WO2012159984A1 - Nuclear fuel assembly for boiling water reactor comprising a fuel channel spacer - Google Patents

Nuclear fuel assembly for boiling water reactor comprising a fuel channel spacer Download PDF

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Publication number
WO2012159984A1
WO2012159984A1 PCT/EP2012/059248 EP2012059248W WO2012159984A1 WO 2012159984 A1 WO2012159984 A1 WO 2012159984A1 EP 2012059248 W EP2012059248 W EP 2012059248W WO 2012159984 A1 WO2012159984 A1 WO 2012159984A1
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WO
WIPO (PCT)
Prior art keywords
plate
fuel
fuel assembly
support
sidewall
Prior art date
Application number
PCT/EP2012/059248
Other languages
French (fr)
Inventor
Dirk Blavius
Erhard Friedrich
Bernd Block
Viktor Ruder
Corey Long
Michael Walker
Original Assignee
Areva Np
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Areva Np filed Critical Areva Np
Priority to EP12721312.2A priority Critical patent/EP2710603B1/en
Priority to JP2014510820A priority patent/JP6084208B2/en
Priority to KR1020137032614A priority patent/KR20140025509A/en
Priority to US13/822,508 priority patent/US20140064435A1/en
Priority to ES12721312.2T priority patent/ES2585064T3/en
Priority to CN201280024518.8A priority patent/CN103548091B/en
Publication of WO2012159984A1 publication Critical patent/WO2012159984A1/en

Links

Classifications

    • 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
    • G21C3/34—Spacer grids
    • G21C3/356—Spacer grids being provided with fuel element supporting members
    • G21C3/3566—Supporting members formed only of elements fixed on the strips
    • 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
    • G21C3/332—Supports for spacer 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
    • G21C3/34—Spacer grids
    • 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

