forschungszentrum karlsruhe technik und umwelt irs /fzk w.m.schikorreurotrans wp1.5 safety meeting :...
TRANSCRIPT
Forschungszentrum KarlsruheTechnik und Umwelt
IRS /FzK W.M.SchikorrEUROTRANS WP1.5 Safety Meeting : Lyon, Oct 11-12. 2006 1
EFIT (PB) - Design and EFIT (PB) - Design and Preliminary ULOF(ss) AnalysisPreliminary ULOF(ss) Analysis
M. Schikorr, D. Struwe (FzK)M. Schikorr, D. Struwe (FzK)
EUROTRANS: DM1 WP1.5 : “Safety”
Lyon , 10-11 October 2006
Forschungszentrum KarlsruheTechnik und Umwelt
IRS /FzK W.M.SchikorrEUROTRANS WP1.5 Safety Meeting : Lyon, Oct 11-12. 2006 2
1. Design Criteria for EFIT (Pb)
2. EFIT (Pb) design Data for Transient Analysis
3. Some EFIT (Pb) results to the ULOF transient
Topics:
Forschungszentrum KarlsruheTechnik und Umwelt
IRS /FzK W.M.SchikorrEUROTRANS WP1.5 Safety Meeting : Lyon, Oct 11-12. 2006 3
1. Use MgO as fuel matrix for the MA-based fuel
2. Assure an optimal MA burning rate
3. Operate the system as a sub-critical system (k_eff ~ 0.95 - 0.97)
4. Account for the relatively low fuel temperatures allowable
T_fuel_max < 1600 °C
5. Also use T91 as clad material (as of now).
6. Design core and primary system in such a manner to allow sufficient natural convection flow rate to survive a ULOF transient for at least 30 minutes without „large number“ of pin failures (via gas blowout)
1. Some important thermohydraulic EFIT Design Criteria:
Forschungszentrum KarlsruheTechnik und Umwelt
IRS /FzK W.M.SchikorrEUROTRANS WP1.5 Safety Meeting : Lyon, Oct 11-12. 2006 4
Assure a sufficiently large natural convection flow rate ( > 25 % nominal flow) under ULOF conditions.
This implies :
1. keep pressure drop across the core „low“ (~< 0.5 bar) by selecting an appropriate fuel pin / subassembly design
2. minimize pressure losses throughout the primary / DHRS system such that total system pressure loss <~ 0.8 bar
3. assure a height differential between the core midplane and the heat sink midplane of ~ 3.7 m
EFIT ULOF Design Criteria requires :
Forschungszentrum KarlsruheTechnik und Umwelt
IRS /FzK W.M.SchikorrEUROTRANS WP1.5 Safety Meeting : Lyon, Oct 11-12. 2006 5
Option 1 :
1. Assume a constant fuel matrix (i.e. 50% MgO) and vary the fuel pin / sub-assembly design in the two core zones in order to flatten the power profile.
Several variations in pin diameters and sub-assembly sizes were tried but it was difficult to achieve a satisfactory radial power distribution without excessive radial form factors.
Option 2:
Assume a uniform geometric pin / SA design for the two core zones but vary the fuel matrix composition.
