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
  • G21C3/33—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
  • G21C3/331—Comprising hold-down means, e.g. springs
• • 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
• • 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
  • G21C3/334—Assembling, maintenance or repair of the bundles
• • 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 nuclear reactor fuel element according to the preamble of patent claim 1.
• Such a nuclear reactor fuel element is already common.
• the guide tube on the outside of the holding plate of the fuel element head is the holding tube itself.
• a control rod or a measuring instrument is inserted into the nuclear reactor fuel element in this holding tube in a pressurized water nuclear reactor.
• the holding tube is both loose through the holding plate of the fuel assembly head and loose through the parallel plate.
• One end of the coupling tube which is coaxial with the holding tube, is welded to the holding plate of the fuel assembly head and also loosely engages through the parallel plate.
• the ends of the union tube and the holding tube are welded together over this parallel plate.
• the fuel assembly head cannot be removed from the holding tube if a fuel rod has to be replaced to repair the nuclear reactor fuel element, but in this case the fuel assembly as a whole is to be disposed of.
• the invention has for its object to remedy this situation and to upgrade the nuclear reactor fuel element for repairs.
• a nuclear reactor fuel element of the type mentioned at the outset has the features of the characterizing part of patent claim 1.
• the detent between the guide tube projecting beyond the upper side of the parallel plate and the throwing tube represent a rotation lock which is effective when the guide tube projecting over the parallel plate and the union tube are locked together.
• the subclaims are directed to advantageous developments of the nuclear reactor fuel element.
• Figure 1 shows a highly schematic and side view of a nuclear reactor fuel element according to the invention.
• FIG. 2 shows a longitudinal section of the nuclear reactor fuel element according to FIG. 1.
• FIG. 3 shows a cross section of the guide tube and coupling tube of the nuclear reactor fuel element according to FIGS. 1 and 2.
• FIG. 4 shows a longitudinal section to FIG. 3.
• the nuclear reactor fuel element according to FIG. 1 is intended for a pressurized water nuclear reactor and has a fuel element base 2 and a fuel element head 3 which are spaced apart.
• the fuel assembly base 2 has a holding plate 4 and the fuel assembly head 3 has a holding plate 5.
• the holding plates 4 and 5 are parallel to one another.
• Fuel rods filled with fuel are located between their inner sides, of which a fuel rod 6 is shown.
• This fuel rod 6 is parallel to the longitudinal axis 7 of the nuclear reactor fuel element. Its rod ends are at a distance from the holding plate 4 or 5.
• a holding tube 8, which is also parallel to the longitudinal axis 7, has a longitudinal axis which penetrates the holding plate 4 of the fuel element base 2 and the holding plate 5 of the fuel element head 3 at right angles.
• This holding tube 8 is held at one end on the fuel assembly base 2 and at the other end on the fuel assembly head 3.
• spacers 29 which are lattice-shaped and spaced apart, which are shown schematically in FIG.
• the holding tube 8 is guided through a mesh of the grid-shaped spacers 29, and these grid-shaped spacers 29 are positively held on the holding tube 8.
• the fuel rod 6, is guided through another mesh of the grid-shaped spacers 29, which is likewise not recognizable, and in each mesh in this mesh with the aid of a radially acting spring which is located in the mesh on a mesh wall and the fuel rod 6 against two likewise in the mesh rigid knobs located on two other mesh walls are pressed, held in a force-fitting manner.
• FIG. 2 shows, in which the same parts are provided with the same reference numerals as in FIG. 1, the holding tube 8 is at one end, at which it has an opening with only a small cross section, on the holding plate 4 of the fuel element base 2 screwed tight.
• the fuel assembly head 3 not only has the holding plate 5, but a parallel plate 9 above the outside of the fuel assembly plate 5 at a distance from the fuel assembly plate 5.
• This parallel plate 9 is rigidly attached to the holding plate 5 with struts 10.
• the holding tube 8 passes through the holding plate 5.
• the holding tube 8 has at this end an outer flange 10 which bears against the inside of the holding plate 5.
• the holding tube 8 has an external thread 11 on the outside of the holding plate 5, onto which a coaxial guide tube 12 with an internal thread 13 is screwed open at both ends. As a result, the holding tube 8 is screwed onto the holding plate 5.
• the guide tube 12 loosely extends through the parallel plate 9 and a support plate 14 which is arranged at a distance from the parallel plate 9 above the upper side of the parallel plate 9 facing away from the holding plate 5.
• a coupling tube 15 which is coaxial with the guide tube 12 and open at both ends, has an external thread 16 at one end, with which it mates with a counter thread 17 within a
• Bushing is screwed into the parallel plate 9 through which the guide tube 12 is guided.
• the internal thread 13 on the guide tube 12 and the external thread 11 as a counter thread on the holding tube 9 on the one hand, and the external thread 16 on the coupling tube 15 and the counter thread 17 on the parallel plate 9 on the other hand, are in opposite directions.
• the union tube 15 with the guide tube 12 located therein loosely engages through the support plate 14, on which a helical spring 18 surrounding the union tube 15 is supported at one end.
• the other end of this helical spring 18 is supported on the upper side of the parallel plate 9.
• a tie rod 19 is screwed to the top of the parallel plate 9, which loosely engages through the support plate 15 and on the side facing away from the parallel plate 9
• Top of the support plate 14 has a stop head 20 for the support plate 14.
• the holding plate 5 with the parallel plate 9 of the fuel assembly head 3 can be displaced towards the supporting plate 14 against the spring action of the helical spring 18 which represents a compression spring, so that a supporting structure in the reactor core of a pressurized water core reactor can act on this supporting plate 14. in which the nuclear reactor fuel element is held on the fuel element base 2 and on the fuel element head 3.
• the union tube 15 has windows 21 which extend in the longitudinal direction of the union tube 15 at the end above the upper side of the parallel plate 9 and in each of which there is a leaf spring 22 which extends in the axial direction of the union tube 15 and which is on the outside of the union ⁇ throw tube 15 is riveted at both ends, for example.
• This leaf spring 22 extends through the window 21 radially inwards and engages there in a longitudinal slot 23 which is open at the end of the guide tube 12 above the parallel plate 9, so that the coupling tube 15 and the guide tube 12 are locked against one another in a rotationally secure manner.
• a wrench that engages in the longitudinal slots 23 on the guide tube 12 can be inserted into this guide tube 12. This wrench urges the respective leaf spring 22 radially outward through the window 21 and thus raises the locking of the coupling tube 15 with the
• the guide tube 12 can then be unscrewed from the holding tube 8 unhindered and the fuel assembly head 3 can be lifted off this holding tube 8.

Landscapes

• 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)
• Fuel Cell (AREA)

Priority Applications (3)

Applications Claiming Priority (2)

Publications (1)

Family

ID=6437234

Family Applications (1)

Country Status (5)

Cited By (1)

Citations (4)

• 1991
  • 1991-07-29 DE DE4125084A patent/DE4125084A1/de not_active Withdrawn
• 1992
  • 1992-07-06 CZ CS932848A patent/CZ282611B6/cs not_active IP Right Cessation
  • 1992-07-06 RU RU9294011636A patent/RU2095860C1/ru not_active IP Right Cessation
  • 1992-07-06 WO PCT/DE1992/000561 patent/WO1993003488A1/de active IP Right Grant
• 1993
  • 1993-12-08 BG BG98279A patent/BG60732B1/bg unknown

Patent Citations (4)

Non-Patent Citations (1)

Also Published As

Similar Documents

Legal Events