Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D35/00—Filtering devices having features not specifically covered by groups B01D24/00 - B01D33/00, or for applications not specifically covered by groups B01D24/00 - B01D33/00; Auxiliary devices for filtration; Filter housing constructions
  • B01D35/02—Filters adapted for location in special places, e.g. pipe-lines, pumps, stop-cocks
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D29/00—Filters with filtering elements stationary during filtration, e.g. pressure or suction filters, not covered by groups B01D24/00 - B01D27/00; Filtering elements therefor
  • B01D29/01—Filters with filtering elements stationary during filtration, e.g. pressure or suction filters, not covered by groups B01D24/00 - B01D27/00; Filtering elements therefor with flat filtering elements
• • G—PHYSICS
  • G21—NUCLEAR PHYSICS; NUCLEAR ENGINEERING
  • G21C—NUCLEAR REACTORS
  • G21C3/00—Reactor fuel elements and their assemblies; Selection of substances for use as reactor fuel elements
  • G21C3/30—Assemblies of a number of fuel elements in the form of a rigid unit
  • G21C3/32—Bundles of parallel pin-, rod-, or tube-shaped fuel elements
  • G21C3/3206—Means associated with the fuel bundle for filtering the coolant, e.g. nozzles, grids
• • G—PHYSICS
  • G21—NUCLEAR PHYSICS; NUCLEAR ENGINEERING
  • G21C—NUCLEAR REACTORS
  • G21C3/00—Reactor fuel elements and their assemblies; Selection of substances for use as reactor fuel elements
  • G21C3/30—Assemblies of a number of fuel elements in the form of a rigid unit
  • G21C3/32—Bundles of parallel pin-, rod-, or tube-shaped fuel elements
  • G21C3/33—Supporting or hanging of elements in the bundle; Means forming part of the bundle for inserting it into, or removing it from, the core; Means for coupling adjacent bundles
  • G21C3/3305—Lower nozzle
• • 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 nuclear fuel assembly is arranged vertically in a vessel of a nuclear reactor, being placed on a lower core plate provided with openings through which a cooling fluid enters which circulates vertically from bottom to top through nuclear fuel assembly.
• One of the aims of the invention is to provide an anti-debris filter which has limited hydraulic resistance while having a satisfactory debris retention capacity.
• An area with passages having larger deflections has a higher holding capacity and higher resistance to flow and an area with passages having smaller deflections has a lower holding capacity and resistance to flow. weaker flow.
• each passage is between 0° and 60°;
• passages have inlet axes making a non-zero angle with the direction of flow of the fluid through the grid, and/or passages have outlet axes parallel to the direction of flow of the fluid through Grid ;
• the invention also relates to a nuclear fuel assembly, in particular for a pressurized water nuclear reactor, comprising an anti-debris filter as defined above.
• FIG. 9 is a partial sectional view of an anti-debris filter according to another exemplary embodiment, illustrating two adjacent passages of the grid
• the longitudinal axis L extends vertically when the nuclear fuel assembly 2 is placed in a core of a nuclear reactor. In operation, a cooling fluid circulates vertically from bottom to top through the nuclear fuel assembly 2 as shown by the arrows F in Figure 1.
• the terms “vertical”, “horizontal”, “top”, “bottom”, “longitudinal”, “transverse”, “upper” and “lower” are understood with reference to the position of the nuclear fuel assembly 2 in the core of the nuclear reactor, the longitudinal axis L being substantially vertical.
• the guide tubes 12 extend along the longitudinal axis L and connect the lower end 8 and the upper end 10 between them, maintaining the spacing between the lower end 8 and the upper end 10.
• the pencils of nuclear fuel 4 are received between the lower end 8 and the upper end 10.
• Each guide tube 12 is open at its upper end to allow the insertion of a control bar (not shown) inside the guide tube 12, through the upper end piece 10.
• a control bar allows to control the reactivity of the nuclear reactor core in which the nuclear fuel assembly 2 is inserted.
• the spacer grids 14 are distributed along the guide tubes 12 while being spaced from each other along the longitudinal axis L. Each spacer grid 14 is rigidly fixed to the guide tubes 12, the guide tubes 12 s 'extending through each spacer grid 14.
