R&D Back-Up Activities for the Kurion Media System …1 R&D Back-Up Activities for the Kurion Media...
Transcript of R&D Back-Up Activities for the Kurion Media System …1 R&D Back-Up Activities for the Kurion Media...
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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
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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
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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
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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)
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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
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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
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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
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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
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(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
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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