Chernobyl reactors 1-3

nikkkom

MOX is a very dangerous chemical element #133 ;)
Even Wikipedia is afraid to have an article about it, don't try to find and read it there ;)

a.ua.

nikkkom
No.
The ratio of cesium (134/137) in Chernobyl 0.65 - 0.7
In Fukushima 0.85- 0.9
In this math is important initial figure. And she is very large.
As you can see in 2007 the level of gamma roof Shelter still great.
3 hours and dialed dose
The radiation level in the "Central Hall" is 12 Sv,
in some other places, there is a residual fuel 0.1 - 6 Sv

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nikkkom

What "no"? It is not too far from 1:1. Cs-134 in both cases was (in Fukushima, still is) a significant contribution to gamma fields.

Kutt

WOW!!! Even Wikipedia is afraid to talk about it?

Where can I find detailed info about MOX fuel in relation to Fukushima?

russ_watters

[cough]
http://en.wikipedia.org/wiki/MOX_fuel

a.ua.

I think, 0.65 and 0.9 are different.

Moreover, there are large differences in the size of the physical size of the particles of cesium.
In Fukushima plume they are minimal (removal in pairs).
They are more mobile and quickly washed away by rain into the sea.
In general, 15 years later, the situation with radiation in Fukushima exclusion zone will be much better than in Chernobyl.

Kutt

How much contaminated radioactive material leaked from Fukushima and into the sea?

nikkkom

Please learn to follow your own train of thought.

You asked me why I think Chernobyl needed to be cleaned up by about year 2000.

I explained to you that in my opinion the first 10 years could be reasonably used to "wait out" shorter-lived contaminants, and gave you an example of such contaminant, Cs-134, which is (a) volatile and thus a lot of it escaped, (b) abundant, and (c) half-life 2 years.

Why do you jump to Fukushima topic now?

Why do you bicker about exact Cs-137/134 ratio? It *isn't essential* to my argument whether it was 1:1 or 1:0.6, 1:0.6 still results in very significant gamma contribution from Cs-134!

nikkkom

That is the least problematic part of the Fukushima contamination. Pacific Ocean is *BIG*.

Measurements show that by now, all leaked contamination has been diluted far below the natural radioactivity level of seawater (10-15 Bq/l depending of the salinity), most of which comes from Potassium-40.

Japanese were lucky. Most of the time, wind was blowing Fukushima's gases and steam out to the ocean.

a.ua.

OK, I understand you.
Maybe I was a little boring, do not get angry.:)
However, they did start the second phase of the elimination in 2000,
But this is not the reduction of radiation levels.

+1

Kutt

Did any of the radioactive contamination from Fukushima reach the west coast of the United States across the pacific ocean via the prevailing winds?

I read that this radiation is not at high enough levels to be considered a health risk.

nikkkom

Sure! "Some" radioactive contamination from Fukushima exists even on the desk you are sitting at - regardless where that desk is.

In one gram of Cs-137 there are about 4400 billions of billions (4.4*10^21) of atoms. That's a HUGE number. Evenly distributed over surface of Earth, it is about 8.5 million atoms per every square meter.

Fukushima released way more than one gram of Cs-137.

I bet you wanted to ask a different question :)


Exactly. In US, Fukushima's contamination is WAY below levels of any detectable effect on health.

It is useful to remember a few numbers when you want to make sense of contamination levels.

Seawater's radioactivity is 10-15 Bq/L.

Human body, on average, contains 4000 Bq of K-40 radioactivity (that is, ~50 Bq/kg). And 1200 Bq of C-14.

There is an edible nut (some "Brazil nut") which has 444 Bq/kg. It is probably the upper end of what can be considered "natural levels of radioactivity in food". Useful when you read about e.g. the rules Japan now establishes for allowable activity in their food.

(Anyone knows what's an average natural soil radiation in Bq/m^2, and what is the typical variability depending on soil type?)

Kutt

Currently, what are the radiation readings at the Fukushima plant itself? Especially outside the shattered reactor buildings. Is it much higher than the Chernobyl exclusion zone?

a.ua.

Notice about abnormal situation

12.02.13. Partial failure of the wall slabs and light roof of the Unit 4 Turbine Hall occurred at 14.03 above non-maintained premises on the level 28.00 meters in the axes 50-52 from range A to rage B. The area of damage is about 600m2. This construction is not critical structure of the "Shelter" object.
There is no violation of limits and conditions of "Shelter" object safe operation in accordance with the technological regulations. There are no changes in radiation situation at ChNPP industrial site and in Exclusion zone. There were no.
http://www.chnpp.gov.ua/index.php?op...mid=11&lang=en

a.ua.

Work is being completed on clearing the in the local area "Shelter"



http://www.chnpp.gov.ua/index.php?op...mid=11&lang=ru


In addition

Today, on the 20 of February, were resumed the activities on assembling the NSC metal structures and Arch cladding, which are performed by personnel of Joint Venture “Novarka” within free access area. The “Novarka” management informed the SSE ChNPP about this in written form on February 19, 2013.
http://www.chnpp.gov.ua/index.php?op...11&lang=en

LabratSR

http://www.tepco.co.jp/en/nu/fukushi...20130307-e.pdf


Also http://www.tepco.co.jp/en/nu/fukushi...20130225-e.pdf

nikkkom

I think first link has incorrect units: Sv/h, should be mSv/h.