Fukushima Nuclear Accident

Radiological monitoring and consequences

30 March 2011

Gamma Dose Rates in µSv/hour

14-29 March

Natural Background: 0.1 µSv/hour

0.000

0.200

0.400

0.600

0.800

1.000

1.200

1.400

1.600 Ibaraki(Mito)

Saitama(Saitama)

Tokyo(Shinjyuku)

Gamma dose rate / 21 March[Japan-MEXT measurement/IAEA intepretation]

Maximum levels @ 30 km zone : 90 µSv/h)

Normal natural background of gamma dose-rate: 0.1 µSv/h

I-131 and Cs-137 deposition to soil

• Measurements done by Japan authorities

• Soil sampling from March 18-26:

– 25-58 km from Fukushima NPP

– depth: 5 cm

– 9 locations

• Results:

– High deposition and large variability

– I-131: 0.2 to 25 MBq/m2

– Cs-137: 0.02 to 3.7 MBq/m2

I-131 and Cs-137 deposition to soil

• Highest value in a relative small area N-West to Fukushima NPP

• The first assessment indicates that one of the IAEA operational criteria for evacuation is exceeded in Iitate village

Pu-238 and Pu-239/240 in soil(Japanese authorities)

• Measured at Fukushima NPP: within the range of Japanese background

• Seeking further information about origin

Monitoring of drinking water

• Most recent data are below the levels established by Japanese authorities

• Recommendations for restrictions on drinking water being lifted in most locations.

• As of 28 March, recommendations for restrictions based on I-131 concentration remain in place in 4 locations of Fukushima prefecture.

Vegetables, fruits and milk24-29 March

• 98 food samples taken from 11 prefectures (Chiba, Fukushima, Gunma, Ibaraki, Kanagawa, Miyagi, Nagano, Niigata, Saitama, Tochigi and Yamagata)

• I-131, Cs-134 and Cs-137:

• Level not detected or below Japanese regulation values

I-131 Test in children’s Thyroid 24-28 March

• Japanese authorities

• 203 measurements

• Kawamata and Iwaki

• Quantitative detailed data not provided

• “Did not reveal any levels of exposure that would be a health concern”

IAEA Experts Dispatched to Japan

• Radiation Monitoring Team

– Team 1 (4) : 17 March-01 April, Tokyo

– Team 2 (4) : 21 March -04 April, Fukushima

– Team 3 (4) : 30 March – to replace Team 1

• Food and Safety Team (3) : 25 March- 04 April– Food safety ( IAEA), Analytical approach and data analysis

(IAEA) , food safety in emergency situation (FAO)

• Marine Monitoring Assessment Observer: 02 April

IAEA Radiation monitoring teams

March 29, 1st team • 8 locations in Tokyo region • Gamma-dose rates: 0.02 to 0.19 µSv/h• Natural background: 0.1 µSv/h

March, 29, 2nd team • Radius of 32 to 62 km from the Fukushima NPP• Dose rates: 0.5 to 6.8 µSv/h

• Beta-gamma contamination: 0.05 to 0.45 MBq/m2

Joint FAO/IAEA Food Safety Assessment Team

Met with local government authorities in Fukushima, Ibaraki and Tochigi prefectures

Discussed various issues related to the contamination of food and the agricultural environment

Local government authorities briefed the team on:

• Principal agricultural products affected

• Main production areas and production methods (greenhouses, open-air)

• Levels of contamination found (air, tap/ground water, vegetables)

• Monitoring of soil contamination

Focus of mission:

Remediation strategies and techniques related to plant and animal production, food traceability and water/soil characterization

IAEA/Joint Radiation Emergency Management Plan

• Regular activities via tele/videoconference

• As of March 30: WHO liaison officer working at IEC

Singapore Radiation Monitoring Information

• Cabbages imported from Japan:

• I-131: 936 Bq/Kg (C.A 100 Bq/Kg)

• Up to 9 times the recommended values of the Codex Alimentarius.