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List of Figures
Fig. 2- 1 Simplified representation of the MYRRHA primary cooling system during
the 6th European Framework Program of the EUROTRANS XT-ADS design phase……….……. 2-3
Fig. 2- 2 General layout of the MYRRHA reactor vessel showing how the spallation target is split up in a center and an off-center part and how the two parts are connected. Hatched area
indicates LBE primary coolant……….……….... 2-4
Fig. 2- 3 Top view of the center of the reactor core, in which three elements are removed
to create space for the beam tube………... 2-5
Fig. 2- 4 Schematization of the two different target configurations developed for the MYRRHA reactor
(“Window design” on the left side and “Windowless design” on the right side)……….……. 2-6
Fig. 2- 5 A cut-out view of the spallation target area with a detached flow design.
The LBE flow is indicated in red, the proton beam in yellow and the fuel assemblies is orange………….…… 2-6
Fig. 2- 6 XT-ADS nozzle design called v0.10LBE. The red contour indicates the expected
LBE flow profile……….……… 2-7
Fig. 2- 7 Conventions used for pressure profile calculation……….……… 2-9
Fig. 2- 8 Characteristic pump curve……….………. 2-10
Fig. 2- 9 Spallation loop main dimensions……….……….. 2-12
Fig. 3- 1 Displaced grid of CVs and junctions……….……. 3-11
Fig. 3- 2 ATHLET nodalization of the spallation loop……….… 3-16
Fig. 3- 3 Axial distribution of the power deposition by the proton beam in the spallation area……….. 3-17
Fig. 3- 4 Four-quadrant pump curves obtained for different rotation velocities……….….. 3-19
Fig. 3- 5 Main pump rotation velocity……….………. 3-23
Fig. 3- 6 LBE mass flow rate in the secondary side of the HX……… 3-23
Fig. 3- 7 Thermal power imposed on target zone……….……… 3-23
Fig. 3- 8 LBE mass flow rate in the primary loop……….... 3-24
Fig. 3- 9 Temperature through the target area……….………. 3-24
Fig. 3- 10 Temperature upstream and downstream of the primary side of the HX……….……... 3-25
Fig. 3- 11 Inlet and outlet pressure in the main pump……….... 3-26
Fig. 3- 12 Inlet and outlet pressure in the target region……….………. 3-26
Fig. 3- 13 Liquid level variation in main vessel and beam tube components……….… 3-27
Fig. 3- 14 LBE mass flow rate in the primary loop……….…... 3-28
Fig. 3- 15 Temperature through the target area……….. 3-29
Fig. 3- 16 Temperature upstream and downstream of the primary side of the HX……….…... 3-29
Fig. 3- 17 Liquid level variation in main vessel and beam tube components……….…… 3-29
Fig. 3- 18 LBE mass flow rate in the primary loop……….…... 3-31
Fig. 3- 19 Temperature through the target area……….………. 3-32
Fig. 3- 20 Temperature upstream and downstream of the primary side of the HX……….……... 3-32
Fig. 3- 21 Liquid level variation in main vessel and beam tube components……….…… 3-33
Fig. 3- 22 Thermal power imposed on target zone……….…… 3-34
Fig. 3- 23 LBE mass flow rate in the primary loop……….…... 3-34
Fig. 3- 24 Liquid level variation in main vessel and beam tube components……… 3-34
Fig. 3- 25 Temperature through the target area……….. 3-34
Fig. 3- 26 LBE mass flow rate in the secondary side of the HX……… 3-35
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Fig. 3- 28 Temperature through the target area……….….…. 3-36
Fig. 3- 29 Temperature upstream and downstream of the primary side of the HX………..……... 3-36