  • Nuclear fuel assembly for boiling water reactor comprising a fuel channel spacer
  • the present invention relates to a nuclear fuel assembly for boiling water reactor comprising a base, a head, a bundle of fuel rods extending longitudinally between the base and the head, a tubular fuel channel encasing the bundle of fuel rods, and at least one fuel channel spacer for transversely spacing the fuel assembly from an adjacent element.
  • fuel assemblies are arranged side-by-side in 2x2 arrays of fuel assemblies.
  • the upper ends of the fuel assemblies are received in a cell of the reactor upper core grid.
  • the fuel assemblies are arranged with a spacing between them for allowing insertion of a cross-shaped control rod between the nuclear fuel assemblies, and a spacing with the cell walls. Controlling these spacings between the fuel assemblies is important for the nuclear reaction in normal operation and for making sure to allow insertion of the control rod for slowing down the nuclear reaction.
  • a nuclear fuel assembly for boiling Water Reactor comprises a bundle of longitudinally extending fuel rods arranged in a lattice, at least one tubular water channel or water rod replacing some fuel rods in the bundle, a tubular fuel channel encasing the bundle of fuel rods, and a base and a head at the longitudinal ends of the fuel assembly.
  • US 4 851 187 discloses a nuclear fuel assembly comprising a fuel channel fastener comprising a support adapted for fitting over a corner of the fuel channel and two springs extending along the support.
  • the support is screwed to an upper tie plate of the nuclear fuel assembly with a bolt extending longitudinally for connecting the fuel channel to the upper tie plate.
  • Each spring has an upper end screwed to the support with a transverse screw and a lower end slidable in a slot of the support.
  • the fuel channel fastener combines the functions of fastening the fuel channel to the upper tie plate and spacing the fuel channel from an adjacent nuclear fuel assembly.
  • Such a fuel channel fastener which has to be geometrically controlled and to withstand high forces is obtained at high cost. Furthermore, there is a risk of bending of the fuel channel fastener during handling of the nuclear fuel assembly using a handle connected to the upper tie plate.
  • An object of the invention is therefore to provide a nuclear fuel assembly for a boiling water reactor in which spacing can be obtained easily and reliably at low cost.
  • the invention proposes a nuclear fuel assembly for boiling water reactor comprising a base, a head, a bundle of fuel rods extending longitudinally between the base and the head, a tubular fuel channel encasing the bundle of fuel rods, and at least one fuel channel spacer for transversely spacing the fuel assembly from an adjacent element, wherein the or each fuel channel spacer comprises a support having at least one plate and at least one corresponding leaf spring supported by the corresponding plate, the or each plate being fixed to a corresponding sidewall of the fuel channel.
  • the nuclear fuel assembly may comprise one or several of the following features:
  • the or each plate is fixed to the sidewall by a single plate-rivet and/or screw.
  • each spring is snap-fitted in the plate
  • the spring has two end portions each slidably received in a respective slot provided in the plate;
  • the support comprises two plates at right angle, the support is fitted onto a corner at the intersection of two sidewalls, each plate being fixed to a respective sidewall;
  • the support ends before the upper end of the fuel channel.
  • FIG. 1 is a schematic side elevation view illustrating a nuclear fuel assembly for a boiling water reactor according to the invention
  • Figure 2 is a schematic top view of the nuclear fuel assembly of Figure 1 illustrating spacer and stops;
  • FIG. 3 is a side view of the upper end of the fuel assembly of Figure 1 illustrating a spacer and a stop;
  • FIG. 4 is a cross-section view of the spacer along IV-IV on Figure 3;
  • FIG. 5 is a cross-section view of the spacer and the stop along V-V on Figure 3;
  • Figure 6 - 8 are views similar to that of Figure 3 illustrating variants of the invention.
  • FIG. 1 shows a nuclear fuel assembly 2 for a boiling water reactor (BWR). This fuel assembly 2 extends along a longitudinal direction L.
  • BWR boiling water reactor
  • Such a fuel assembly is intended to be placed with the longitudinal direction L oriented vertically in a core of a nuclear reactor where coolant flows upwardly during operation.
  • the terms “lower” and “upper” refer to the position of the fuel assembly 2 in the reactor.
  • the fuel assembly 2 comprises :
  • tubular fuel channel 14 encasing the bundle of fuel rods 8 and fitted to the base 4 and the head 6.
  • Each fuel rod 8 comprises a tubular cladding filled with stacked nuclear fuel pellets and closed at its ends by end plugs.
  • the bundle of fuel rods 8 includes full-length fuel rods and part-length fuel rods.
  • the part-length fuel rods are shorter than the full-length fuel rods.
  • the head 6 comprises an upper tie plate 16 and a handle 18 rigidly connected to the upper tie plate 16 for handling the fuel assembly 2.
  • the upper tie plate 16 is connected to the fuel channel 14 with bolts 20 extending in the longitudinal direction L.
  • the bolts 20 are schematically illustrated by dash-dotted lines on Figure 1 .
  • the fuel assembly 2 comprises fuel channel spacers 22 placed at the upper end of the fuel channel 14 for transversely spacing the fuel channel 14 from adjacent element, i.e. nuclear fuel assemblies 2 and/or walls of the reactor upper core grid as illustrated by a dash-doted line 24.
  • the fuel channel 14 has a quadrangular cross-section and comprises four sidewalls
  • the fuel channel 14 comprises triangular reinforcement angle brackets 30 provided at the upper end, each angle brackets 30 extending transversely between two adjacent sidewalls 26.
  • the handle 18 extends diagonally between two corners 28 and the bolts 20 extend in the longitudinal direction L through the angle brackets 30 provided at said two corners 28.
  • the fuel assembly 2 comprises one spacer 22 fitted on one of the two other diagonally opposed corners 28.
  • the fuel assembly 2 may comprise two spacers 22, each fitted on one of the two other diagonally opposed corners 28. If needed, the fuel assembly 2 may comprise one spacer 22 at each corner 28.
