was literally melted nuclear fuel laying about on the ground are likely at extremely high risk of cancer.

 

[a.ua.]

There are motion pictures from days after the accident of people atop the building tossing pieces of reactor back down into the pit. They'd get a very high dose in just one few second run.

That was self sacrifice.

That's the movie
http://www.youtube.com/watch?v=FfDa8tR25dk&feature=youtu.be

It was the most contaminated, and therefore the most dangerous, place in the zone. The remains of the roof coating of the 4th reactor. The operation on decontaminating the roof lasted more than five months. We will tell about only two days. About the most important two days in the life of an explorer - dosimetrist Valeriy Starodumov. He participated in this operation until it was over. He himself came out to the roof and led people there. He himself planted the "victory banner" at the level of 75 meters, as the signal for the zone: the roof coating has been decontaminated! Now, 25 years later, Valeriy Starodumov comes back to the zone. Now Chernobyl is a tourist object. But not for him...

 

[Hiddencamper]

ONLY robots should be used to approach areas of the Chernobyl reactor that are too radioactive for people.

The workers who entered areas of the reactor where there was literally melted nuclear fuel laying about on the ground are likely at extremely high risk of cancer.

not necessarily true.

for accute exposure cases, you can linearly assume something like a .04% increase in chance of cancer over your lifetime per 10 Rem. A single chronic case shouldn't have a very large increase over the chance you already have to get cancer over all sorts of other stuff.

It's usually in long term chronic exposure that cancer rates start to rise greatly.

 

[Kutt]

not necessarily true.

for accute exposure cases, you can linearly assume something like a .04% increase in chance of cancer over your lifetime per 10 Rem. A single chronic case shouldn't have a very large increase over the chance you already have to get cancer over all sorts of other stuff.

It's usually in long term chronic exposure that cancer rates start to rise greatly.

Standing within a few feet of melted uranium for any period of time is enough to become dangerously contaminated with radiation. Even less than one minute of exposure will get you a dose of 20-40 rads.

 

[Hiddencamper]

Standing within a few feet of melted uranium for any period of time is enough to become dangerously contaminated with radiation. Even less than one minute of exposure will get you a dose of 20-40 rads.

No offense but you need to know what you are talking about before you make statements.

First off, uranium is virtually negligible in terms of radiation. Uranium gives off very low levels of alpha particles and will do virtually nothing to you. I've physically held fuel pellets in the manufacturing facility and received 0 exposure, none, zip. It is the waste/fission products and other byproducts of utilizing uranium that give off dangerous levels of radiation, NOT the Uranium (exception U-232...but that's generally only seen in thorium type reactors).

Secondly, just standing next to radioactive material does not contaminate you. If your claim was true, that just standing next to it would contaminate you, then that means that somehow, magically, standing next to as solid chunk of core material magically causes all that radioactive material to go into your body, then you carry the radioactive material and emit radiation wherever you go. That's not the case. RADIATION != CONTAMINATION.

Contamination is the uncontrolled spread of radioactive MATERIAL. NOT RADIATION.

RADIATION and RADIOACTIVE MATERIAL are different. RADIOACTIVE MATERIAL GIVES OFF RADIATION. But RADIATION does not make an object radioactive.

That solid mass of core material (which is what it should be called, not "uranium"), is a solid form. It is not going to be somehow releasing radioactive material into the air around it. Any radioactive MATERIAL in the area is stuff that was already there. It is not going to somehow magically contaminate you. Contamination is when radioactive material gets ON or IN your body in an uncontrolled fashion. The danger with contamination is prolonged internal exposure. If the MATERIAL does not get ON or IN you, you are NOT contaminated.

Simply standing in a radiation field does NOT contaminate you.

The solid mass of core material DOES give off a very high radiation field.

This is an ACUTE exposure of radiation. Acute exposures of radiation typically have low impact on your overall cancer risk (As in less than 1%, of the 40% you normally have just for being a living breathing human). Simply getting blasted once or twice in your lifetime with a very high rad dose in a short period of time will not give you a massive cancer risk increase. It may cause radiation poisoning effects, but it will not magically make your cancer rates skyrocket.

It is CHRONIC exposure, that is, exposure to moderate levels of radiation for extended periods of time, especially internal exposure, that start to greatly increase your cancer risk.