• the cooling fluid passes through each opening 18, enters the nuclear fuel assembly 2 via the lower nozzle 8, flows along the nuclear fuel rods 4 and exits the nuclear fuel assembly 2 via the upper end 10.
• the lower tip 8 is provided with an anti-debris filter 30 configured to filter the cooling fluid.
• the grid 32 has a first face 32A and a second face 32B opposite each other.
• the grid 32 has fixing holes 34 for the passage of the fixing screws 24.
• the grid 32 has passages 36 extending through the grid 32 for the flow of cooling fluid through the grid 32.
• the grid 32 is for example formed by elongated grid elements 38, 40 which are intersected.
• each passage 36 has for example side walls defined by two first adjacent grid elements 38 intersecting with two second adjacent grid elements 40.
• each passage 36 extends between an inlet 36A, located on the first face 32A, and an outlet 36B, located on the second face 32B.
• the inlet 36A of each passage 36 has an input axis A1 and the outlet 36B of each passage 36 has an output axis A2.
• Each passage 36 extends from its inlet 36A to its outlet 36B along a central line C of this passage 36.
• each passage 36 is tangent to the inlet axis A1 at the inlet 36A of the passage 36 and tangent to the outlet axis A2 at the outlet of the passage 36.
• the input axis A1 and the output axis A2 of each passage 36 define between them an angle of inclination 0.
• the angle of inclination 0 is also called the deflection angle.
• the angle of inclination 0 between the input axis A1 and the output axis A2 of each passage 36 of the grid 32 is for example between 0° and 60°.
• Each passage 36 having a zero inclination angle 0 corresponds to a rectilinear passage 36.
• the input axis A1 and the output axis A2 coincide.
• Passage 36 has zero deflection between its inlet 36A and its outlet 36B. Input 36A and output 36B are aligned
• Each passage 36 having a non-zero angle of inclination 0 between its input axis A1 and its output axis A2 presents a non-zero deflection between its input 36A and its output 36B.
• Each passage 36 having a non-zero angle of inclination 0 between its input axis A1 and its output axis A2 preferably has its input 36A and its output 36B offset transversely relative to each other considering the direction of flow of the fluid through the grid 32.
• the grid 32 has passages 36 having angles of inclination 0 between their input axis A1 and their output axis A2 different.
• the grid 32 has passages 36 having different respective deflections.
• the output axes A2 of all passages 36 are parallel to each other, the input axes A1 of passages 36 having different angles of inclination 0 being inclined relative to each other.
• the outlet axes A2 of the passages 36 are parallel to the direction of flow of the fluid. This makes it possible to limit disturbances to the flow of fluid at the outlet of grid 32.
• passages 36 with different inclination angles 0 makes it possible to differentiate the retention capacity and the resistance to flow of different zones of the grid 32.
• the grid 32 has a first zone Z1, the first zone Z1 having a plurality of passages 36, and at least one second zone Z2, each second zone Z2 having a plurality of passages 36, the angles of inclination 0 of the passages 36 located in each second zone Z2 being unharmed and greater than or equal to the maximum angle of inclination 0 of the passages 36 located in the first zone Z1.
• the grid 32 has for example four second zones Z2 distributed on the grid 32 of quadrangular and in particular square shape, the second zones Z2 being for example distributed according to a 2X2 matrix distribution.
• the grid 32 has a thickness strictly greater than the thickness of the grid 32 in the first zone Z1.
• the grid 32 has a substantially constant thickness, called first thickness E1.
• each grid element 38, 40 has a substantially constant height or first height H1.
• the first height H1 corresponds to the first thickness E1.
• the grid 32 has for example a variable thickness, varying between the first thickness E1 at the periphery of each second zone Z2 up to a second thickness E2, for example at the center of the second zone Z2.
• each second zone Z2 at least part of the grid elements 38, 40 has a height strictly greater than the first height H1.
