Post-facta Analysis of Fukushima Daiichi Accident …symbio-newsreport.jpn.org/.../presentation_1392399264.pdfPost-facta Analysis of Fukushima Daiichi Accident by Simple Physical Model

Post-facta Analysis of Fukushima Daiichi Accident by Simple Physical Model

The 17th International Workshop on Nuclear Safety & Simulation Technology

Kyoto, Japan, January 21, 2014

TANABE, Fumiya

Sociotechnical Systems Safety Research Institute

SOCTEX

a) Cladding of burnable poison rod b) Ag-In-Cd c) Assumed based on educated guess

0.0001

0.001

0.01

0.1

Time after reactor shutdown (sec)

1E-1 1E+0 1E+1 1E+2 1E+3 1E+4 1E+5 1E+6 1E+7 1E+8 1E+9

Nor

mal

ized

pow

er

Time dependent nuclear decay heat

Core water level calculation model:

Heat and hydrogen generation by zirconium-steam reaction All steam assumed to react with zirconium higher than 1500K

0.00E+00

2.00E+07

4.00E+07

6.00E+07

8.00E+07

1.00E+08

1.20E+08

0 1000 2000 3000 4000 5000

Zr 0% oxidized

Zr 20% oxidized

Zr 40% oxidized

Zr 60% oxidized

Zr 80% oxidized

Zr 100% oxidized

Temperature (K)

Ener

gy (k

cal)

Total core and lower plenum energy curve for 1F-1 nuclear reactor

0

0.5

1

1.5

2

2.5

3

3.5

4

0 1000 2000 3000 4000 5000 6000 7000 8000 9000 10000

Time after the beginning of core uncovering (s) 2011/03/11 16:50

Cor

e w

ater

leve

l (m

) Core water level in １F-1 nuclear reactor accident

Core material temperature in the 1F-1 nuclear reactor accident

0

500

1000

1500

2000

2500

3000

3500

4000

0 5000 10000 15000 20000 25000 30000 35000

Core material

Core material without Zr-steam reaction

Core and lower plenum material

Time after the beginning of core uncovering (s)

Tem

pera

ture

(K)

2011/03/11 16:50

MP(Fe)

MP(Zr)

MP(ZrO2)

MP(UO2)

0

50

100

150

200

250

300

350

400

450

500

0 1000 2000 3000 4000 5000 6000 7000 8000 9000 10000


Hyd

roge

n m

ass

(kg)

2011/03/11 16:50

Calculated hydrogen generation in 1F-1nuclear reactor

0.01

0.1

1

10

100

1000

10000

100000

2011/3/11 0:00 2011/3/12 0:00 2011/3/13 0:00 2011/3/14 0:00 2011/3/15 0:00 2011/3/16 0:00 2011/3/17 0:00 2011/3/18 0:00 2011/3/19 0:00

正門付近（1～3号機の南西）

MP-4付近（1～3号機の北西）

西門（1～3号機の西）

事務本館北（1～3号機の北）

空間放射線量率（μS

v/h）

１Fサイト空間放射線量率

0.01

0.1

1

10

100

1000

10000

3/12 0:00 3/12 12:00 3/13 0:00 3/13 12:00 3/14 0:00 3/14 12:00 3/15 0:00 3/15 12:00 3/16 0:00 3/16 12:00 3/17 0:00

浪江町幾代橋(北8.2km）IC 双葉町郡山（北北西2.8km）NaI 双葉町新山（北北西3.9km）IC 浪江町浪江（北北西8.6km）IC 双葉町上羽鳥（北西5.6km）IC 双葉町山田（西北西4.1km）IC 大熊町大野（西南西4.9km）IC 大熊町向畑（南西4.0km）NaI 大熊町夫沢（南南西1.6km）NaI 富岡町夜の森（南南西7.3km）IC 楢葉町松館（南南西14.2km）IC 楢葉町山田岡（南18.7km）IC


v/h）

0.01

0.1

1

10

100

1000

10000

0:00 1:00 2:00 3:00 4:00 5:00 6:00 7:00 8:00 9:00 10:00 11:00 12:00 13:00 14:00 15:00 16:00 17:00 18:00 19:00 20:00 21:00 22:00 23:00 0:00



v/h）

0.01

0.1

1

10

100

2011/3/11 0:00 2011/3/12 0:00 2011/3/13 0:00 2011/3/14 0:00 2011/3/15 0:00 2011/3/16 0:00 2011/3/17 0:00 2011/3/18 0:00 2011/3/19 0:00