ENEA / ANSALDO decided for Option 2 with the following design :
Several EFIT design iterations were performed :
Forschungszentrum KarlsruheTechnik und Umwelt
IRS /FzK W.M.SchikorrEUROTRANS WP1.5 Safety Meeting : Lyon, Oct 11-12. 2006 6
EFIT (Pb) Design Data used: Inner Core Zone CZ1, Fuel 62.5% MgO
Fuel Bundle and Pin Design
Dimensions UnitsNumber of pins 169Number of anchoring SS pins per SA 1Active Fuel Heights 90.0 cmPitch to Diameter Ratio 1.563Pin diameter 8.72 mmPitch 13.63 mmAnnulus diameter 0.0 mmNumber of Pin rows in SA 7Clad Thickness 0.6 mmCold Gap between clad and fuel 0.155 mmPellet diameter 7.210 mmAvailable inter-pin gap for spacers 7.7 mmSpace pin - inner wrapper 2.0150 mmWidth over inner flats 178.00 mmThickness Wrapper 4.00 mmGap between SA´s 5.00 mmWidth over outer flats (wrapper) 186.00 mmWidth over unit cell (includes Sgap) 191.00 mm
Number Fuel Subassemblies 48Number of SA spallation zone 19Number Grid Spacers 6
Thermal power 104.9 MW
Average Linear Power 144.5 W/cm
Axial Form Factor f_ax 1.143Radial Form Factor f_rad_hot_SA 1.29
f_peak_pin 1f_rad_tot 1.290f_tot_hot_SA 1.474f_tot_peak_pin 1.474
Peak Burn Up 100 MWd/kgiHM
62.5% MgO - 37.5% MOX Fuel BOC EOC
Porosity of MgO 10% 10%Porosity of Fuel 10% 10%O/M 1.88 1.88
T_in 400 °CT_out 480 °CMass Flow Rate 8980 kg/s
Heights difference core / heat sink 3.70 m
Forschungszentrum KarlsruheTechnik und Umwelt
IRS /FzK W.M.SchikorrEUROTRANS WP1.5 Safety Meeting : Lyon, Oct 11-12. 2006 7
EFIT (Pb) Design Data used: Outer Core Zone CZ2, Fuel 50% MgO
Fuel Bundle and Pin Design
Dimensions UnitsNumber of pins 169Number of anchoring SS pins per SA 1Active Fuel Heights 90.0 cmPitch to Diameter Ratio 1.563Pin diameter 8.720 mmPitch 13.63 mmAnnulus diameter 0.0 mmNumber of Pin rows in SA 7Clad Thickness 0.6 mmCold Gap between clad and fuel 0.155 mmPellet diameter 7.210 mmAvailable inter-pin gap for spacers 7.7 mmSpace pin - inner wrapper 2.0150 mmWidth over inner flats 178.00 mmThickness Wrapper 4.00 mmGap between SA´s 5.00 mmWidth over outer flats (wrapper) 186.00 mmWidth over unit cell (includes Sgap) 191.00 mm
Number Fuel Subassemblies 174Number of SA spallation zone 19Number Grid Spacers 6
Thermal power 290 MW
Average Linear Power 110.2 W/cm
Axial Form Factor f_ax 1.133Radial Form Factor f_rad_hot_SA 1.45
f_peak_pin 1.00f_rad_tot 1.450f_tot_hot_SA 1.643f_tot_peak_pin 1.643
Peak Burn Up 100 MWd/kgiHM
50% MgO - 50% MOX Fuel BOC EOC
Porosity of MgO 10% 10%Porosity of Fuel 10% 10%O/M 1.88 1.88
T_in 400 °CT_out 480 °CMass Flow Rate 24825 kg/s
Forschungszentrum KarlsruheTechnik und Umwelt
IRS /FzK W.M.SchikorrEUROTRANS WP1.5 Safety Meeting : Lyon, Oct 11-12. 2006 8
EFIT (Pb) Fuel Design: Inner and Outer Core Zones
Source : D1.6 Draft Sept.2006Source : V. Sobolev Sep. 2006 Source : D1.6 Draft Sept.2006
Forschungszentrum KarlsruheTechnik und Umwelt
IRS /FzK W.M.SchikorrEUROTRANS WP1.5 Safety Meeting : Lyon, Oct 11-12. 2006 9
Calc. Pressure Drops:Spacers 0.042 barCore Inlet/Outlet - Core zone gagged 0.105 barFriction 0.183 barTotal Core 0.330 barTotal Prim. System 0.495 bar