• At least part of the grid elements 38, 40 has for example a high variable, varying for example between the first height H1 and a second height H2.
• the first height H1 corresponds to the first thickness E1 and the second height H2 corresponds to the second thickness E2.
• each grid element 38, 40 has a height greater than the first height H1 or only part of the grid elements 38, 40 has a height greater than the first height H1.
• each first grid element 38 or only part of the grid elements 38 has a height greater than the first height H1 and/or each second grid element 40 or only part of the second elements of grid 40 has a height greater than the first height H1.
• each passage 36 are defined by the portions of the grid elements 38, 40 delimiting the passage 36.
• the side walls of the passages located in each second zone Z2 are higher than the side walls of the passages located in the first zone Z1.
• each passage 36 is delimited between two opposite side walls which extend substantially parallel while being curved
• each of these passages 36 extends in a curvilinear manner, its inlet 36A and its outlet 36B being offset transversely with respect to one another and inclined with respect to one another.
• each first grid element 38 of variable height, and in particular each first grid element 38 has an upper portion 42 which extends higher than the rest of the first face 32A of the grid 32 in the first zone Z1.
• each first grid element 38 is for example curved to define the curved passages 36.
• Each of the second grid elements 40 extends for example substantially along a plane.
• second grid elements 40 of variable height have upper portions 44 which intersect the upper portions 42 of the first grid elements 38 of variable height.
• the input axes A1 of the passages 36 are parallel to each other and the output axes A2 of the passages 36 are parallel to each other.
• passages 36 Due to the variation in thickness of the machined grid 32, certain passages 36 are reduced in height, and passages 36 finally have input axes A1 inclined relative to each other.
• passages 36 located in each second zone Z2 have an angle of inclination 0 greater than the passages 36 located in the first zone Z1.
• each passage 36 of variable cross section having a converging inlet section 46 (considering the direction of flow of the fluid in passage 36 from inlet 36A to outlet 36B) and/or a diverging outlet section 48.
• a converging inlet section 46 or a diverging outlet section 48 is obtained for example by providing a chamfer on the side walls respectively of the inlet section 46 and the outlet section.
• each side wall of each passage 36 is preferably rounded. This makes it possible to promote the flow of the fluid by limiting the resistance to the flow of the grid 32.
• first zone Z1 with a first thickness E1 and one or more second zones Z2 with a thickness strictly greater than the first thickness E1 makes it possible to easily form passages 36 with angles of inclination 0 between the entrance 36A and the outlet 36B smaller in the first zone Z1 and passages 36 with angles of inclination 0 between the inlet 36A and the outlet 36B larger in each second zone Z2, from a grid blank of constant thickness whose passages 36 are parallel with angles of inclination 0 between the inlet 36A and the identical and unharmed outlet 36B.
• the second zone(s) Z2 can be placed on the grid 30 at the location(s) where the probability of debris passing is greatest, which is most of the time. time with respect to the openings 18 of the lower core plate 16 through which the cooling fluid arrives under the nuclear fuel assemblies 2.
• first zone Z1 having a first thickness E1 and at least a second zone Z2 having a second thickness E2 is advantageous independently of the fact that the passages 36 have angles of non-zero inclination between an input axis A1 and an output axis A2, in particular differentiated inclination angles between different passages 36.
• the invention proposes an anti-debris filter for a lower end piece of a nuclear fuel assembly, the anti-debris filter being formed of a grid 32 having a first face 32A and a second face 32B opposite each other. , the grid 32 having passages 36 extending between an inlet 36A located on the first face 32A and an outlet 36B located on the second face 32B for the flow of a cooling fluid through the grid 32, the grid 32 having a first zone Z1 and at least a second zone Z2 in which the grid 32 has a thickness greater than that of the plate in the first zone Z1, passages 36 being present in the first zone Z1 and in each second zone Z2.
