Transcript DCOM - Royal Institute of Technology

Status of He-EFIT Design
Pierre Richard – J. F Pignatel – G. Rimpault
WP1.5 Meeting, Lyon, October 10-11 , 2006, P. Richard, J. F. Pignatel, G. Rimpault
1
Outline
 Recall of the Design Approach
 Main Issues Addressed since the February (Bologna) Meeting
 Updated Table of He-EFIT Main Characteristics
 Presentation of the current core design : Core, Spallation module,
Power Conversion Cycle
 DHR Approach
 Conclusions – Next steps
WP1.5 Meeting, Lyon, October 10-11 , 2006, P. Richard, J. F. Pignatel, G. Rimpault
2
He-EFIT Design Approach
1 – Spallation module design using the outcome of the PDS-XADS Project
2 - Define the Proton Beam Intensity (for a maximum proton energy of
800 MeV), the reactor power and the Keff (assuming the potential
reactivity insertions and burn up swing which have to be checked later)
3 - Design the core taking into account the design objectives (MA
burning, Keff considerations,…) and the core design constraints (Fuel
composition, cladding composition, pressure drops,…)
---------------------------------------------------------------------------------4 - Define the approach for the DHR and design the DHR main
components (blowers, HX,…)
5 - Design the primary system
6 - Design the Balance of Plant and Containment and implementation of
the plant (cooling loops, confinment building, …)
Steps 2 and 3 require iteration loops with neutronics, T/H and geometry
considerations  Required some time
WP1.5 Meeting, Lyon, October 10-11 , 2006, P. Richard, J. F. Pignatel, G. Rimpault
3
Evolutions since the Bologna Meeting (1/3)

Proton beam characteristics :
 Energy changed from 600 MeV to 800 MeV which is currently
considered as an upper limit : over 800 MeV, the radio-toxicity increase
rapidly
 Need for higher proton beam intensity 18-22 mA instead of 10-20 mA

Plant Efficiency :
 First Assessment made at CEA : with Tin/Tout = 400/550 °C
 AMEC/NNC : incentive to increase the Tcore from 150 °C to 200 °C
Decision from the Lyon meeting (03/06) : Tin/Tout = 350/550 °C
Plant efficiency increased to 43.3 %
Fuel Characteristics :
 CERCER (MgO matrix) limit temperature at nominal conditions
decreased from 1860 °C to 1380 °C
 CERMET (Mo matrix) considered as back up solution (decision from the
Cadarache meeting in June)


S/A Characteristics :
 S/A Outer width over flats reduced from 162 mm to 137 mm : target
size corresponding to 19 S/A at the center of the core
WP1.5 Meeting, Lyon, October 10-11 , 2006, P. Richard, J. F. Pignatel, G. Rimpault
4
Evolutions since the Bologna Meeting (2/3)

Core Design :
 Core power decreased to 400 MWth (600 MWth before)
 3 zones core with different pin diameters

Peaking factors :
 Total peaking factor changed from 1.61 to 1.839 : iteration with
neutronic calculations

Adaptation to He-EFIT of the objectives defined by the “Specialist Meetings”
(March-June 2006) :







42 Kg MA burnt par TWhth
Flat Keff versus BU
Reasonably low current requirement < 20 mA
Low pressure drop < 1.0 bar
Clad temperature limit < 1600°C (transient),
< 1200°C (nominal)
Coolant speed < 50 m/s
Others : Wrapper Thickness, Number of grids, …
WP1.5 Meeting, Lyon, October 10-11 , 2006, P. Richard, J. F. Pignatel, G. Rimpault
5
Evolutions since the Bologna Meeting (3/3)

Cross-check with FzK and modifications of the correlations for Heat
Exchange Coefficients, Core Pressure Drops and Fuel Conductivities
(According to DM3 recommendations) :

Rather good agreement :





Core composition f < 0.05 %
Fuel Max Temperatures T< 20 °C
Cladding Max Temperatures T< 6 °C
Pressure drops : incoherency in the Dh calculations
but small consequences : (P) < 0.034 bar
Safety :

Pressure drop limited to 1 bar for the core and 1.5 bar for the whole
primary circuit
 Provisional value to be checked by appropriate transient calculations