南相馬市

飯館村

福島市

郡山市

白河市

いわき市

Total core energy curve for the Fukushima Daiichi-Unit 3 and Unit 2 nuclear reactor

0.00E+00

1.00E+07

2.00E+07

3.00E+07

4.00E+07

5.00E+07

6.00E+07

7.00E+07

8.00E+07

9.00E+07

1.00E+08

0 1000 2000 3000 4000 5000

Zr 0% oxidized

Zr 20% oxidized

Zr 40% oxidized

Zr 60% oxidized

Zr 80% oxidized

Zr 100% oxidized

Temperature (K)

Ener

gy (k

cal)

MP(Fe) MP(Zr) MP(ZrO2)

MP(UO2)

0

0.5

1

1.5

2

2.5

3

3.5

4

0 5000 10000 15000 20000 25000

Present calculation

Measured

Cor

e w

ater

leve

l (m

)

2011/3/13 03:29

Core water level in 1F-3 nuclear reactor accident

0

500

1000

1500

2000

2500

3000

3500

0 5000 10000 15000 20000 25000

Core material without Zr-steam reaction

Core material

core and lower plenum material


Tem

pera

ture

(K)

2011/03/13 03:29

MP(Fe)

MP(Zr)

MP(ZrO2)

MP(UO2)

Core material temperature in 1F-3 nuclear reactor accident

0

200

400

600

800

1000

1200

1400

0 2000 4000 6000 8000 10000 12000 14000 16000 18000


H

ydro

gen

mas

s (k

g)

2011/03/13 03:29

Calculated hydrogen generation in 1F-3 nuclear reactor

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

6:00 7:00 8:00 9:00 10:00 11:00 12:00 13:00 14:00 15:00 16:00 17:00 18:00

A系原子炉圧力（Mp abs） B系原子炉圧力（Mpa abs） D/W圧力（MPa abs） S/C圧力（MPa abs）

0.01

0.1

1

10

100

1000

10000

100000

2011/3/11 0:00 2011/3/12 0:00 2011/3/13 0:00 2011/3/14 0:00 2011/3/15 0:00 2011/3/16 0:00 2011/3/17 0:00 2011/3/18 0:00 2011/3/19 0:00






v/h）


0.01

0.1

1

10

100

1000

10000

3/12 0:00 3/12 12:00 3/13 0:00 3/13 12:00 3/14 0:00 3/14 12:00 3/15 0:00 3/15 12:00 3/16 0:00 3/16 12:00 3/17 0:00



v/h）

0.01

0.1

1

10

100

2011/3/11 0:00 2011/3/12 0:00 2011/3/13 0:00 2011/3/14 0:00 2011/3/15 0:00 2011/3/16 0:00 2011/3/17 0:00 2011/3/18 0:00 2011/3/19 0:00

南相馬市

飯館村

福島市

郡山市

白河市

いわき市

0.00E+00

2.00E+07

4.00E+07

6.00E+07

8.00E+07

1.00E+08

1.20E+08

1.40E+08

0 500 1000 1500 2000 2500 3000 3500 4000 4500

Zr 0% 0xidizedZr 20% oxidizedZr 40% oxidizedZr 60% oxidizedZr 80% 0xidizedZr 100% oxidized

Temperature (K)

Ener

gy (k

cal)

Total core and lower plenum energy curve for 1F-2 and 1F-3 nuclear reactor

0

0.5

1

1.5

2

2.5

3

3.5

4

0 1000 2000 3000 4000 5000 6000 7000 8000

Measured

Assumed in thepresent analysis

Time after beginning of core uncoverying(s)

Cor

e w

ater

leve

l (m

)

2011/03/14 16:20

Core water level in １F-2 nuclear reactor accident

0

500

1000

1500

2000

2500

3000

3500

0 5000 10000 15000 20000 25000 30000 35000 40000

Core material

Core and lower plenummaterial


Tem

pera

ture

(K)

2011/03/14 16:20

MP(Zr)

MP(UO2)

MP(Fe)

Core material temperature in 1F-2 nuclear reactor accident

0

0.5

1

1.5

2

2.5

3

3.5

A-system reactor pressure（MPag）

D/W pressure（MPaA）

S/C pressure（MPaA）

Pres

sure

(MPa

)