  • the fuel assembly 2 further comprises stops 32 fixed to the sidewalls 26.
  • the fuel assembly 2 comprises one stop 32 on each sidewall 26 adjacent a corner 28 not occupied by a spacer 22.
  • the spacer 22 will be described in greater detail with reference to Figures 3 - 5.
  • the spacer 22 comprises a support 34 and two separate leaf springs 36.
  • the support 34 has the shape of a corner piece and comprises two plates 38 at right angles imparting a V-shaped cross-section to the support 34.
  • each plate 38 ends upwardly below or at the height of the upper edge 39 of the fuel channel 14.
  • the plates 38 do not protrude upwardly from the upper edge 39.
  • each plate 38 is placed on the outer face of a sidewall 26 and fixed to the sidewall 26 by riveting.
  • Each plate 38 is riveted with one single plate-rivet 40 extending through a fixing hole 42, 43 in the plate 38 and the corresponding sidewall 26 in a fixing direction F perpendicular to the plate 38 and the longitudinal direction L.
  • each plate 38 may be fixed with more than one plate-rivet 40, e.g. two plate- rivets 40.
  • the support 34 is single piece and the two plates 38 are made integrally in one piece.
  • the support 34 is preferably made of a piece of metal.
  • Each spring 36 is elongated longitudinally and extends along a respective plate 38. Each spring 36 is individually supported by the corresponding plate 38.
  • each spring 36 has two end portions 44 snap-fitted into slots 46 formed in the plate 38 and an intermediate portion 48 bulging away from the plate 38.
  • Each end portion 44 is slidable longitudinally in the corresponding slot 46.
  • Each plate 38 comprises on its outer face a groove 50 extending longitudinally.
  • Each slot 46 extends the groove 50 longitudinally within the thickness of the plate 38.
  • Each slot 46 is blind.
  • the spring 36 and the slots 46 are configured for allowing the spring 36 to be elastically deformed by biasing the intermediate portion 48 towards the plate 38, whereby the end portions 44 slide in the slots 46 away one from the other.
  • the fuel assembly 2 comprises two stops 32 fixed to the sidewalls 26 delimiting the corner 28 onto which the spacer 22 is fitted.
  • Each stop 32 is fixed to a sidewall 26 at a distance from the spacer 22.
  • each stop 32 is riveted to the corresponding sidewall
  • each stop 32 is riveted with more than one stop-rivet 52, e.g. two stop-rivets
  • Each stop 32 is rigid and ensures a minimal spacing with a wall facing the sidewall 26 and thus prevents overstress of the spring 36 provided on the same sidewall 26.
  • the plates 38 of the support 34 are fixed exclusively to sidewalls 26 of the fuel channel 14 without the support 34 being fixed to an angle bracket 30.
  • the support 34 is fixed to the fuel channel 14 separately from the fixing of the fuel channel 14 to the upper tie plate 16. It is thus prevented from being bent, damaged and/or displaced due to handling of the fuel assembly 2.
  • the support 34 can be manufactured easily at low cost.
  • the support 34 is fitted onto a corner 28 of the fuel channel 14 and rigidly fixed with two plate-rivets 40 extending each in one of two perpendicular directions. This ensures a reliable fixing.
  • the support 34 shaped as a corner piece further reinforces the fuel channel 14 at the corresponding corner 28.
  • Fixing the support 34 by riveting allows providing the support 34 in a metal which is not compatible with the metal of the fuel channel 14 in terms of welding.
  • the metal used for the support 34 can thus be a metal of lower cost than that of the fuel channel 14.
  • the fuel channel 14 is usually made of zirconium alloy whereas the metal of the support 34 may be for instance stainless steel.
  • Riveting allows fixing the support 34 simply and economically. Riveting merely requires providing riveting holes 43 in the sidewalls 26 of the fuel channel 14.
  • the support 34 may be screwed to sidewalls 26 with at least one screw extending through each plate 38 and the corresponding sidewall 26, transversely to said plate 38 and to the longitudinal direction L.
  • each stop 32 may be screwed to the sidewall 26 with a screw-passing-through hole in the stop 32 and the corresponding sidewall 26.
  • each plate 38 is welded onto a sidewall 26 of the fuel channel 14.
  • Each plate 38 is welded to the sidewall 26 along edges 54 of the plate 38.
  • the weld joints 56 extend partially along each welded edge 54 extends partially along said edge.
  • the weld joint 56 is continuous. Alternatively, it may be discontinuous.
  • the stops 32 are also welded to the sidewalls 26 with weld joints 56 extending partially along the edges of the stops 32.
  • the support 34 is made in this case of a metal that is compatible with the metal of the fuel channel 14 in terms of welding.
  • the fuel channel 14 is usually made of zirconium alloy and the support 34 is for example in zirconium or in titanium alloy.
  • Figure 7 differs from that of Figures 2 - 6 in that the stops 32 are formed in the support 34 and made one piece with the plate 38.
  • the support 34 comprises two arms 60 each extending from a plate 38 and each stop 32 is formed at the free end of an arm 60. Only one arm 60 is shown on Figure 7.
  • the stops 32 integral with the support 34 allow fixing of the spacer 22 in one operation.
  • the spacer 22 further reinforces the fuel channel 14.
  • the fixing of the support 34 is operated by riveting as illustrated on Figure 7 and alternatively by screwing or welding as previously described.
  • Figure 8 differs from that of Figures 2 - 7 in that a spacer with the shape of a corner piece fitted on the corner 28 is replaced by two separate individual flat spacers 22 each fixed to one respective sidewall 26 adjacent a corner 28 at the intersection of said sidewalls 26.
  • Each spacer 22 comprises a support 34 formed of a single plate 38 and a spring 36 having end portions 44 snap-fitted into slots 46 formed in the plate 38.
  • Each fuel spacer 22 of Figure 8 corresponds to half a fuel channel spacer 22 of Figure 2 - 5.
  • each spacer 22 is fixed to the corresponding sidewall 26 by riveting, screwing and/or welding as described above.
  • each stop 32 separated from the spacer 22 is provided on each sidewall 26.
  • each stop 32 is made in one piece with the plate 38 and formed at the end of an arm 60 extending from the plate 38 as illustrated in dotted lines on said Figure 8.