DHR strategy - Comparison of different two approaches :
“XADS-like” approach / GCFR approach
WP1.5 Meeting, Lyon, October 10-11 , 2006, P. Richard, J. F. Pignatel, G. Rimpault
6
Main Characteristics of the Gas-Cooled EFIT (1/3)
Design Parameter
Coolant
Core Power
Core Power Density
Plant Efficiency
Core Inlet/outlet Temp
Power conversion
Accelerator
Target Unit interface
Loading Factor
Value/Characteristic
Comments
PLANT GENERAL CHARACTERISTICS
Helium at 70 bars
Identical to GCFR value
400 MW th
After iterations with neutronic
calculations
3
50 MW/m
60 MW/m3 proposed in June
2005
43.3 % without acc.
Requirement : 40 %
350°C/550°C
Indirect cycle S-CO2 with recompression
LINAC
E : 800 Mev
I : 18-22 mA
Window Target
Solid Target
75 %
Delta T increase by 50 °C
Over 800 MeV, Spallation
Products have longer half-life 
Upper limit fixed to 800 MeV
W rods cooled by helium –
separate cooling of the window
Provisional value to be checked
later
WP1.5 Meeting, Lyon, October 10-11 , 2006, P. Richard, J. F. Pignatel, G. Rimpault
7
Main Characteristics of the Gas-Cooled EFIT (2/3)
Fuel Composition
Fuel (pellet) Power
density
Fuel content Ratio
Fuel and MA Vectors
Fuel Pin Spacer
Fuel Assembly type
Fuel Assembly cross
section
Core zoning
S/A pitch
Peaking Factor
Core height
Core Pressure Drop
CORE GENERAL CHARACTERISTICS
(Pu, Am, Cm)O2 + MgO
50/50 % Fuel/Matrix ratio
App. 200 W/cm³
To be adjusted after transmutation
optimisation
30 % (Pu/MA+Pu)
To be adjusted after transmutation
optimisation
Provided by GR
Grid
5 grid spacers
Wrapper
4 mm thickness
Hexagonal
3 Zones
137 mm
1.839
1.25 m
Range 0.7-1 bar
Different pin diameters
Adjusted for an optimum target size
Same peaking factors considered in
the three zones
Based on GCFR assessment. To be
checked at a second stage by
transient calculations
WP1.5 Meeting, Lyon, October 10-11 , 2006, P. Richard, J. F. Pignatel, G. Rimpault
8
Main Characteristics of the Gas-Cooled EFIT (3/3)
PIN CHARACTERISTICS
Cladding material
Cladding thickness
SiC
1 mm
Fuel/Cladding Gap
100 µm for 5.8 mm in
Diameter – Changed
proportionally to the pellet
diameter
DESIGN CRITERIA
1380 °C
DBC cat. I
1580 °C
DBC cat. II
1780 °C
DBC cat. III
1200 °C
DBC cat. I
1300 °C
Long-term transient(>24h)
1600 °C
Short-term transient(<24h)
SAFETY ISSUES
The plant shall be designed The analysis of protected transients similarly to the
to accommodate
XADS is to be done (transient list to be checked
PLOF/PLOCA
with WP1.5)
No Back-up pressure (no
guard containment)
Core-catcher
Under nominal pressure :
Decay Heat Curve deduced from the banchmark
Nat. circulation
Depressurised cond. :
active DHR systems to
remove Decay Heat
Tfuelmax
Tfuelmax
Tfuelmax
Tcladmax
Tcladmax
Tcladmax
Protected transients
DHR Approach
DHR
Minimum Thickness for Feasibility reasons (to be
checked by CEA)
Provided by DM3
WP1.5 Meeting, Lyon, October 10-11 , 2006, P. Richard, J. F. Pignatel, G. Rimpault
9
Current Design
 A three zone core has been preliminarily studied :
 Zone 1 (inner) : 45 MWth, 42 sub-assemblies
 Zone 2 (intermediate) : 165 MWth, 156 sub-assemblies
 Zone 3 (outer) : 191 MWth, 180 sub-assemblies
The main hypothesis and/or design objectives accounted are the following :
Core heigth : 125 cm
External width over flat : 137 mm
Fuel (fuel+matrix) fraction in the diffrent zones : 11%, 21.5 % and 35
(for respectively zone 1, 2 and 3)
Matrix volmue fraction in the fuel pellet : 50 %
The total form factor was assumed to be the same in the three zones
(1.839)
Remarks :
1 - Core pressure drops are not equilibrated (too many design constraints).
They are respectively 0.84, 0.74 and 1 bar in zone 1, 2 and 3  some gagging
will be necessary
2- The pellet diameter in zone 1 is rather small (2.3 mm). If this induces some
problem, the number of pin rows per S/A can be reduced to 11 row per S/A.



