Materi yang disampaikan pada Workshop on Evaluation of HTGR Pebble Bed Type, Rabu 22 April 2015.
Mencakup:
- perbedaan antara High Temp. Gas-cooled Reactor (HTGR) dengan Light Water Reactor (LWR)
- Prinsip Keselamatan HTGR tipe pebble bed: Control, Cooling, Contain.
- Perhitungan kritikalitas dan equilibrium teras reaktor HTGR tipe pebble bed.
1. High Temperature Gas-cooled Reactor
Topan Setiadipura
tsdipura@batan.go.id
Pusat Teknologi dan Keselamatan Reaktor Nuklir
BATAN
T.Setiadipura, Workshop Evaluasi Desain HTGR, BAPETEN, 22 April 20154/23/2015 1
2. Bahasan
1. Desain HTGR (Vs. PWR)
2. Fitur Keselamatan HTGR
3. Desain dan Analisis HTGR
1. Konsep desain dan keselamatan
2. Perhitungan Kritikalitas
3. Perhitungan Equilibrium (burnup)
4. Sejarah HTGR
T.Setiadipura, Workshop Evaluasi Desain
HTGR, BAPETEN, 22 April 2015
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15. Fitur Keselamatan
• Power density yang rendah (~3 W/cm3)
• Heat capacity dan conductivity yang tinggi.
• Pengungkungan produk fisi yang baik pada
bahan bakar hingga pada temp. tinggi. (limit
1620oC, karena teknologi TRISO ).
• Koeff. temp. negatif yang tinggi.
• Kemampuan `afterheat removal through the
vessel wall` (diameter teras yang kecil ~3m)
• Excess reactivity yang rendah (karena on-line
refueling).
T.Setiadipura, Workshop Evaluasi Desain
HTGR, BAPETEN, 22 April 2015
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16. Fitur Keselamatan(1): Control
Secara inherent/melekat teras reaktor dapat mengkontrol laju reaksi fisi
bahkan hingga menghentikannya.
T.Setiadipura, Workshop Evaluasi Desain
HTGR, BAPETEN, 22 April 2015
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HTR-Module
Siemens Design
17. Fitur Keselamatan(1): Control
Secara inherent/melekat teras reaktor dapat mengkontrol laju reaksi fisi
bahkan hingga menghentikannya.
T.Setiadipura, Workshop Evaluasi Desain
HTGR, BAPETEN, 22 April 2015
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HTR-Module
Siemens Design
18. Fitur Keselamatan(2): Cooling
Mampu mengeluarkan panas yang dihasilkan dengan hanya bergantung
pada mekanisme alamiah tanpa perlu tindakan aktif:
T.Setiadipura, Workshop Evaluasi Desain
HTGR, BAPETEN, 22 April 2015
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rcore
19. Fitur Keselamatan(3): Contain
Rilis zat radioaktif yang sangat kecil kepada lingkungan dalam
kondisi apapun, bahkan pada kecelakaan terparah sekalipun:
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HTGR, BAPETEN, 22 April 2015
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20. TRISO Integrity
T.Setiadipura, Workshop Evaluasi Desain
HTGR, BAPETEN, 22 April 2015
Faktor utama dari fitur keselamatan `contain` tersebut adalah lapisan SiC
(Silikon Karbida) pada partikel bahan bakar TRISO.
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FailedParticleFraction
German Fuel
21. TRISO Integrity
T.Setiadipura, Workshop Evaluasi Desain
HTGR, BAPETEN, 22 April 2015
Faktor utama dari fitur keselamatan `contain` tersebut adalah lapisan SiC
(Silikon Karbida) pada partikel bahan bakar TRISO.
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22. Skema Operasi Pebble Bed Reactor(1)
Skema strategi pengisian bahan bakar Multipass dan OTTO pada reaktor
PBR.
T.Setiadipura, Workshop Evaluasi Desain
HTGR, BAPETEN, 22 April 2015
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23. Skema strategi pengisian bahan bakar peu-a-peu pada
reaktor PBR.
Skema Operasi Pebble Bed Reactor(2)
T.Setiadipura, Workshop Evaluasi Desain
HTGR, BAPETEN, 22 April 2015
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24. Sistem Penanganan Bahan Bakar
HTR-Module
Siemens Design
(Multipass)
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T.Setiadipura, Workshop Evaluasi Desain
HTGR, BAPETEN, 22 April 2015
32. CFP Modeling
• Coated Fuel
Particles (CFP)
are modeled
explicitly in this
benchmarking
calculation.