Assumed Ratio System/Core Pressure Drop
1.500
EFIT (Pb) Data : Inner Core Zone CZ1
Fuel Thermal Cond. Poly Coeffs W/mK W/mKkfuel_k1 34.70 12.610kfuel_k2 -7.05E-02 -1.37E-02kfuel_k3 6.04E-05 4.81E-06kfuel_k4 -2.377E-08 2.259E-10kfuel_k5 3.707E-12 -1.595E-13
EFIT (Pb) Data : Outer Core Zone CZ2
Fuel Thermal Cond. Poly Coeffs W/mK W/mKkfuel_k1 25.66 9.754kfuel_k2 -5.09E-02 -1.01E-02kfuel_k3 4.33E-05 3.42E-06kfuel_k4 -1.694E-08 2.531E-10kfuel_k5 2.643E-12 -1.284E-13
Calc. Pressure Drops:Spacers 0.025 barCore Inlet/Outlet - Core zone gagged 0.190 barFriction 0.114 barTotal Core 0.329 barTotal Prim. System 0.493 bar
Assumed Ratio System/Core Pressure Drop
1.500
Forschungszentrum KarlsruheTechnik und Umwelt
IRS /FzK W.M.SchikorrEUROTRANS WP1.5 Safety Meeting : Lyon, Oct 11-12. 2006 10
Nominal Conditions Inner Core Zone at BOC : EFIT (Pb) Axial Temperature Profile, PbBi-cooled Average Pin 145 W/cm
472
440480
503
1020
871933
723756
1111
300
400
500
600
700
800
900
1000
1100
1200
-45 -35 -25 -15 -5 5 15 25 35 45
Axial Core Position [cm]
Te
mp
era
ture
s [
°C]
Cladding
Coolant
Center Fuel
Surf Fuel
Avg
Axial Temperature Profile, PbBi-cooled Hot SA - avg Pin 186 W/cm
493
452503
533
1200
9931067
786 825
1310
300
500
700
900
1100
1300
1500
-45 -35 -25 -15 -5 5 15 25 35 45
Axial Core Position [cm]
Te
mp
era
ture
s [
°C]
Cladding
Coolant
Center Fuel
Surf Fuel
Avg Fuel
Source : D1.6 Draft Sept.2006
Forschungszentrum KarlsruheTechnik und Umwelt
IRS /FzK W.M.SchikorrEUROTRANS WP1.5 Safety Meeting : Lyon, Oct 11-12. 2006 11
Nominal Conditions Outer Core Zone at BOC : EFIT (Pb)
Source : D1.6 Draft Sept.2006
Axial Temperature Profile, PbBi-cooled Average Pin 110 W/cm
468
440480
500
928
801852
674703
1002
300
400
500
600
700
800
900
1000
1100
-45 -35 -25 -15 -5 5 15 25 35 45
Axial Core Position [cm]
Te
mp
era
ture
s [
°C]
Cladding
Coolant
Center Fuel
Surf Fuel
Avg
Axial Temperature Profile, PbBi-cooled Hot SA avg Pin 160 W/cm
498
458516
545
1173
9671035
761 798
1274
300
500
700
900
1100
1300
1500
-45 -35 -25 -15 -5 5 15 25 35 45
Axial Core Position [cm]
Te
mp
era
ture
s [
°C]
Cladding
Coolant
Center Fuel
Surf Fuel
Avg Fuel
Forschungszentrum KarlsruheTechnik und Umwelt
IRS /FzK W.M.SchikorrEUROTRANS WP1.5 Safety Meeting : Lyon, Oct 11-12. 2006 12
Nominal Conditions Inner Core Zone at EOL : EFIT (Pb) Axial Temperature Profile, PbBi-cooled Average Pin 146 W/cm
472
440480
503
775
639680
502528
840
300
400
500
600
700
800
900
-45 -35 -25 -15 -5 5 15 25 35 45
Axial Core Position [cm]
Te
mp
era
ture
s [
°C]
Cladding
Coolant
Center Fuel
Surf Fuel
Avg
Axial Temperature Profile, PbBi-cooled Hot SA - avg Pin 186 W/cm
493
452503
533
915
723780
531564
1008
300
400
500
600
700
800
900
1000
1100
-45 -35 -25 -15 -5 5 15 25 35 45
Axial Core Position [cm]
Tem
per
atu
res
[°C
]
Cladding
Coolant
Center Fuel
Surf Fuel
Avg Fuel
Note that peak clad temperatures exceed 500 °C requiring „coating“ of the T91 clad material.