%

-
WP1.5 Meeting, Lyon, October 10-11 , 2006, P. Richard, J. F. Pignatel, G. Rimpault
10
Current Design – 50 MW/m3 (1/2)
EFIT Type
Thermal Power (MWth)
Coolant Type
Coolant Pressure (bar)
Inlet Temperature (°C)
Outlet Temperature (°C)
Cladding Type
Spallation module
Zone
Matrix Type
Matrix Fraction
Volume of the fissile zone (m^3)
Core Geometry
Outer Diameter of the fissile zone
Height of Sub-Assemblies
Number of fissile sub-assemblies
Fissile Height (H)
Wrapper Width over outer Flats
Wrapper Thickness
Inter-Wrapper Gap
Coolant Volume Fraction (%)
Fuel Volume Fraction (%)
Matrix Volume Fraction (%)
Structure Volume Fraction (%)
He-EFIT
400
He
71
350
550
SiC
Solid W He cooled
1 (inner)
2 (intermediate)
MgO
MgO
50%
50%
0,915 m3 / 0.917
3,39 m3 / 3.40
1,16 m / 1.165
2.75 m
42
1,25 m
137 mm
4,0 mm
5,0 mm
49.8% / 48.03
5.58% / 6.00
5.58% / 6.00
39.05% / 40.02
2,19 m / 2.197
2.75 m
156
1,25 m
137 mm
4,0 mm
5,0 mm
44.75% / 42.62
10.85% / 10.81
10.85% / 10.81
33.56% / 34.23
3 (outer)
MgO
50%
3,93 m3 / 3.93
2,97 m / 2.97
2.75 m
180
1,25 m
137 mm
4,0 mm
5,0 mm
37.19% / 34.08
17.49% / 17.51
17.49% / 17.51
27.83% / 28.44
WP1.5 Meeting, Lyon, October 10-11 , 2006, P. Richard, J. F. Pignatel, G. Rimpault
11
Current Design – 50 MW/m3 (2/2)
Sub-Assembly Bundle Geometry
Number of Pin per S/A
Number of Pin rows per SA
Pin outer Diameter
Cladding Roughness
Pitch to Rod Ratio
Pitch (mm)
Hydraulic Diameter
Cladding Thickness
Pellet/Cladding Gap
Pellet Diameter
Core Thermal-Hydraulics
Average Coolant Speed in the Fissile Core m/s
Average Reynolds Number in the Core
Average Prandtl Number in the Core
Average Nusselt Number in the Core
Average Pin Linear Power W/m
Form Factor
Max Pin Linear Power W/m
Hottest Channel Thermics
Max Cladding Temperature in the Hottest Channel °C
Max Fuel Temperature in the Hottest Channel °C
Core Pressure Drop (bar)
Grid Number
Total Core Pressure Drop bar
Total Regular Pressure Drop bar
Total Singular Pressure Drop bar
Power MW
469
12
4,38 mm
Smooth
1,35
5,89 mm
4.36 / 4.16
1,00 mm
0,040 mm
2,30 mm
217
8
6,87 mm
Smooth
1,25
8,60 mm
5 / 4.86
1,00 mm
0,081 mm
4,71 mm
91
5
11,57 mm
Smooth
1,14
13,20 mm
5.05 / 5.05
1,00 mm
0,160 mm
9,25 mm
30 / 29.8
16958 / 16147
0.64 / 0.672
44 / 46.4
18 / 18
1.839 / 1.839
33 / 33
34.5 / 34.4
22621 / 21771
0.64 / 0.67
54 / 57.2
39 / 39
1.839 / 1.839
72 / 72
45 / 45.3
29643 / 29749
0.64 / 0.67
65 / 70.8
93 / 93
1.839 / 1.839
171 / 171
686 / 682
792 / 772
700 / 694
950 / 927
711 / 704
1310 / 1322
5
0.84 / 0.874
0.47 / 0.49
0.37 / 0.383
45 / 44
5
5
1.01 / 0.978
0.81 / 0.816
0.2 / 0.16
191 / 190
0.74 /
0.52 /
0.22 /
165 /
0.734
0.525
0.21
165
Note 1 : the number after the slash ( / ) are SIM-ADS results 15. Sept.06
WP1.5 Meeting, Lyon, October 10-11 , 2006, P. Richard, J. F. Pignatel, G. Rimpault
12
170
“Cold” Window Concept (1/2)
200
200
Di 370 Ep. 10
3
750
9755
252
840
200
200
180
267
307
WP1.5 Meeting, Lyon, October 10-11 , 2006, P. Richard, J. F. Pignatel, G. Rimpault
13
“Cold” Window Concept (2/2)
Proton Beam
He flow
Target central part made of a bundle
of horizontal W-rods (see detail A)
Radial pitch
Helium
Dext = 266 mm
Axial pitch
Target lower peripheral ring also in
W (assume a porosity of 50% for
He flow))
WP1.5 Meeting, Lyon, October 10-11 , 2006, P. Richard, J. F. Pignatel, G. Rimpault
14
Power Conversion Cycle – AMEC-NNC Assessment