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  • Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Plasma & Fusion (AREA)
  • General Engineering & Computer Science (AREA)
  • High Energy & Nuclear Physics (AREA)
  • Monitoring And Testing Of Nuclear Reactors (AREA)

Abstract

The nuclear fuel assembly (2) for boiling water reactor comprises a base (4), a head (6), a bundle of fuel rods (8) extending longitudinally between the base (4) and the head (6), a tubular fuel channel (14) encasing the bundle of fuel rods (8), and at least one fuel channel spacer (22) for transversely spacing the fuel assembly (2) from an adjacent element. According to one aspect of the invention, the or each fuel channel spacer (22) comprises a support (34) having at least one plate (38) and at least one corresponding leaf spring (36) supported by the corresponding plate (38), the or each plate (38) being fixed to a corresponding sidewall (26) of the fuel channel (14).

Description

Nuclear fuel assembly for boiling water reactor comprising a fuel channel spacer
The present invention relates to a nuclear fuel assembly for boiling water reactor comprising a base, a head, a bundle of fuel rods extending longitudinally between the base and the head, a tubular fuel channel encasing the bundle of fuel rods, and at least one fuel channel spacer for transversely spacing the fuel assembly from an adjacent element.
In a boiling water reactor (BWR in the following description), fuel assemblies are arranged side-by-side in 2x2 arrays of fuel assemblies. The upper ends of the fuel assemblies are received in a cell of the reactor upper core grid. The fuel assemblies are arranged with a spacing between them for allowing insertion of a cross-shaped control rod between the nuclear fuel assemblies, and a spacing with the cell walls. Controlling these spacings between the fuel assemblies is important for the nuclear reaction in normal operation and for making sure to allow insertion of the control rod for slowing down the nuclear reaction.
A nuclear fuel assembly for boiling Water Reactor (BWR) comprises a bundle of longitudinally extending fuel rods arranged in a lattice, at least one tubular water channel or water rod replacing some fuel rods in the bundle, a tubular fuel channel encasing the bundle of fuel rods, and a base and a head at the longitudinal ends of the fuel assembly.
US 4 851 187 discloses a nuclear fuel assembly comprising a fuel channel fastener comprising a support adapted for fitting over a corner of the fuel channel and two springs extending along the support. The support is screwed to an upper tie plate of the nuclear fuel assembly with a bolt extending longitudinally for connecting the fuel channel to the upper tie plate. Each spring has an upper end screwed to the support with a transverse screw and a lower end slidable in a slot of the support. The fuel channel fastener combines the functions of fastening the fuel channel to the upper tie plate and spacing the fuel channel from an adjacent nuclear fuel assembly.
Such a fuel channel fastener which has to be geometrically controlled and to withstand high forces is obtained at high cost. Furthermore, there is a risk of bending of the fuel channel fastener during handling of the nuclear fuel assembly using a handle connected to the upper tie plate.
An object of the invention is therefore to provide a nuclear fuel assembly for a boiling water reactor in which spacing can be obtained easily and reliably at low cost.
To this end, the invention proposes a nuclear fuel assembly for boiling water reactor comprising a base, a head, a bundle of fuel rods extending longitudinally between the base and the head, a tubular fuel channel encasing the bundle of fuel rods, and at least one fuel channel spacer for transversely spacing the fuel assembly from an adjacent element, wherein the or each fuel channel spacer comprises a support having at least one plate and at least one corresponding leaf spring supported by the corresponding plate, the or each plate being fixed to a corresponding sidewall of the fuel channel.
According to specific embodiments, the nuclear fuel assembly may comprise one or several of the following features:
- the or each plate is welded to a sidewall;
- the or each plate is riveted to a sidewall of the fuel channel;
- the or each plate is screwed to a sidewall;
- the or each plate is fixed to the sidewall by a single plate-rivet and/or screw.
- each spring is snap-fitted in the plate;
- the spring has two end portions each slidably received in a respective slot provided in the plate;
- the support comprises two plates at right angle, the support is fitted onto a corner at the intersection of two sidewalls, each plate being fixed to a respective sidewall;
- the two plates are one piece; and
- the support ends before the upper end of the fuel channel.
The invention and its advantages will be better understood on reading the following description given solely by way of example and with reference to the following drawings:
- Figure 1 is a schematic side elevation view illustrating a nuclear fuel assembly for a boiling water reactor according to the invention;
- Figure 2 is a schematic top view of the nuclear fuel assembly of Figure 1 illustrating spacer and stops;
- Figure 3 is a side view of the upper end of the fuel assembly of Figure 1 illustrating a spacer and a stop;
- Figure 4 is a cross-section view of the spacer along IV-IV on Figure 3;
- Figure 5 is a cross-section view of the spacer and the stop along V-V on Figure 3; and
- Figure 6 - 8 are views similar to that of Figure 3 illustrating variants of the invention.
Figures 1 shows a nuclear fuel assembly 2 for a boiling water reactor (BWR). This fuel assembly 2 extends along a longitudinal direction L.
Such a fuel assembly is intended to be placed with the longitudinal direction L oriented vertically in a core of a nuclear reactor where coolant flows upwardly during operation. In the following, the terms "lower" and "upper" refer to the position of the fuel assembly 2 in the reactor. The fuel assembly 2 comprises :
- a base 4,
- a head 6,
- a bundle of nuclear fuel rods 8 extending longitudinally between the base 4 and the head 6,
- a tubular water channel 10 replacing at least one fuel rod in the bundle and connecting the base 4 to the head 6,
- a plurality of spacer grids 12 spaced apart along the longitudinal direction L and maintaining longitudinally and transversely the fuel rods 8; and
- a tubular fuel channel 14 encasing the bundle of fuel rods 8 and fitted to the base 4 and the head 6.
Only a portion of the fuel channel 14 is shown on Figure 1 .
Each fuel rod 8 comprises a tubular cladding filled with stacked nuclear fuel pellets and closed at its ends by end plugs. The bundle of fuel rods 8 includes full-length fuel rods and part-length fuel rods. The part-length fuel rods are shorter than the full-length fuel rods.
The head 6 comprises an upper tie plate 16 and a handle 18 rigidly connected to the upper tie plate 16 for handling the fuel assembly 2. The upper tie plate 16 is connected to the fuel channel 14 with bolts 20 extending in the longitudinal direction L. The bolts 20 are schematically illustrated by dash-dotted lines on Figure 1 .
As illustrated on Figure 2, the fuel assembly 2 comprises fuel channel spacers 22 placed at the upper end of the fuel channel 14 for transversely spacing the fuel channel 14 from adjacent element, i.e. nuclear fuel assemblies 2 and/or walls of the reactor upper core grid as illustrated by a dash-doted line 24.
The fuel channel 14 has a quadrangular cross-section and comprises four sidewalls
26 intersecting at corners 28. The fuel channel 14 comprises triangular reinforcement angle brackets 30 provided at the upper end, each angle brackets 30 extending transversely between two adjacent sidewalls 26.
The handle 18 extends diagonally between two corners 28 and the bolts 20 extend in the longitudinal direction L through the angle brackets 30 provided at said two corners 28.
The fuel assembly 2 comprises one spacer 22 fitted on one of the two other diagonally opposed corners 28. In alternative the fuel assembly 2 may comprise two spacers 22, each fitted on one of the two other diagonally opposed corners 28. If needed, the fuel assembly 2 may comprise one spacer 22 at each corner 28. The fuel assembly 2 further comprises stops 32 fixed to the sidewalls 26. The fuel assembly 2 comprises one stop 32 on each sidewall 26 adjacent a corner 28 not occupied by a spacer 22.
The spacer 22 will be described in greater detail with reference to Figures 3 - 5. The spacer 22 comprises a support 34 and two separate leaf springs 36.
The support 34 has the shape of a corner piece and comprises two plates 38 at right angles imparting a V-shaped cross-section to the support 34.
As shown on Figure 3, each plate 38 ends upwardly below or at the height of the upper edge 39 of the fuel channel 14. The plates 38 do not protrude upwardly from the upper edge 39.
As shown on Figure 5, each plate 38 is placed on the outer face of a sidewall 26 and fixed to the sidewall 26 by riveting. Each plate 38 is riveted with one single plate-rivet 40 extending through a fixing hole 42, 43 in the plate 38 and the corresponding sidewall 26 in a fixing direction F perpendicular to the plate 38 and the longitudinal direction L. Alternatively, each plate 38 may be fixed with more than one plate-rivet 40, e.g. two plate- rivets 40.
The support 34 is single piece and the two plates 38 are made integrally in one piece. The support 34 is preferably made of a piece of metal.
Each spring 36 is elongated longitudinally and extends along a respective plate 38. Each spring 36 is individually supported by the corresponding plate 38.
As shown on Figure 4, each spring 36 has two end portions 44 snap-fitted into slots 46 formed in the plate 38 and an intermediate portion 48 bulging away from the plate 38. Each end portion 44 is slidable longitudinally in the corresponding slot 46.
Each plate 38 comprises on its outer face a groove 50 extending longitudinally. Each slot 46 extends the groove 50 longitudinally within the thickness of the plate 38. Each slot 46 is blind.