Forschungszentrum KarlsruheTechnik und Umwelt
IRS /FzK W.M.SchikorrEUROTRANS WP1.5 Safety Meeting : Lyon, Oct 11-12. 2006 13
Nominal Conditions Outer Core Zone at EOL : EFIT (Pb) Axial Temperature Profile, PbBi-cooled Average Pin 110 W/cm
468
440480
500
736
613648
491518
789
300
400
500
600
700
800
900
-45 -35 -25 -15 -5 5 15 25 35 45
Axial Core Position [cm]
Te
mp
era
ture
s [
°C]
Cladding
Coolant
Center Fuel
Surf Fuel
Avg Fuel
Axial Temperature Profile, PbBi-cooled Hot SA avg. Pin 159 W/cm
498
458516
545
926
729784
531570
1014
300
400
500
600
700
800
900
1000
1100
-45 -35 -25 -15 -5 5 15 25 35 45
Axial Core Position [cm]
Te
mp
era
ture
s [
°C]
Cladding
Coolant
Center Fuel
Surf Fuel
Avg Fuel
Note that peak clad temperatures exceed 500 °C requiring „coating“ of the T91 clad material.
There is not much margin to the temperature limit of coated T91 of ~ 550 °C !!
Note: Hot spot analysis still pending
Forschungszentrum KarlsruheTechnik und Umwelt
IRS /FzK W.M.SchikorrEUROTRANS WP1.5 Safety Meeting : Lyon, Oct 11-12. 2006 14
ULOF (ss) Inner / Outer Core Zone at BOC and EOL :
1. Natural Convection flow rate of EFIT under ULOFss conditions ~ 43 % !!
(much higher than the ~ 25% for XT-ADS)
1. This leads to lower T91 cladding temperatures ( < 700 °C ) for EFIT (Pb) in comparison to XT-ADS ULOFss temperatures ( 790 – 800 °C )
Forschungszentrum KarlsruheTechnik und Umwelt
IRS /FzK W.M.SchikorrEUROTRANS WP1.5 Safety Meeting : Lyon, Oct 11-12. 2006 15
ULOF (ss) Inner / Outer Core Zone at BOC :EFIT (Pb) Inner Core Zone Hot SA avg Pin ULOF 187 W/cm
576
520
642
681
1303
10881174
874935
1420
300
500
700
900
1100
1300
1500
-45 -35 -25 -15 -5 5 15 25 35 45
Axial Core Position [cm]
Te
mp
era
ture
s [
°C]
Cladding surf
Coolant
Center Fuel
Surf Fuel
Avg Fuel
EFIT (Pb) Outer Core Zone Hot SA avg Pin ULOF 160 W/cm
579
528
657
693
1272
10581141
845909
1383
300
500
700
900
1100
1300
1500
-45 -35 -25 -15 -5 5 15 25 35 45
Axial Core Position [cm]
Te
mp
era
ture
s [
°C]
Cladding surf
Coolant
Center Fuel
Surf Fuel
Avg Fuel
Time to Failure [hr] of T91 Cladding
4.1E+04
1.E-01
1.E+01
1.E+03
1.E+05
1.E+07
1.E+09
1.E+11
1.E+13
1.E+15
400 450 500 550 600 650 700 750 800 850 900
Cladding Temperature [°C]
Tim
e t
o F
ailu
re [
hr]
BOL : Pgas = 10 bar
EOL Design: Pgas = 50 bar
Pgas = 100 bar
EFIT peak pin
30 min Failure Limit
Time to Failure [hr] of T91 Cladding
1.4E+04
1.E-01
1.E+00
1.E+01
1.E+02
1.E+03
1.E+04
1.E+05
1.E+06
1.E+07
1.E+08
1.E+09
1.E+10
1.E+11
1.E+12
1.E+13
400 450 500 550 600 650 700 750 800 850 900
Cladding Temperature [°C]
Tim
e t
o F
ailu
re [
hr]
BOL : Pgas = 10 bar
EOL Design: Pgas = 50 bar
Pgas = 100 bar
EFIT peak pin
30 min Failure Limit
Clad failure not an issue at these clad temps.
