IAEAInternational Atomic Energy Agency

Marine Environment

-Fukushima NPPs Potential Impact on

the Marine Environment –

Assessment of IAEA Environmental Laboratories on Data provided by

Japan

IAEA-Environmental Laboratories, Monaco

IAEA

Seawater sampling off Fukushima (26 March 2011) carried out by Japanese Authorities

Seawater sampling locations of Japanese Authorities

• Transect about 30 km offshore, sample locations separated by 10 kilometres

• Levels of dose rates were also measured as indicated

IAEA

Temporal trend on concentrationsData submitted by Japanese authorities

Cs-137

IAEA

Temporal trend on concentrationsData submitted by Japanese authorities

I-131

IAEA

1 103 104 105 106102101 107 108

April 200530 km

Bq.m-3

[1 – 101]

1 103 104 105 106102101 107 108

24, 25 March 2011

Bq.m-3

[103– 104]

[105– 107]

Monitoring of the Marine environment

• Comparison of Cs-137 seawater concentration with historical data• 30 km offshore surface water concentrations are 3 to 4 orders of magnitude higher

than the values measured in 2005• 330 m East of Fukushima Dai-ichi concentrations are up to 3 orders of magnitude

higher than the values measured offshore

Cs-137 Bq.m-3

Monitoring of the Marine environment seawater concentration 1. 30 km :

• 28 march, Concentrations increase at station 5

• Spatial distribution is more heterogeneous

2. 20 km :• New station since 28 of march #9

3. 300 m : • Concentrations increase 2 orders of

magnitude since 28 March

TEPCO

MEXT

28 march, depth 132 m : Cs -137 not detected

IAEA

Temporal trends of concentration in seawater 330 m east of Discharge point

Units 1 to 4

IAEA

Temporal trends of concentrations in seawater at Units 5/6

IAEA

Modelling

Dispersion of an arbitrary initial discharge

Dispersion of an arbitrary initial discharge

Courtesy to the Group SIROCCO of the Observatoire Midi-Pyrenées of the University of Toulouse, CNRS

Animations to be seen at:

http://sirocco.omp.obs-mip.fr/outils/Symphonie/Produits/Japan/SymphoniePreviJapan.htm

Courtesy to the Group SIROCCO of the Observatoire Midi-Pyrenées of the University of Toulouse, CNRS

Animations to be seen at:

http://sirocco.omp.obs-mip.fr/outils/Symphonie/Produits/Japan/SymphoniePreviJapan.htm

IAEA

Modelling

Dispersion of an arbitrary initial discharge

Dispersion of an arbitrary initial discharge

IAEA

Modelling

Dispersion of an arbitrary initial discharge

Dispersion of an arbitrary initial discharge

IAEA

Modelling

Modelling of the deposition on the sea surface and subsequent concentration

Modelling of the deposition on the sea surface and subsequent concentration