-
8/10/2019 Fukushima derived radionuclides in the ocean.pdf
1/12
-
8/10/2019 Fukushima derived radionuclides in the ocean.pdf
2/12
Decay corrected accumulative fallout of 137Csderived from atmospheric weapons tests as of 1970
Michio Aoyama, Katsumi Hirose and Yasuhito Igarashi, Re-construction and updating our understanding on the globalweapons tests 137 Cs fallout, Journal of Environmental
Monitoring , 8, 431-438, 2006.
In Northern Hemisphere765 79 PBq 1970In the North Pacific Ocean
290
30 PBq
197069 7 PBq 2011
Chernobyl accident 1986
85 PBq
-
8/10/2019 Fukushima derived radionuclides in the ocean.pdf
3/12
A pathway of weapons tests derived137 Cs in the North Pacific Ocean,
tracer of sea water movement
Fig. S2 Possible pathway of 137 Cs in the Pacific Ocean based on 3-Dobservations of 137 Cs in 2000s (Aoyama et al., 2013)
We can expect that Fukushimaorigin radiocaesium should gosame pathway
-
8/10/2019 Fukushima derived radionuclides in the ocean.pdf
4/12
Pathways of Fukushima derivedradionuclides to the Ocean
Atmospheric deposition Direct release Groundwater discharge River runoff
TEPCO Press release
137 Cs : 1.8E+12 Bq/m 3
Simulated atmospheric deposition of137 Cs (Bq m -2) (by Masingar II of MRI)(Aoyama et al., in preparation)
4
-
8/10/2019 Fukushima derived radionuclides in the ocean.pdf
5/12
Boiling Water Reactor Systems "NuclearReactor Concepts" Workshop Manual,U.S. NRC
3.6 0.7 PBq to the ocean(Tsumune et al., 2013)
14 17 PBq to the atmosphere
700 PBq was in the three core 140 PBq in stagnant water(Nishihara et al.,, 2011) (Nishihara et al., 2011)
140 PBq in stagnant water
12 - 15 PBq to the ocean
137 Cs mass balance
-
8/10/2019 Fukushima derived radionuclides in the ocean.pdf
6/12
More than 99% of released radioaesium to the oceanwas transported offshore, then to the ocean interior
30 GBq day -1Revised estimation
-
8/10/2019 Fukushima derived radionuclides in the ocean.pdf
7/12
R/V Mirai
NYK AQUARIUS
R/V Hakuho Maru
NYK Heijin
Sampling locations during the period fromMarch 2011 to Oct. 2012
-
8/10/2019 Fukushima derived radionuclides in the ocean.pdf
8/12
l l
(Aoyama et al., BG 10 3067-3078, 2013)
Apr-Jun2011
Jul-Sep2011
Oct-Dec2011
Jan-Mar2012
Surface speed of contaminated water ca. 7 km day -1
8
X
-
8/10/2019 Fukushima derived radionuclides in the ocean.pdf
9/12
0 5 10 15 20 250
100
200
300400
500
600700
800
KS1109-3101
RF1205-4418
134Cs / Bq m -3
D e p
t h / m Oxygen maximum
Sigma0=26.3Year 2011 2012Month 10 6
Bq m -2 Bq m -2
134Csinventory 2710+-210 2350+-190
0 - 200 m 2150 520
Deeper than200 m 520 1830
Oct. 2011
ver time, Cs moves east and subducted in the ocean interior
June 2012
-
8/10/2019 Fukushima derived radionuclides in the ocean.pdf
10/12
Bq m -3
137 Cs cross section along 165 E in June 2012
Start of travel into ocean interior N
-
8/10/2019 Fukushima derived radionuclides in the ocean.pdf
11/12
Possible pathway of Fukushima derivedradionuclides in the North Pacific Ocean
Fig. S2 Possible pathway of 137 Cs in the Pacific Ocean
We found start of travel of Fukushima derivedradioactivity in the ocean interior.
-
8/10/2019 Fukushima derived radionuclides in the ocean.pdf
12/12
Summary of budget of 137 Csfor pre- and after the Fukushima accident
Main portion of Fukushima derived radioactivityalready subducted into the ocean interior and is
moving to southwest ward.