Pgas =~10 bar
Pgas =~10 bar
Forschungszentrum KarlsruheTechnik und Umwelt
IRS /FzK W.M.SchikorrEUROTRANS WP1.5 Safety Meeting : Lyon, Oct 11-12. 2006 16
ULOF (ss) Inner / Outer Core Zone at EOL :EFIT (Pb) Inner Core Hot SA avg Pin ULOF 187 W/cm
576
520
642
681
1034
824915
613
1159
300
400
500
600
700
800
900
1000
1100
1200
1300
-45 -35 -25 -15 -5 5 15 25 35 45
Axial Core Position [cm]
Te
mp
era
ture
s [
°C]
Cladding surf
Coolant
Center Fuel
Surf Fuel
Avg Fuel
EFIT Outer Core Zone Hot SA avg Pin ULOF 160 W/cm
579
528
657
693
1038
825
918
611
1159
300
400
500
600
700
800
900
1000
1100
1200
1300
-45 -35 -25 -15 -5 5 15 25 35 45
Axial Core Position [cm]
Tem
per
atu
res
[°C
]
Cladding surf
Coolant
Center Fuel
Surf Fuel
Avg Fuel
Clad failure not an issue at these clad temps.
Pgas = 178 bar tent.
Pgas = 178 bar tent.
Time to Failure [hr] of T91 Cladding
1.1E+01
1.E-01
1.E+00
1.E+01
1.E+02
1.E+03
1.E+04
1.E+05
1.E+06
1.E+07
1.E+08
1.E+09
1.E+10
1.E+11
1.E+12
1.E+13
400 450 500 550 600 650 700 750 800 850 900
Cladding Temperature [°C]
Tim
e to
Fai
lure
[hr]
BOL : Pgas = 10 bar
EOL Design: Pgas = 50 bar
Pgas = 100 bar
EFIT peak pin
30 min Failure Limit
Time to Failure [hr] of T91 Cladding
5.3E+00
1.E-01
1.E+00
1.E+01
1.E+02
1.E+03
1.E+04
1.E+05
1.E+06
1.E+07
1.E+08
1.E+09
1.E+10
1.E+11
1.E+12
1.E+13
400 450 500 550 600 650 700 750 800 850 900
Cladding Temperature [°C]
Tim
e t
o F
ailu
re [
hr]
BOL : Pgas = 10 bar
EOL Design: Pgas = 50 bar
Pgas = 100 bar
EFIT peak pin
30 min Failure Limit
Forschungszentrum KarlsruheTechnik und Umwelt
IRS /FzK W.M.SchikorrEUROTRANS WP1.5 Safety Meeting : Lyon, Oct 11-12. 2006 17
Conclusions on current EFIT (Pb) TH – design (1/2) :
1.) From the TH point of view the current EFIT(PB) design as proposed by ENEA / ANSALDO is quite viable assuming the cladding is „coated“ as clad temperatures exceed 500 °C under nominal conditions.
2.) The calculations thus far have not assumed a form factor to account for the peak pin within the hottest subassembly (f_peak_pin should be ~ 1.04 instead of 1.0 as has been assumed). This will lead to even higher cladding temperatues of the peak pin, possibly in excess of 550 °C.
Forschungszentrum KarlsruheTechnik und Umwelt
IRS /FzK W.M.SchikorrEUROTRANS WP1.5 Safety Meeting : Lyon, Oct 11-12. 2006 18
Conclusions on current EFIT (Pb) TH - design (2/2):
3.) Under ULOF steady state conditions at EOL clad failure times are in excess of 1000 hrs as clad temperatures remain below 700 °C
MgO fuel temperatures also remain below 1430 °C ( a limit of ~1500 °C was decided not to be exceeded )
4.) The design exhibits excellent natural convection characterisitics with w_nat ~ 45 % under ULOF conditions ( low pressure losses < 500 mbar )
5.) The ULOF transient behavior of the design still needs to be analysed in detail