Classifications

• • G—PHYSICS
  • G21—NUCLEAR PHYSICS; NUCLEAR ENGINEERING
  • G21C—NUCLEAR REACTORS
  • G21C1/00—Reactor types
  • G21C1/32—Integral reactors, i.e. reactors wherein parts functionally associated with the reactor but not essential to the reaction, e.g. heat exchangers, are disposed inside the enclosure with the core
  • G21C1/322—Integral reactors, i.e. reactors wherein parts functionally associated with the reactor but not essential to the reaction, e.g. heat exchangers, are disposed inside the enclosure with the core wherein the heat exchanger is disposed above the core
• • G—PHYSICS
  • G21—NUCLEAR PHYSICS; NUCLEAR ENGINEERING
  • G21C—NUCLEAR REACTORS
  • G21C1/00—Reactor types
  • G21C1/32—Integral reactors, i.e. reactors wherein parts functionally associated with the reactor but not essential to the reaction, e.g. heat exchangers, are disposed inside the enclosure with the core
• • G—PHYSICS
  • G21—NUCLEAR PHYSICS; NUCLEAR ENGINEERING
  • G21C—NUCLEAR REACTORS
  • G21C1/00—Reactor types
  • G21C1/02—Fast fission reactors, i.e. reactors not using a moderator ; Metal cooled reactors; Fast breeders
• • G—PHYSICS
  • G21—NUCLEAR PHYSICS; NUCLEAR ENGINEERING
  • G21C—NUCLEAR REACTORS
  • G21C1/00—Reactor types
  • G21C1/02—Fast fission reactors, i.e. reactors not using a moderator ; Metal cooled reactors; Fast breeders
  • G21C1/03—Fast fission reactors, i.e. reactors not using a moderator ; Metal cooled reactors; Fast breeders cooled by a coolant not essentially pressurised, e.g. pool-type reactors
• • G—PHYSICS
  • G21—NUCLEAR PHYSICS; NUCLEAR ENGINEERING
  • G21C—NUCLEAR REACTORS
  • G21C15/00—Cooling arrangements within the pressure vessel containing the core; Selection of specific coolants
  • G21C15/18—Emergency cooling arrangements; Removing shut-down heat
• • G—PHYSICS
  • G21—NUCLEAR PHYSICS; NUCLEAR ENGINEERING
  • G21C—NUCLEAR REACTORS
  • G21C15/00—Cooling arrangements within the pressure vessel containing the core; Selection of specific coolants
  • G21C15/24—Promoting flow of the coolant
  • G21C15/243—Promoting flow of the coolant for liquids
  • G21C15/247—Promoting flow of the coolant for liquids for liquid metals
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
  • Y02E30/00—Energy generation of nuclear origin
  • Y02E30/30—Nuclear fission reactors

