Chernobyl reactors 1-3


by Kutt
Tags: chernobyl, reactors
nikkkom
nikkkom is offline
#37
Feb3-13, 04:33 PM
P: 549
Quote Quote by a.ua. View Post
>> I would hazard to guess that Chernobyl's proportion of Cs-134/Cs-137 wasn't terribly different from Fuku.

No.
The ratio of cesium (134/137) in Chernobyl 0.65 - 0.7
In Fukushima 0.85- 0.9
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
Kutt is offline
#38
Feb3-13, 06:09 PM
P: 236
Quote Quote by nikkkom View Post
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 ;)
WOW!!! Even Wikipedia is afraid to talk about it?

Where can I find detailed info about MOX fuel in relation to Fukushima?
russ_watters
russ_watters is offline
#39
Feb3-13, 10:11 PM
Mentor
P: 22,001
Quote Quote by nikkkom View Post
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 ;)
[cough]
http://en.wikipedia.org/wiki/MOX_fuel
a.ua.
a.ua. is offline
#40
Feb4-13, 01:56 AM
P: 115
Quote Quote by nikkkom View Post
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.
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
Kutt is offline
#41
Feb4-13, 03:30 AM
P: 236
Quote Quote by a.ua. View Post
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.
How much contaminated radioactive material leaked from Fukushima and into the sea?
nikkkom
nikkkom is offline
#42
Feb4-13, 04:36 AM
P: 549
Quote Quote by a.ua. View Post
I think, 0.65 and 0.9 are different.
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
nikkkom is offline
#43
Feb4-13, 04:48 AM
P: 549
Quote Quote by Kutt View Post
How much contaminated radioactive material leaked from Fukushima and into the sea?
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.
a.ua. is offline
#44
Feb5-13, 05:54 PM
P: 115
Quote Quote by nikkkom View Post
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.
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.

That is the least problematic part of the Fukushima contamination. Pacific Ocean is *BIG*.
+1
Kutt
Kutt is offline
#45
Feb5-13, 07:02 PM
P: 236
Quote Quote by nikkkom View Post
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.
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
nikkkom is offline
#46
Feb6-13, 04:35 AM
P: 549
Quote Quote by Kutt View Post
Did any of the radioactive contamination from Fukushima reach the west coast of the United States across the pacific ocean via the prevailing winds?
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 :)

Quote Quote by Kutt View Post
I read that this radiation is not at high enough levels to be considered a health risk.

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
Kutt is offline
#47
Feb6-13, 04:25 PM
P: 236
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.
a.ua. is offline
#48
Feb12-13, 02:02 PM
P: 115
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.
a.ua. is offline
#49
Feb20-13, 11:05 AM
P: 115
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
LabratSR is offline
#50
Mar9-13, 03:50 PM
P: 173
Quote Quote by Kutt View Post
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?
http://www.tepco.co.jp/en/nu/fukushi...20130307-e.pdf


Also http://www.tepco.co.jp/en/nu/fukushi...20130225-e.pdf
nikkkom
nikkkom is offline
#51
Mar14-13, 12:48 PM
P: 549
I think first link has incorrect units: Sv/h, should be mSv/h.
a.ua.
a.ua. is offline
#52
Mar14-13, 01:57 PM
P: 115
microsieverts per hour
a.ua.
a.ua. is offline
#53
Jun2-13, 03:15 PM
P: 115
Maybe someone is interested

Project "New Safe Confinement Construction"


May 24, 2013

Within the NSC Project at the construction site the following works are being performed:
Assembly of the Arch metal structures (for 2nd lifting)
According to the design - 4,097 tons
3,720.63 tons (90.81%) performed
Installation of the Arch roof’s outer cladding:
Surface area of roof cladding before 2nd lifting - 13,952.2 м2.
Overall progress in the Arch outer cladding installation before 2nd lifting – 79%
And
* mounting of a crane (Terex Demag CC8800-1), with the aid of which soon will disassemble the vent pipe, which was one of the symbols of the Chernobyl nuclear power plant.


20 microsieverts where crane
Attached Thumbnails
????2136.jpg   ????2138.jpg  
zapperzero
zapperzero is offline
#54
Jul24-13, 09:14 AM
P: 1,030
Quote Quote by nikkkom View Post
The basements and ground floors of Chernobyl Unit 4 can be just filled with concrete, completely covering all corium and heavily contaminated structures; then the remaining structures on top can be dismantled. But that is way too CHEAP!
Again with the irresponsible suggestions? How could you ensure the integrity of the concrete? (don't answer, that's a rethorical question, you can't, not really). How do you plan to check that the corium is still there in 50 years' time? How do you deal with gasses? How do you deal with infiltrated water? (more rhetorical questions, you have no such plan because your thinking does not extend past the present day and CHEAP CHEAP CHEAP).

As expensive and nasty as it is, the corium must be recovered and accounted for, to the limits of what is possible, not to those of what is convenient.


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