There are some exceptions. Iodine-131 is an exception as it bioaccumulates and gives a very dangerous accute dose which will damage the thyroid.

Long story short, you really need to go out and get some understanding of the differences between radiation and contamination.

And last but not least, stop making statements that are not only incorrect, but not backed up by science. For example, see this link: http://hps.org/publicinformation/ate/q2410.html
For exposures in the 15-20 Rem range, it is actually very difficult to show ANY change in cancer risk. Your claim that somehow 20-40 rads will give you a DRASTIC increase in cancer risk is nothing more then speculation and sensationalism. And there are MANY different studies by reputable organizations which are all consistent that low to moderate chronic doses are very difficult to even determine if it affected your cancer rate.

 

[jim hardy]

http://news.nationalgeographic.com/...quidators-firefighters-roof_35076_600x450.jpg

 

[jim hardy]

That's the movie
http://www.youtube.com/watch?v=FfDa8tR25dk&feature=youtu.be

Thank you a.ua.
that is a moving documentary.
Around 19 minutes...

the fields on the roof were quite enough to knock out semiconductor electronics in less than an hour, as apparently happened to 'joker' robot.
So they had to throw people at it.
Graphite blocks right out of the core- by hand -
there are not words...

old jim

 

[Kutt]

No offense but you need to know what you are talking about before you make statements.

First off, uranium is virtually negligible in terms of radiation. Uranium gives off very low levels of alpha particles and will do virtually nothing to you. I've physically held fuel pellets in the manufacturing facility and received 0 exposure, none, zip. It is the waste/fission products and other byproducts of utilizing uranium that give off dangerous levels of radiation, NOT the Uranium (exception U-232...but that's generally only seen in thorium type reactors).

Secondly, just standing next to radioactive material does not contaminate you. If your claim was true, that just standing next to it would contaminate you, then that means that somehow, magically, standing next to as solid chunk of core material magically causes all that radioactive material to go into your body, then you carry the radioactive material and emit radiation wherever you go. That's not the case. RADIATION != CONTAMINATION.

Contamination is the uncontrolled spread of radioactive MATERIAL. NOT RADIATION.

RADIATION and RADIOACTIVE MATERIAL are different. RADIOACTIVE MATERIAL GIVES OFF RADIATION. But RADIATION does not make an object radioactive.

That solid mass of core material (which is what it should be called, not "uranium"), is a solid form. It is not going to be somehow releasing radioactive material into the air around it. Any radioactive MATERIAL in the area is stuff that was already there. It is not going to somehow magically contaminate you. Contamination is when radioactive material gets ON or IN your body in an uncontrolled fashion. The danger with contamination is prolonged internal exposure. If the MATERIAL does not get ON or IN you, you are NOT contaminated.

Simply standing in a radiation field does NOT contaminate you.

The solid mass of core material DOES give off a very high radiation field.

This is an ACUTE exposure of radiation. Acute exposures of radiation typically have low impact on your overall cancer risk (As in less than 1%, of the 40% you normally have just for being a living breathing human). Simply getting blasted once or twice in your lifetime with a very high rad dose in a short period of time will not give you a massive cancer risk increase. It may cause radiation poisoning effects, but it will not magically make your cancer rates skyrocket.

It is CHRONIC exposure, that is, exposure to moderate levels of radiation for extended periods of time, especially internal exposure, that start to greatly increase your cancer risk.

There are some exceptions. Iodine-131 is an exception as it bioaccumulates and gives a very dangerous accute dose which will damage the thyroid.

Long story short, you really need to go out and get some understanding of the differences between radiation and contamination.

And last but not least, stop making statements that are not only incorrect, but not backed up by science. For example, see this link: http://hps.org/publicinformation/ate/q2410.html
For exposures in the 15-20 Rem range, it is actually very difficult to show ANY change in cancer risk. Your claim that somehow 20-40 rads will give you a DRASTIC increase in cancer risk is nothing more then speculation and sensationalism. And there are MANY different studies by reputable organizations which are all consistent that low to moderate chronic doses are very difficult to even determine if it affected your cancer rate.

I'm sorry, I shouldn't talk about things I have only minimal knowledge of.