Definitions

• the invention relates to a sodium - cooled nuclear reactor called Sodium Fast Reactor (SFR), which is part of the so - called fourth generation reactor family.
• SFR Sodium Fast Reactor
• the invention relates to a sodium-cooled nuclear reactor, of integrated type, that is to say for which the primary circuit is completely contained in a vessel also containing the primary pumps and heat exchangers.
• the invention proposes an improvement to the application WO 2010/057720 which proposed an innovative architecture of the primary circuit contained in the reactor vessel to improve its compactness, to facilitate the design of certain parts and to improve natural convection sodium in the tank.
• Sodium-cooled nuclear reactors usually have a tank in which the heart is located, with a heart control cap above the heart.
• the extraction of heat is performed by circulating the so-called sodium sodium primary by means of a pumping system placed in the tank.
• This heat is transferred to a circuit intermediate, via one or more exchanger (s) intermediate (s) (El), before being used to produce steam in a steam generator (GV).
• This steam is then sent to a turbine to transform it into mechanical energy, which in turn is transformed into electrical energy.
• the intermediate circuit comprises, as a coolant, sodium and is intended to isolate (or otherwise contain) the primary sodium which is in the tank, relative to the steam generator and this, because of the violent reactions likely to occur between the sodium and the water vapor contained in the steam generator in case of a possible rupture of a tube of the latter.
• the architecture highlights two circuits in sodium: one said primary charged to transfer the heat between the heart and one (or) heat exchanger (s) intermediate (s), the other said secondary responsible for transferring the heat of the exchanger (s) intermediate (s) to the steam generator.
• SFR sodium cooled reactors
• the tank is closed on the top by a closure slab so that the primary sodium is not in contact with the outside air. All the components (heat exchangers, pumps, pipes, ...) pass through this slab vertically so that they can be dismantled by lifting them vertically by means of a lifting device.
• the dimensions of the through holes in this slab depend on the size and number of components. More holes are important (in size and number), plus the diameter of the tank will be important.
• Loop-type SFR reactors are characterized in that the intermediate exchanger and the primary sodium pumping devices are located outside the vessel.
• a loop type SFR reactor is, for a given power, to obtain a vessel of smaller diameter than that of an integrated type SFR reactor, because the vessel contains fewer components. The tank is therefore more easily manufactured and therefore less expensive.
• a loop-type SFR reactor has the major disadvantage of removing primary sodium from the tank, which complicates the primary circuit architecture and poses significant safety problems.
• the advantages of reduced size and easier manufacturing of the tank are offset by the additional costs of adding devices related to the design of loops and special means to manage possible leakage of primary sodium.
• SFR reactors of integrated type are characterized in that the intermediate exchangers and the pumping means of the primary sodium are entirely located in the tank, which makes it possible to avoid getting the primary circuit out of the tank and therefore constitutes a important advantage in terms of safety with respect to a loop type SFR reactor.
• the inventors of the present application have proposed in the application WO 2010/057720 a solution to improve the SFR integrated type reactors.
• the object of the invention is therefore to provide an improvement to the integrated type SFR reactor according to the application WO 2010/057720 which aims to overcome all or part of the disadvantages mentioned above.
• an integrated type SFR nuclear reactor comprising a vessel adapted to be filled with sodium and inside which are arranged a core, pumping means for circulating the primary sodium, first heat exchangers, so-called intermediate exchangers, adapted to evacuate the power produced by the heart during normal operation of the second heat exchanger adapted to evacuate the residual power produced by the heart when the stop when the means are also stopped, a separation device delimiting a hot zone and a cold zone in the tank, comprising:
• a separation device consisting of two walls each with a substantially vertical portion arranged around the heart and a part substantially horizontal, the substantially horizontal portions being separated from one another by a height and the space delimited above the horizontal portion of the upper wall forming the hot zone while the space defined below the part horizontal of the bottom wall forms the cold zone and the substantially horizontal portions are arranged with them relative to the tank,
• Variable flow pumping means divided into two groups in hydraulic series, one arranged below the horizontal portion of the bottom wall for circulating sodium from the cold zone to the hot zone through the heart, the another to circulate sodium from the hot zone to the cold zone through the intermediate heat exchangers,
• Temperature acquisition means arranged in the space delimited between the horizontal portions of the two walls being distributed along a substantially vertical axis in order to determine in real time the thermal stratification in this space
• servo means connected on the one hand to the temperature acquisition means and on the other hand to the two pumping groups, to modify if necessary the flow of at least one pumping group in order to maintain a satisfactory level of stratification during normal operation
• Second heat exchangers arranged substantially vertically above the cold zone
• exit windows of the intermediate exchangers are each surrounded in an envelope in fluid communication with a torus-shaped duct,
