Nuclear reactor fuel assembly with a supporting coolant tube
AssigneeSiemens Aktiengesellschaft
InventorsWerner Meier, Hans-Joachim Lippert, Hans Lettau, Kurt Kraus
Life of this patent
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Abstract
In order to obviate the use of supporting rods, an upper end piece of a coolant tube penetrates a fuel assembly head of a nuclear reactor fuel assembly and is supported on the fuel assembly head. A lower end piece of the coolant tube is fastened to and supported by a fuel assembly foot, in particular with rods of partial lengths. A supporting skeleton therefore includes the foot and the coolant tube with spacers. The fuel assembly head and a handle are placed on the skeleton and screwed onto the coolant tube after fuel rods are pushed into meshes of the spacer.
Claims32
A nuclear reactor fuel assembly, comprising:
- a) at least one coolant tube with an upper end having an opening formed therein and an upper end piece and a lower end having an opening formed therein and a lower end piece;
- b) a bottom plate being supported by said coolant tube and joined to said lower end piece in a dimensionally rigid manner, said bottom plate having inlet openings formed therein for liquid coolant;
- c) a cover plate retaining said upper end piece and having outlet openings formed therein for a liquid/steam mixture of coolant;
- d) gridlike spacers defining meshes therein, means for retaining said spacers on said coolant tube between said plates;
- and
- e) a plurality of fuel rods each being guided through a respective one of said meshes, each of said fuel rods being filled with nuclear fuel and each of said fuel rods being joined to at most one of said plates.
A nuclear reactor fuel assembly, comprising:
- a) a bundle of mutually parallel fuel rods containing nuclear fuel;
- b) a fuel assembly head being disposed above said bundle and having a top with a bundle;
- c) a bottom plate being disposed under said bundle and being permeable to liquid coolant;
- and
- d) a coolant tube being disposed in said bundle, being parallel to said fuel rods and having upper and lower open ends;
- e) said coolant tube having a lower end piece on said lower end being supportingly retained on said bottom plate for retaining said coolant tube on said bottom plate;
- and
- f) supporting means for attaching said coolant tube to said fuel assembly head, said coolant tube having an upper end piece on said upper end being supportingly retained on said fuel assembly head and protruding from below into a recess formed substantially in a center portion of said fuel assembly head, said supporting means consisting essentially of said upper end piece and said recess.
A fuel assembly of a boiling water reactor, comprising:
- a) a laterally outer fuel assembly case having an interior and open upper and lower ends;
- b) a cover plate covering said upper end of said case and having coolant outlets formed therein;
- c) a bottom plate covering said lower end of said case and having coolant inlets formed therein;
- d) a coolant tube extending in axial direction in the interior of said case and having upper and lower ends, each of said upper and lower ends having at least one opening formed therein for the passage of water, said coolant tube having a lower end piece joined to said bottom plate with a rigid connection transmitting substantially all forces exerted upon said bottom plate to said lower end piece and to said coolant tube, and said coolant tube having an upper end piece, and a releasable connection supporting said upper end piece at said cover plate;
- e) a plurality of spacers being substantially perpendicular to and retained on said coolant tube at predetermined axial positions, said spacers containing support ribs;
- f) a plurality of fuel rods being parallel to said case, being respectively supported on said support ribs and having lower ends, some of said fuel rods extending substantially as far as said cover plate;
- and
- g) lower closure caps standing unscrewed on said bottom plate and being disposed on said lower ends of at least all of said fuel rods extending substantially as far as said cover plate.
Dependencies are inferred from the claim text.