• each second zone Z2 has passages 36 extending in a non-rectilinear manner
• the grid 32 is formed of intersecting grid elements 38, 40 between which the passages 36 are delimited, including at least one grid element 38, 40 of variable height extending in the first zone Z1 and at least one second zone Z2, the height of each grid element 38, 40 of variable height being greater in each second zone Z2 crossed by the grid element 38, 40 of variable height and smaller in the first zone Z1;
• - grid 32 has four second zones Z2;
• the second zones Z2 are distributed on the grid 32 in a matrix manner
• the grid 32 of the anti-debris filter 30 illustrated in Figures 10 and 1 1 comprises a plurality of cells 50 separated by partitions 52. Each cell 50 passes through the grid 32. Each cell 50 extends between the first face 32A of the grid 32 and the second face 32B of the grid 32. Each cell 50 allows the flow of fluid through the grid 32, as illustrated by the arrow F in Figure 11.
• the grid 32 has, in each cell 50, a plurality of separate passages 36.
• the passages 36 of each cell 50 are separated from each other by side walls or separation walls 54, which are for example intersecting grid elements.
• the grid 32 has a plurality of cells 50, the number of cells 50 preferably being equal to or greater than five.
• the cells 50 are for example distributed on the grid 32 following a matrix distribution.
• the partitions 52 are for example higher than the passages 36 and/or the separation walls 54.
• Each cell 50 has a first empty section 50A and a second section 50B in which the passages 36 are delimited, i.e. across which the separation walls 54 extend.
• the grid 32 has a variable thickness, with in particular a first zone Z1 that is less thick and a second zone Z2 in which the grid has a thicker thickness.
• the first zone Z1 has a thickness strictly less than that of the second zone Z2.
• Each cell 50 in which the grid 32 has a variable thickness, includes passages 36 of different heights.
• Cell 50 includes in particular lower passages 36, located in the first zone Z1, and higher passages 36, located in the second zone Z.
• the first zone Z1 is for example a peripheral zone of the cell 50, the second zone Z2 being a central zone of the cell 50.
• the grid 32 is for example non-planar on the side of the first face 32A and flat on the side of the second face 32B.
• the first face 32A is for example of generally convex shape.
• the first face 32A is for example in the general shape of a spherical cap projecting from the side of the first face 32A.
• the grid 32 having cells 50 separated by partitions 52 with a plurality of separate passages 36 delimited in each cell 50, in particular passages 36 of different heights, for example due to a variable height of the grid 32, allows a effective filtering of debris.
• one or more passages 36 present a non-zero deflection between the inlet 36A and the outlet 36B of this or these passages 36.
• the grid 32 includes passages 36 which have different deflections.
• passages 36 of the same cell 50 have different deflections.
• passages of the cell 50 have different deflections.

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• Physics & Mathematics (AREA)
• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Plasma & Fusion (AREA)
• General Engineering & Computer Science (AREA)
• High Energy & Nuclear Physics (AREA)
• Structure Of Emergency Protection For Nuclear Reactors (AREA)
• Filtration Of Liquid (AREA)
• Nozzles (AREA)

Applications Claiming Priority (2)

Publications (1)

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Family Applications (1)

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Family Cites Families (6)

• 2022
  • 2022-10-07 FR FR2210307A patent/FR3140704B1/fr active Active
• 2023
  • 2023-10-03 AR ARP230102646A patent/AR130670A1/es unknown
  • 2023-10-05 WO PCT/EP2023/077601 patent/WO2024074625A2/fr not_active Ceased
  • 2023-10-05 EP EP23783452.8A patent/EP4599464A2/de active Pending
  • 2023-10-05 CN CN202380070386.0A patent/CN119998893A/zh active Pending

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