Time and date

3/14 18:00 3/14 21:00 3/15 0:00 3/15 3:00 3/15 6:00 3/15 9:00 3/15 12:00

Measured pressure in 1F-2 nuclear reactor accident

0.01

0.1

1

10

100

1000

10000

100000

2011/3/11 0:00 2011/3/12 0:00 2011/3/13 0:00 2011/3/14 0:00 2011/3/15 0:00 2011/3/16 0:00 2011/3/17 0:00 2011/3/18 0:00 2011/3/19 0:00






v/h）


0.01

0.1

1

10

100

1000

10000

3/12 0:00 3/12 12:00 3/13 0:00 3/13 12:00 3/14 0:00 3/14 12:00 3/15 0:00 3/15 12:00 3/16 0:00 3/16 12:00 3/17 0:00



v/h）

0.01

0.1

1

10

100

2011/3/11 0:00 2011/3/12 0:00 2011/3/13 0:00 2011/3/14 0:00 2011/3/15 0:00 2011/3/16 0:00 2011/3/17 0:00 2011/3/18 0:00 2011/3/19 0:00

南相馬市

飯館村

福島市

郡山市

白河市

いわき市

Fukushima Daini NPP

Kitaibaraki

Takahagi

Mito

Tokyo (Shinjuku)

103

102

101

100

10-1

10-2

3/11 3/12 3/13 3/14 3/15 3/16 3/17 3/18 3/19

Time and date

0

5

10

15

20

25W

ater

flow

rate

(m3 /h

)

Time and date

Minimum decay heat removal flow rate

Injection flow rate

3/11 3/13 3/15 3/17 3/19 3/21 3/23 3/25

Injection water flow rate in 1F-1 nuclear reactor accident

0.00E+00

5.00E+07

1.00E+08

1.50E+08

2.00E+08

2.50E+08

[炉心物質(Zr100%酸化）]溶融

[炉心物資(Zr100%酸化）＋下部プレナム物質]溶融

[崩壊熱ー徐熱]積算

崩壊熱積算

3/20 3/21 3/22 3/23

Ene

rgy

(kca

l) 1F-1

0

50

100

150

200

250

300

350

400

450

Feed water nozzleN4B end

RPV bottom

Time and date

Tem

pera

ture

(℃)

3/20 3/22 3/24 3/26 3/28 3/30

Measured temperature in 1F-1 nuclear reactor accident.

0

5

10

15

20

25

30

35

40W

ater

flow

rate

(m3 /h

)

Time and date

Injection water flow rate


3/11 3/13 3/15 3/17 3/19 3/21 3/23 3/25


0.00E+00

1.00E+08

2.00E+08

3.00E+08

4.00E+08

5.00E+08

6.00E+08


[炉心物資(Zr100%酸化）＋下部プレナム物質]溶融

[崩壊熱ー徐熱]積算

崩壊熱積算

3/21 3/22 3/23 3/24 3/25

Ener

gy (k

cal) 1F-3

0

10

20

30

40

50

60

70

80

90W

ater

flow

rate

(m3/

h )

Time and date


Injection water flow rate

3/11 3/16 3/21 3/26 3/31 4/5


0.00E+00

5.00E+07

1.00E+08

1.50E+08

2.00E+08

2.50E+08


[炉心物資(Zr100%酸化）＋下部プレナム物質]溶融 [崩壊熱ー徐熱]積算

[崩壊熱ー徐熱1]積算

3/28 3/29 3/30

1F-2

-200

-100

0

100

200

300

400

500

600Feed water nozzle N4B end

CRD housing upper part

RPV bottom

RPV support skirt upper part

RPV drain pipe upper part

Tem

pera

ture

(℃)

Time and date

3/20 3/25 3/30 4/4 4/9 4/14

Measured temperature in 1F-2 nuclear reactor accident

0

200

400

600

800

1000

2011/3/19 0:00 2011/3/21 0:00 2011/3/23 0:00 2011/3/25 0:00 2011/3/27 0:00 2011/3/29 0:00 2011/3/31 0:00

福島第一原発/事務本館北 *0.1

福島第一原発/正門

福島第一原発/西門

Dos

e ra

te (μ

Sv/h

)

