1111

Comparison of radioactive contamination between Chernobyl and Fukushima

Imanaka T.Research Reactor Institute, Kyoto University

June 27, 2012

Chernobyl April 1986

Fukushima March 2011

22

チェルノブイリ型原発（左）と福島型原発（右）

RBMK BWR

黒鉛減速沸騰軽水冷却チャンネル炉 軽水減速沸騰軽水冷却

圧力容器炉

3333

“Period after Fukushima”began also in Japan

Significant contamination with radiocesiums occurred along the coast of the northern half of Honshu island.

44

55

Fukushima and Chernobyl- Evacuation area near NPP -

60 km 30 km

立入禁止区域

ベラルーシ

ウクライナ キエフ貯水湖

チェルノブイリ周辺立入禁止区域

60 km 30 km

立入禁止区域

ベラルーシ

ウクライナ キエフ貯水湖

チェルノブイリ周辺立入禁止区域

Both accidents indicate consequences of the worst Both accidents indicate consequences of the worst situation at NPP that core radioactivity in the situation at NPP that core radioactivity in the

core was directly released into the environment.core was directly released into the environment.

26 years after Chernobyl Fukushima

66

April 261986

Чернобыльский репортаж (1988)

Chernobyl

77

InIn--air explosion opinion by air explosion opinion by ChecherovChecherov

Checherovら2005

88

Radioactivity release

0

10

20

30

40

50

60

70

4/26 4/27 4/28 4/29 4/30 5/1 5/2 5/3 5/4 5/5 5/6

放射

能放

出量

（ＭＣ

ｉ）

1986

Daily release (without rare gases)Based on 1986 USSR report.

Direction of radioactive plumes．Izrael（2005.12 Moscow）．

①4/26

② 4/26-27

③ 4/27-28

④ 4/27-28

⑤ 4/28

⑥ 4/29

⑦ 4/29-5/1

⑧ 5/2

1010

Radiation situation on June 1, 1986 Kozubovら 1991Red color indicates “Red forest”

1111

チェルノブイリ原発周辺10km

１ｋｍ

１ ヤノフ駅

プリピャチ市

５

１．１～４号炉（４号炉は西端） ２．５，６号炉（事故当時建設中） ３．取水路 ４．放水路 ５．引き込み線路 実線は道路

○

○

○

○

○

○

○

○

４

３ ５

冷却池

プリピャチ川

ウソフ村

クラースノエ村

シェペレチ村

チスタゴルフカ村

コパチ村

ジモビシチェ村

クリバヤ・ゴラ村

スタロセル村

２

○ レレフ村

プリピャチ市より 2005年10月

1212Baliffら 1996

Radiation dose in the 30km zoneMay 1, 1986、μSv/h

1313

チェルノブイリでは出力暴走により原子炉と建屋が爆発・炎上

Чернобыльский репортаж (1988)

２年後、TVカメラを入れてみると炉心は空っぽだった

1414

Fukushima accident

美浜の会ホームページ

1515

March12, Hydrogen

explosion #1

March14, Hydrogen

explosion #3

1616

March 15, Containment failure #2

1717

Containment pressure and radiation monitoring data at NPP

TEPCO Interim report, Dec. 2011

1818

0

10

20

30

40

50

60

70

12

日

13

日

14

日

15

日

16

日

17

日

18

日

19

日

20

日

21

日

22

日

23

日

24

日

25

日

26

日

27

日

28

日

29

日

30

日

31

日

放射

能放

出量

, P

Bq/

day

I-131

Cs134+Cs137

2011年3月

Fig.4. Daily release of I-131 and Cs-137+Cs134 from the Fukushima Daiichi NPP accident up to March 31. Daily values are calculated form the results by Chino et al[8], assuming the same release of Cs-134 as Cs-137.

Daily release from NPP

Prepared by Imanaka

1919

About 80,000 people were evacuated from the 20 km

zone on March 12.

But, no data of radioactive contamination was released from the authorities, only

saying “No danger fro public health”.

2020

SPEEDI simulation on March 15

2121

飯舘村の放射線レベル

福島県20-30km圏放射線量率の変化：２０１１年３月１５日～

0

10

20

30

40

50

3/14 0

:00

3/15 0

:00

3/16 0

:00

3/17 0

:00

3/18 0

:00

3/19 0

:00

3/20 0

:00

3/21 0

:00

3/22 0

:00

3/23 0

:00

3/24 0

:00

3/25 0

:00空

間線

量率

、マ

イク

ロシ

ーベ

ルト

／時

南相馬市24

飯舘村40

葛尾村26

福島空港58

川内村22

いわき市平

田村市35

田村市40

Data from Fukushima prefecture HP

2222

Sample Monitoring on March 15

ヨウ素131が100万Bq/kgのほうれん草を100g食べると、10万Bqの取り込み。

それが乳児であれば、甲状腺の等価線量は。2.8×10-3[mSv/Bq]×105[Bq]＝280mSvとなる。

Data from HP

2323

Knowing that awful contamination occurred outside

30 km zone, no warning was issued from the authorities.