Fig. 3- 30 Liquid level variation in main vessel and beam tube components……….……. 3-37
Fig. 4- 1 2D (left) and 3D (right) CV used for Cartesian grids……….….…… 4-6
Fig. 4- 2 Mesh element (ANSYS CFX)……….…….…... 4-9
Fig. 4- 3 Steep spatial gradients due to the UDS (ANSYS CFX)……….……….…… 4-10
Fig. 4- 4 Non-physical oscillation due to discretization with specified blend factor (ANSYS CFX)………..…. 4-11
Fig. 4- 5 XT-ADS Target design (v0.10LBE)……….….. 4-26
Fig. 4- 6 Computational domain realized with ANSYS Design Modeler……….… 4-26
Fig. 4- 7 Mesh generated using ICEM CFD tool……….…….…. 4-27
Fig. 4- 8 Final statistic of the angles in the structured mesh……….….… 4-28
Fig. 4- 9 Boundary conditions applied for the target domain……….... 4-30
Fig. 4- 10 3D representation of the boundary conditions (BCs) for the target domain………... 4-31
Fig. 4- 11 LBE volume fraction distribution obtained with ANSYS CFX code (blue is liquid LBE,
red is NC gas)………...………... 4-32
Fig. 4- 12 Absolute pressure distribution obtained using ANSYS CFX code………... 4-32
Fig. 4- 13 LBE velocity distribution obtained using ANSYS CFX code……….…... 4-32
Fig. 4- 14 Velocity vectors plotted in the return line of the computational domain……….….….. 4-34
Fig. 5- 1 Coupling approach……….…. 5-11
Fig. 5- 2 Surface coupling……….….… 5-11
Fig. 5- 3 Hydraulic coupling parameters………. 5-12
Fig. 5- 4 Thermal coupling parameters……….….… 5-12
Fig. 5- 5 Shared library structure……….….………. 5-14
Fig. 5- 6 Flow chart of the coupled ANSYS CFX code with the ATHLET code………….……….…... 5-14
Fig. 5- 7 Flow chart showing the finalization of the coupled code………...…….... 5-16
Fig. 5- 8 FEBE extrapolation algorithm……….…... 5-16
Fig. 5- 9 Exchange parameters for “Opening - Opening” boundary conditions………..……….. 5-19
Fig. 5- 10 Explicit coupling scheme………..…….. 5-19
Fig. 5- 11 Semi-implicit coupling scheme………..……. 5-21
Fig. 5- 12 ATHLET nodalization of the open TH configuration………..…... 5-23
Fig. 5- 13 ICEM CFD mesh of one fourth pipe………..…………. 5-24
Fig. 5- 14 Open TH configuration with two coupling interfaces……….. 5-24
Fig. 5- 15 LBE mass flow variation set up in FILL junction………..…. 5-25
Fig. 5- 16 LBE velocity in Node 2 of Pipe 2………. 5-25
Fig. 5- 17 LBE pressure in Node 2 of Pipe 2……… 5-25
Fig. 5- 18 FILL temperature………... 5-25
Fig. 5- 19 LBE temperature at the inlet of ANSYS CFX pipe……….. 5-26
Fig. 5- 20 LBE temperature in Node 2 of Pipe 2………... 5-26
Fig. 5- 21 Cold LBE enters the CFD pipe from the inlet………... 5-26
Fig. 5- 22 Hot LBE enters the CFD pipe from the outlet………... 5-26
Fig. 5- 23 Thermal-hydraulic exchange parameters in the open configuration………...………. 5-28
Fig. 5- 24 Difference between the total inlet and outlet mass flow rates obtained in the ANSYS CFX
stand-alone simulation………..…... 5-30
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Fig. 5- 26 LBE mass imbalance in the new target domain for the three meshes………..……... 5-33
Fig. 5- 27 LBE volume fraction distribution obtained with ANSYS CFX code (blue is liquid LBE,
red is NC gas)………... 5-34
Fig. 5- 28 Pressure distribution obtained with ANSYS CFX code………..…… 5-34
Fig. 5- 29 Velocity distribution obtained with ANSYS CFX code………..………… 5-34
Fig. 5- 30 LBE velocity calculated at the inlet and outlet boundaries of the CFD domain………... 5-35
