1. Internal contamination of
Fukushima citizens
- What we have learned from the recent
whole body counter measurements -
Ryu Hayano
Professor of Physics, The University of Tokyo
hayano
2. My research at CERN
“antimatter”
purely fundamental
no practical use
not this →
12. Cesium release from Fukushima Daiichi
137Cs (Bq)
Total (before the accident)
70 x 1016
3 reactors
Release to atmosphere 1 2 x 1016
Release to ocean 0.4 x 1016
Release fraction about 3%
13. Q: Radiation in downtown
Tokyo has returned to the
“pre-3.11” level
23. My proposal to the mayor of Minamisoma city,
20 km north of Fukushima Daiichi
東京大学 2004.2.12
シンボルマーク+ロゴタイプ
新東大ブルー
UNIVERSITY OF TOKYO
基本形
SCHOOL OF SCIENCE, DEPARTMENT OF PHYSICS
7-3-1 HONGO, BUNKYO-KU, TOKYO 113-0033, JAPAN
Professor Ryugo S. Hayano TELEPHONE: +81-3-5841-4235
TELEFAX: +81-3-4496-4043
漢字のみ 早野 龍五 e-mail: hayano@phys.s.u-tokyo.ac.jp
http://nucl.phys.s.u-tokyo.ac.jp/hayano
2011年10月28日
英語のみ
南相馬市長
桜井勝延様
FAX 0244-24-5214
南相馬市学校給食丸ごとセシウム検査の御提案
桜井市長,初めてお便り差し上げます,東京大学理学部物理の早野龍五と申します.
38. Minamisoma (25km north of Fukushima Daiichi) WBC
(Measured between Sep 2011 to Mar 2012, n = 9,502)
Relative number of people
Chernobyl (5-10 years after the accident)
WBC in Russia, Ukraine, Belarus, n=119,306
Hoshi et al, Health Phys. 67 (1994) 272
137Cs Bq/kg
39. Minamisoma (25km north of Fukushima Daiichi) WBC
(Measured between Sep 2011 to Mar 2012, n = 9,502)
Relative Number of people
Chernobyl n=119,306
WBC in Russia, Ukraine, Belarus,
5-10 years after the accident
Hoshi et al, Health Phys. 67 (1994) 272
137Cs Bq/kg
wild bore in Fukushima
Bq/kg
40. Q: Once you eat 137Cs,
it continues to damage
your body for some 30
years
42. Can we tell which of these curves apply?
Bqêbody
20 000
15 000
昨年3月吸入
Inhalation, March 2011
constant ingestion
10 000 15.5Bqê日摂取
15.5 Bq/day
昨年吸入+10Bqê日摂取
Inhalation+10Bq/day
5000
200 400 600 800 1000
days
日
43. Cs-level increase found=in 2 cases
137 n 25
137 30 40Bq/kg
n = 9502
Bq/body
①
②
detection limit
250Bq/body
125Bq Days
44. 137 n = 25
137 30 40Bq/kg
30Bq/day
Bq/body
20Bq/day
①
10Bq/day
0Bq/day
250Bq/body
125Bq
46. 134+137Cs
Bq/body Hirata Hospital (FastScan)
全データ:検査日ごとの総セシウム Bqêbody
n= 15593
Cs on cloths suspected
80008000
“half life” too short ND = 13422 (86%)
re-measured 163
60006000
40004000
20002000
0 0
Nov Jan Mar May
Nov Jan Mar May
47. These WBC results are
consistent with
“Co-op Fukushima” duplicate
portion studies
64. ‣ Quake&Tsunami devastated north-eastern part of
Japan
‣ 3 Fukushima-Daiichi reactors were damaged,
releasing radioactive Xe, I, Cs, …,
‣ Luckily, various results consistently show that
the internal contamination level of Fukushima
citizens is low
‣ Food screening has been effective
‣ But we need to continue food/WBC
measurements for many more years to come