Environment & Energy

wtmusic

(39,166 posts) Wed Mar 6, 2013, 11:40 AM Mar 2013

Aerial survey finds contamination "significantly reduced" at Fukushima

"The latest aerial survey of the Fukushima region reveals a pattern of contamination significantly reduced in the space of a year by natural processes of radioactive decay and dispersal.

The Ministry of Education, Culture, Sports, Science and Technology (MEXT) released the latest map on 1 March, based on data collected by a survey during October and December last year. Compared to the version from October and November 2011 it shows widespread recolouring, with each colour change indicating a reduction by half in surveyed radiation dose.

Most obvious is a marked reduction in the size of the red portion, which represents high radiation dose rates of over 19.0 microSieverts per hour (uSv/h) - some 166 milliSieverts per year (mSv/y). Anything above 50 mSv/y is characterised as 'difficult to return to' by Japanese authorities. "

http://www.world-nuclear-news.org/RS_Radiation_declines_at_Fukushima_0603131.html

4 replies

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Aerial survey finds contamination "significantly reduced" at Fukushima (Original Post) wtmusic Mar 2013 OP

Not much of a surprise FBaggins Mar 2013 #1

BioAccumulation - Cesium 5,100 times safe level found in fish (Feb 2013) kristopher Mar 2013 #2

So? BioAccumulation is not the same thing as bio-multiplication. FBaggins Mar 2013 #4

levels almost half the "difficult to return" to area extend 20+km away CreekDog Mar 2013 #3

FBaggins

(26,748 posts)

1. Not much of a surprise

Reply to wtmusic (Original post)

Wed Mar 6, 2013, 03:19 PM

Mar 2013

There are some physical constants involved.

kristopher

(29,798 posts)

2. BioAccumulation - Cesium 5,100 times safe level found in fish (Feb 2013)

Reply to wtmusic (Original post)

Wed Mar 6, 2013, 03:46 PM

Mar 2013

Record cesium level found in Fukushima fish
March 01, 2013

THE ASAHI SHIMBUN
A record concentration of radioactive cesium--5,100 times the government's food safety standard--was detected in a fish caught near the crippled Fukushima No. 1 nuclear plant, the plant’s operator said Feb. 28.

Tokyo Electric Power Co. said the reading of 510,000 becquerels per kilogram in the greenling is the highest ever recorded in the utility’s seafood sampling surveys following the March 2011 disaster at the nuclear plant.

The finding was announced Feb. 28 at a meeting of leaders of the Fukushima Prefectural Federation of Fisheries Cooperative Associations.

The greenling was found caught Feb. 17 in a gill net at the mouth of the plant's port. The net was installed to prevent fish from drifting outside.

FBaggins

(26,748 posts)

4. So? BioAccumulation is not the same thing as bio-multiplication.

Reply to kristopher (Reply #2)

Wed Mar 6, 2013, 04:13 PM

Mar 2013

(of course there is no such thing).

In general, exposure for the population is going down - from already very low levels. Bioaccumulation in bottom-feeding fish that nobody was going to eat anyway is scientifically interesting, but nothing has been found to date that would unexpectedly expose a member of the public to dangerous levels of contamination.

CreekDog

(46,192 posts)

3. levels almost half the "difficult to return" to area extend 20+km away

Reply to wtmusic (Original post)

Wed Mar 6, 2013, 03:52 PM

Mar 2013

even nearly two years later.

i wouldn't call this good news.

i'd call it slightly less bad than awful news.

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