Fig. 5- 31 LBE mass flow rate calculated at the inlet and outlet boundaries of the CFD domain……… 5-36
Fig. 5- 32 LBE absolute pressure calculated at the inlet and outlet boundaries of the CFD domain……… 5-36
Fig. 5- 33 New open configuration for the coupled code simulation………..…. 5-37
Fig. 5- 34 LBE absolute pressure provided by ANSYS CFX to the upper edge of ATHLET network………... 5-38
Fig. 5- 35 LBE velocity provided by ATHLET to the inlet opening of the CFD domain………...…. 5-38
Fig. 5- 36 LBE absolute pressure provided by ATHLET to the outlet opening of the CFD domain………...…… 5-38
Fig. 5- 37 LBE mass flow rate provided by ANSYS CFX to the lower edge of ATHLET network……… 5-38
Fig. 5- 38 Fill mass flow rate in the first transient simulation……….…... 5-40
Fig. 5- 39 LBE absolute pressure provided by ANSYS CFX to the upper edge of ATHLET network……… 5-40
Fig. 5- 40 LBE velocity provided by ATHLET to the inlet opening of the CFD domain……… 5-40
Fig. 5- 41 LBE absolute pressure provided by ATHLET to the outlet opening of the CFD domain………... 5-41
Fig. 5- 42 LBE mass flow rate provided by ANSYS CFX to the lower edge of ATHLET network……… 5-41
Fig. 5- 43 LBE volume fraction distribution plotted 1 second (on the left side) and 14 seconds
(on the right side) after the beginning of the simulation………..……….... 5-42
Fig. 5- 44 Fill mass flow rate in the second transient simulation……….. 5-43
Fig. 5- 45 LBE absolute pressure provided by ANSYS CFX to the upper edge of ATHLET network………... 5-43
Fig. 5- 46 LBE velocity provided by ATHLET to the inlet opening of the CFD domain……… 5-43
Fig. 5- 47 LBE absolute pressure provided by ATHLET to the outlet opening of the CFD domain………... 5-44
Fig. 5- 48 LBE mass flow rate provided by ANSYS CFX to the lower edge of ATHLET network……… 5-44
Fig. 5- 49 LBE volume fraction distribution plotted 1 second (on the left side) and 14 seconds
(on the right side) after the beginning of the simulation……….……. 5-45
Fig. 5- 50 LBE velocity vector distribution plotted 1 second (on the left side) and 14 seconds
(on the right side) after the beginning of the simulation……….. 5-47
Fig. 5- 51 Closed loop configuration used in the coupled code simulations……….... 5-49
Fig. 5- 52 LBE absolute pressure provided by ANSYS CFX to the upper edge of ATHLET network……… 5-49
Fig. 5- 53 LBE velocity provided by ATHLET to the inlet opening of the CFD domain………... 5-49
Fig. 5- 54 LBE absolute pressure provided by ATHLET to the outlet opening of the CFD domain……….….. 5-50
Fig. 5- 55 LBE mass flow rate provided by ANSYS CFX to the lower edge of ATHLET network……… 5-50
Fig. 5- 56 Main pump rotation velocity during the first transient simulation………... 5-51
Fig. 5- 57 LBE mass flow rate obtained in the closed loop……….. 5-51
Fig. 5- 58 LBE absolute pressure obtained at the inlet and outlet boundaries of the CFD domain………. 5-51
Fig. 5- 59 LBE volume fraction distribution plotted 5 second (on the left side) and 19 seconds
(on the right side) after the beginning of the simulation……….. 5-52
Fig. 5- 60 Main pump rotation velocity during the second transient simulation……….. 5-53
Fig. 5- 61 LBE mass flow rate obtained in the closed loop……….. 5-53
Fig. 5- 62 LBE absolute pressure obtained at the inlet and outlet boundaries of the CFD domain………. 5-53
Fig. 5- 63 LBE volume fraction distribution plotted 5 second (on the left side) and 19 seconds
