Transcript Diapositiva 1 - Royal Institute of Technology

6th FRAMEWORK PROGRAM EURATOM
Management of Radioactive Waste
EUROTRANS - DM1
WP 1.5 Meeting
Forschungszentrum Karlsruhe, 27-28 November, 2008
Analysis of EFIT Protected and
Unprotected Accidental Transients
with PARCS/RELAP5 Coupled Code
Massimiliano Polidori, Giacomino Bandini, Paride Meloni
Italian National Agency for New Technologies, Energy and Environment
Advanced Physics Technology Division
Via Martiri di Monte Sole 4, 40129 Bologna, Italy
Outline
Description of the Codes
The RELAP5 Model of EFIT
The PARCS Model and Assumption of EFIT
Analysis of Protected Transients
Spurious Beam Trip 1 sec
Analysis of Unprotected Transients
Loss of Flow (ULOF)
Loss of Heat Sink (ULOH)
ULOF + ULOH
Beam Overpower from Hot Full Power (HFP)
Beam Overpower from Hot Zero Power (HZP)
Conclusions
EUROTRANS DM1 – WP 1.5 Progress Meeting, Forschungszentrum Karlsruhe, November 27-28, 2008
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PARCS/RELAP Coupled Code
Our State-of-the-Art code to simulate the Neutronic-T/H coupled
phenomena for safety purpose is:
PARCS v1.01 – 3D Neutronic coarse mesh code that solves the 2group diffusion equation in cartesian geometry, modified to treat fast
spectrum and external neutron source.
RELAP5 mod 3.2.2b – Thermal-Hydraulic 1D code modified to treat
heavy liquid metal (lead, LBE)
PVM
GI
RELAP5
Fuel/Coolant
Temperature and Density,
Void Fraction, ..
PARCS
D Cross Section
Neutron Flux
Reactor Power
EUROTRANS DM1 – WP 1.5 Progress Meeting, Forschungszentrum Karlsruhe, November 27-28, 2008
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The RELAP5 Model of EFIT
22
82
Jun23
Primary system layout by D1.26 of
ANSALDO (November 2007)
62
Jun83
Jun63
branch
branch
branch
175
02
01
176
(177/8/9)
171
Gagging at core inlet according to SIMADS
02
01
01
01
branch
151
SGs
SGs
SGs
Pb side
water side
Pb side
152
153
154
173
annulus
181
182/3/4
Pth
pipe
281
282/3/4
Active Core Region is represented by rings
in according with the designed layout.
170
pipe
381
382/3/4
Ring 1 – 18 FA (Inner Zone)
112
DHR
113
01
06
01
pumps
plenum
branch
121
05
branch 160
Ring 3 – 30 FA (Interm Zone)
UPPER PLENUM
branch 120
Ring 4 – 36 FA (Interm Zone)
Jun106
Jun104
07
06
05
04
03
02
01
109
311
310
211
210
111
110 108
161
09
Jun105
Target
Ring_1
Ring_2
Ring_3
Ring_4
Ring_5
102
08
07
Ring 5 – 42 FA (Outer Zone)
Ring 6 – 30 FA (Outer Zone)
Ring_6
Bypass & Reflector
Jun114
Ring 2 – 24 FA (Inner Zone)
Pumps
06
05
04
03
02
LOWER PLENUM
branch 100
RELAP5 Noding Scheme
01
09
GAP behavior at BOC according to FZKSIMADS analysis (114 μm).
It is considered also the target and bypass
(reflector) regions with their own thermal
power deposition.
EUROTRANS DM1 – WP 1.5 Progress Meeting, Forschungszentrum Karlsruhe, November 27-28, 2008
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The PARCS Model and Assumption of EFIT
PARCS Mesh Dimension
At Cold (20°C) Conditions:
Width = 8.27 cm
Height = 9.55 cm
EFIT Core Layout
At Nominal Power:
Width = 8.33 cm
Height = 9.62 cm
EUROTRANS DM1 – WP 1.5 Progress Meeting, Forschungszentrum Karlsruhe, November 27-28, 2008
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The PARCS Model and Assumption of EFIT
Axial View of EFIT Core Layout
PARCS
RELAP5
20
18
17
19
16
15
18
14
17
13
16
12
15
11
14
10
13
9
12
8
11
7
10
6
9
5
8
4
7
3
6
2
5
1
4
3
2
1
Axial Nodal
Correspondance
EUROTRANS DM1 – WP 1.5 Progress Meeting, Forschungszentrum Karlsruhe, November 27-28, 2008
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The PARCS Model and Assumption of EFIT - XSEC
XSEC Formalism in PARCS
Tfuel
400°C
Tcoolant
400°C
750°C
1100°C
O
O
O
440°C
O
550°C
O
keff  0. 960778
O
XSEC Data Set to Find the
Derivative Cross Sections
at BOC Conditions
Omogenized
Collapsed in 2 groups
(0.079 MeV Cutting Energy)
at nominal power condition
Normalization of kSf to achieve the desired
Power in each Zone (not each Ring)
EUROTRANS DM1 – WP 1.5 Progress Meeting, Forschungszentrum Karlsruhe, November 27-28, 2008
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Steady-State Nominal Power Conditions
Neutronics Parameters
k-eff
Total Fission Power (MW)
Power Inner Core (MW)
Power Intermediate Core (MW)
Power Outer Core (MW)
T/H Parameters
T Inlet Core (°C)
T Outlet Core (°C)
Tmax fuel Inner Core (°C)*
Tmax clad Inner Core (°C)*
Tmax lead Inner Core (°C)*
Tmax fuel Intermediate Core (°C)*
Tmax clad Intermediate Core (°C)*
Tmax lead Intermediate Core (°C)*
Tmax fuel Outer Core (°C)*
Tmax clad Outer Core (°C)*
Tmax lead Outer Core (°C)*
RELAP5 S.A.
