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
  • G21C3/02—Fuel elements
  • G21C3/04—Constructional details
  • G21C3/06—Casings; Jackets
  • G21C3/12—Means forming part of the element for locating it within the reactor core
• • G—PHYSICS
  • G21—NUCLEAR PHYSICS; NUCLEAR ENGINEERING
  • G21C—NUCLEAR REACTORS
  • G21C19/00—Arrangements for treating, for handling, or for facilitating the handling of, fuel or other materials which are used within the reactor, e.g. within its pressure vessel
  • G21C19/20—Arrangements for introducing objects into the pressure vessel; Arrangements for handling objects within the pressure vessel; Arrangements for removing objects from the pressure vessel
  • G21C19/205—Interchanging of fuel elements in the core, i.e. fuel shuffling
• • G—PHYSICS
  • G21—NUCLEAR PHYSICS; NUCLEAR ENGINEERING
  • G21C—NUCLEAR REACTORS
  • G21C19/00—Arrangements for treating, for handling, or for facilitating the handling of, fuel or other materials which are used within the reactor, e.g. within its pressure vessel
  • G21C19/16—Articulated or telescopic chutes or tubes for connection to channels in the reactor core
• • 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 straightening device for fuel elements of a pressurized water reactor.
• a nuclear plant in particular in a nuclear power plant, material that can be split to produce electrical energy is usually subjected to controlled nuclear splitting.
• the fissile material is stored in a number of fuel rods in which the material, for example in the form of so-called pellets, is surrounded by suitable cladding tubes.
• a plurality of such fuel rods are usually combined to form a fuel assembly.
• a nuclear power plant has a large number of these fuel elements, which are essentially elongate-square or in particular also elongate-square and are located in the reactor core.
• the fuel assemblies are located next to one another in a fuel assembly storage rack located in the reactor core, adjacent fuel assemblies being positioned at a comparatively small distance from one another.
• control rods or control rods which are introduced into the fuel elements by control rod guide tubes contained in the fuel elements.
• control rod guide tubes are closed by so-called throttle bodies. These are required to evenly distribute the coolant throughput over the reactor core.
• the nuclear fuel contained in the fuel elements is consumed, with the result that fuel elements have to be replaced from time to time.
• spent fuel elements have to be moved out of the reactor core into a fuel pool and fresh, unused or only partially used fuel elements have to be moved out of the fuel pool into the reactor core.
• the exchange of fuel assemblies usually takes place after an operating cycle of the nuclear power plant of several, in particular 12 to 18, Months. To do this, the nuclear power plant must be shut down and the reactor core depressurized.
• the reactor core is accessible from above by dismantling the pressure vessel cover and removing various internals. This is done when the reactor pool is flooded in order to maintain the water shielding for the exposed reactor core.
• a so-called fuel loading machine which is designed as a crane-like lifting device, is generally used for changing the fuel assemblies.
• This loading machine can move to the various positions of the fuel elements to be replaced by means of a corresponding crane construction, which is arranged above the reactor basin, and pull a fuel element with a vertically upward movement from the fuel element storage rack or the reactor core with the aid of a correspondingly designed gripper.
• the gripper is designed such that it is generally possible to lift and move both a fuel assembly and a control rod individually and, alternatively, fuel assembly and control rod together.
• the invention is therefore based on the object of specifying a straightening device for fuel assemblies of a pressurized water reactor described above, with which fuel assemblies can be straightened comparatively easily and quickly.
• the straightening device has a straightening body which is extended in the longitudinal direction and whose side surfaces, which are formed by side plates, can be displaced perpendicularly to the longitudinal direction from a rest position, the cross-sectional dimensions of the side surfaces of the straightening body in the rest position being around a predetermined nominal value are chosen to be smaller than the corresponding cross-sectional dimension of a reference fuel element.
• the invention is based on the consideration that deformed fuel assemblies should be straightened with a corresponding straightening device in such a way that the replacement of the fuel assemblies and in particular the use of a fuel assembly in an empty space in the reactor core is possible due to the shape correction of the fuel assemblies by the straightening device.
• the alignment device should therefore be able to be positioned at an empty location of the fuel assembly storage rack in order to align the adjacent fuel assemblies at the empty location for the use of a new fuel assembly.
• the cross section of the straightening device should be smaller than that of a corresponding reference Fuel element so that the alignment device does not collide with it due to deformed neighboring fuel elements when used in the reactor core.
• the straightening device is provided with movable side plates. These can correspondingly correct deformations of adjacent fuel elements over their entire surface facing the straightening body.
• the cross-section of the straightening body can be changed and, in particular, enlarged for straightening, by shifting two opposite side plates from the rest position in a transverse direction of the straightening device.
• the directional device is supported on both sides in a transverse direction when it is enclosed between two adjacent fuel elements by points of contact with them.
• the fuel assemblies to be aligned are in turn supported by adjacent fuel assemblies on the side facing away from the alignment device.
• the nominal value of the straightening device is advantageously 16 mm.
• link guides are advantageously assigned to a side plate, via which a side plate is fastened to the straightening device by means of associated shift bolts.
• the link guides are expediently shaped in such a way that they convert a movement of the sliding bolts in the longitudinal direction into a movement of the side plates perpendicular to the longitudinal direction.
• a side plate expediently has a number of guide grooves on each attachment, which are perpendicular to the longitudinal direction of the side panel and run in each engages with an associated sliding bolt which is moved and guided within a supporting frame of the straightening device.
• shift bolts which are assigned to a link guide are preferably connected to one another via a fastening device which can be moved hydraulically or mechanically in the longitudinal direction of the straightening device.
• a fastening device which can be moved hydraulically or mechanically in the longitudinal direction of the straightening device.
• a display device for monitoring the spreading position is expediently provided.
• the fastening device is expediently connected to the movable head of the straightening device.
• the straightening process can thus be controlled or carried out via the movement of the head of the straightening device.
• the head of the straightening device is preferably dimensioned like the fuel element head of a reference fuel element. This dimensioning means that the alignment device for the gripper of the loading machine is compatible with the fuel assemblies.
• the straightening device can in particular also be designed for movement of its active components in a purely mechanical manner and without the supply of auxiliary energy.
• the fuel assembly loading machine can be used both for transport and for carrying out the straightening process, so that no additional infrastructure is required for the operation of the straightening device in the reactor core or in the reactor pool.
• the straightening device is also particularly suitable for use as a so-called fuel element or support insulation in the manner of a placeholder when a vacancy in the fuel element grid is temporarily occupied. Due to the suitable dimensioning of the cross section of the straightening device and also the frictional forces between the fuel assemblies and the straightening device are kept particularly suitable during lifting and lowering.
• FIG. 1 is a plan view of the core of a pressurized water reactor
• Fig. 3 shows a detail from Fig. 2
• Fig. 4 shows the straightening device according to Fig. 2 in cross section
• FIG. 1 schematically shows the top view of a reactor core of a pressurized water reactor with fuel elements 1 which contain a number of fuel rods 2.
• fuel elements 1 which contain a number of fuel rods 2.
• they are arranged at a comparatively small distance from one another by standing lengthwise in the reactor core.
• a straightening device 6 for fuel assemblies 1 is shown in FIG. This is dimensioned for straightening fuel assemblies 1 in such a way that it can be positioned at an empty location in the reactor core of the pressurized water reactor, in particular also when adjacent fuel assemblies 1 are deformed.
• the cross-section of the straightening device 6 is dimensioned such that in the rest position it has a smaller cross-section than a fuel assembly 1.
• the alignment of the straightening device is similar to that of a fuel assembly 1 in that it consists of a straightening body 8 and a head 10 and a foot 12 so that it can be positioned in the reactor core or in the fuel assembly storage rack 4.
• the straightening body 8 of the straightening device 6 is extended in the longitudinal direction, its side surfaces being formed from displaceable side plates 14 perpendicular to the longitudinal direction and thus sideways from a rest position.
• the side plates 14 are dimensioned such that the cross-sectional dimensions of the side surfaces of the straightening body 8 in the rest position of the side plates 14 are reduced by a predetermined nominal value. are selected as that of a fuel element 1.
• the lateral displacement of the side surfaces 14 enables the cross section of the straightening body 8 to be enlarged in a controlled manner.
• the side plates are assigned a number of link guides 16, by means of which the side plates 14 via assigned displacement bolts 18 on the Straightening device 6 are fastened, the link guides 16 being shaped such that they convert a movement of the displacement bolts 18 in the longitudinal direction into a movement of the side plates 14 perpendicular to the longitudinal direction.
• the link guides 16 are inserted into reinforcing ribs 20, which are connected to the side plates 14.
• each displaceable side plate 14 is assigned a number of guide grooves 19 which are perpendicular run to the longitudinal direction of the straightening body 8 and into which an associated holding bolt 17 engages, which is fastened to a holding pocket 22 in each case.
• all of the support brackets for the displacement bolts 18 are connected to one another via a driver 24 which, from the rest position, is opposite the side plates 14 in the longitudinal direction of the straightening device 6 can be moved hydraulically or mechanically.
• the implementation can take place in particular in that the required output forces are applied by selective movement of the head 10 in the longitudinal direction of the straightening body 8 in the manner of a pumping or positioning movement.
• a lifting pump is actuated via a shaft which can be displaced within the carrying and guide sleeve and is connected to a centrally arranged lifting cylinder.
• the drivers are attached to the lifting cylinder by connecting rods moved.
• In the end positions of the lifting cylinder there are actuating elements, by means of which the direction of the lifting movement can be mechanically reversed, so that the spreading or straightening process is repeated with a further lifting movement.
• the head 10 is dimensioned like the head of a fuel assembly 1.
• the nominal value is 16 mm.
• the straightening device 6 is shown in cross section in FIG.
• the straightening body 8 is shown in the row position of the side plates 14.
• the dashed line shows the position in which the side plates 14 are exposed to the outside in order to carry out a straightening process by the predetermined nominal values, so that the cross-sectional enlargement required for straightening is obtained.