• the pumping unit for circulating the sodium from the hot zone to the cold zone through the intermediate exchangers also has each of its inputs in fluid communication with the toroid, so that the primary sodium from the hot zone and outgoing intermediate exchangers circulates through the torus to be directed to the cold zone by said pumping group.
• the two hydraulic series variable flow pumping units are mechanically independent and each consists of rotodynamic pumps
• the drive shaft extends vertically over the height of the tank through the slab of closure and the horizontal parts of both walls of the separating device arranged substantially vertically with clearances, the them between the support of the pumps and the two walls of the separating device being also previously determined for, in normal operation, resume the differential movements between them and the tank and to allow to establish in normal operation thermal stratification of the primary sodium in the space delimited between the horizontal parts of the two walls and, in case of unexpected stoppage of a pumping group, limiting the mechanical stresses to the walls due to the part of the flow of primary sodium passing into said games.
• the two hydraulic series variable flow pumping units are mechanically dependent and consist of at least one double-wheel centrifugal rotodynamic pump, a first wheel arranged with its inlet for axially sucking the primary sodium. in the torus and its outlet to discharge the primary sodium in the cold zone and the second wheel, mounted on the same drive shaft line as the first wheel, and arranged with its inlet to suck the primary sodium in the cold zone and his exit to drive back to the heart. Coupling on the same shaft line the two wheels described above allows to similarly vary the primary sodium flow through the core and through the intermediate exchangers, especially in the intermediate flow regimes. . This also has the advantage of simplifying the mode of piloting and adjustment of flow rates.
• centrifugal double-wheel pump differs from those known according to the state of the art in that there is an intermediate zone of large volume between the two impellers of the same pump and that this Intermediate zone is common to several pumps. This intermediate zone of large volume is the cold zone of the reactor according to the invention.
• the first wheel of the pump (the one that sucks in the torus) undergoes some kind of direct heat shock, but the second wheel undergoes a gradual rise in the temperature of sodium, because the hot sodium leaving the first wheel is gradually mixed with the cold sodium already present in the cold collector.
• the flow adjustment means (s) consist (s) in additional means (s) of pumping (s), distinct (s) of the (the) pump (s) ) electromechanical two-wheeled, and whose (their) input is (are) in fluid communication with the torus, the sum of the primary sodium flows provided by the means (s) pumping additional (s) and the double-wheel pump is approximately equal to the flow rate through the intermediate exchangers.
• the value of the flow rate provided by the impeller of the double impeller pump having its suction in the torus can be between 90 to 95% of that of the flow rate passing through the intermediate exchangers. It goes without saying that the flow rate provided by the double-wheel pump may depend on the speed of rotation of the drive shaft line.
• the additional pumping means (s) provide the additional flow rate by adjusting it so that the flow rate passing through the intermediate exchangers is equal to that crossing the heart. It is preferably ensured that the additional pumping means provides a low flow rate, typically from 5 to 10% of the flow rate through the intermediate exchangers.
• the additional means (s) for pumping (s) is (are) constituted (s) by a rotodynamic pump and / or an electromagnetic pump.
• the drive shaft line of the two impellers of the pump comprises at least two coaxial shafts integral in rotation and adapted to be displaced axially relative to each other, the lower end of one of the shafts. supporting at least one part of the rotor blades while the lower end of the other tree supports the other part of the wheel;
• a double-wheel centrifugal rotodymanic pump is manufactured to have a hydraulic circulation in a wheel between two discs. One of these disks is fixed while the other is fixed on the wheel supporting the blades. Thus, usually, in order to obtain the maximum efficiency, provision is made for minimal assembly between the edges of the blades of the mobile disk and the fixed disk.
• judiciously, by making a retractable blade assembly in the mobile disk one can adjust the clearance between them and the fixed disk and thereby degrade more or less the efficiency of the pump that is to say its pressure characteristics as a function of flow.
• An integrated type SFR reactor according to the invention may comprise a number of six intermediate exchangers, six second exchangers and three centrifugal rotodynamic double wheel pumps.
• FIG. 1 is a schematic view in longitudinal section of an integrated type SFR reactor according to the invention
• FIG. 1A is a schematic view in partial longitudinal section of an integrated type SFR reactor according to the invention illustrating an alternative arrangement between an intermediate exchanger and a torus-shaped duct according to the invention
• FIG. 2 is a diagrammatic view illustrating a solution for collecting sodium at the outlet of intermediate exchangers in a torus and for pumping sodium according to the invention, with two centrifugal double-rotor pumps as pumping means,
• FIG. 3 shows the characteristic curves of the pressure as a function of the flow rate of a centrifugal pump with a double impeller according to the invention
• FIG. 4 is another schematic view in longitudinal section of an integrated type SFR reactor according to the invention, in which the arrangement of a double-wheel pump is shown