0.01

0.1

1

10

100

2011/3/11 0:00 2011/3/16 0:00 2011/3/21 0:00 2011/3/26 0:00 2011/3/31 0:00

南相馬市飯館村福島市郡山市白河市いわき市

0.01

0.1

1

10

100

1000

10000Fukushima Daini NPPKitaibarakiTakahagiMitoTokyo(Shinjuku)YamagataFukushima Daiichi NPP Main Office Bdg. NorthFukushima Daiichi NPP Main GateFukushima Daiichi NPP West Gate

3/19 3/21 3/23 3/25 3/27 3/29 3/31

Dos

e ra

te (μ

Sv/h

) Measured dose rate

0.04

0.045

0.05

0.055

0.06

0.065

0.07

0.075

0.08

Time and date

3/14 3/19 3/24 3/29 4/3

Dose rate in Niigata

0.001

0.01

0.1

1

10

100

I-131(JCAC)

Cs-137(JCAC)

Cs-134(JCAC)

3/14 3/16 3/18 3/20 3/22 3/24 3/26 3/28 3/30 4/1 4/3 4/5 4/7

Air r

adio

activ

ity c

once

ntra

tion

(Bq/

m3 )

Air Radioactivity concentration (Bq/m3)

0.001

0.01

0.1

1

Cs-137/I-131(JCAC)

Cs-137/I-131(Prediction)

3/14 3/16 3/18 3/20 3/22 3/24 3/26 3/28 3/30 4/1 4/3 4/5 4/7

Air r

adio

activ

ity c

once

ntra

tion

ratio

Air radioactivity concentration ratio of Cs-137 and I-131

0.1

1

10

100

I-131(JCAC in Chiba)

I-131(KEK in Tsukuba)

Rad

ioac

tivity

con

cent

ratio

n (B

q/m

3 )

3/14 3/19 3/24 3/29 4/3

Time and date

Air radioactivity concentration of I-131 in Chiba and Tsukuba

1.000E-03

1.000E-02

1.000E-01

1.000E+00

Cs-137/I-131(Prediction)

Cs-137/I-131(JCAC in Chiba)

Cs-137/I-131(KEK in Tsukuba)

Rad

ioac

tivity

con

cent

ratio

n ra

tio

3/14 3/19 3/24 3/29 4/3

Time and date

Air radioactivity concentration rate of Cs-137 and I-131

Xe-133の観測

1E-05

0.0001

0.001

0.01

0.1

1

10

100

3/12 3/13 3/14 3/15 3/16 3/17 3/18 3/19 3/20 3/21 3/22 3/23 3/24 3/25 3/26 3/27 3/28 3/29 3/30 3/31 4/1

I-131放出率(TEPCO)

I-131放出率(JAEA)

I-131 放出率（Modifed JAEA rev.2：Tanabe)

I-131 放出率（Modifed JAEA rev.1：Tanabe)

Estimated discharge rate of I-131 from Fukushima Daiichi NPP Station D

isch

arge

rate

(PBq

/h)

1E-06

1E-05

0.0001

0.001

0.01

0.1

1

3/12 3/13 3/14 3/15 3/16 3/17 3/18 3/19 3/20 3/21 3/22 3/23 3/24 3/25 3/26 3/27 3/28 3/29 3/30 3/31 4/1

Cs-137放出率(TEPCO)

Cs-137放出率(JAEA)

Cs-137 放出率（Modifed JAEA rev.2：Tanabe) Cs-137 放出率（Modifed JAEA rev.1：Tanabe)

Estimated discharge rate of Cs-137 from Fukushima Daiichi NPP Station

Zry melting starts (terminates) 03/14 20:34 (20:51)

Tanabe’s English papers on Fukushima Daiichi NPP accident F. Tanabe, “Analysis of core melt in Fukushima Daiichi-Unit 1 nuclear reactor”, Journal of Nuclear Science and Technology, Vol.48, No.8, August (2011) pp.1135-1139 F. Tanabe, “Analysis of core Melt and re-melt in the Fukushima Daiichi nuclear reactors”, Journal of Nuclear Science and Technology, Vol.49, No.1, January (2012) pp.18-36 F. Tanabe, “A scenario of large amount of radioactive materials discharge to the air from the Unit 2 reactor in the Fukushima Daiichi NPP accident”, Journal of Nuclear Science and Technology, Vol.49, No.4, April (2012) pp.360-365

Post-facta Analysis of Fukushima Daiichi Accident …symbio-newsreport.jpn.org/.../presentation_1392399264.pdfPost-facta Analysis of Fukushima Daiichi Accident by Simple Physical Model

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