Transcript Document

17th Symposium of AER
on VVER Reactor Physics and Reactor Safety
Reduced
leakage
September 24-29, 2007, Yalta, Crimea, Ukraine
ADVANCED FUEL CYCLES
FOR VVER-1000 REACTORS
Semchenkov Y.M., Pavlovichev A.M., Pavlov V.I., Spirkin E.I.,
Styrin Y.A. and Kosourov E.K.
RRC “Kurchatov Institute”
Moscow, Russia
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Introduction
In the present report following themes are discussed:
 Reduced
Stages of development of the Russian uranium fuel from the
leakage
point of view of increase of safety and profitability of fuel
loadings operation
 Neutron-physical and economic characteristics of present-day
and perspective uranium fuel cycles
 Potential of uranium-plutonium regenerate use in VVER-1000
reactors
 Potential of weapon-grade plutonium disposition in VVER1000 reactors
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Evolution of VVER-1000 fuel cycles
Factor
FA structural material
Burnable absorber
Factor score
Yesterday Today Future
steel
zirconium
Hf
Boric rods
U-Gd fuel
Results
Deleterious neutron
absorption
Radio-active waste
Max Kr, Ql
Stability of FA geometry
Low
High
FA burnup limit
Max Kr, Ql
Fuel enrichment, %
no more than 4.4
Pellet outside diameter, mm
7.57
Central hole diameter, mm
1.5/1.4
Fuel height, mm
3530
FA burnup limit,
MWd/kgU
Number of fresh FA on core
periphery , %
49
100
55
~ 60
4.95
7.6 7.8
1.2 0.0
3530 (3680)
FA energy potential
60-68
0 - 30
Neutron leakage
Neutron flux on
reactor vessel
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Average burnup versus number of loaded FAs,
FA enrichment and cycle length
Reduced
leakage
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Natural uranium consumption versus number of loaded FAs,
FA enrichment and cycle length
270
1
Natural uranium consumption, g/MWd
Reduced
260
leakage
250
1
– 81 FA, steel
2
– 54 FA, steel
3
– 48 FA
– 42 FA
240
2
5.0%
4.4% 4.6% 4.8%
4.2%
4.0%
78
3.6% 3.8%
230
72
66
220
60
54
210
48
3
200
42
36
190
200
250
300
350
400
450
500
550
Cycle length, EFPD
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Cost of electricity generation versus number of loaded FAs,
FA enrichment and cycle length (cost of fuel-20%, reloading – 65 days)
Reduced
leakage
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Cost of electricity generation versus number of loaded FAs,
FA enrichment and cycle length (cost of fuel-30%, reloading – 65 days)
Reduced
leakage
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Cost of electricity generation versus number of loaded FAs,
FA enrichment and cycle length (cost of fuel-20%, reloading – 40 days)
Reduced
leakage
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Average burnup versus number of loaded FAs,
FA enrichment and cycle length
70
Average burnup, MW*d/kgHM
B1 – Fuel rod characteristics -7.57/ 1.4/ 353 cm, reduced leakage
B2 – Fuel rod characteristics - 7.57/ 1.4/ 353 cm, low leakage
Reduced
65
B3 – Fuel rod characteristics -7.60/ 1.2/ 368 cm, low leakage
leakageB4 – Fuel rod characteristics -7.8/ 0/ 368 cm, low leakage
60
36
42
55
54
50
66
36
42
5.0%
54
45
66
В2
78 В1
40
В3
В4
В3
78 В2
В4
4.4%
35
250
300
350
400
450
500
550
600
650
Cycle length, EFPD
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Loading patterns of advanced equilibrium cycles
Height of core – 3680 mm, fuel pellet diameter -7,6 mm, central hole - 1,2 mm
12-month cycle (36 FAs)
Average enrichment – 4,83%
Reduced
Cycle length – 324 EFPD
leakage time – 4 or 5 cycles
FA operational
18-month cycle (60 FAs)
Average enrichment – 4,88%
Cycle length – 478 EFPD
FA operational time – 2 or 3 cycles
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Main neutronic characteristics of advanced equilibrium cycles
Today's Advanced cycles
12-month 12-month 18-month
Core height, cm
353
368
368
Amount of loaded uranium FAs, pcs
42
36
60
Amount of UGBA rods in loaded uranium FAs, pcs
252
216
900
Average enrichment, %
4,33
4,83
4,88
8,1
8,4
9,5
Reactivity compensated by liquid boron, % k/k (BOC)
Cycle length, EFPD
297
324
478
Burnup of unloaded uranium Average
49,2
58,5
52,0
FAs, MWd/kg HM
53
62
61
Maximum over FAs
Boric acid critical concentration at BOC, HFP, (g/kgH2O)
6,3
7,2
8,7
Maximal relative power of fuel rods in the core, Krmax
1,46
1,59
1,56
Maximal value of fuel rods linear heat rate, W/cm
285
323
318
-4,4
-0,6
Moderator temperature reactivity coefficient at BOC, HZP ( pcm/C) -4,7
Boric acid concentration at BOC, CZP, no Xe, =-2% (g/kg H2O)
10,7
12,4
13,8
o
Repeated criticality temperature at EOC, Xe и Sm, no boron ( С)
182
195
182
Effective fraction of delayed neutrons, %
BOC 0,63
0,63
0,66
EOC 0,56
0,56
0,55
Natural uranium consumption, g/MWd
200
188
214