• FIG. 5 is a detail view in section of a spinning wheel of the centrifugal pump with means for adjusting the sodium flow
• FIG. 6 is a schematic view in partial longitudinal section of an integrated type SFR reactor according to the invention illustrating the relative arrangement between exchanger dedicated to the residual power evacuation, temperature acquisition means and separation device. between hot zone and cold zone according to the invention,
• FIG. 7 is another view similar to Figure 4, in which in addition to the drive motor, is shown the control mechanism of the blades of a wheel of a pump according to the invention.
• the terms “horizontal”, “vertical”, “lower”, “upper”, “below” and “above” are to be understood by reference to a reactor vessel arranged vertically and vertically. arrangement with respect to the cold or hot zone.
• the upper wall according to the invention refers to the wall closest to the hot zone, while the bottom wall refers to the one closest to the cold zone.
• a pump according to the invention arranged below the bottom wall is that located in the cold zone.
• upstream and downstream are to be understood by reference to the flow direction of the sodium.
• a group of pumping means upstream of an intermediate exchanger is first traversed by the sodium which then circulates through the intermediate exchanger.
• a group of pumping means downstream of an intermediate exchanger is traversed by the sodium which has previously passed through the intermediate exchanger.
• the integrated reactor comprises a core 11 in which the heat is released following the nuclear reactions.
• This core 11 is supported by a support 110.
• This support 110 comprises a bed base 1100 in which are pressed the feet of the assemblies 111 constituting the heart, this bed 1100 being supported by a decking 1101 resting on the bottom 130 of the tank 13.
• Au Above the core is the heart control plug (BCC) including the instrumentation necessary for the control and proper functioning of nuclear reactions.
• BCC heart control plug
• the heat evacuation circuit followed by the primary sodium in normal operation of the core 11 is schematically represented by the arrows in CN solid lines: at the exit of the heart, the sodium opens into a hot collector 12.
• the hot collector 12 is separated from the cold collector 14 below, by a suitable separation device 15.
• This separation device between collectors (or zones) 12 hot and cold 14 consists of two walls 150, 151 perforated. These two walls 150, 151 perforated are each with a substantially vertical portion 1501, 1511 arranged by surrounding the heart and a substantially horizontal portion 1500, 1510. The horizontal portions 1500, 1510 are separated by a height H. In the illustrated modes, they are interconnected by a rounded. The vertical portions of each wall 150, 151 are fixed to the support 110 of the core 11. The space delimited above the horizontal portion 1500 of the upper wall 150 forms the hot zone while the space defined below the horizontal portion 1510 of the bottom wall 151 forms the cold zone.
• the substantially horizontal portions 1500, 1510 are arranged with them relative to the tank 13.
• Each intermediate heat exchanger 16 is disposed vertically through the closure slab 24.
• the primary sodium supplying the intermediate heat exchangers 16 in normal operation is taken into the hot collector 12 and is discharged into the cold collector 14.
• the intermediate heat exchangers 16 pass through the two horizontal parts 150, 151 wall with functional clearance j2 and without any particular seal.
• variable flow pumping means 3 divided into two groups 30, 31 in hydraulic series are provided.
• One of the groups 31 is provided to circulate the sodium of the cold zone 14 to the hot zone 12 by passing through the core 11
• the other of the groups 30 is provided to circulate the sodium from the hot zone 12 to the zone cold 14 while passing through the intermediate exchangers 16.
• the pumping unit 30 for circulating the sodium from the hot zone 12 to the cold zone 14 also has each of its inputs in fluid communication with the torus 21, so that the primary sodium from the hot zone 12 and leaving the intermediate exchangers 16 circulates through the torus 21 to be directed to the cold zone by said pumping unit 30.
• an advantageous embodiment consists in producing at least one pumping means 3 in common between the two groups 30, 31 constituted by a double-wheel centrifugal rotodynamic pump.
• the first group is constituted by the impeller 30 of the pump 3 and is arranged with its inlet 300 to aspirate axially the primary sodium in the torus 21 and with its outlet 301 to discharge the primary sodium in the cold zone 14.
• the second group is constituted by the impeller 31 of the same pump 3 and is mounted on the same drive shaft line 32 as the first impeller 30, and it is arranged with its inlet 310 to radially suck the primary sodium into the cold zone 14 and with its output 311 to push back to the heart 11.
• the two wheels 30, 31 it is possible to vary in a similar manner the primary sodium flow that passes through the core 11 and the one that passes through the intermediate exchangers 16, particularly in the heating systems. intermediate flow.
• FIG. 3 is a characteristic diagram of the flow versus pressure curves for the two wheels 30, 31 of the same pump 3 with a common zone 14. It can be seen here that:
• the variation of the primary sodium flow through the core 11 is equal to the variation of the sodium flow through the intermediate exchangers 16.
• Figure 4 shows the arrangement of the same centrifugal pump with double impeller 30, 31 in the reactor.
• the support 321 of the double-wheel pump in which the shaft line 32 extends extends vertically substantially over the entire height of the tank 13 through the closure slab 24 and the horizontal portions 1500, 1501 of the two walls 150 , 151 of the separation device arranged substantially vertically with them.
