1

R&D Back-Up Activities for the Kurion Media System of the Contaminated Water Treatment

in Fukushima Daiichi Nuclear Power Station

Takeshi Tsukada1), Tadafumi Koyama1), Takatoshi Hijikata1), Kenta Inagaki1),

Keiji Ishikawa2), Shoichi Ono2), Shunichi Suzuki2), Mark Denton3), Gaetan Bonhomme3) and John Raymont3)

1) CRIEPI, 2) TEPCO, 3) KURION

2

Overview of Water Treatment System in Fukushima Daiichi

Since 9/14

Reactor Unit #1

Amount= 100,000m3

Radioactivity > 106 Bq/ml

Impurity= sea water, oil

Basement of Turbine Building

Contaminated Water

=> 250,000m3

Over flow ?

Since 8/18

2nd Cs Adsorption

TOSHIBA/Shaw

1200 ton/day

KURION

AREVA

Oil Separation

Cs

Precipitation Desalination

TOSHIBA Since 6/17

HITACHI-GE, AREVA

Since6/27 Since 6/24

Cs Adsorption

3

TMI Experience and Fukushima Challenges

Composition: -Radioactive elements similar to TMI

-Impurities of sea salt & mechanical oil

Throughput: 250,000ton/year (6,000ton/year for TMI)

Environment: Need to use existing building

-Limitation in weight and function of crane

-No water pool => Individual sielding

Lead time： About 2 months (2 years for TMI)

Difficulties compared with TMI water treatment system

CRIEPI others

Advisory and back-up R&Ds by Japanese

Specialists JAEA

HITACHI-GE TOSHIBA KURION AREVA

Government / TEPCO

Others

Back-up R&Ds carried out by CRIEPI to optimize design and operation of the KURION system.

1) Ion-exchange property 2) Small columns tests 3) Simulate code development 4) Estimation and optimization of the operation condition

Construction

4

Ion Exchange Property depends on Salt Content

KURION media for Cs absorption: H (Herschelite)

a b

0.0 56,200 29,900

0.034 28,100 16,000

0.34 4,000 2,040

1.0 1,290 782

2.0 777 462

3.4 465 267

Sea salt (wt%)

Langmuir coefficients

for the simulation code

bC

aCQ

1

: Cs loading (mmol/g) : Equilibrium Cs concentration in the solution (mmol/ml) , : Langmuir coefficients

C

Q

a b

0.0001

0.001

0.01

0.1

1

10

Cs

load

ing

(mm

ol/

g)

10-8

10-7

10-6

10-5

10-4

10-3

10-2

10-1

100

Equilibrium concentration (mmol/ml)

Sea salt contents: 0.0wt%: 0.034wt%: 0.34wt%: 1.0wt%: 2.0wt%: 3.4wt%

(Line:Langmuir equation)

5

Small-scale Column Experiments

Small-scale column test apparatus Typical break-through curves

0

0.2

0.4

0.6

0.8

1.0

0 1000 2000 3000 Bed Volumes

Sea salt = 0 %

Sea salt = 1 %

sea salt = 3 %

AGH H1 H2 H3

In order to simulate experimentally the adsorption behaviors in the KURON media system, a small-scale zeolite column was newly installed.

It consisted of four zeolite columns of 20 or 30 mm in dia. and 120 mm in length connected in series.

Specific flow rate is adjusted to around 14 to 81 cm/min for simulating the actual flow rate.

Rela

tive c

oncen

tration o

f C

s

C/C

0

6

Simulation Code Development for Zeolite Column

Diffusion and Convection

Migration to Surface

)|()1(3

2

2

Rr

pb

b

bfb

b

b

ccR

k

x

cu

x

cD

t

c

diffusion convection migration to surface

Inter-Particle

Intra-Particle

)2

(

)1(

12

2

r

c

rr

cD

c

Qt

c pp

pp

ppp

p

diffusion adsorption

0

0.2

0.4

0.6

0.8

1.0

0 1000 2000 3000

Bed Volumes

Rela

tive c

oncentr

ation o

f C

s

C/C

0

Sea salt=0wt%

sea salt=1wt% sea salt= 3wt%

diffusion

adsorption

Inter- particle

Intra-particle

7

Adaptation of Code to Actual KURION System

Kinetic properties were expected to be same as those obtained in small-scale column tests, because specific flow rate is same. Simulation code agreed well with measured DF in KURION System

Cs adsorption behavior

A G H

H 1

H 2

H 3

Inlet

10 20 0 30 40

1

2

3

0

Time /hr

Ad

sorb

ed C

s /

mo

l

Ou

tlet

7

1

10

102

103

104

105

106

DF

計算結果

7/2 7/6 7/10 7/14 7/18 7/22 7/26 7/30 8/3 8/7 8/11 8/15 8/19

date

2wt%

Concentration in contaminated water

1.95wt% 1.8wt% 1.7wt%

0.5ppm Cs 0.7ppm

Cs137 Cs134

Calculation

Measurement

sea salt= 3wt.%

Verification of Code by Actual Operation

8

Optimization of the Operational Plan

Estimation of DF

Actual operation plan was optimized with an assistance of

code.

A G H

H 1

H 2

H 3

Inlet

Ou

tlet

Spent column New column

Interval to exchange column /day

Flow rate (m3/hr)

Operational Parameters

10 1

10 3

10 5

10 7

10 9

10 11

10 13

10 15

DF

35 30 25 20 15 10 5 0

days

6m3/h, 2 days

8m3/h, 2days

12m3/h, 2days

10m3/h, 2days

4m3/h, 5days

5m3/h, 4days

6.6m3/h, 3days

Target DF

Flow & interval

9

(as Conclusions) How Much Water Has Been Treated ?

161,580 ton in total till Nov.14th Since September, water level has kept around 3,000 mm

O.P., where overflow can be avoided even for strong rainfall.

6/17 7/2 7/17 8/1 8/16 8/31 9/15 9/30 10/15

2800

3000

3200

3400

3600

3800

4000

8/18 2nd Cs adsorption start operation

6/17 start operation

Water level(mm) 161,580 ton

140,000

120,000

100,000

80,000

60,000

40,000

20,000

0

Total Treated

Amount

Treated amount (ton)

Target level

U3-T/B

U2-T/B

10/30 11/15

160,000

10

Appendix: Zeolite column engineering for dry-reprocessing technology

Long experience in zeolite column engineering as dry-reprocessing technology for spent nuclear fuels.

Spent molten salt （electrolyte）

Recycle to electrorefiner

A zeolite