Japan earthquake - contamination & consequences outside Fukushima NPP

clancy688

I think that fits here better:

A discussion in another thread raised the question whether the Hiroshima and Nagasaki contaminations were worse or not.

I searched for the answer and found a very interesting document by the US military:

http://www.dtra.mil/documents/ntpr/r...ATR805512F.pdf

It's dealing with radiation doses for US occupational forces in late 1945 in Nagasaki. On page 58 they calculate surface contamination rates for several isotopes at a location one mile east of and 45 days after the blast. The location was shielded, so there's no neutron activation, only surface deposition.
They get 0.37 uCi/m², or ~14.000 Bq/m² Cs-137. In Fukushima, large areas are contaminated with 1.000.000 to 30.000.000 Bq/m² Cs-137...

Overall they get 340 uCi/m², which's around 13.000.000 Bq/m², but most of those isotopes are short living ones which are gone after 1-2 years.

So at least for me it looks like the Fukushima contamination is way worse than the Nagasaki bomb contamination. Apparently, the blast produced many short living fission products, but less long lived.

I think that's to be expected. A nuclear reactor's core load fissures over a period of months and creates a hundred or thousand times more energy a Nagasaki sized nuclear bomb releases during that interval.
Which means that there's a hundred or thousand times more fission products which accumulate, especially the long living ones.


But I'd still be interested in more documents regarding the surface contamination of Hiroshima and Nagasaki.


Btw: Don't know if it's been posted before, but the french report linked in the first post is available in english now.

http://www.irsn.fr/EN/news/Documents...H-23052011.pdf

Borek

Hardly surprising. If not for other reasons, compare mass of the bomb with mass of the fuel in the reactor.

clancy688

Apparently it was surprising for a certain user who should know better... that's why I posted it here... ^^;

clancy688

I have one question regarding the IRSN evaluation I posted:

Do I understand correctly, that most of the paper is only about the population which's outside the 20km zone?
So there are up to ~70.000 people outside the 20km zone who are in need of evacuation and ~85.000 people inside the 20km zone who have already been evacuated? All in all 110.000 to 150.000 people who'll lose their homes forever?

jlduh

Some days ago, there was a discussion on the forum about comparing the impacts between a majpr accident in a nuclear plant and any other industrial accident. I was saying that there is no other industrial accident that has a so big impact on social communities than a nuclear one (I'm talking about a big one like this one for example, which could have been much worse in fact, I think that even some professionals from nuke industry start to, hardly but finally i would say, recognize it -think of one or several completely explosed SFP with fuel thrown in the air and falling around, with all he domino effects to anticipate). Some people were arguing that chemical accident like Bhopal did more dead people immediatly than Fukushima, which is true if you consider the time factor.

But can you list one single other INDUSTRIAL accident that creates what you describe, currently 110 to 150 000 people losing their homes? I don't...

That's why in my mind, nuke industry is no way an industry like the others. The potential social impacts are too big.

clancy688

That's exactly why I'm confused... if you take a look at the LAST page of the paper, you'll find a comparison between Chernobyl and Fukushima.

They say there's an "inital evacuation zone at Chernobyl (30km, 135.000 people) and Fukushima (20km, 85.000 people).
And then there are "strictly controlled zones" or "evacuation zones" with 270.000 people at Chernobyl (that's the number they're often quoting in the text as being evacuated) and 70.000 at Fukushima (also often quoted).
It's my understanding now that those 135.000 and 85.000 from the "inital evacuation zones" do NOT include the numbers from the "strictly controlled zones".

They say the following on page 4:
My interpretation is that we're dealing with TWO zones, both at Chernobyl and Fukushima. The first one is a strict 30/20km perimeter which was evacuated IMMEADIATELY after the accident, regardless of actual radiation levels.
The second one is an extension of the first one based on actual radiation data. And while the first was evacuated within the first few days of the accidents, the second one was and will be evacuated over a course of months.
But both zones will stay off limits.

tsutsuji

table 1 page 18/28 (pdf page number 17 , http://www.irsn.fr/EN/news/Documents...H-23052011.pdf ) says that the 69,400 population figure applies to "Affected population (excluded the no-entry zone)".

Conversely, among the people already evacuated from the no-entry zone, those from the North and those between 15 and 20 km away in the South-West where the contamination is low should be able to go back home. So you should ultimately subtract that number from the total displaced population.

clancy688

Hm, let's do a "best case/worst case" calculation:

Let's say from those 70.000 mentioned in the report, only ~25.000 need to be evacuated (because the government tells <20mSv/a is still okay or something like this). In the 20km zone, the towns of Tomioka, Okuma, Futaba and Namie are probably in need of permanent abandonment. They have a total population of 55.000 people.

So the "best case" may be that 80.000 people lose their homes and the worst case 150.000.