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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)
• Attitude Control For Articles On Conveyors (AREA)
• Machine Tool Units (AREA)

Applications Claiming Priority (2)

Publications (1)

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ID=33440840

Family Applications (1)

Country Status (9)

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Family Cites Families (29)

• 2003
  • 2003-05-14 DE DE10321827A patent/DE10321827B3/de not_active Expired - Fee Related
• 2004
  • 2004-05-13 CN CNB2004800164699A patent/CN100428366C/zh not_active Expired - Fee Related
  • 2004-05-13 KR KR1020057021714A patent/KR100854553B1/ko not_active IP Right Cessation
  • 2004-05-13 RU RU2005138858/06A patent/RU2307409C2/ru not_active IP Right Cessation
  • 2004-05-13 CA CA002529424A patent/CA2529424A1/en not_active Abandoned
  • 2004-05-13 JP JP2006529808A patent/JP5069002B2/ja not_active Expired - Fee Related
  • 2004-05-13 EP EP04732594A patent/EP1625595A2/de not_active Withdrawn
  • 2004-05-13 WO PCT/EP2004/005141 patent/WO2004102584A2/de active Search and Examination
• 2005
  • 2005-11-14 US US11/273,148 patent/US7397884B2/en not_active Expired - Fee Related

Non-Patent Citations (1)

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