• the them between the support 321 of the pump in which the shaft line 32 of the pump is located and the two walls of the separating device are predetermined in order, in operation normal, take the differential shifts between them and the tank 13 and to establish in normal operation a thermal stratification of the primary sodium in the space between the horizontal portions of the two walls 150, 151.
• the drive shaft line comprises at least two coaxial shafts 320, 321 able to be moved axially relative to each other.
• the lower end of the shaft 320 supports the blades while the lower end of the other shaft 321 supports the other part of the wheel which is fixed axially.
• the blades 3000 are retracted. This increases the clearance between the edges of the blades 3000 and the fixed disk 302, which makes it possible to degrade more or less the pump efficiency, ie its pressure characteristics as a function of flow rate. This adjusts the flow to through the intermediate exchangers 16 with respect to the flow rate through the core 11 and independently of the rotational speed of the shaft line 320, 321.
• FIG. 5 Shown in FIG. 5 is the retraction of the blades 300 on the impeller 30 which sucks the sodium from the core 21 to adjust the flow rate through the intermediate exchangers 16 with respect to the flow rate through the core 11.
• FIG. 6 shows an embodiment optimized to improve the efficiency of the thermal stratification in the space of height H separating the two horizontal parts 1500, 1510 from the upper and lower walls 150, 151 and thus to improve the natural convection Cr (residual circulation) of the primary sodium in stopping operation of nuclear reactions.
• An aperture 15000 is provided in the horizontal portion 1500 of the upper wall 150 under each exchanger.
• the exchange zone of the exchangers 25 dedicated to the residual power evacuation is entirely placed in the hot collector.
• the exit window 250 is positioned just below the horizontal portion 1500 of the top wall 150.
• a functional clearance j3 between the aperture 15000 of the top wall 150 and the exchanger 25 allows the differential movement between these components.
• the exit window 250 of the secondary heat exchanger 25 being placed just below the horizontal portion 1500 of the upper wall 150, the cold sodium leaving the heat exchanger 25 in operation decreases more easily towards the cold collector 14 since one of the walls 150 is already crossed, and this without mixing with the sodium of the hot collector 12, in other words, the hydraulic path during operation at a standstill in natural convection is improved,
• the sodium passes through the horizontal part 1510 of the lower wall 151 via openings 15100 arranged under the exchanger dedicated to the residual power evacuation and via the holes constituted by the functional clearances between the lower wall and the intermediate exchangers and the functional clearance between wall of the redan and reactor vessel.
• the height H of the space between the horizontal portions 1500, 1510 of the two walls 150, 151 is relatively large (of the order of two meters) to allow proper lamination.
• the distance between the vertical portions 1501, 1511 of the two walls is small (of the order of a few centimeters).
• the height space H is in communication with the hot collector 12 and the cold collector 14 by the following functional games:
• the objective of the walls is indeed to mark a physical limit between zones 12, 14 where the flows are at high speeds: hot collector 12 and cold collector 14, with a calm zone where must be established a thermal stratification without which there is no need to have a seal.
• hot collector 12 and cold collector 14 with a calm zone where must be established a thermal stratification without which there is no need to have a seal.
• specific arrangements can be made.
• the functional elements j1, j2 and j3 and the height H between the horizontal portions 1500, 1510 of the two walls of the separating device are predetermined in order, in normal operation, to take up the differential displacements between the walls 150 , 151, exchangers 16, 25, pump 3 and tank 13 and to allow to establish in normal operation a thermal stratification of the primary sodium in the space delimited between the horizontal parts of the two walls 150, 151 and for, in case of stopping unexpectedly of a pumping unit 30 or 31 (when they are decoupled), limiting the mechanical stresses to the walls due to the part of the primary sodium flow passing in said them.
• the thermal stratification thus determined is thus in a way to provide a sufficiently large volume over the height between the two walls 150, 151 and to limit the parasitic flow rates of primary sodium between hot zone 12 and cold zone 14.
• the total cross section of the horizontal part of the upper wall is about 6 m 2 .
• This total estimate is valid for the upper wall 150.
• These openings 15100 preferably have a hydraulic diameter equivalent to the other openings, a diameter of about 0.10 m.
• the number of these openings 15100 is preferably such that their total section is at least equal (in order of magnitude) to the total section created by the functional clearance j3 around the residual power evacuation exchangers 25.
• this section being of the order of 1 m 2 , there is provided at least twenty holes 15100 under each exchanger 25 dedicated to the residual power evacuation.
• the passage section through the perforated walls 150, 151 is in order of magnitude, satisfactory for all the following different operating conditions:
• the walls 150, 151 do not undergo excessive mechanical stress in the event of a sudden total stoppage of a pumping unit 30 or 31 when these two groups are mechanically independent (decoupled).
• the sodium flow in normal operation is of the order of about 22.5 m 3 / s.
• part of the sodium flow continues to circulate in the intermediate exchangers 16 and the other part through them jl, j2, j3 between components 3, 16, 25, 13 and walls 150, 151.