Futaba District will probably nearly become a ghost district. Of all cities (total population: 75.000) only the villages of Kawauchi. Naraha and Hirono (only 17.000 people) lie outside the >1MBq/m² zone.

tsutsuji

Thank you for the link. I think the 0.5 μSv/h　spot centered in the North of Chiba prefecture, extending west on both sides of the Edogawa river could have a link with the 22 March water crisis when significant levels of contamination were found in the Kanamachi water purification plant, which takes water from the Edogawa.

SteveElbows

I am talking about reactor 2 releases on the main thread, and because this quickly gets into contamination issues I am following up something posted there in this thread instead:


Using SPEEDI wind data, Reactor 3 explosion-related stuff seems to go out into sea where I am not convinced they will have tried to estimate it properly. Reactor 1 plume prediction area strongly overlaps north-west area that is implicated in reactor 2 release, further complicating matters.

Strength of wind, height of release, timing of rain and snow all complicate things further. At the moment if we assume reactor 2 is largely to blame, then one possible explanation is that initial release that went south spread out over a very wide area, hence no intense concentrations of contamination to the south, it dispersed much more widely. Then in the afternoon when wind direction shifted so that stuff went north-west, rain/snow timing caused large concentrations of this stuff to fall in a smaller area.

Either that or the quantity of radioactive substances released increased well after the explosive event of the 15th. On site radiation readings show around 3mSv during reactor 2 venting after 9pm on the 14th March, and then falling levels. After 6am 15th explosion the levels start to climb again, with highs of 8mSv at 8.31am and 11mSv at 9am. Levels go back up again to values such as 8mSv late on the 15th and also several highs on the 16th, with official reports blame both reactor 2 & reactor 3 for the march 16th releases. From what I can tell from SPEEDI & site wind info, we are looking at a period of roughly 1pm 15th->1am 16th (SPEEDI) or 12 noon 15th->11pm 15th (Site data) that the wind is blowing in a direction that would cause contamination to the north west.

There are also unknowns about how much of March 15th radiation on site & beyond may have been caused by events occuring at reactor building 4 on the same day, although subsequent evidence that 4 spent fuel damage may not be great might help us somewhat rule out 4 as a large factor.

QuantumPion

There was a coal mine fire in 1962 in Centralia, Pennsylvania. All of the residents had to leave due to the area being unstable and dangerous. It is still burning to this day, rendering the area off-limits, and is expected to continue for 250-1000 years.

http://en.wikipedia.org/wiki/Centralia,_Pennsylvania

Luca Bevil

1.000 evacuees according to wikipedia, , with quite some time to realise the health danger, quite difficult to compare with either Chernobyl or Fukushima consequences.

I do not think anyone thinks that no-other energy related human endeavours can lead to very serious accidents, but I still have to find worst case scenarios and real accidents that are of a comparable scale.

SteveElbows

Try the Bhopal disaster.

clancy688

...

We had that discussion a while ago. http://physicsforums.com/showthread.php?t=486089

Starts at post #237


Basic statement for Bhopal: High death toll came into being because the plant was right in the middle of a slum. Population in a radius up to 1km around the plant was 100.000 people. No wonder they get thousands of deaths if something blows up. Still it didn't contaminate half of the district as happened in Chernobyl and Fukushima. Today there are people living around the Bhopal plant. There won't be people living near Fukushima or Chernobyl for the next hundred years.

Luca Bevil

Yep. Quoted 100 %.
BTW, Steve my thanks for your painstaking efforts in the main 3d.
Great work no matter what the reliability of the underlying data was.

Gary7

Arnie Gundersen is again the darling of the conspiracy theorists due to his recent video claiming residents of Tokyo were breathing in 10 "hot particles" per day during April. He is also claiming that residents of Seattle were breathing in from 5 to 10 hot particles as well. Fukushima residents were apparently breathing in 30x as many hot particles.

He also drags out another factoid; that residents of Japan are tasting a "metallic taste" which is indicative of radioactive contamination.

I no longer know what to think about Arnie. Earlier on in the disaster, I found his discussion to be be very digestible and credible, but as time goes on I'm really concerned because he seems to be getting his information from some of the alternative news web sites, and it seems he is no longer looking at things with any objectivity. He bought the "Leaning Reactor #4" story hook, line, and sinker. He's now regurgitating the metallic taste myth, even though this has never been reported in Japan. Regarding the hot particle story, he says his information comes from "scientists using air filters".

Do any of the physicists here have an opinion on this hot particle story. Is it credible? Is it a worry? Tokyo and its environs has about 30 million people in it - me being one of them. Are we all breathing in 300+ hot particles, and if so, is there any meaning in this?

zapperzero

What's this hot particle thing? I thought exposure was measured in Sievert?