The spring 36 and the slots 46 are configured for allowing the spring 36 to be elastically deformed by biasing the intermediate portion 48 towards the plate 38, whereby the end portions 44 slide in the slots 46 away one from the other.
As shown on Figure 2, the fuel assembly 2 comprises two stops 32 fixed to the sidewalls 26 delimiting the corner 28 onto which the spacer 22 is fitted. Each stop 32 is fixed to a sidewall 26 at a distance from the spacer 22.
As shown on Figures 3 and 5, each stop 32 is riveted to the corresponding sidewall
26 with a single stop-rivet 52 extending through the stop 32 and the sidewall 26. Alternatively, each stop 32 is riveted with more than one stop-rivet 52, e.g. two stop-rivets Each stop 32 is rigid and ensures a minimal spacing with a wall facing the sidewall 26 and thus prevents overstress of the spring 36 provided on the same sidewall 26.
The plates 38 of the support 34 are fixed exclusively to sidewalls 26 of the fuel channel 14 without the support 34 being fixed to an angle bracket 30. The support 34 is fixed to the fuel channel 14 separately from the fixing of the fuel channel 14 to the upper tie plate 16. It is thus prevented from being bent, damaged and/or displaced due to handling of the fuel assembly 2. The support 34 can be manufactured easily at low cost.
The support 34 is fitted onto a corner 28 of the fuel channel 14 and rigidly fixed with two plate-rivets 40 extending each in one of two perpendicular directions. This ensures a reliable fixing. The support 34 shaped as a corner piece further reinforces the fuel channel 14 at the corresponding corner 28.
Fixing the support 34 by riveting allows providing the support 34 in a metal which is not compatible with the metal of the fuel channel 14 in terms of welding. The metal used for the support 34 can thus be a metal of lower cost than that of the fuel channel 14. The fuel channel 14 is usually made of zirconium alloy whereas the metal of the support 34 may be for instance stainless steel.
Riveting allows fixing the support 34 simply and economically. Riveting merely requires providing riveting holes 43 in the sidewalls 26 of the fuel channel 14.
In an alternative embodiment, the support 34 may be screwed to sidewalls 26 with at least one screw extending through each plate 38 and the corresponding sidewall 26, transversely to said plate 38 and to the longitudinal direction L. Similarly, each stop 32 may be screwed to the sidewall 26 with a screw-passing-through hole in the stop 32 and the corresponding sidewall 26.
The embodiment of Figure 6 differs from that of Figure 2 - 5 by the means for fixing the plates 38 to the sidewalls 26. More specifically, each plate 38 is welded onto a sidewall 26 of the fuel channel 14.
Each plate 38 is welded to the sidewall 26 along edges 54 of the plate 38. In the illustrated embodiment, the weld joints 56 extend partially along each welded edge 54 extends partially along said edge. The weld joint 56 is continuous. Alternatively, it may be discontinuous.
As illustrated, the stops 32 are also welded to the sidewalls 26 with weld joints 56 extending partially along the edges of the stops 32.
Fixing the support 34 by welding is reliable and economical and ensures an efficient reinforcement of the fuel channel 14 by the support 34. The support 34 is made in this case of a metal that is compatible with the metal of the fuel channel 14 in terms of welding. The fuel channel 14 is usually made of zirconium alloy and the support 34 is for example in zirconium or in titanium alloy.
The embodiment of Figure 7 differs from that of Figures 2 - 6 in that the stops 32 are formed in the support 34 and made one piece with the plate 38. The support 34 comprises two arms 60 each extending from a plate 38 and each stop 32 is formed at the free end of an arm 60. Only one arm 60 is shown on Figure 7.
The stops 32 integral with the support 34 allow fixing of the spacer 22 in one operation. The spacer 22 further reinforces the fuel channel 14. The fixing of the support 34 is operated by riveting as illustrated on Figure 7 and alternatively by screwing or welding as previously described.
The embodiment of Figure 8 differs from that of Figures 2 - 7 in that a spacer with the shape of a corner piece fitted on the corner 28 is replaced by two separate individual flat spacers 22 each fixed to one respective sidewall 26 adjacent a corner 28 at the intersection of said sidewalls 26.
Each spacer 22 comprises a support 34 formed of a single plate 38 and a spring 36 having end portions 44 snap-fitted into slots 46 formed in the plate 38. Each fuel spacer 22 of Figure 8 corresponds to half a fuel channel spacer 22 of Figure 2 - 5.
The support 34 of each spacer 22 is fixed to the corresponding sidewall 26 by riveting, screwing and/or welding as described above.
A stop 32 separated from the spacer 22 is provided on each sidewall 26. Alternatively, each stop 32 is made in one piece with the plate 38 and formed at the end of an arm 60 extending from the plate 38 as illustrated in dotted lines on said Figure 8.

