How did this worker approach this fuel mass at Chernobyl?

[SteamKing]

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

Picture not apparent. Linked to some hipster music site.

 

[nikkkom]

Google for images "Chernobyl elephant foot" if you want to see it.

 

[KeenJane]

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.

"Doesn't matter, got the shot!" The photographer in me would be super excited.

 

[Warpspeed13]

Hmmm I believe the word I'm looking for is expendable.

 

[Morbius]

Off-topic, but how do roentgens convert to rads? Which unit is greater?

Kutt,

They don't! Roentgens and rads are units for two DIFFERENT quantities. It's like asking how do meters convert to kilograms and which unit is greater.

Roentgens are a unit of of ionizing radiation; an amount that liberates one esu ( electro-static unit of charge ) per cubic centimeter.

A Rad is a unit of absorbed dose. You need to specify what material is absorbing the radiation. A rad was originally defined as 100 ergs of absorbed dose energy per gm of material. The rad has been superceded by the SI unit "Gray" which equals 1 Joule absorbed dose per kilogram.

 

[Paterick Meyer]

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

No, they diddn't...

 

[YvesSch]

Just to be clear the "abnormalities" of this photo:

are NOT due to the radiation. This is a completely normal photographic artifact, caused by a low shutter speed and a shaky camera. The radiation most certainly did not cause "the lower half of the worker to appear transparent

Reference https://www.physicsforums.com/threa...-approach-this-fuel-mass-at-chernobyl.672660/".

 

[IceIceDeadBabies]

wow this is a great forum! esp the talk about contamination and radiation! lol I just have a question about the video of the guys going into the sarcophagus, at the end of the video he is filming what looks like the top of the blown sideways reactor core, cause that's what it looks like?! thanks jim hardy and all who posted, and as for the two people picture, their is literally no distortion / grain look to the film beside the guy obv... So how is that possible?? Not radiation that's how.lol. keep the videos of chernobly coming i can't get enough. and thanks again to all i know this all started 3 years ago!.

 

[Aufbauwerk 2045]

http://chernobylgallery.com/chernobyl-disaster/radiation-levels/

http://www.csmonitor.com/World/Glob...t-least-3-000-years-say-nuclear-experts-video

The town of Pripyat was ordered evacuated. Obviously the Soviets had to explain why.

From the above article: "Asked when the reactor site would again become inhabitable, Ihor Gramotkin, director of the Chernobyl power plant, replies 'At least 20,000 years.'"See the documentary Chernobyl Uncensored.

Here someone finds a fuel fragment.

 

[Aufbauwerk 2045]

This is not the same situation, but interesting, particularly if you live in Utah.

http://www.deseretnews.com/article/250010322/Toxic-Utah-A-land-littered-with-poisons.html

 

[mheslep]

From the above article: "Asked when the reactor site would again become inhabitable, Ihor Gramotkin, director of the Chernobyl power plant, replies 'At least 20,000 years.'"

Perhaps so, with no remediation, no cleanup. But radiation levels will have fallen suffciently to allow an effective cleanup in 300 years, with today's technology.

 

[nikkkom]

From the above article: "Asked when the reactor site would again become inhabitable, Ihor Gramotkin, director of the Chernobyl power plant, replies 'At least 20,000 years.'"

Well, the "the reactor site" per se is a rather small area, maybe 1x1 kilometer. Of course it is heavily contaminated - it has many tons of formerly molten spent nuclear fuel and burnt reactor graphite in it, not to mention other material. That sort of material is not something which decays to safe radiation levels in "only" a few centuries.

But apart from that small area, the remaining lands around the plant (which are vastly larger in area) are much better off: almost all radiation there is due to Cs-137 and Sr-90. Basically, every passed 30 years will be halving radiation levels.

 

[mheslep]

Well, the "the reactor site" per se is a rather small area, maybe 1x1 kilometer. Of course it is heavily contaminated - it has many tons of formerly molten spent nuclear fuel and burnt reactor graphite in it, not to mention other material. That sort of material is not something which decays to safe radiation levels in "only" a few centuries.

Not safe to live beside, but once the fission products have decayed away the remaining actinide alpha emitters should be at levels (100X that of uranium ore) where disposal and site mitigation is feasible.

 

[nikkkom]

Not safe to live beside, but once the fission products have decayed away the remaining actinide alpha emitters should be at levels (100X that of uranium ore) where disposal and site mitigation is feasible.

There were 190 tons of fuel in the reactor. Roughly 0.5% of that was plutonium, almost entirely Pu239 and Pu240, half-lives of 24110 years and 6561 years. A few centuries don't change much for these isotopes' activity. It's way more radioactive than "100X that of uranium ore". More like "100000X that of uranium ore".

About a **metric ton** of that stuff, melted, oxidized, pulverized into dust, formed compounds with all kinds of other materials, is seriously not something anyone would enjoy having to clean up.

 

[mheslep]

There were 190 tons of fuel in the reactor. Roughly 0.5% of that was plutonium, almost entirely Pu239 and Pu240, half-lives of 24110 years and 6561 years. A few centuries don't change much for these isotopes' activity. It's way more radioactive than "100X that of uranium ore". More like "100000X that of uranium ore".

Depends on what "it" refers to. One gram of U ore vs one gram of Pu, yes, the Pu is more radioactive. But this is not the relative comparison for sake of clean up, which is, say, 100 tons of U ore vs 100 tons of Chernobyl reactor melt mass.