 

[DEvens]

Some notes about Chernobyl:

Those "bio-robots," the guys on the roof tossing debris back in the pit. There were many thousands of them. The direct radiation effect is tiny, hardly measurable. It is entirely swamped by another effect. The media and all their friends and relatives assured them they were doomed to a horrible death due to this. So they started drinking and smoking and otherwise not caring for themselves. So they are suffering much more from liver disease, heart disease, smoking-related lung cancer, etc., than the background. But their cancer rates, other than lung cancer, are basically indistinguishable from the background.

That's right. The effects of doom-and-gloom over the radiation dose these guys got was by far larger than the effect of the dose itself.

 

[jim hardy]

While on the subject of hype:


Plutonium is not for pizza topping but it isn't what the "screamers" claim either.

TOXICITY


Plutonium never was “the most toxic substance known to man”, as has so often been asserted by its detractors. It is indisputably very toxic but in a different way from more familiar poisons such as cyanide or botulin. In the worst imaginable circumstances plutonium lodged in the body might cause cancer 20 years later. Cyanide can kill in minutes.

What was perhaps the world’s most exclusive club comprised a handful of Americans who became contaminated in accidents with plutonium in the scramble to make the first plutonium weapons. All were young white males who had been working under laboratory conditions acknowledged to have been “extraordinarily crude” in 1944-5, on one of four chemical processes: purification, fluorination, metal reduction and recovery. The kinds of accident they suffered included chemical burns by plutonium salt solutions. Members were enrolled by medics at Los Alamos because they were judged to have experienced the highest exposures to plutonium of all people engaged in the Manhattan Project. The chosen 26 were excreting the highest levels of plutonium in their urine. In 1952, when the club was formed, each was estimated to be contaminated with between 0.1-1.2µg of plutonium.

Most of the men left Los Alamos soon after the war ended and scattered throughout the USA. Three of them continued to work with plutonium. Four had been involved with three or more accidents with the stuff. The medics traced all 26 in 1952-3 and carried out their first follow-up of medical studies. Thereafter they were given a complete medical examination about every five years. Two decades later, in 1971-2, 22 of them returned to Los Alamos for a more complete study of their plutonium body burden, with two more opting for their own doctors instead of Los Alamos’s. One had died.

By 1979, when George L Voelz and his colleagues published their 32-year medical follow-up of club members, two had died: the first from a heart attack in 1959, aged 36; and another from a road accident in 1975, aged 52. The surviving 24 had suffered no cancers other than two skin cancers “that have no history or basis that relate them to plutonium exposure”, they reported. They found the diseases and physical changes in club members were “characteristic of a male population in their 50s and 60s”. The mortality rate of the club was about 50% of the expected deaths among white American males at that time.

The moral of this story is not, of course, that plutonium is good for you, but that it’s nowhere near as deadly as it’s been cracked up to be. Admittedly, the club members were above-average intelligence – college students or chemical engineering graduates in their early-20s who had been called up for the US Army and drafted to Los Alamos. Many returned to college after the war. Within a few years almost all were in supervisory, administrative or professional positions where they were no longer exposed significantly to any toxic chemicals or radioactive materials. Nine never smoked. Four had reached their sixties, one 69.

Voelz, speaking in 1999 after his retirement, recalled that he’d arrived in Los Alamos in 1952 for a year of in-plant training in industrial medicine and was intrigued with all the concern for protecting and following people exposed to plutonium. “I had never heard of plutonium until I got to Los Alamos”. The club had already been started. Describing the exposures of the 26, Voelz noted: “The work during World War II was done in ordinary wood frame buildings with openfaced chemical hoods”. Some work, such as weighing and centrifuging, was actually done outside the hoods”. Club members expressed no serious fears or concerns about their exposures to plute. “They are interested in hearing the results of our studies and have been fully cooperative through these many years”. He stressed the importance of a close rapport and kept in touch personally with letters and presentations, encouraging them to call if they had any questions – as any good club might do. None ever filed claims for compensation.

