Workshop on Advanced Reactors With Innovative Fuels
February 16-18, 2005 • Oak Ridge, TN USA
Eugene Shwageraus1
Pavel Hejzlar2 and Mujid S. Kazimi2
1Ben-Gurion
University of the Negev, Israel
2Center
for Advanced Nuclear Energy Systems
Massachusetts Institute of Technology, Cambridge MA
Workshop on Advanced Reactors with Innovative Fuels , February 16-18, 2005 • Oak Ridge, TN USA
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Outline
Introduction
Options for Multi-recycling of TRU in PWR
Description of COTTU concept
Calculation Methodology
Results
Summary and Conclusions
Workshop on Advanced Reactors with Innovative Fuels , February 16-18, 2005 • Oak Ridge, TN USA
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TRU Multi-Recycling
“Expensive”
Repository
Spent fuel
Once – Through
TRU+FP
Fuel Cycle
“Cheap” Repository
Multi-Recycling
Short-lived FP
TRU+LLFP
Reprocessing losses
Fuel Fabrication Plant
Fuel Reprocessing Plant
Workshop on Advanced Reactors with Innovative Fuels , February 16-18, 2005 • Oak Ridge, TN USA
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TRU Multi-Recycling Options
Fertile free fuel
CONFU
CONFU
Uranium MOX
Homogeneous
(MIX)
Heterogeneous
(CORAIL, APA)
CORAIL
UO2
Thorium MOX
Homogeneous
Heterogeneous
(COTTU)
MOX
Guide tube
Workshop on Advanced Reactors with Innovative Fuels , February 16-18, 2005 • Oak Ridge, TN USA
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Effect of Complete TRU Recycling
Workshop on Advanced Reactors with Innovative Fuels , February 16-18, 2005 • Oak Ridge, TN USA
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COTTU Assembly Concept
Combined TRU-ThO2 and UO2 Assembly
Similar to CORAIL and CONFU
Advantages of using Thorium
Existing experience as a fuel
Limits TRU generation
Efficient TRU destruction
Low TRU inventory
Some experience with reprocessing
Drawbacks
Reprocessing is more difficult than U-MOX
Handling issues due to U232
Workshop on Advanced Reactors with Innovative Fuels , February 16-18, 2005 • Oak Ridge, TN USA
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Calculated Cases
CONFU-1:
60 FFF-TRU pins per assembly, “small” TRU inventory
CONFU-2:
48 FFF-TRU pins per assembly, “large” TRU inventory
(equilibrium cycle only)
COTTU-1:
60 Th-TRU pins per assembly, 233U recycled together with
TRU in Th pins
COTTU-2:
60 Th-TRU pins per assembly, 233U recycled separately
from TRU in UO2 pins
UO2:
Standard Reference UO2 fuel, 4.2% enrichment
Workshop on Advanced Reactors with Innovative Fuels , February 16-18, 2005 • Oak Ridge, TN USA
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CONFU and COTTU Assembly Options
Standard
UO2 Pins
Guide
Tube
Guide
Tube
Standard
UO2 Pins
ThO2/FFFTRU Pins
FFF Pins
CONFU-2
CONFU-1, COTTU-1, COTTU-2
Workshop on Advanced Reactors with Innovative Fuels , February 16-18, 2005 • Oak Ridge, TN USA
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Calculation Methodology
Typical PWR 17x17 fuel assembly geometry
Typical PWR operating conditions
2-D Assembly level calculations
CASMO-4 code
Linear reactivity model, 3% leakage reactivity
3-batch core, 18 Months cycle
20 years decay time between TRU recycles
Workshop on Advanced Reactors with Innovative Fuels , February 16-18, 2005 • Oak Ridge, TN USA
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Results
Workshop on Advanced Reactors with Innovative Fuels , February 16-18, 2005 • Oak Ridge, TN USA
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Concepts Comparison
CONFU-1 CONFU-2 COTTU-1 COTTU-2
UO2 loading, kg/assembly
Reference
UO2
355
375
355
353
459
5
5
5
5
4.2
12.5
17.5
23.5
16.0
-
60
48
60
60
-
89:11
80:20
78:22
87:13
-
0.0
- 0.1
- 0.1
0.0
+ 5.7
Discharge assembly burnup,
EFPD
1298
1348
1336
1267
1330
Max. assembly pin power
peaking factor
1.18
1.21
1.25
1.22
1.06
UO2 enrichment, w/o
TRU loading (BOL), kg/assembly
No. of TRU pins per assembly
TRU pin composition, v/o
Matrix:(TRU)O2
Net TRU production, kg/assembly
Workshop on Advanced Reactors with Innovative Fuels , February 16-18, 2005 • Oak Ridge, TN USA
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Results: TRU Inventory, kg/assembly
CONFU - 1
TRU inventory (at EOL+20y), kg/assembly
24.0
COTTU - 1, TRU only
COTTU - 1, TRU + U233
22.0
COTTU - 2, TRU only
COTTU - 2, TRU + U233
20.0
18.0
16.0
14.0
12.0
10.0
8.0
1
2
3
4
5
6
7
8
9
10 11 12 13 14 15 16 17 18 19 20
Recycle stage
Workshop on Advanced Reactors with Innovative Fuels , February 16-18, 2005 • Oak Ridge, TN USA
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Results: Discharge Burnup