Claims

1 . Nuclear fuel assembly (2) for boiling water reactor comprising a base (4), a head (6), a bundle of fuel rods (8) extending longitudinally between the base (4) and the head (6), a tubular fuel channel (14) encasing the bundle of fuel rods (8), and at least one fuel channel spacer (22) for transversely spacing the fuel assembly (2) from an adjacent element, wherein the or each fuel channel spacer (22) comprises a support (34) having at least one plate (38) and at least one corresponding leaf spring (36) supported by the corresponding plate (38), the or each plate (38) being fixed to a corresponding sidewall (26) of the fuel channel (14).
2. Nuclear fuel assembly according to claim 1 , wherein the or each plate (38) is welded to a sidewall (26).
3. Nuclear fuel assembly according to claim 1 or 2, wherein the or each plate (38) is riveted to a sidewall (26) of the fuel channel (14).
4. Nuclear fuel assembly according to claim 1 or 2, wherein the or each plate (38) is screwed to a sidewall (26).
5. Nuclear fuel assembly according to claim 3 or 4, wherein the or each plate (38) is fixed to the sidewall (26) by a single plate-rivet (40) and/or screw.
6. Nuclear fuel assembly according to any preceding claim, wherein each spring (36) is snap-fitted in the plate (38).
7. Nuclear fuel assembly according to any preceding claim, wherein the spring has two end portions (44) each slidably received in a respective slot (46) provided in the plate (38).
8. Nuclear fuel assembly according to any preceding claim, wherein the support (34) comprises two plates (38) at right angle, the support (34) is fitted onto a corner (28) at the intersection of two sidewalls (26), each plate (38) being fixed to a respective sidewall (26).
9. Nuclear fuel assembly according to claim 8, wherein the two plates (38) are one piece.
10. Nuclear fuel assembly according to any preceding claim, wherein the support (34) ends before the upper end of the fuel channel (14).
PCT/EP2012/059248 2011-05-20 2012-05-18 Nuclear fuel assembly for boiling water reactor comprising a fuel channel spacer WO2012159984A1 (en)

Priority Applications (6)

Application Number Priority Date Filing Date Title
EP12721312.2A EP2710603B1 (en) 2011-05-20 2012-05-18 Nuclear fuel assembly for boiling water reactor comprising a fuel channel spacer
JP2014510820A JP6084208B2 (en) 2011-05-20 2012-05-18 Nuclear fuel assemblies for boiling water reactors containing fuel channel spacers
KR1020137032614A KR20140025509A (en) 2011-05-20 2012-05-18 Nuclear fuel assembly for boiling water reactor comprising a fuel channel spacer
US13/822,508 US20140064435A1 (en) 2011-05-20 2012-05-18 Nuclear fuel assembly for boiling water reactor comprising a fuel channel spacer
ES12721312.2T ES2585064T3 (en) 2011-05-20 2012-05-18 Nuclear fuel assembly for boiling water reactor comprising a fuel channel separator
CN201280024518.8A CN103548091B (en) 2011-05-20 2012-05-18 The nuclear fuel assembly for including fuel channel distance piece for boiling water reactor