• the distribution between the two flows is a function of the relative pressure losses between the intermediate heat exchangers 16 and the two walls 150, 151 An estimate of these pressure drops potentially leads to about 70% of the flow passing through the games j1, j2, j3 is about 16 m 3 / s.
• the average speed between the openings of the walls 150, 151 and the components is therefore 2.7 m / s. This speed is low and does not lead to significant mechanical forces on the walls 150, 151,
• the hydraulic diameter In normal operation, to limit parasitic flow through the holes, the hydraulic diameter must be small.
• the passage sections in the walls 150, 151 are preferably of very elongated shape with a width of about 5 cm. In this case, the hydraulic diameter is substantially equal to twice the width is 10 cm. With such a diameter based on the diameter of a vessel of a reactor according to the invention of about 15 m, the relative value of the hydraulic diameter is therefore equal to about 0.1: 1 or less than 0.7%.
• FIG. 6 shows an optimized embodiment for measuring the thermal gradient in the internal space between horizontal portions 1500, 1510 of wall 150, 151.
• the temperature acquisition means represented here consist of one or more perch 6 immersed (s) in the sodium and passing through the two horizontal portions 1500, 1510 of the two walls 150, 151.
• thermocouples 60 intended to know the temperature of the sodium at different altitudes in the area internal wall height H between walls 150, 151.
• Knowledge of the vertical temperature profile associated with a digital treatment to monitor the evolution of the thermal gradient and enslave the sodium flow passing through the core 11 at the flow rate of the one passing through the intermediate exchangers 16.
• the zone of height H between the two walls 150, 151 constitutes a zone without flow or with low speed flows allowing the establishment of thermal stratification.
• thermocouples or thermal probes 60 fixed at different altitudes to the pole (s) or by another method makes it possible, if necessary, to adjust the relative flow rate between the flow rate passing through the core 11 and flow through intermediate exchangers 16.
• the efficiency of thermal stratification can be evaluated by the Richardson number defined by the following equation:
• H is a characteristic dimension of the volume, typically the height of the volume
• V is the speed of arrival of the fluid in the volume.
• the number of Richardson Ri thus characterizes the ratio between the density or gravitational forces ( ⁇ g H) with the inertial forces (p V 2 ). If the forces of inertia are larger than the gravitational forces, Ri will be less than unity and forced convection will prevail, there is no stratification. If the gravitational forces are larger than the inertial forces, Ri will be greater than unity, which means that there is a stratification that is established within the volume.
• the volume to be considered is the height space H situated between the two horizontal portions 1500, 1510 of the walls 150, 151. Since in normal operation, the flow rates through the core 11 and the intermediate exchangers 16 are equal, there is no flow in this space of height H, so the velocities are zero. In reality, there may be low flow because the two walls being perforated through the functional ones jl, j2, j3, it appears low flow velocities through said games. Evaluation of the Richardson Ri number in a reactor according to the invention
• Reactor power 3600 MW.
• Density of the cold Na ⁇ 857 kg / m 3 .
• Relative size of the volume (corresponding to the height H between the two walls 150, 151): ⁇ 2 m.
• j2, j3 is about 2.25 m 3 / s.
• the speed is therefore approximately equal to 0.37 m / s.
• the number of Richardson Ri is substantially equal to 6. This number being greater than unity, the flow in the space between walls 150, 151 of height H is well stratified.
• Measuring the level of this stratification thus makes it possible to readjust the relative flow rates between the one through the core 11 and the one through the intermediate exchangers 16 by the regulation appropriate, preferably by the retraction of the blades of a wheel 30, 31.
• This appropriate control can also be achieved by additional pumping means provided in the torus 21 to suck a portion of the sodium from the intermediate exchangers 16.
• FIG. 7 shows a preferred arrangement of the two-wheel pump 30, 31 according to the invention with its drive motor 33 and the axial displacement mechanism 34 of the shaft 320 for retracting the blades of the impeller.
• the drive motor 33 of the shaft line is arranged above the closure slab 24 of the reactor and the axial displacement control mechanism 34 for retracting the blades is arranged itself above the engine. 33.
• this mechanism it is possible to use a proven mechanism of the screw-nut or hydraulic cylinder type. Also for reasons of simplification of its assembly, one can arrange the shaft 320 in the center of the shaft driven in rotation by the motor 33.
• An integrated type SFR reactor according to the EFR project under study, according to the patent application WO 2010/0557720 is likely to have a diameter of the tank of the order of 17 to 18 m.
• a SFR reactor of the same power as the EFR project under study, but whose architecture is based on the present invention (represented in FIG. 1) comprising a number of six intermediate exchangers 16, six second exchangers 25 and three centrifugal rotodynamic pumps 3 double-wheel 30, 31 is likely to have a tank diameter of between 15 and 16 m.
• the illustrated embodiment advantageously provides, for a given pumping means 3, a double-wheel pump for pumping the hot zone 12 to the cold zone (wheel 30) and pumping the zone. cold 14 to the hot zone (wheel 31), one can also provide two separate pumps, that is to say, which are not coupled to each other in their operating regime. In such a mode, fluid communication is maintained from the inlet of the pump circulating the primary sodium from the hot zone to the cold zone with the torus according to the invention.