Discharge Burnup, EFPD
1400
1350
CONFU - 1
1300
COTTU - 1
1250
COTTU - 2
1200
1150
1100
1050
1000
1
2
3
4
5
6
7
8
9
10 11 12 13 14 15 16 17 18 19 20
Recycle stage
Workshop on Advanced Reactors with Innovative Fuels , February 16-18, 2005 • Oak Ridge, TN USA
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Results: Pin Power Peaking Factors
Lifetime Maximum Assembly Pin Power Peak
1.40
CONFU - 1
COTTU - 1
1.35
COTTU - 2
1.30
1.25
1.20
1.15
1.10
Recycle stage
Workshop on Advanced Reactors with Innovative Fuels , February 16-18, 2005 • Oak Ridge, TN USA
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Results: Cf-252 Inventory, g/assembly
Cf-252 inventory (at EOL+20y), g/assembly
0.0050
CONFU - 1
0.0045
COTTU - 1
0.0040
COTTU - 2
0.0035
0.0030
0.0025
0.0020
0.0015
0.0010
0.0005
0.0000
1
2
3
4
5
6
7
8
9 10 11 12 13 14 15 16 17 18 19 20
Recycle stage
Workshop on Advanced Reactors with Innovative Fuels , February 16-18, 2005 • Oak Ridge, TN USA
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Reactivity Coefficients
Doppler coefficient (BOL),
pcm/K
Moderator Temperature
Coefficient (BOL), pcm/K
Soluble Boron Worth (BOL),
pcm/ppm
CONFU-2
COTTU-1
1st recycle
-1.77
-2.14
3rd recycle
-1.99
-2.30
15th recycle
-2.00
-2.34
1st recycle
-17.8
-24.9
3rd recycle
-20.6
-26.8
15th recycle
-20.8
-27.0
1st recycle
-4.93
-4.99
3rd recycle
-5.69
-5.30
15th recycle
-5.71
-5.42
Reference
UO2
Workshop on Advanced Reactors with Innovative Fuels , February 16-18, 2005 • Oak Ridge, TN USA
-2.03
-11.26
-6.11
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Summary and Conclusions
Zero net TRU production can be achieved with COTTU
assembly
TRU inventory is larger for COTTU than for CONFU due
to generation of U233
Degradation of TRU isotopics requires an increase in
UO2 pins enrichment to 5%
Similar to CONFU, the COTTU concept appears to be
practical – reactivity coefficients and power peaking are
acceptable
Cm and Cf252 builds up slower in COTTU than in CONFU
Recycling U233 in UO2 improves pin power peaking but
reduces cycle length
Existing experience with Th fuel - main advantage over
CONFU
Workshop on Advanced Reactors with Innovative Fuels , February 16-18, 2005 • Oak Ridge, TN USA
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BACKUP SLIDES
Workshop on Advanced Reactors with Innovative Fuels , February 16-18, 2005 • Oak Ridge, TN USA
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Cm Inventory
Cm inventory (at EOL+20y), kg/assembly
1.0
0.9
CONFU - 1
0.8
COTTU - 1
0.7
COTTU - 2
0.6
0.5
0.4
0.3
0.2
0.1
0.0
1
2
3
4
5
6
7
8
9 10 11 12 13 14 15 16 17 18 19 20
Recycle stage
Workshop on Advanced Reactors with Innovative Fuels , February 16-18, 2005 • Oak Ridge, TN USA
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Pu-238 Inventory
Pu-238 inventory (at EOL+20y), kg/assembly
2.00
1.80
1.60
1.40
1.20
1.00
0.80
0.60
CONFU - 1
0.40
COTTU - 1
0.20
COTTU - 2
0.00
1
2
3
4
5
6
7
8
9 10 11 12 13 14 15 16 17 18 19 20
Recycle stage
Workshop on Advanced Reactors with Innovative Fuels , February 16-18, 2005 • Oak Ridge, TN USA
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Pu-239 Inventory
Pu-239 inventory (at EOL+20y), kg/assembly
5.00
CONFU - 1
COTTU - 1
4.50
COTTU - 2
4.00
3.50
3.00
2.50
2.00
1
2
3
4
5
6
7
8
9 10 11 12 13 14 15 16 17 18 19 20
Recycle stage
Workshop on Advanced Reactors with Innovative Fuels , February 16-18, 2005 • Oak Ridge, TN USA
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Pu-240 Inventory
Pu-240 inventory (at EOL+20y), kg/assembly
4.50
4.00
3.50
3.00
2.50
2.00
1.50
CONFU - 1
1.00
COTTU - 1
COTTU - 2
0.50
0.00
1
2
3
4
5
6
7
8
9 10 11 12 13 14 15 16 17 18 19 20
Recycle stage
Workshop on Advanced Reactors with Innovative Fuels , February 16-18, 2005 • Oak Ridge, TN USA
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Pu-241 Inventory
Pu-241 inventory (at EOL+20y), kg/assembly
0.90
CONFU - 1
COTTU - 1
0.80
COTTU - 2
0.70
0.60
0.50
0.40
0.30
1
2
3
4
5
6
7
8
9 10 11 12 13 14 15 16 17 18 19 20
Recycle stage
Workshop on Advanced Reactors with Innovative Fuels , February 16-18, 2005 • Oak Ridge, TN USA
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Pu-242 Inventory
Pu-242 inventory (at EOL+20y), kg/assembly
3.50
3.00
2.50
CONFU - 1
2.00
COTTU - 1
COTTU - 2
1.50
1.00
1
2
3
4
5
6
7
8
9 10 11 12 13 14 15 16 17 18 19 20
Recycle stage
Workshop on Advanced Reactors with Innovative Fuels , February 16-18, 2005 • Oak Ridge, TN USA
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