Chernobyl reactors 1-3

Shisnu

I'm not sure what you're getting at, from what I understand, the new sarcophagus is designed to correct the problems you have mentioned.

I'm not concerned with your comments such as "billions stolen", as they don't really add anything to the discussion and I'm only interested in the science and the engineering. All I've been trying to say is that I think the best decommissioning plan would be to use this new sarcophagus to contain any airborne contamination whilst the high-level waste is moved to a new site specifically designed to prevent further contamination. In my view this would allow for the greatest remediation of nuclear contamination in the Chernobyl area.

Also please note that my comments about generalisations and ill-informed opinions were not necessarily directed at you in particular. I believe I gave an example of what I was talking about in my previous post.

I think we can at least agree that the handling of the Chernobyl disaster area has always been, and still is, far from ideal?

a.ua.

Shisnu
Sometimes, when a strong wind they spin and it seems that the work continues.

If it were not severe pollution (especially actinides) mechanisms to be dismantled Metal scrap.

winnie_t

kutt,

can i ask where is that image from?

nikkkom

I'm saying that from the Ukrainian citizens' POV, the Chernobyl cleanup saga needs to finish (I would say it had to be finished by about 2000). It's *their taxes* being squandered there.

In a theoretical world where all involved parties honestly want to clean up this mess and be done - yes.

Yes.

a.ua.

nikkkom
Why this time, why not 2016 or 1995?
Or any other time.

nikkkom

During the first few years after the disaster radioactivity, and accompanied dangers to workers' health, is decreasing noticeably.

For example, initially Cs-134 constitutes about half of radioactive Cs inventory (the other half is Cs-137), but its half-life is only 2 years. It makes sense to wait for it to decay. In 10 years, it will decay to 1/64 of initial level.

After ~10 years, waiting more stops making sense.

It's not just Cs-134. See attached file. After 10 years, radioactivity decrease of fission products has a plato. While weathering of ruins doesn't.

Attached Thumbnails

 

Kutt

Sorry, I tried searching but for some reason I can't find it now.

But here's this picture of a mutant tree just outside of the reactor.

nikkkom

No, it isn't a mutated tree. The tree is even older than Chernobyl NPP.

Kutt

Oh, I thought that tree grew around high levels of radiation and thus was deformed.

Aren't the trees in the "red forest" outside of Chernobyl highly irradiated and malformed, and the trees turned red after the disaster?

a.ua.

nikkkom
In fact, the contribution of cesium 134 is not big enough.
And at the time, and now, the bulk of radiation from strontium and cesium 137.(and cerium in the past)
Besides alpha emitters are the big problem.
They have a very long half life.
70 - 100 years It is safest to wait

winnie_t

yes I would guess that's mutated. Didn't some pine needles grew up too 4.5cm.
Amazing pictures!

(and thanks kurt for the searching. you have any more interesting picture?)

winnie_t

as we are talking about the radioactivity, I wonder if it would differ at various height? would there be any data on how it vary as it goes higher into the atmosphere?

nikkkom

I don't think so (unless you mean "...in Chernobyl today").

In Fukushima plume, Cs-134 activity was almost exactly the same as Cs-137 at the beginning. Waiting it out cuts gamma exposure in half.

I would hazard to guess that Chernobyl's proportion of Cs-134/Cs-137 wasn't terribly different from Fuku.

If we are talking specifically about health of today's Chernobyl Unit 4 cleanup workers, then no. Alpha and beta emitters can be counteracted with careful dust control. Gamma can't be.

Kutt

Many of the radionuclides dispersed from Chernobyl and Fukashima have half-lives of tens of thousands of years.

Uranium and Plutonium are just two of them.

Shisnu

It's worth pointing out that if a radionuclide has a very long half life, then it isn't very active, and therefore isn't as dangerous ;)

nikkkom

In fact, there are only a few radionuclides which are volatile enough to spread far and wide after meltdowns. The rest are less volatile.

Google for Chernobyl fallout maps. You will see that Cs-137 contamination area is the largest, next is Sr-90, and it is much smaller.

Plutonium and americium are much smaller still, to the point that you can ignore them: any place with significant plutonium contamination will have A LOT of Cs-137 and be uninhabitable because of that alone.

Kutt

What about MOX fuel, one of the Fuku reactors contained MOX. Apparently it is supposed to be more dangerous than plutonium.