Landscapes

• Physics & Mathematics (AREA)
• Engineering & Computer Science (AREA)
• Plasma & Fusion (AREA)
• General Engineering & Computer Science (AREA)
• High Energy & Nuclear Physics (AREA)
• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Structures Of Non-Positive Displacement Pumps (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=43500264

Family Applications (1)

Country Status (8)

Families Citing this family (11)

Family Cites Families (13)

• 2010
  • 2010-10-04 FR FR1058016A patent/FR2965655B1/fr not_active Expired - Fee Related
• 2011
  • 2011-10-03 JP JP2013532147A patent/JP2013543586A/ja active Pending
  • 2011-10-03 CN CN2011800584854A patent/CN103238186A/zh active Pending
  • 2011-10-03 US US13/877,906 patent/US20130216015A1/en not_active Abandoned
  • 2011-10-03 KR KR1020137010658A patent/KR20130116258A/ko not_active Application Discontinuation
  • 2011-10-03 WO PCT/EP2011/067206 patent/WO2012045691A1/fr active Application Filing
  • 2011-10-03 RU RU2013120317/07A patent/RU2013120317A/ru not_active Application Discontinuation
  • 2011-10-03 EP EP11764178.7A patent/EP2625690A1/fr not_active Withdrawn

Non-Patent Citations (1)

Also Published As

Similar Documents

Legal Events