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Uranium-plutonium regenerate in VVER-1000
It was proposed to use uranium-plutonium regenerate in
Reduced
thermal reactors by using spent fuel of these reactors cleaned from
leakage
other actinides and fission products, and by following mixing of
cleaned fuel with enriched uranium
Weight fraction of uranium-plutonium regenerate and
highly enriched uranium at their mixing is 0,8 and 0,2
correspondingly
Enrichment of highly enriched uranium has been defined
from a set of calculations under condition that the equilibrium
cycle of VVER-1000 with feed by 42 fresh FAs has the same cycle
length as the design uranium cycle. The enrichment of highly
enriched uranium for uranium-plutonium fuel was 17,1%
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Isotopic content of regenerated fuel (kg/tHM)
Nuclide
Reduced
leakage
234
U
U
236
U
238
U
U
238
Pu
239
Pu
240
Pu
241
Pu
242
Pu
Pu
235
U+239Pu+241Pu
235
Uranium
fuel,
Regenerated
uranium fuel,
kg/tHM
0
43,3
0
956,7
1000
0
0
0
0
0
0
43,3
kg/tHM
1,5E-3
44,98
4,77
950,25
1000
0
0
0
0
0
0
44,98
Regenerated
uraniumplutonium fuel,
kg/tHM
1,5E-3
41,40
4,71
943,90
990
0,25
5,37
2,55
1,14
0,69
10
47,91
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Main neutronic characteristics of equilibrium cycles with
regenerated uranium-plutonium fuel
Reduced
leakage
Amount of loaded FAs, pcs
Content of 235U, %
Content of 235U+239Pu +241Pu, %
Cycle length, EFPD
Reactivity compensated by liquid boron, BOC, % k/k
Boric acid critical concentration at BOC, HFP, g/kg H2O
Maximal relative power of fuel rods in the core (Krmax)
Maximal value of fuel rods linear heat rate, W/cm
Moderator temperature reactivity coefficient at BOC, HZP, pcm/C
Boric acid concentration at BOC, CZP,=-2%, g/kg H2O
Repeated criticality temperature at EOC, Xe и Sm, no boron, oС
Effective fraction of delayed neutrons, %
BOC
EOC
-5
Effective lifetime of fission prompt neutrons, 10 s
BOC
EOC
Natural uranium consumption, g/MWd
Uranium Regenerated Regenerated
fuel
uranium
uraniumfuel
plutonium
fuel
42
4,33
4,48
4,14
4,33
4,48
4,79
297
8,1
8,0
6,4
6,3
1,46
285
-4,7
10,7
182
0,63
0,56
2,0
2,3
200
6,3
1,47
293
-6,0
11,2
183
0,63
0,56
1,9
2,2
185
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6,0
1,46
288
-11,6
12,3
185
0,58
0,55
1,6
1,9
168
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Weapon Plutonium MOX FA in VVER-1000 core
Preliminary researches with participation of US, French and
German experts have shown possibility of use of W-МОХ
fuel
in existing VVER-1000.
Reduced
leakage
Fuel rod with high plutonium
content
Fuel rod with medium
plutonium content
Fuel rod with low plutonium
content
Low
leakage
UGBA rod
Guide tube
Instrumental tube
The pattern of the typical MOX FA
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Loading patterns of equilibrium cycles with MOX FAs
Reduced
leakage
MOX FAs- 30, UOX FAs-24
307 EFPD
684 UGBA
MOX FAs- 36, UOX FAs- 36
465 EFPD
1188 UGBA
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Main characteristics of equilibrium cycles with MOX fuel
Amount of loaded uranium FAs, pcs
Reduced
Amount of loaded MOX FAs, pcs
leakage
MOX
fuel rods part in core, %
Cycle length, EFPD
Annual plutonium consumption, kg
Average burnup of unloaded uranium FAs, MWd/kg HM
Average burnup of unloaded MOX FAs, MWd/kg HM
Maximal relative power of fuel rods in the core (Krmax)
Maximal value of fuel rods linear heat rate, W/cm
Boric acid critical concentration at BOC, HFP, (g/kg H2O)
Moderator temperature coefficient ( pcm/C)
1218month month
24
36
30
36
38.2
40.3
307
465
445
450
50.4
46.3
31.1
43.5
1.41
1.47
278
306
7.7
10.7
-6
-1
Boric acid concentration at BOC,CZP,=-2%,(g/kg H2O) 13.2
180*
Repeated criticality temperature, oС
Natural uranium consumption, g/MWd
200
16.2
177*
185
* CR CPS boron is enriched by the isotope boron-10 up to 80%
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Conclusion
Advanced uranium fuel cycles for VVER-1000 ensure under meeting
safety requirements:
Reduced
effective use of natural uranium;
leakage
possibility of cycle length variation in a wide interval and consequently
possibility of NPP power production adaptation to demands of power net and
to eventual changes in relations between components of electricity generation
cost;
reducing of neutron fluence on reactor vessel in view of its service life
prolongation.
Expanding of fuel raw material nomenclature is possible for VVER1000 by using regenerated uranium and uranium-plutonium fuel.
VVER-1000 reactors could ensure a high rate of weapon-grade
plutonium disposition at effective using of plutonium power potential.
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