375.00
94.00
140.00
141.00
RELAP5 S.A.
400.00
479.80
1193.00
513.00
490.00
1237.00
510.00
491.00
1248.00
517.00
502.00
PARCS/RELAP5
ERANOS
0.96078 0.97631
375.68
378.77
94.19
95.98
140.19
142.31
141.30
140.48
PARCS/RELAP5
399.24
479.37
1199.81
503.80
482.30
1212.2
508.691
486.528
1115.56
(*) The temperature of RELAP S.A.
505.534
refers to the Average Pin of Hot FA.
489.236
It doesn't make sense a direct comparison between the two model due to the different
hypothesis unless to consider that RELAP5 stand-alone refers to 1 HOT FA instead of
those could be considered the "HOT FAs" in RELAP5/PARCS, i.e. 18(CZ1-RING1),
30(CZ2-RING3), 42(CZ3-RING5).
Weighting the lead outlet temperatures of each ring for the numbers of relative FAs, we
obtain the same outlet average temperatures in each core zone obtained by RELAP5
stand-alone 482°C (same mass flowrates).
EUROTRANS DM1 – WP 1.5 Progress Meeting, Forschungszentrum Karlsruhe, November 27-28, 2008
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T/H-Neutronic Coupled Simulations
TRANSIENT ANALYZED FOR PB-COOLED EFIT DESIGN WITH RELAP5/PARCS
Number
Transient
Description
BOC
PROTECTED TRANSIENTS
P-10
Spurious beam trip
beam trip for 1s
(and 10s intervals)
X
O
UNPROTECTED TRANSIENTS
U-1
ULOF
Total loss of forced circulation in
primary system (4 pumps)
X
U-2
UTOP
500 pcm jump in reactivity at HFP
O
U-4 DEC
ULOH
Total loss of secondary loops
(4 loops)
X
1100
U-5 DEC
ULOF + ULOH
Total loss of forced circulation and
secondary loops
X
2100
U-11
Beam Overpower Jump
to 120% at HFP
X
1000
U-12
Beam Overpower Jump
to 120% at HZP
X
1000
600
EUROTRANS DM1 – WP 1.5 Progress Meeting, Forschungszentrum Karlsruhe, November 27-28, 2008
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Spurious beam trip of 1 sec
Reactivity
Fission and Total Exchanged Power
450
Power [MW]
50000
Switch-off and switch-on in 1ms
45000
400
40000
350
35000
300
30000
250
25000
200
20000
PARCS Neutronic Power
SG Total Exchanged Power
Core Inlet Mass Flowrate
150
100
50
15000
Mass Flowrate [kg/s]
500
10000
5000
0
0
90
100
110
Time [s]
120
130
the prompt and strong power drop following the source switch-off agrees with what is
expected for a sub-critical reactor dominated by the prompt neutrons of source
this transients is too fast to appreciate a change in SGs thermal power exchange
thermal feedback, due to the fast cooling of the fuel, is responsible for a slight increase of
the reactivity and a consequent peak of the fission power at the accelerator restart
EUROTRANS DM1 – WP 1.5 Progress Meeting, Forschungszentrum Karlsruhe, November 27-28, 2008
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Spurious beam trip of 1 sec
Lower and Upper Plenum Temperature Fuel, Clad and Lead Max Temperature
1400
RING - 3
1200
500
Temperature [°C]
Temperature [°C]
550
450
400
1000
Fuel Centerline
External Clad
Outlet Lead
800
600
Upper Plenum Temperature
Lower Plenum Temperature
350
400
90
100
110
Time [s]
120
130
90
100
110
Time [s]
120
130
-4°C in the Upper Plenum after about 10s
No variation of Inlet Core temperature also after 600s of transients
Jump of fuel max temperature of 164°C
Jump of clad and outlet lead temperature of 16°C
EUROTRANS DM1 – WP 1.5 Progress Meeting, Forschungszentrum Karlsruhe, November 27-28, 2008
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Unprotected Loss of Flow
450
45000
400
40000
350
35000
300
30000
250
200
150
PARCS Neutronic Power
SG Total Exchanged Power
Core Inlet Mass Flowrate
25000
20000
15000
100
10000
50
5000
0
Reactivity
Mass Flowrate [kg/s]
Power [MW]
