Re:Ocean Radiation and the Fukushima Disaster
by rhizome on Saturday January 04, 2014 @04:35PM
(#7013053)
I thought the bigger problem with Fukushima was not the Cs-137, but the Sr-90.
Re:Ocean Radiation and the Fukushima Disaster
by throwaway_yy2Di on Saturday January 04, 2014 @04:37PM
(#7013062)
I don't think Fukushima released much strontium (do you have a source otherwise)? The atmospheric release concentrated elements with high vapor pressures, in particular iodine and cesium.
edit: Here's a paper [0] which measured Sr-89 and Sr-90 in seawater near Japan: they found a ratio of about 0.026 of Sr-90 : Cs-137 -- relatively little strontium. Their estimate for total Sr-90 released is 90-900 TBq, corresponding to Cs-137 release estimates of 3.5 - 35 PBq. The figures for Chernobyl [1] are 10 PBq and 85 PBq respectively -- that is, Chernobyl released 10-100 times more Sr-90 than Fukushima. The Sr-90 : Cs-137 ratio was even higher (0.63) for atmospheric weapons tests: 600 PBq Sr-90, 900 PBq Cs-137 [2].
edit2: Made a table:
Sr-90 [PBq] Cs-137 [PBq] ratio ref
Fukushima 0.09 - 0.9 3.5 - 34 0.026 [0]
Chernobyl 10 85 0.12 [1]
Weapons 590 930 0.63 [2]
[1] (large pdf) http://www.unscear.org/docs/reports/2008/11-80076_Report_200... (table 1, page 9)
Specifically: nuclear testing released about 30 times more Cs-137 (in particular) than Fukushima, also mostly into the Pacific. An estimated 25 MCi [0] = 925 PBq, vs. 23-50 PBq [1].
[0] http://books.google.com/books?id=JLFX6EMPqBkC&pg=PA34
[1] http://www.pnas.org/content/109/16/5984.full
(copied from an older HN comment I wrote)