I read this 9gag post (Okay, 9gag isn't really reliable for facts), where it says :

enter image description here

I then checked it at Wikipedia (Again, not the most reliable, really, but it does the job when necessary), and found out that it became a "dump site" for radioactive material.

Is it true that you would die by being near the lake for an hour, or any other short amount of time?

  • 1
    It's easy to find sites other than 9GAG, e.g. The Daily Mail, which also make this claim.
    – ChrisW
    Nov 4, 2014 at 10:45
  • 20
    I would trust 9gag over the DM.
    – Jamiec
    Nov 4, 2014 at 11:16
  • 3
    On that subject, I would trust Wikipedia over almost anything else. Every general-purpose source of information, certainly. It’s repeatedly been shown to be more reliable than any other such source. Nov 4, 2014 at 11:49
  • In another question I complained that if a poster only on exists on 9gag then perhaps it's only a joke, and not a real claim-to-be-factual. So I Google for this one, and it does also exist in newspapers et. al., IOW it is an actual claim.
    – ChrisW
    Nov 4, 2014 at 13:44
  • Wikipedia is claiming 600 roentgens/hour which means that if someone can find a secondary source this should be a fairly easy question to answer.
    – rjzii
    Nov 4, 2014 at 16:50

2 Answers 2



This claim is probably too broad and the information is outdated, but the general idea is correct. A quick search revealed a few relevant details:

From Atlas Obscura:

According to the Natural Resources Defense Council, the lake is so polluted that its waters will kill a human within an hour.

From Basement Geographer (which is referencing a broken link):

spending just an hour on its shores would result in certain death

Also, from the Wikipedia article

The radiation level in the region near where radioactive effluent is discharged into the lake was 600 röntgens per hour (approximately 6 Sv/h) in 1990

According to Basement Geographer, the last reactor in the area closed in 1990, so the radiation will only have gone down since then. Also, I didn't see any information as to the radiation levels any place other than where the radioactive waste enters the lake. As such, I don't know what the current levels of radiation are at various places around and in the lake.

Something else to consider is how good water is at stopping radiation. According to the XKCD What-If blog,

For the kinds of radiation coming off spent nuclear fuel, every 7 centimeters of water cuts the amount of radiation in half.

Of course, Randall looked at a scenario where the radioactive material is not mixed with the water. In Lake Karachay the radioactive material is not contained, but the radiation from the material at or near the bottom of the lake would not reach you unless you were underwater. If all (or at least most) of the radioactive material has settled to the bottom in the decades since they stopped dumping waste into the lake, then it might actually be safe to float in the middle of the lake (getting past the radioactive shores would still be a problem, however).

So other than going to Lake Karachay with a geiger counter, we can't know for sure whether or not there are areas where the radiation levels are safe. There is a lot of radioactive material there, so it is almost certain that there are parts of the lake or the area around it where you could receive a lethal dose of radiation within hours.

In any case, the lake in the picture looks like a fine place to visit - the healthy trees, the size of the lake, and the island (see Basement Geographer for satellite image of the lake) make it obvious that that isn't a picture of Lake Karachay. It is actually Phantom Ship, an island in Crater Lake, Oregon, USA. [Hat tip: @ChrisW]. This photo of the lake appears to be the original (or at least derived from the same source):

enter image description here

  • 7
    The picture seems to be of Phantom Ship island, in Crater Lake, Oregon, USA.
    – ChrisW
    Nov 4, 2014 at 20:24
  • 1
    @ChrisW: Good spot. This list (or one like it) may be the source of the confusion between photos.
    – Oddthinking
    Nov 5, 2014 at 3:11
  • 1
    Actual photos are few and far between because access to this location is restricted, however these appear to be the real photos, appearing in multiple articles and consistent with the fact that the lake was filled to restrict sediment movement: one, two
    – RomanSt
    Nov 10, 2014 at 21:40

It was true in 1990 (narrowly true, not true "everywhere").

On page 10 of this PDF (which has "page 519" printed in the header of the page), which is on the Natural Resources Defense Council web site, it confirms 600 roentgens per hour (death in one hour), citing a (presumably Russian) document titled Practical rehabilitation of territories contaminated as a result of implementation of nuclear material production defense.

That's at a specific place (where the effluent is discharged into the lake).

The same paragraph suggests that radiation levels are less elsewhere on the shore (e.g. 20 rems/hour), and fall quickly as you move away from the lake shore (e.g. 600 mrem/hour at 10 metres from the lake shore).

The next page says they that were covering the lake with concrete and emptying it of water in 1991, and expecting to finish doing that by 1995.

The Soviet Union "collapsed" in about 1991.

However Overview of Dose Assessment Developments and the Health of Riverside Residents Close to the “Mayak” PA Facilities, Russia, which is dated 2009, says,

Plans exist to fill in and cap R9 [i.e. Lake Karachay] with hollow concrete blocks, gravel, and soil and clay layers in an effort to stabilise the site and stop the groundwater contamination plume. Only partial infilling is believed to have occurred to date.

Given how much the dose varied at its peak I expect that even "partial infilling" will have made an orders-of-magnitude difference to the 'peak' exposure levels.

  • Do you know if they actually did drain the lake? According to Google maps' satellite images there is currently water in the lake.
    – Rob Watts
    Nov 5, 2014 at 3:45
  • @RobWatts: Concreting it then allowing it to refill would perhaps make more sense than leaving it empty.
    – Ken Y-N
    Nov 5, 2014 at 4:21
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    @RobWatts Towards the end of the article titled IN SOVIET RUSSIA, LAKE CONTAMINATES YOU, the author wrote (in 2008), "The surface of Lake Karachay is now made up of more concrete than water, however the lake's payload of fission products is not completely captive. Recent surveys have detected gamma-emitting elements in nearby rivers, indicating that undesirable isotopes have been seeping into the water table." It also says, "In 1990, as the Soviet Union teetered at the brink of collapse ...", so perhaps the planned ...
    – ChrisW
    Nov 5, 2014 at 13:28
  • ... work didn't go according to schedule, but I don't know.
    – ChrisW
    Nov 5, 2014 at 13:28
  • @KenY-N The 'lake' is a marshy area which was originally chosen as a nuclear dump site because it doesn't have any water flowing out of it (not supposed to have water flowing out of it; some radioactivity is leaking into the ground water).
    – ChrisW
    Nov 6, 2014 at 11:38

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