Nuclear accident follows Japanese earthqauke

biffvernon · Post by **biffvernon** » 21 Apr 2011, 11:54

foodimista wrote:What do they know that they aren't letting on about?

80,000 livelihood ruined.

This is what they are telling us:

http://atmc.jp/

Ippoippo · Post by **Ippoippo** » 21 Apr 2011, 12:18

Does anyone know where I can get a map of background radiation levels for the UK.
Interested in doing a comparison of UK with Japan (pre-tsunami and post-tsunami)

Post by **clv101** » 21 Apr 2011, 12:31

Ippoippo wrote:Does anyone know where I can get a map of background radiation levels for the UK.
Interested in doing a comparison of UK with Japan (pre-tsunami and post-tsunami)

Some data here:
http://archive.defra.gov.uk/evidence/st ... dradon.htm

An average of 1.3 mSv per year (0.15 uSv/hr) with some areas 10x that.

This Nature paper estimates average UK natural exposure is 2.5 mSv/yr (0.29 uSv/hr). The average dose in Cornwall is ~3x higher at 7.8 mSv/yr (0.9 uSv/hr) with some areas at over 20 mSv/yr (2.3 uSv/hr).

Ippoippo · Post by **Ippoippo** » 21 Apr 2011, 12:48

clv101 wrote:
Ippoippo wrote:Does anyone know where I can get a map of background radiation levels for the UK.
Interested in doing a comparison of UK with Japan (pre-tsunami and post-tsunami)
Some data here:
http://archive.defra.gov.uk/evidence/st ... dradon.htm

An average of 1.3 mSv per year (0.15 uSv/hr) with some areas 10x that.

This Nature paper estimates average UK natural exposure is 2.5 mSv/yr (0.29 uSv/hr). The average dose in Cornwall is ~3x higher at 7.8 mSv/yr (0.9 uSv/hr) with some areas at over 20 mSv/yr (2.3 uSv/hr).

Are the statistics only for radon derived radiation, or is it other sources as well (but radon is the primary contributor)? Ahh, looks like the Nature one takes into account other things??

EDIT: Ignore me, reading it now. Cheers for the links

Post by **clv101** » 21 Apr 2011, 14:29

I hadn't seen this before:

From: http://www.economist.com/blogs/dailycha ... _accidents

biffvernon · Post by **biffvernon** » 22 Apr 2011, 10:21

Evacuation area extended to include areas to north-west where hogher levels of radioactivity have been measured.

http://www3.nhk.or.jp/daily/english/22_20.html

The Japanese government has announced the official expansion of the evacuation zone around the troubled Fukushima Daiichi nuclear power plant to selected areas beyond the existing 20-kilometer radius. Residents of the new areas are being asked to evacuate by the end of May.

Chief Cabinet Secretary Yukio Edano said on Friday that the government made the designation since residents there could be exposed to cumulative radiation levels of 20 millisieverts or more per year if they stay.

So 20mSv/year is the new evacuation threshold.

biffvernon · Post by **biffvernon** » 22 Apr 2011, 10:29

An unexpected, sad consequence of nuclear accidents:

http://www.yomiuri.co.jp/dy/national/T110421006295.htm

This probably wouldn't happen if a wind turbine blade fell off.

2 As and a B · Post by **2 As and a B** » 22 Apr 2011, 12:08

biffvernon wrote:Evacuation area extended to include areas to north-west where hogher levels of radioactivity have been measured.

http://www3.nhk.or.jp/daily/english/22_20.html

The Japanese government has announced the official expansion of the evacuation zone around the troubled Fukushima Daiichi nuclear power plant to selected areas beyond the existing 20-kilometer radius. Residents of the new areas are being asked to evacuate by the end of May.

Chief Cabinet Secretary Yukio Edano said on Friday that the government made the designation since residents there could be exposed to cumulative radiation levels of 20 millisieverts or more per year if they stay.
So 20mSv/year is the new evacuation threshold.

Looks suspiciously like a plume of radiation from those southerly winds.

Edano also designated parts of areas within 20 to 30 kilometers of the plant as areas in which residents should remain indoors or be prepared to evacuate at any time in case of an emergency.

With this designation, the government lifted an earlier instruction to stay indoors for people in the 20- to 30-kilometer zone.

What possible emergency could there be now? Everything is being brought under control isn't it?

- - - - -

Any news about the other Fukushima site? Will that be abandoned now, or will men in radiation-protection suits continue to operate it? What a vision of the future!

Ippoippo · Post by **Ippoippo** » 22 Apr 2011, 23:23

biffvernon wrote:
So 20mSv/year is the new evacuation threshold.

Reading Japan Today (http://www.japantoday.com/category/nati ... lear-plant), I saw....

He said there is a possibility of residents of the five municipalities receiving a dose of 20 millisieverts during the course of a year, even if they live outside the no-go zone.

The International Atomic Energy Agency recommends that the highest planned residual radiation over one year should be in the range of 20 to 100 millisieverts in an emergency.