T.Setiadipura, Workshop Evaluasi Desain
HTGR, BAPETEN, 22 April 2015
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33. Pebble Fuel Model
Statistical Geometry Model Regular Lattice Model
Statistical Vs. Regular Lattice Model
T.Setiadipura, Workshop Evaluasi Desain
HTGR, BAPETEN, 22 April 2015
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36. ASTRA Benchmark Model(1)
1. Annular Core
2. Bottom reflector
3. Lower part IR support
structure (air)
4. Upper part IR support
structure (metal)
5. Side graphite
reflector
6. Separating sheet
7. Top reflector
8. Internal reflector (IR)
T.Setiadipura, Workshop Evaluasi Desain
HTGR, BAPETEN, 22 April 2015
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37. ASTRA Benchmark Model(2)
Borings Function
CR1, … CR7 Channels for
Control rods
CR1-CR7
MR Channel for
Manual Rod
SR1, …SR8 Channels for
Safety rods
SR1-SR8
LIPR1, LIPR2 Channels for
Placement of
Rods LIPR1
and LIPR2
Outer dimension of side reflector is 380 cmT.Setiadipura, Workshop Evaluasi Desain
HTGR, BAPETEN, 22 April 2015
4/23/2015 37
38. ASTRA Benchmark Model(3)
Model of
-Control
Rods (CR)
- Safety Rods
(SR)
- Leave in
Place Rods
(LIPR)
Contain B4C
material.
Model of Manual Rods (MR),
made of Aluminum.
T.Setiadipura, Workshop Evaluasi Desain
HTGR, BAPETEN, 22 April 2015
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39. ASTRA Benchmarking Cases
Cas
e
Position, Z, along the channel height,
cm*
Core
Height**
Packing
Fraction
LIPR1 LIPR2 MR CR5 Hc fi
1 OUT OUT 178.8 402.6 180.354 0.59914
2 42.6 OUT 160.5 402.6 215.134 0.60304
3 42.6 42.6 225.1 402.6 292.584 0.6048
4 42.6 42.6 403.5 184.6 321.044 0.60618
5 42.6 42.6 403.5 93 321.044 0.60618
Case
Position, Z, along the channel height, cm
CR1 CR2 CR3 CR4 CR6 CR6 SR 1-8
All
Case
404.8 402.8 391.2 398.7 395.1 395 400
* Z vertical distance between the bottom of the graphite reflector (bottom
surface of SRf and BR) and bottom of the poison rod
** Core height is from the upper boundary of the bottom reflector of lower
boundary of the core.
T.Setiadipura, Workshop Evaluasi Desain
HTGR, BAPETEN, 22 April 2015
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41. Perhitungan Teras Equilibrium
Burnup Calculation of Moving Core Pebble Bed Reactor
T.Setiadipura, Workshop Evaluasi Desain
HTGR, BAPETEN, 22 April 2015
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42. Concept of PBR BU Calculation
The interdependence of neutron flux and nuclide density requires
that the depletion equation should be solve simultaneously with
neutronic core calculation. The common method applied multi-
group neutron diffusion approximation for neutronic core
calculation.
Depletion analysis in PBR type needs to account simultaneously for the
movement of the fuel elements and for the changes of their composition.
Modeled as
T.Setiadipura, Workshop Evaluasi Desain
HTGR, BAPETEN, 22 April 2015
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43. Equilibrium Analysis of 10MWt Small PBR
Design parameters [units] Values
Power [MWt] 10
Core height [cm] 196.5
Core diameter [cm] 180
Top reflector height [cm] 90
Bottom reflector height [cm] 121
Void region height [cm] 42
Power density [W/cc] 2
U-235 enrichment [wt%] 10
Axial fuel velocity [cm/day] 0.5
Core residence time [days] 393
Initial and equilibrium keff for different HM/pebble
T.Setiadipura, Workshop Evaluasi Desain
HTGR, BAPETEN, 22 April 2015
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44. T.Setiadipura, Workshop Evaluasi Desain
HTGR, BAPETEN, 22 April 2015
• Effective multiplication factor for different HM-loading with 20% U-
235 enrichment. HM-loading of 2.1 g/pebble was the lowest to
achieve a critical equilibrium core.
• The related optimized burnup is of 69.4 MWd/kg-HM achieved
by 20% U-235 enrichment and 2.1 gHM/pebble.
0.95
1
1.05
1.1
1.15
1.2
1.25
1.3
0 100 200 300 400 500 600 700 800 900
EffectiveMultiplicationFactor
Operation Time (days)
1.4 gHM/pebble
1.6 gHM/pebble
1.8 gHM/pebble
2 gHM/pebble
2.1 gHM/pebble
2.5 gHM/pebble
3 gHM/pebble
4 gHM/pebble
Parametric survey for 20wt% enrichment
Equilibrium Analysis of 10MWt Small PBR
4/23/2015 44
45. T.Setiadipura, Workshop Evaluasi Desain
HTGR, BAPETEN, 22 April 2015
Effect of lower HM loading (also means lower burnup):
- increase the burnup
- increase and shift the peak power density to the upper part
of the core.