Dust reduction recelves attention in Uranium mining per sources like the WNA. I imagine accident cleanup would receive similar attention.

 

[etudiant]

So in under 10,000 years, we'll be back to normal, assuming living with uranium ore is normal.

Separately, does the plutonium get shielded to some extent by the surrounding uranium in the elephants foot?
Otherwise, even years after the accident it is surprising the worker could be so close to corium mass. Is all that residual radiation alpha particles?

 

[nikkkom]

So in under 10,000 years, we'll be back to normal, assuming living with uranium ore is normal.

Separately, does the plutonium get shielded to some extent by the surrounding uranium in the elephants foot?

Pu239 and Pu240 are alpha-active. They are shielded even by air. The worker appears to wear protection which ensures he does not get any dust contamination on/in his body, so his main worries in this situation are gammas.

 

[nikkkom]

The diagram is for waste from spent fuel reprocessing. Reprocessing (at least its type now actively in use by French) removes Uranium _and Plutonium_, thus diagram's "actinades" [sic] probably excludes Pu.

 

[mheslep]

The diagram is for waste from spent fuel reprocessing. Reprocessing (at least its type now actively in use by French) removes Uranium _and Plutonium_, thus diagram's "actinades" [sic] probably excludes Pu.

Yes I believe you are correct. Sorry about that.

 

[ThomasGeorgeAlan]

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...

View attachment 159172

This isn't due to radiation emission this is basic long exposure photography in low light the technician is illuminating the subject whilst the camera takes a long exposure, I see no visible influence on the film from the elephants foot

 

[franklyamazed]

I would just add a few comments to the interesting discussion...

Firstly, the ghosting in the photograph is due to a long exposure (long open shutter time) used to get a brighter clearer photograph in low light conditions. The figure moved from upright to bending forward (or vice-versa) but spent longer leaning forwards during the photograph which is why that ghost image is clearer and the hat appears blue in colour. If you wish to see scary effects then watch the early video captured of the accident where you can witness bright beta/gamma flashes randomly bursting onto the film, and some shots fade to grey from the amount of alpha waves being absorbed by the film.Secondly, when the ghost person moved they also moved the torchlight they are holding. The path of the torch appears as the squiggle and that squiggle is also reflected in the water pooled on the floor (a reflection). It is likely they were moving the torch to spread light across the exposure, and this is why the photograph is so strangely lit.

There very well maybe nuclear aberations captured in the photograph, but I cannot spot anything distinctive.

It surprised scientists that the 'Elephant's Foot' had a VERY high close proximity radiation reading and a VERY low reading one metre away, I believe it was a thousand times less, though I cannot find the source I referenced that from at the moment. Yes, it is notable that it is Corium, but very strange Corium, with a strange composition, decaying unpredictably. Based on that knowledge, the ghost got a lot more exposure than the photographer.

Thirdly, when the accident initially happened a lot of people were over-exposed to radiation, the workers in the main cooling pump room, one manager in the turbine hall (who prevented the other electricians from going closer), the control room staff, the firemen who attended what they falsely believed to be a fire, and was more likely an open nuclear reaction, some local fishermen fishing the cooling ponds, and anyone openly observing the accident without protection.

Once the Soviets accepted and understood that the reactor was breached they took scientific advice about personal exposure limits. Having said that, it is likely that they set limits way higher than anywhere else would have been likely to, and appeared to use conscripted people to do work as "ordered', so I am uncertain about 'Heroic Actions', and simple do not know how many people participated in the clear up operations and subsequent building of the sarcophagus of their free will, or were they under orders?

They used about 4,000 people to clear the roof, the idea was simply to allow one to two minutes of exposure each. Most of these people seem unscathed by the exposure, and one of the greatest lessons learned from the accident seems to be that the human body is really more resilient to radiation than previously understood. The people left in Pripyat for 36 hours too long seem to have suffered many biological side effects of that overstay.

In fact, studies have shown that the deeper and more serious side effects were psychological. Many involved in the incident went on to have a kind of deathwish mentality, drinking and smoking too much because they believed they were doomed from the radiation exposure, and died from lung cancer or liver damage due to those excesses. It is possible that a good percentage of Worldwide cancer death has been caused by Chernobyl but that data is also likely to be even higher from the dispersed inventory of nuclear weapons testing of the last century.

The human body can repair radiation damage, we are incredibly regenerative, we have evolved on a radioactive planet, but there are limits to how much damage we can sustain and how quickly we can repair it. When those limits are breached we become ill, and when severely breached we die. We are more susceptible to certain radioactive nuclides, such as Iodine 131 because it can accumulate in our thyroid glands and tissue. It is a sophisticated subject and I am oversimplifying it.

Fourthly, I beieve that the greatest unknowns about the Chernobyl accident are the exact cause and mechanism of the explosions, the makeup of the core inventory, and where that core inventory is now. How much of the core uranium was burned up, how much fuel was new, how much plutonium was present, is it possible that the poisoned reactor actually started to superbreed plutonium? The reactivity of that core on that night was staggering.

I suspect that there may be much less of the core left in the 'core' than anyone thinks. I would really enjoy reading a discussion about how much of core could have simply vapourised, scientists suggested that the spread of radiation across the World was from steam, whereas I suspect that the majority of the core inventory was substantially vapourised into the atmosphere, and that there is a lot less left in block 4 than we think.

I look forward to your views and the ongoing discussion!