So, they are suggesting 20mS/yr, yet IAEA is suggesting a max bound of between 20 to 100? That's quite a significant range of values and suggests the government are being quite cautious. (As has been seen already with the info and advice coming out when water was affected with Iodine in Chiba and Tokyo).

biffvernon · Post by **biffvernon** » 23 Apr 2011, 08:20

100mSv/year was the limit for workers in the industry until they found that wouldn't work and moved the goalposts to 250mSv/yr.

Whether you consider the Japanese government as cautious or reckless probably hinges on whether you think that there is a threshold below which there is zero harm or whether harm decline is linear all the way to zero exposure. The difference is one of thousands of excess deaths.

Ippoippo · Post by **Ippoippo** » 23 Apr 2011, 13:22

Hmmm, interesting.
If we go with 20mSv/year, that's 2.283 microSv/hour (if my maths is correct).

I'm looking at http://radiationmap.duostack.net/ (which gets it's data from Fukushima prefecture government). (Data from 23 April 11:50 local time)

Places like Iwaki, Shirakawa, Minanmisoma are quite elevated compared to normal (ranging from 0.53 to 0.77) but I think lower compared to the background levels you get in Cornwall.
However, Kouriyama (a larger town) is up at 2.17 and close to that 2.283 figure. Fukushima city itself has exceed that magic number! (Not good, have a friend living there).

I'm also trying to get a translation of some Japanese TV that's being shown on a english language Japan blog I read. (http://www.japanprobe.com/2011/04/23/te ... n+Probe%29)

Watching it though, I can see some rather pee'd off folks. Body language tells me enough without a thorough translation. 1.15 in, the TEPCO boss meets the Fukushima prefecture mayor. TEPCO boss bows rather deeply... mayor barely manages a head nod. Translation.... F$%K YOU!

biffvernon · Post by **biffvernon** » 23 Apr 2011, 15:28

Yes I think your maths is correct. It's hard to get your head around converting millisieverts per year to microsieverts per hour so I made a little one or two sig. fig. ready reckoner:

mSv/yr~mSv/hr~μSv/hr
1~~~~0.00~~~~0.1 Backgroundish
2~~~~0.00~~~~0.2
5~~~~0.00~~~~0.6
10~~~0.00 ~~~~1
20~~~0.00 ~~~~2 Evacuate the area - you don't want to live there
100~~0.01~~~~10 Nuclear industry workers' allowable amount per year
200~~0.02~~~~20
250~~0.03~~~~30 Nuclear industry workers' allowable amount per year after they moved the goal posts
1000~0.11~~~~100
5000~0.57~~~~600
10000~1.14~~~1000 You'd get the workers annual allowable amount in just one hour

Here's a map:

Red squares show locations above 19 μSv/h

You really, really don't want to live there.

And I'm pretty sure those measurements were taken before it rained last Tuesday.

biffvernon · Post by **biffvernon** » 23 Apr 2011, 20:51

And this contains another couple of interesting numbers:

The operator of the damaged Fukushima Daiichi nuclear power plant says that concrete debris emitting a high level of radiation has been found near the Number 3 reactor.

Tokyo Electric Power Company, or TEPCO, says its workers detected radioactivity of 900 millisieverts per hour being emitted from a 30-by-30 centimeter concrete fragment, 5 centimeters thick, on Wednesday.

The workers were using heavy equipment to remove rubble near the electrical switchyard.

TEPCO says the workers were exposed to 3.17 millisieverts of radiation during the clean-up and the concrete block has been stored safely in a container with other debris.

http://www3.nhk.or.jp/daily/english/24_01.html

900 mSv/hr is a lot more than concrete is capable of producing. This was contaminated with something out of the core. My little ready reckoner needs to be extended by two orders of magnitude!

biffvernon · Post by **biffvernon** » 24 Apr 2011, 08:34

Slowly, reality leaks out:

Trillion becquerels of radioactivity released into the atmosphere last 154 day ...

http://www.yomiuri.co.jp/science/news/2 ... from=main7

biffvernon · Post by **biffvernon** » 24 Apr 2011, 18:10

And today we have news of more highly radioative material scattered about:

Radiation levels around the Number 3 reactor building, which was damaged by a powerful hydrogen explosion, are higher than in other locations, and 300 millisieverts per hour of radiation was detected in debris on a nearby mountainside.

Work started on April 6th to remove contaminated rubble, which had been obstructing the restoration process.

TEPCO says much of the debris around the former office building has been removed, and it has started clearing the rubble around the Number 3 and Number 4 reactors.

Enough debris has been removed to fill 50 containers, and it is being kept in a field on the mountainside.

The radiation levels one meter away are 1 to 2 millisieverts per hour.
Sunday, April 24, 2011 22:32 +0900 (JST)

http://www3.nhk.or.jp/daily/english/24_17.html

300mSv/hr is not what you need to stand close to for long.