Fukushima Marine Environment Monitoring - 5 May 2011

Marine Environment Monitoring
Assessment of IAEA Environment Laboratories on Data from the Marine Environment provided by Japan
Update 05 May 2011
IAEA Environment Laboratories, Monaco
H. Nies, M. Betti, I. Osvath, E. Bosc

General comments
The contamination of the marine environment has occurred both through atmospheric deposition or washout with precipitation, and through discharges of contaminated water into the sea
Authorized discharge of low level contaminated water (beginning of April for about 5 days)
There is a further continuous discharge of contaminated water into the marine environment.
TEPCO and MEXT are continuing to conduct programmes for sea water sampling and to perform measurements. Further sampling positions were added recently about 15 km offshore and at the Ibaraki coast.
Also marine food and one sediment station is now monitored.
6 May 2011

Marine discharges due to leaking cable pit at Unit 2
In a news release issued on 25 April, NISA has communicated their evaluation of a report submitted by TEPCO on April 21 in relation to water containing radionuclides with high activity that flowed out from Unit 2 of Fukushima Daiichi Nuclear Power Station.
The outflow rate is estimated to have been approximately 4.3 m³/h.
Concentration values, estimated from measurements, are:
I-131: 5.4 GBq/L
Cs-134: 1.8 GBq/L
Cs-137: 1.8 GBq/L
leading to an estimated overall amount of total release of about 4.7 PBq(4.7 x 1015Bq)
6 May 2011

Measures to prevent further spreading of contaminated water into the sea
6 May 2011

Activity concentration in sea water at the screen of Unit 2
The activity concentrations of I-131, Cs-134 and Cs-137 (in Bq/cm3) in sea water at the screen of Unit 2 from 02 April 2011 until 02 May 2011
6 May 2011

Seawater sampling carried out by TEPCO and MEXT
TEPCO is sampling four near- shore stations (TEPCO1-4)
Since 5th of April six points situated 15 km off-shore along a north-south transect (TEPCO 5-10)
Following a Directive from NISA, on 16 April TEPCO announced that they will increase the number of sampling points. Four points will be added at 3 km from the coast and two points at 8 km from the coast.
6 May 2011

Concentrations in sea water near discharge point of
TEPCO 1-4
6 May 2011

Activityconcentrations
I-131
Cs-134
Cs-137
in sea water
atcoastaland off-shorestations
Surfacewater, middlelayerandnearseafloor
6 May 2011

New sea water sampling stations by MEXT near the Ibaraki prefecture
MEXT also launched sampling at 5 off-shore points in Ibaraki Prefecture.
The samples are taken by the Japanese Coast Guard and analysed by TEPCO.
Map 1
6 May 2011

Monitoring of marine food
Sampling locations of marine fish products as of 30 April (issued by the Japanese Ministry of Agriculture, Forestry and Fisheries)
In Ibarakiprefecture, three samples of seafood (sand lance) from
28 April: one sample
29 April: two samples
were above the regulation values set by the Japanese authorities for Cs-134/Cs-137
Sand lances are so far the only fish species, which showed levels above the recommended limits.
6 May 2011

Modelling Activities by the Group SciroccoModel prediction for two different scenarios
The group SIROCCO of the University of Toulouse continues with the modelling of the ocean impact. The modelling results are continuously compared with the measurements.
Atmospheric deposition simulation
Liquid release simulation
6 May 2011

Model output for 2 different scenario
Atmospheric deposition simulation
Liquid release simulation
6 May 2011

Comparison between observation and model (Bq/l)
6 May 2011

IAEA Environment Laboratories: Monitoring of atmospheric radioactivity in Monaco
Programme started in 1986
Sampling of atmospheric aerosols and deposition currently in 2 locations
Roof of Oceanographic Museum
Roof of building at Quai Antoine
6 May 2011

Routine monthly sampling and analysis of gamma emitters (e.g. Cesium-137), beta emitters (e.g. Strontium-90) and alpha emitters (Plutonium and Americium)
Increased frequency of sampling and measurements in special situations: aerosol samples collected twice daily, wet and dry deposition collected as often as relevant
6 May 2011

6 May 2011

Additional measurements during March-April 2011:
Detector continuously monitoring ambient gamma emitters
Hourly and two-hourly measurements of ambient dose-rate with hand-held devices (stationary, continuous monitor with on-line access to measurement results is necessary)
6 May 2011

Cs-137 in atmospheric aerosols in Monaco from 1986 to 2011
Note: maximum values measured in March-April 2011, after the Fukushima accident,
are about 2000 lower than those measured in May-June 1986, after the Chernobyl accident.
6 May 2011

Radio-Cesium in atmospheric aerosols in Monaco after the Chernobyl accident
Rep. from Whitehead et al. JER 7 (1988) 249-264
6 May 2011

Iodine-131 in atmospheric aerosols in Monaco after the Chernobyl accident
Data from Chernobyl accident
6 May 2011

Cesium-137 in atmospheric aerosols in Monaco 1997-2010
Temporal variation of 137Cs concentration in the Monaco air (the peak in May-June 1998 is due to the Algeciras (Spain) accidental release). Pham et al. submitted to JER. 2011
6 May 2011

Radio-Cesium in atmospheric aerosols measured in Monaco after the Fukushima accident
6 May 2011

Iodine-131 in atmospheric aerosols measured in Monaco after the Fukushima accident
6 May 2011

Comparison between levels of radionuclides in atmospheric aerosols measured in Monaco after Chernobyl and Fukushima accidents
Maximum levels measured after the Fukushima accident (March-April 2011) are much lower than those measured after the Chernobyl accident (May-June 1986)
I-131 120 times lower
Cs-134 700 times lower
Cs-137 2000 times lower
Levels are similar to those measured elsewhere in Europe (France, Italy, Germany)
6 May 2011

Conclusions on the impact to the marine environment in the Pacific
The highest levels are still measured close to the Nuclear Power Stations Fukushima, namely at the screen of Unit 2, 30 m, 330 m and 10 km near-shore even though with a decreasing trend.
Concentration data from about 30 km off-shore show a generally decreasing temporal trend and partly, the concentrations are below the limit of detection at the applied methods.
It can be expected that, if no additional releases occur, the levels measured at the stations 30 km off-shore will continue to decrease significantly by dilution into deeper layers and dispersion by ocean currents
6 May 2011

Conclusions
It can be expected that the traces from the discharge and deposition to the marine environment from Fukushima NPPs will be taken up by the Kuroshio current system in the north Pacific
It will be possible to follow these traces – mainly Cs-137 and Cs-134 - over the next few years in the northern Pacific
Water with such traces will reach the Canadian and US Coast probably in one to two years’ time
IAEA environmental Laboratories in Monaco will be part of international teams to measure these impact to the Pacific and will support and co-ordinate initiated environment assessment studies
6 May 2011

Fukushima Marine Environment Monitoring - 5 May 2011

by IAEA on May 06, 2011

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Fukushima Marine Environment Monitoring - 5 May 2011 — Presentation Transcript