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									         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              Value/Characteristic              Comments
                           PLANT GENERAL CHARACTERISTICS
Coolant                     Helium at 70 bars        Identical to GCFR value
Core Power                  400 MW th                After iterations with neutronic
                                                     calculations
                                     3
Core Power Density          50 MW/m                  60 MW/m3 proposed in June
                                                     2005
Plant Efficiency            43.3 % without acc.      Requirement : 40 %

Core Inlet/outlet Temp      350°C/550°C                         Delta T increase by 50 °C
Power conversion            Indirect cycle S-CO2 with re-
                            compression
Accelerator                 LINAC                               Over 800 MeV, Spallation
                            E : 800 Mev                         Products have longer half-life 
                            I : 18-22 mA                        Upper limit fixed to 800 MeV
Target Unit interface       Window Target                       W rods cooled by helium –
                            Solid Target                        separate cooling of the window
Loading Factor              75 %                                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)

                             CORE GENERAL CHARACTERISTICS
Fuel Composition            (Pu, Am, Cm)O2 + MgO 50/50 % Fuel/Matrix ratio
Fuel (pellet) Power         App. 200 W/cm³       To be adjusted after transmutation
density                                          optimisation
Fuel content Ratio          30 % (Pu/MA+Pu)      To be adjusted after transmutation
                                                 optimisation
Fuel and MA Vectors                              Provided by GR
Fuel Pin Spacer             Grid                 5 grid spacers
Fuel Assembly type          Wrapper              4 mm thickness
Fuel Assembly cross         Hexagonal
section
Core zoning                 3 Zones                            Different pin diameters
S/A pitch                   137 mm                             Adjusted for an optimum target size
Peaking Factor              1.839                              Same peaking factors considered in
                                                               the three zones
Core height                 1.25 m
Core Pressure Drop          Range 0.7-1 bar                    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      SiC
  Cladding thickness     1 mm                         Minimum Thickness for Feasibility reasons (to be
                                                      checked by CEA)
  Fuel/Cladding Gap      100 µm for 5.8 mm in         Provided by DM3
                         Diameter – Changed
                         proportionally to the pellet
                         diameter
                                             DESIGN CRITERIA
  Tfuelmax               1380 °C                      DBC cat. I
  Tfuelmax               1580 °C                      DBC cat. II
  Tfuelmax               1780 °C                      DBC cat. III
  Tcladmax               1200 °C                      DBC cat. I
  Tcladmax               1300 °C                      Long-term transient(>24h)
  Tcladmax               1600 °C                      Short-term transient(<24h)
                                              SAFETY ISSUES
  Protected transients   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)
  DHR Approach           No Back-up pressure (no
                         guard containment)
                         Core-catcher
  DHR                    Under nominal pressure :     Decay Heat Curve deduced from the banchmark
                         Nat. circulation
                         Depressurised cond. :
                         active DHR systems to
                         remove Decay Heat