Imanaka supposed that headquarters of our government also melted down as well as three

reactors in Fukushima.

2424

Radiation monitoring in Iitate village in 28-28 March

30μSv/h in Nagadoro-Magata

2525

Fig. 7. Location of Iitate village (left) and the contour of radiation dose rate in Intate village on March 29th, 2011 (right). Dose rates were measured in a car moving along main roads inside village using a pocket survey meter ALOKA PDR101. Unit: Sv/h.

Dose rate map on March 29, 2011 in Iitate

Imanaka et.al Health Physics 2012

2626

Estimates of radioactivity release into the atmosphere

単位：PBq＝１×1015 Bq

Fukushima Chernobyl

#１～#3 Total 2.03 GWe 1GWe

NSC

（April 12）

NISA

（May 16）

Stohl etal

(ACPD 2011)

Chernobyl Forum

(2005)

Xe-133 － 11,000

(97%) 16,700

6,500

(100%)

I-131 150 160

(2.5%) －

1,760

(55%)

Cs-137 12 15

(2.6%) 35.8

85

(30%)

Sr-90 － 0.14

（0.03%） －

10

(5%)

Pu-239,240 － 0.0000064

(0.0002%) －

0.03

(1.5%)

( ): Released fraction of the core inventory.

2727

90Sr、239,240Pu contamination in Iitate

Siol contamination, Bq/m2

Cs-137 Sr-90* Pu-239,240**

＜Iitate village: NW30-40km＞

＃53 1,000,000 390 0.01

#88 590,000 300 0.07

#165 2,200,000 790 0.2

＜Kyiv city：S110km Garger et al. Health Physics1996＞

Average of 6

samples 25,000 5,800 160

＊ （財）九州環境管理協会に測定を依頼．Global を含む

**山本（金沢大）による測定．Pu-238 との比から、Global を差し引いた値．

Contamination ratio of Sr90 to 137 is 1/2000～1/3000,compared with Kyiv. For Pu isotopes, it is less than 1/1 million．

2828

137Cs、90Sr、239,240Pu around Chernobyl

Pu-234,240 Gaydar KURRI-KR-79 (2002)Cs-137 UNSCEAR（2000）

Sr-90 UNSCEAR (2000)

Sr90 and Pu isotopes are about 10 % and 1 $of Cs137, respectively.

2929

Cs137 body burden in Belarus (upper) and Russia (lower) after Chernobyl

Zvnova et al.Radiation Protection Dosimetry

2000

Minenko et.alHealth Physics 2006

3030

Recent Cs137 body burden od children in contaminated area in Belarus.

Data from Belrad.

39.9

311.7

220.2

331.6

218.7

185.6

84.6

110.3

74.270.3

172.386.4 81.3

1120

575.6

1142.7

632.9

662.7

189.6 262.4

97.9

247

54.4

528.2

228.3 219.3

0

300

600

900

1200

28.11

.2001

(n=90

)

23.01

.2002

(n=73

)

13.03

.2002

(n=88

)

18.04

.2002

(n=70

)

23.05

.2002

(n=87

)

11.06

.2002

(n=46

)

18.06

.2003

(n=44

)

16.12

.2003

(n=23

)

8-9.04

.2004

(n=11

8)

28.04

.2005

(n=26

)

22.11

.2006

(n=70

)

23.01

.2007

(n=56

)

22.05

.2007

(n=79

)

WBC検査日（n：人数）

平均

体内

セシ

ウム

137量

、B

q/kg

検査グループ全体 危険グループ

3131

WBC results in children of Minami-soma city

Data from Minami-Soma city HP

3232

Forecast of external dose rate change from deposited radiocesiums

セシウムによる空間線量率変化の予測（移行なしモデルと環境半減期13年モデル）

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

0 2 4 6 8 10 12 14 16 18 20

経過年数

空間

線量

率の

相対

強度

移行なしモデル

環境半減期13年モデル

3333

Summary

The same scale of radiological consequences as Chernobyl occurred around Fukushima #1 NPP.

Released amounts into the atmosphere by the Fukushima accident seem to be double for Xe-133 and 20 – 40 % for Cs-137．

Contamination by Sr-90 and Pu-239,240 was significantly lower than Chernobyl．

So far, internal contamination by radiocesiumsare surprisingly lower than Chernobyl.