Fission and Total Exchanged Power
0
50 100 150 200 250 300 350 400 450 500 550 600
Time [s]
All the primary pumps stop at 100 s, the accelerator remain at the same flux level
Small peak of power of 11 MWth after which return at the same initial level 376 MWth
SGs reduced their exchange capability for 25s, until the natural circulation is started
Core mass flowrate undershoot to the 30%
Peak of reactivity of 130 pcm due mainly to the positive effect of coolant temperature
EUROTRANS DM1 – WP 1.5 Progress Meeting, Forschungszentrum Karlsruhe, November 27-28, 2008
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Unprotected Loss of Flow
700
1400
650
1300
1200
600
550
500
450
Upper Plenum Temperature
Lower Plenum Temperature
400
Temperature [°C]
Temperature [°C]
Lower and Upper Plenum Temperature Fuel, Clad and Lead Max Temperature
1100
Fuel Centerline
External Clad
Outlet Lead
1000
900
800
700
600
350
500
300
400
50 100 150 200 250 300 350 400 450 500 550 600
Time [s]
RING - 3
50 100 150 200 250 300 350 400 450 500 550 600
Time [s]
Outlet plenum temperature maximum value of 631°C, stable at 621°C
Inlet core temperature overcooling at 359°C
Fuel temperature peak to 1390°C with a jump of 177°C
Clad temperature peak up to 790°C
EUROTRANS DM1 – WP 1.5 Progress Meeting, Forschungszentrum Karlsruhe, November 27-28, 2008
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Unprotected Loss of Heat Sink
450
45000
400
40000
350
35000
300
30000
250
25000
PARCS Neutronic Power
SG Total Exchanged Power
DHR Removal Power
Core Inlet Mass Flowrate
200
150
100
20000
15000
10000
50
Reactivity
Mass Flowrate [kg/s]
Power [MW]
Fission and Total Exchanged Power
5000
0
0
50
250
450
650
Time [s]
850
1050
All the secondary pumps stops at 100 s, the accelerator remain at the same flux level
The power level remain the same, Core mass flowrate slightly decrease
DHR system (3 out of 4 units) reaches full operation (21 MW) after 280s
Coolant temperature positive effect and Fuel temperature negative effect
EUROTRANS DM1 – WP 1.5 Progress Meeting, Forschungszentrum Karlsruhe, November 27-28, 2008
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Unprotected Loss of Heat Sink
Lower and Upper Plenum Temperature
Fuel, Clad and Lead Max Temperature
1000
1600
1400
800
Temperature [°C]
Temperature [°C]
900
700
600
500
Upper Plenum Temperature
400
Lower Plenum Temperature
150 250 350 450 550 650 750 850 950 1050
Time [s]
8000
1000
7000
RING - 3
900
6000
800
5000
700
4000
600
3000
DHR Inlet Temperature
DHR Outlet Temperature
DHR Inlet Mass Flowrate
300
2000
1000
0
50
150 250 350 450 550 650 750 850 950 1050
Time [s]
DHR Temperature and Mass Flowrate
Mass Flowrate [kg/s]
1100
Temperature [°C]
800
400
50
400
1000
600
300
500
Fuel Centerline
External Clad
Outlet Lead
1200
All the temperature increase and
they can go on if nothing happen
DHR mass flowrate increase just
after the pumps trip
Delta Temperature over the DHR
20°C
50 150 250 350 450 550 650 750 850 950 1050
Time [s]
EUROTRANS DM1 – WP 1.5 Progress Meeting, Forschungszentrum Karlsruhe, November 27-28, 2008
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ULOF + ULOH
Reactivity
450
45000
400
40000
350
35000
Power [MW]
300
30000
PARCS Neutronic Power
SG Total Exchanged Power
DHR Removal Power
Core Inlet Mass Flowrate
250
200
150
25000
20000
15000
100
10000
50
5000
0
Mass Flowrate [kg/s]
Fission and Total Exchanged Power
0
50
550
1050
Time [s]
1550
2050
The superposition of the effects come true!
Seems that the reactivity inserted could reach the 0 or a negative value.