Today there are over 1200 plute-contaminated people under constant medical observation, with no detectable effects so far, Eric Voice, a British scientist who worked with plutonium at Harwell and Dounreay, told me in the summer of 2004. In retirement in 1992 Voice participated in several experiments, in one of which plutonium citrate solution was deliberately injected into several volunteers, for biomedical researchers to follow the patterns of plute excretion and movement of plute in blood, tissues, liver and bones. These metabolic experiments used short-lived plutonium isotopes. Twelve years later he’d reached the age of 80 and accumulated no fewer than 15 reports of results and deductions about these experiments published in the professional press. Is getting plutonium inside the body more dangerous than any radioactivity we already have inside us? No, Voice asserted, the radium in the world around us is twenty times more dangerous than the same mass of plutonium. “And there is no evidence that any human on Earth has ever died or suffered any health consequences whatever from plutonium radioactivity”.

Eric Voice died in September 2004 from motor neurone disease. An obituary in the Daily Telegraph recounted how in one experiment “Voice was one of a dozen guinea pigs who inhaled trace amounts of plutonium isotopes of the sort found in nuclear reactors. Measurements were then made tracking the progress of the substances through the body. The study was designed to find out how to treat people in the event of a nuclear accident”. He had lived for another five years after the UKAEA declared in 1999 that all of its guinea pigs were still alive and healthy.

http://www.neimagazine.com/opinion/opinionthe-drama-of-plutonium
I think I posted this article someplace before - was glad to find it again.

 

[nikpav73]

I think the picture was taken many years after the disaster.

10.000 R/hour activity was observed in first minutes after the accident - it is way lower by now.

Still, one has to note that at least one person from reactor 4 personal who was right at the spot during the explosion still alive ( however has quite some medical problems because of radiation exposure of 1000 R or so.).

 

[a.ua.]

nikpav73

10.000 R/hour activity was observed in first minutes after the accident - it is way lower by now

I'm sorry it's machine translation


Large radiation fields have their own smell. And if you feel it, do not exhibit any heroism, and very quickly Jacked ".


"How do they smell?"

"Ozone. First Commandment: Fear the smell of ozone."

Found it in one of the rooms at a 6 m fall of 1986 to see the 'ivory leg "had to crawl through a narrow enough, anyway, for my size, slit. After a few meters slot takes you to the corridor service. Right in this corridor was the door to the room is very useful to us for thermal reconnaissance. As it turned out, it was located down and across from the location of the major accumulations of lava. In this room was full of tubes and very hot, over 40 degrees Celsius. However, dose rates remained quite acceptable. Left - corridor widened and there somewhere, far away, and wore a black, smooth surface, a huge drop. She blew cool and the radiation field, reaches 8000 r / hr
http://berkovich-zametki.com/2008/Zametki/Nomer9/Borovoj1.php

Inside the reactor, Elena

 

[nikkkom]

I think the picture was taken many years after the disaster.

10.000 R/hour activity was observed in first minutes after the accident - it is way lower by now.

Correction. Not minutes. Weeks and months.

 

[skeptic2]

I remember reading at the time that the workers, in a macho display of bravura, tried to outdo each other in how much radiation they exposed themselves to

 

[a.ua.]

http://www.youtube.com/watch?feature=player_detailpage&v=BghKU-GgtB4#t=682
The route number 6.
The study of the sensors.
from 7 to 50 millisieverts in areas where they filmed.

 

[HowlerMonkey]

The guys who went in and gazed directly at the flipped upper biological shield and looked directly into the core all died within a few days or a couple of weeks.

The guy who held the door as they quickly glanced around it endured many skin grafts.

 

[.Scott]

Here is another photo of the "elephant's foot." You can see distortions and abnormalities in the photograph caused by EXTREME levels of radiation. This radiation (thousands of rads per hour) actually caused the lower half of the worker to appear transparent.

Crazy... absolutely crazy...

This worker appears transparent because this is a time-exposure (I would guess at least 5 seconds) during which the worker moved.

http://www.jonmwang.com/blog/wp-content/uploads/2011/04/chernobyl-elephants-foot.jpg

 

[.Scott]

Is that the actual elephants foot? I don't think so that kind of looks like it might be a turbine or something, and I thought no one EVER got that close to the "elephants foot" in person... I thought the only photo(s) they got of it was with a robot.

Robots couldn't hack it. They needed to use people.
Some modern robots are now able to tolerate the heat, radiation, and obstacles.