1
1.2
1.4
1.6
1.8
2
2.2
2.4
0 2 4 6 8 10 12 14 16 18 20
PowerDensity[W/cm3]
Axial Region (top to bottom)
4 ; 20wt%
3 ; 20wt%
2.5 ; 20wt%
2.1;20wt%
Power density profile for different HM-loading.
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46. T.Setiadipura, Workshop Evaluasi Desain
HTGR, BAPETEN, 22 April 2015
1.3494
1.3857
1.3597
1.3282
1.2867
1.2642
1.2338
1.0114
1.0333
1.0448 1.0537 1.0603 1.0565 1.0519
0.9000
1.0000
1.1000
1.2000
1.3000
1.4000
1.5000
5 7 9 11 13 15 17 19 21
Eff.MultiplicationFactor
HM-Loading[g-HM/pebble]
Init. Core
Equil. Core
Effective multiplication for different HM loading with 15wt% U-235 enrichment of initial and
equilibrium core.
For 15wt% enrichment of U-235, the lowest HM-loading to achieve critical equilibrium condition
is 8 gHM/pebble.
Equilibrium Analysis of 200MWt PBR
4/23/2015 46
47. T.Setiadipura, Workshop Evaluasi Desain
HTGR, BAPETEN, 22 April 2015
Effective multiplication for different HM loading with 17wt% U-235
enrichment of initial and equilibrium core
1.461 1.445
1.435
1.427
1.373
1.341
1.300
1.278
1.250
1.0229
1.0800
1.0876 1.0862 1.0827 1.0805
0.900
1.000
1.100
1.200
1.300
1.400
1.500
0 5 10 15 20 25
Eff.MultiplicationFactor
HM-Loading [g-HM/pebble]
Init. Core
Equil. Core
For 17wt% enrichment of U-235, the lowest HM-loading to achieve critical equilibrium condition
is 7 gHM/pebble.
Equilibrium Analysis of 10MWt Small PBR
4/23/2015 47
48. T.Setiadipura, Workshop Evaluasi Desain
HTGR, BAPETEN, 22 April 2015
Effective multiplication for different HM loading with
20wt% U-235 enrichment of initial and equilibrium core
1.483
1.477
1.464
1.447
1.393
1.360
1.319
1.298
1.270
1.039
1.083
1.121 1.125 1.121 1.116 1.115
0.900
1.000
1.100
1.200
1.300
1.400
1.500
1.600
0 5 10 15 20 25
Eff.MultiplicationFactor
HM-Loading [g-HM/pebble]
Init. Core
Equil. Core
For 20wt% enrichment of U-235, the lowest HM-loading to achieve critical equilibrium condition
is 6 gHM/pebble.
Equilibrium Analysis of 10MWt Small PBR
4/23/2015 48
50. Power Density & Effect of Velocity
6.34
3.41
0.00
1.00
2.00
3.00
4.00
5.00
6.00
7.00
0 2 4 6 8 10 12 14 16 18 20
PowerDensity[kW/pebble]
Axial Region (top to bottom)
v=0.5cm/day v=0.8cm/day
200MWt ; 20wt% ; 6 gHM/pebble
T.Setiadipura, Workshop Evaluasi Desain
HTGR, BAPETEN, 22 April 2015
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51. Parameter Desain
T.Setiadipura, Workshop Evaluasi Desain
HTGR, BAPETEN, 22 April 2015
• Skema pemuatan bahan bakar: Multipass /
OTTO / Peu a Peu
•Geometri teras dan bahan bakar
• Pengayaan U-235
• Pemuatan Heavy Metal (HM) per pebble
(fraksi volume CFP di fuel zone pebble bed)
• Kecepatan axial rerata bahan bakar / core
residence time.
• BU target
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52. Tantangan dan Peluang ?
- Cost memperkecil biaya pembangkitan.
- Resource memperbesar energi densitas (energi
per bahan bakar, MWd/TU), membangun konsep
pembiak?.
- Accident Inherent safety aspect, keselamatan
bergantung pada hukum alam yang availability-nya
100%.
- Bomb aspek Non-proliferasi (kemudahan untuk
digunakan sebagai bom).
- Waste konsep reaktor nuklir pemakan `sampah
nuklir`, close-cycle system.
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T.Setiadipura, Workshop Evaluasi Desain
HTGR, BAPETEN, 22 April 2015