Assumptions :

Keeping the indirect Supercritical CO2 cycle with recompression

CO2 remains super-critical : CO2 characteristics above the
Critical Point (74 bar/32 °C). This avoids the presence of water
in the compressors (badly known behaviour of the components)

CEA Low Heat sink Temperature considered too restrictive :
16 °C  21 °C
Parametric study on the core inlet temperature : +/- 50 °C
WP1.5 Meeting, Lyon, October 10-11 , 2006, P. Richard, J. F. Pignatel, G. Rimpault
15
Power Conversion Cycle
Main
Compressor
Auxiliary
Compressor
251.4 bar
201 °C
Turbine
70 bar
550 °C
CO2s
He
250 bar
520 °C
59.5 bar
214 °C
59.9 bar
355 °C
58.7 bar
21 °C
59.1 bar
63 °C
251.8 bar
46 °C
71 bar
400 °C
69.6 bar
394 °C
251 bar
315 °C
251.4 bar
196 °C
water
16 °C
  43.3 %
WP1.5 Meeting, Lyon, October 10-11 , 2006, P. Richard, J. F. Pignatel, G. Rimpault
16
Decay Heat Removal - Approach

Goal :


Compare different strategies :
•
Active/Passive
•
Guard Containement/No guard Containment
Background :

GCFR Approach

PDS-XADS (He-cooled XADS)
WP1.5 Meeting, Lyon, October 10-11 , 2006, P. Richard, J. F. Pignatel, G. Rimpault
17
Schematic of DHR system (CEA initial proposal)
pool
Exchanger #2
Secondary loop
H2
Exchanger #1
dedicated DHR loops
H1
Guard
containment
-3 loops of DHR
-3 pools
core
-1 guard containment
WP1.5 Meeting, Lyon, October 10-11 , 2006, P. Richard, J. F. Pignatel, G. Rimpault
18
DHR (CEA studies)
Preliminary design of a Decay Heat Removal system from the GFR 600 MWth : primary loop
STATUS ON THE DHR SYSTEM CAPABILITY
Fuel plates core 100 MW/m3,, simplified steady approach
Backup pressure (Bar)
Fully natural convection, considering Hdriving = 15 m
25 bar
(34 bar)
(for Pn of 40 bar/TinCore 480°C/TfuelMax 1300°C, Hdriving required : ~15 m)
5 10
~
kWe
kWe
7 bar
5 50
~
kWe
kWe
Fully natural conv. (15 m)
Forced convection required during a long time (>1 month)
7 bar
3
265
~
500
kWe
kWe
bar
11bar
Forced convection required during a very long time
75,00% 3%P N (~ 5 mn) 125,00%
175,00%0,6%P N (1 day) 225,00%
Residual power (ANS+10% : %PN)
TinCore = 330°C (480°C)
TinCore = 110°C
Tfuel < 1600°C
Tfuel < 1300°C
WP1.5 Meeting, Lyon, October 10-11 , 2006, P. Richard, J. F. Pignatel, G. Rimpault
19
GFR STRATEGY (CEA Approach)
•For the GFR 2400MWth
-The high back-up pressure strategy (25Bar) is not kept
-for GFR the intermediate back-up pressure strategy (~5 Bar) is
studied
-Back Up solution :The full depressurisation (1Bar) (still not
studied)
WP1.5 Meeting, Lyon, October 10-11 , 2006, P. Richard, J. F. Pignatel, G. Rimpault
20
PDS-XADS
Basic Reactor options:
• Reactor power : 80MWth