EUROTRANS DM1 – WP 1.5 Progress Meeting, Forschungszentrum Karlsruhe, November 27-28, 2008
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ULOF + ULOH
Lower and Upper Plenum Temperature
Fuel, Clad and Lead Max Temperature
1700
2000
Upper Plenum Temperature
1500
Lower Plenum Temperature
1300
Temperature [°C]
Temperature [°C]
RING - 3
1800
1100
900
700
1600
1400
1200
1000
800
500
600
300
400
50
550
1050
Time [s]
1550
2050
Fuel Centerline
External Clad
Otlet Lead
50
550
1050
Time [s]
1550
2050
Fuel temperature peak 1410°C than 1930° after 2000s of transient
Lead temperature at outer ring 3 reach 1510°C
The transient is ended by time step card, but seems that should crash in few more seconds
EUROTRANS DM1 – WP 1.5 Progress Meeting, Forschungszentrum Karlsruhe, November 27-28, 2008
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Beam Overpower to 120% from HFP
Reactivity
500
50000
450
45000
400
40000
350
35000
300
30000
250
PARCS Neutronic Power
25000
200
SG Total Exchanged Power
20000
150
DHR Removal Power
15000
100
Core Inlet Mass Flowrate
10000
50
Mass Flowrate [kg/s]
Power [MW]
Power Evolution
5000
0
0
50
250
450
650
Time [s]
850
1050
Source overpower of +20% at 100 s without recovery action
Peak of power of 75 MWth (20%) after which the core power have no variation
SGs increase their performances and DHR start to work after 600s of transient
As expected it is the fuel reactivity that have the major worth with a peak of 30 pcm
EUROTRANS DM1 – WP 1.5 Progress Meeting, Forschungszentrum Karlsruhe, November 27-28, 2008
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Beam Overpower to 120% from HFP
Lower and Upper Plenum Temperature
Fuel, Clad and Lead Temperature
600
1600
1400
Temperature [°C]
Temperature [°C]
550
RING - 3
500
450
400
1200
Centerline Fuel
External Clad
Outlet Lead
1000
800
Upper Plenum Temperature
350
600
Lower Plenum Temperature
300
400
50
250
450
650
850
1050
Time [s]
50
250
450
650
850
1050
Time [s]
Fuel temperature peak 1375°C than 1410° at the end of transient
Clad temperature 565°C
Lead temperature at outer ring 3 reach 539°C
EUROTRANS DM1 – WP 1.5 Progress Meeting, Forschungszentrum Karlsruhe, November 27-28, 2008
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Beam Overpower to 120% from HZP
Reactivity
500
50000
450
45000
400
40000
350
35000
300
30000
250
PARCS Neutronic Power
25000
200
SG Total Exchanged Power
20000
150
DHR Removal Power
15000
100
Core Inlet Mass Flowrate
10000
50
Mass Flowrate [kg/s]
Power [MW]
Power Evolution
5000
0
0
0
500
Time [s]
1,000
1,500
Source overpower from 0 level to +120% at 0s without recovery action
Instantaneous jump of power at about 450 MWth
SGs increase their performances and DHR start to work after 600s of transient
Overpower at HFP vs HZP without difference regarding the reactivity inserted
EUROTRANS DM1 – WP 1.5 Progress Meeting, Forschungszentrum Karlsruhe, November 27-28, 2008
20
Beam Overpower to 120% from HZP
Fuel, Clad and Lead Max Temperature
600
1600
550
1400
Temperature [°C]
Temperature [°C]
Lower and Upper Plenum Temperature
500
450
400
Upper Plenum Temperature
350
RING - 3
1200
Fuel Centerline
External Clad
Outlet Lead
1000
800
600
Lower Plenum Temperature
400
300
0
500
1000
1500
0
500
Time [s]
1000
1500
Time [s]
Fuel temperature peak 1375°C than 1410° at the end of transient
Clad temperature 570°C after 1500s
Lead temperature at outer ring 3 reach 544°C after 1500s
EUROTRANS DM1 – WP 1.5 Progress Meeting, Forschungszentrum Karlsruhe, November 27-28, 2008
21
Conclusions
The analyses of the thermalhydraulics-neutronics behavior of the
EFIT reactor have been conducted with the coupled code
RELAP5/PARCS.
Nominal steady state conditions achieved with the coupled model are
in line with those calculated by RELAP5 stand-alone, taking into
account the large modelling differences over the core.
In the transients analyzed the feedback effects are quite negligible as
expected unless we consider an accident that take into account a
partial or total coolant voiding.
All the unprotected transient analyzed shows that no major
challenging situation are expected for the materials in accidental
conditions and that there is a lot of time to recover those situations.
EUROTRANS DM1 – WP 1.5 Progress Meeting, Forschungszentrum Karlsruhe, November 27-28, 2008
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