                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                                                                                He-EFIT
Thermal Power (MWth)                                                                       400
Coolant Type                                                                               He
Coolant Pressure (bar)                                                                     71
Inlet Temperature (°C)                                                                     350
Outlet Temperature (°C)                                                                    550
Cladding Type                                                                              SiC
Spallation module                                                                   Solid W He cooled
Zone                                                                      1 (inner)                2 (intermediate)      3 (outer)
Matrix Type                                                                  MgO                          MgO              MgO
Matrix Fraction                                                              50%                          50%               50%
Volume of the fissile zone (m^3)                                      0,915 m3 / 0.917              3,39 m3 / 3.40    3,93 m3 / 3.93
Core Geometry
Outer Diameter of the fissile zone                                     1,16 m / 1.165               2,19 m / 2.197     2,97 m / 2.97
Height of Sub-Assemblies                                                   2.75 m                       2.75 m             2.75 m
Number of fissile sub-assemblies                                              42                          156                180
Fissile Height (H)                                                         1,25 m                       1,25 m             1,25 m
Wrapper Width over outer Flats                                            137 mm                       137 mm             137 mm
Wrapper Thickness                                                          4,0 mm                      4,0 mm             4,0 mm
Inter-Wrapper Gap                                                          5,0 mm                      5,0 mm             5,0 mm
Coolant Volume Fraction (%)                                            49.8% / 48.03               44.75% / 42.62     37.19% / 34.08
Fuel Volume Fraction (%)                                                5.58% / 6.00               10.85% / 10.81     17.49% / 17.51
Matrix Volume Fraction (%)                                              5.58% / 6.00               10.85% / 10.81     17.49% / 17.51
Structure Volume Fraction (%)                                          39.05% / 40.02              33.56% / 34.23     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                                                             469              217                 91
Number of Pin rows per SA                                                          12               8                   5
Pin outer Diameter                                                             4,38 mm          6,87 mm            11,57 mm
Cladding Roughness                                                              Smooth          Smooth              Smooth
Pitch to Rod Ratio                                                                1,35            1,25                1,14
Pitch (mm)                                                                     5,89 mm         8,60 mm             13,20 mm
Hydraulic Diameter                                                            4.36 / 4.16      5 / 4.86           5.05 / 5.05
Cladding Thickness                                                             1,00 mm          1,00 mm             1,00 mm
Pellet/Cladding Gap                                                            0,040 mm        0,081 mm            0,160 mm
Pellet Diameter                                                                2,30 mm         4,71 mm              9,25 mm
Core Thermal-Hydraulics
Average Coolant Speed in the Fissile Core m/s                                  30 / 29.8      34.5 / 34.4          45 / 45.3
Average Reynolds Number in the Core                                         16958 / 16147    22621 / 21771       29643 / 29749
Average Prandtl Number in the Core                                           0.64 / 0.672      0.64 / 0.67        0.64 / 0.67
Average Nusselt Number in the Core                                            44 / 46.4         54 / 57.2           65 / 70.8
Average Pin Linear Power W/m                                                    18 / 18          39 / 39             93 / 93
Form Factor                                                                  1.839 / 1.839   1.839 / 1.839       1.839 / 1.839
Max Pin Linear Power W/m                                                        33 / 33          72 / 72           171 / 171
Hottest Channel Thermics
Max Cladding Temperature in the Hottest Channel °C                            686 / 682       700 / 694            711 / 704
Max Fuel Temperature in the Hottest Channel °C                                792 / 772       950 / 927           1310 / 1322
Core Pressure Drop (bar)
Grid Number                                                                        5               5                    5
Total Core Pressure Drop bar                                                 0.84 / 0.874     0.74 /   0.734      1.01 / 0.978
Total Regular Pressure Drop bar                                               0.47 / 0.49     0.52 /   0.525      0.81 / 0.816
Total Singular Pressure Drop bar                                             0.37 / 0.383     0.22 /    0.21       0.2 / 0.16
Power MW                                                                        45 / 44       165 /     165        191 / 190

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
       “Cold” Window Concept (1/2)




                          170
                   200




                                200
               Di 370 Ep. 10
                                                                       252




                                            9755
                                      750




                                                                      3
                                                                       200




                    200
840




                   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                          Radial pitch
              of horizontal W-rods (see detail A)


                                                                            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 re-
           compression
          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
                                                                Auxiliary                                   Compressor
                                                                Compressor
                                                                                        251.4 bar

  70 bar                      Turbine                                                   201 °C

  550 °C
                                                       CO2s
           He              250 bar
                           520 °C
                                                         59.5 bar
                                                         214 °C

                                                                                                            58.7 bar
                                      59.9 bar                               59.1 bar                       21 °C
                                      355 °C                                 63 °C


                                                                                                                       251.8 bar
                                                                                                                       46 °C
71 bar                                                                                              water
400 °C          69.6 bar                   251 bar            251.4 bar
                394 °C                     315 °C             196 °C
                                                                                                    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
                                                                  -3 loops of DHR
                                               containment
                                                                  -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

                                           Fully natural convection, considering Hdriving = 15 m
                               25 bar
Backup pressure (Bar)



                              (34 bar)       (for Pn of 40 bar/TinCore 480°C/TfuelMax 1300°C, Hdriving required : ~15 m)



                                    ~ kWe
                                    5 10 kWe                                                           Fully natural conv. (15 m)
                               7 bar



                                    ~ 50 kWe
                                    5 kWe              Forced convection required during a long time (>1 month)
                               7 bar
                               3


                                    ~ 500 kWe
                                    265 kWe
                                                                     Forced convection required during a very long time
                                 bar
                              11bar


                   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

								
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