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EP11305622.0 2011-05-20
EP11305622A EP2525365A1 (en) 2011-05-20 2011-05-20 Nuclear fuel assembly for boiling water reactor comprising a fuel channel spacer

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US10438704B2 (en) * 2014-12-23 2019-10-08 Westinghouse Electric Company Llc Nuclear fuel assembly support feature
CN108511093B (en) * 2018-04-16 2019-05-03 西安交通大学 A kind of PWR Fuel cluster high-temperature heating clamping experimental provision
JP2023033260A (en) * 2021-08-23 2023-03-10 日立Ｇｅニュークリア・エナジー株式会社 Boiling-water reactor

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4851187A (en) 1987-02-18 1989-07-25 Siemens Aktiengesellschaft Nuclear reactor fuel assembly
JPH0511084A (en) 1991-07-05 1993-01-19 Toshiba Corp Channel box and its fabrication method
US5339342A (en) * 1992-01-09 1994-08-16 Siemens Aktiengesellschaft Fuel assembly for a boiling water reactor with a redundant support structure and a locked fuel assembly case
US5610961A (en) * 1995-10-12 1997-03-11 General Electric Company Fuel assembly structure using channel for load support
US6097779A (en) 1998-02-17 2000-08-01 General Electric Company Fuel bundle and control rod assembly for a nuclear reactor
JP2002002072A (en) 2000-05-12 2002-01-08 Man Roland Druckmas Ag Cassette of thermal transfer ribbon for forming image line section on printing plate
JP2002006072A (en) * 2000-06-22 2002-01-09 Hitachi Ltd Fuel assembly and fuel channel box

Family Cites Families (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
BE791885A (en) * 1971-11-26 1973-03-16 Gen Electric NUCLEAR REACTOR CORE WITH BYPASS REFRIGERANT CONTROL
IT1168266B (en) * 1982-07-23 1987-05-20 Gen Electric CHANNEL SPACERS
US5267291A (en) * 1992-02-21 1993-11-30 General Electric Company Spacer band with optimized fuel bundle to channel clearance in a boiling water reactor
JP3092366B2 (en) * 1992-12-28 2000-09-25 株式会社日立製作所 Fuel channel box and fuel assembly
TW287280B (en) * 1994-07-22 1996-10-01 Siemens Akitengesellschaft
JPH08327764A (en) * 1995-06-02 1996-12-13 Toshiba Corp Fixing structure of fuel channel spacer
JPH11231084A (en) * 1998-02-16 1999-08-27 Toshiba Corp Channel fastener
CN101824970A (en) * 2009-03-03 2010-09-08 李越 Elastic rigid centralizer

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4851187A (en) 1987-02-18 1989-07-25 Siemens Aktiengesellschaft Nuclear reactor fuel assembly
JPH0511084A (en) 1991-07-05 1993-01-19 Toshiba Corp Channel box and its fabrication method
US5339342A (en) * 1992-01-09 1994-08-16 Siemens Aktiengesellschaft Fuel assembly for a boiling water reactor with a redundant support structure and a locked fuel assembly case
US5610961A (en) * 1995-10-12 1997-03-11 General Electric Company Fuel assembly structure using channel for load support
US6097779A (en) 1998-02-17 2000-08-01 General Electric Company Fuel bundle and control rod assembly for a nuclear reactor
JP2002002072A (en) 2000-05-12 2002-01-08 Man Roland Druckmas Ag Cassette of thermal transfer ribbon for forming image line section on printing plate
JP2002006072A (en) * 2000-06-22 2002-01-09 Hitachi Ltd Fuel assembly and fuel channel box

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JP6084208B2 (en) 2017-02-22
ES2585064T3 (en) 2016-10-03
EP2710603A1 (en) 2014-03-26
CN103548091B (en) 2017-12-19
CN103548091A (en) 2014-01-29
EP2525365A1 (en) 2012-11-21
US20140064435A1 (en) 2014-03-06
JP2014515475A (en) 2014-06-30
KR20140025509A (en) 2014-03-04
EP2710603B1 (en) 2016-05-18

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