Radiological Monitoring and Consequences of Fukushima Nuclear Accident (2 June 2011)

1. Fukushima Nuclear Accident
Radiological Monitoring
and Consequences
2 June 2011

2. Gamma Dose Rate in 47 Prefectures on 31 May
Fukushima prefecture: 1.5 µSv/h

3. Gamma Dose Rates in 7 Prefectures
24 March – 31 May
Natural background: 0.1 microSievert/hour

4. Gamma dose rate in the East of Fukushima prefecture

5. Concentration in air of I‐131 and Cs‐137 detected
at Fukushima Daiichi West Gate (at a distance of 1 Km to NPPs)

6. Deposition of I‐131 and Cs‐137 in 47
prefectures
• I‐131
– Not detected since 18 May
• Cs‐137
– Detected in a few prefectures over a few days
– Low levels ranging from 2.2 to 91 Bq/m2

7. Protective actions
• Drinking water: All restriction lifted
• The Government of Japan has announced
evacuation measures:
– Beyond distances of 30 km from Fukushima
Nuclear Power Plants
– NISA: evacuation of the “Planned Evacuation
Zones” within Iitate village and Kawamata town
commenced on 15 May.

8. Food Monitoring and Food Restrictions
(Reported 19 – 31 May)
• 818 samples from 18 prefectures
• Over 40% of monitoring is in Fukushima prefecture
• Over 93% of samples indicated Cs‐134 /Cs‐137 or I‐131
were not detected or were below the Japanese
regulation values
• Less than 7% were above the Japanese regulation values
for Cs‐134 /Cs‐137 and/or I‐131
• Restrictions on the distribution and/or consumption of
specific foods in certain areas of Fukushima and Ibaraki
prefectures remain in place

9. 350 Total number of food samples tested between 19 and 31 May 2011
300
300
250
Number of samples
Neg
200 Cs-total
Cs-total & I-131
150 116
100
77
55
50
39
36
33
32
28
22
18
11
9
9
9
6
4
4
2
2
2
2
1
1
0
Prefecture

10. 20 Food samples above the regulation values between 19 and 31 May 2011
18
16 Cs-total
14 Cs-total & I-131
Number of samples
12
12
10
10
8
7
6
4
4
3 3
2 2 2 2 2
2
1 1 1
0
Prefecture / Date of sampling

11. 20 Food samples above the regulation values between 19 and 31 May 2011
18
16 Cs-total
16 Cs-total & I-131
14
Number of samples
12
10
10
9
8
6
6
5
4
2
2
1 1 1 1
0
Chiba / tea Fukushima / Fukushima / Fukushima / Fukushima / Fukushima / Fukushima / Gunma / tea Ibaraki / tea Tochigi / tea
Algae Fishery Fruit Mushroom tea Tree /
products perennial plant
shoots
Prefecture / food type