• First core: classical FBR fuel U-PuO2 (35% Pu max)
• Accelerator: designed for 600MeV/6mA but can be upgraded to
800MeV/10mA
• Core and Target Unit designed for 600MeV/6mA
• Separated target: liquid • Primary circuit: He
DHR Strategy :
No Guard Containment
Full depressurization 1 Bar
Integrated SCS (but only 2 MWth to be removed by each SCS)
WP1.5 Meeting, Lyon, October 10-11 , 2006, P. Richard, J. F. Pignatel, G. Rimpault
21
PDS-XADS
SCS Design
Integrated SCS
(Electric Power 55kW)
WP1.5 Meeting, Lyon, October 10-11 , 2006, P. Richard, J. F. Pignatel, G. Rimpault
22
DHR for EFIT
For He-EFIT:
The PDS-XADS solution seems better
Proton beam complexity  Guard containment not keep
If the full depressurization is chosen, a strategy must be
defined :
The blowers must work 1 to 70 Bars : Requires High Power and a complex Blower
Design (or 2 systems : 1-10 bars and 10/70 bars? )
OR
Blowers can work only at low pressure :
 Acton for fast depressurization System systematically used
(safety)
 SIMPLIFICATION of procedures
System implementation :
 3 DHR loops designed for 100 %
 2 Solutions : Loops integrated on the vessel/Ex-vessel loops
WP1.5 Meeting, Lyon, October 10-11 , 2006, P. Richard, J. F. Pignatel, G. Rimpault
23
Conclusions (1/2)
Current Design :
 A three zone core has been preliminarily studied :
 Zone 1 (inner) : 45 MWth, 42 sub-assemblies
 Zone 2 (intermediate) : 165 MWth, 156 sub-assemblies
 Zone 3 (outer) : 191 MWth, 180 sub-assemblies
The main hypothesis and/or design objectives accounted are the
following :
 Core height : 125 cm
 External width over flat : 137 mm
 Fuel (fuel+matrix) fraction in the different zones : 11%, 21.5
% and 35 % (for respectively zone 1, 2 and 3)
 Matrix volume fraction in the fuel pellet : 50 %
- The total form factor was assumed to be the same in the
three zones (1.839)
 DHR Approach under discussion
WP1.5 Meeting, Lyon, October 10-11 , 2006, P. Richard, J. F. Pignatel, G. Rimpault
24
Conclusions (2/2)
Next steps :
Detailed neutronic calculations :
Neutron source behaviour by the mean of MCNPX Calculations
Core neutronics by the means of MCNPX and ERANOS
calculations.
Even if the current core design is not fully defined, He-EFIT main
characteristics (core power, main core dimensions) are sufficiently
defined to go ahead with :
Safety Approach/DHR strategy :
 Pre-sizing of the DHR loop components (AREVA ??)
 CATHARE/SIM-ADS modelling (CEA/FzK ???)
 Remontage (AREVA)
 Dissemination of the main He-EFIT design characteristics –
Iteration with the partners
WP1.5 Meeting, Lyon, October 10-11 , 2006, P. Richard, J. F. Pignatel, G. Rimpault
25