Fuel element for a nuclear reactor

 

(57) Abstract:

The inventive fuel element of a nuclear reactor includes having the form of a grid spacer separator with small tolerances for manufacturing cells. The separator contains two internal rack. One hour internal forms a bending edge, on which the other of the inner strut rigidly welded with the side edge. 3 C.p. f-crystals, 16 ill.

The invention relates to a fuel element of a nuclear reactor with spaced with a gap from each other, near and parallel to each other by rods, of which at least one is containing nuclear fuel in a fuel rod, and which are each respectively through the cell having the form of a grid spacer separator, and with the following characteristics:

a) having the form of a lattice, the separator is placed on the edge of the external enclosure of sheet metal, which is orthogonal to the terminals of the reference plane to form the contour of a regular hexagon external racks

b) having the form of a grid separator has an internal cell walls of cells are formed is put on the inside edge of the loop counters from listowel ogonnelloe to the terminals of the reference plane angles of regular hexagons internal racks, which all have the same length sides,

d) having the form of a grid separator has an outer cells, which contain at least one formed external rack wall of the cell and the other two interlocking with external stand on its inner side formed each inner stand wall of the cell.

Such a fuel element of a nuclear reactor is known from the above-mentioned application Germany 34 01 630.

In the case of this known fuel element of a nuclear reactor internal rack-shaped separator stretched in length and have the form of strips. These internal rack at both ends respectively fixed to the inner side of the external enclosure. The walls of the cells on these internal racks formed in parallel to the rods bending edges. Accordingly, every two of these internal flat racks interlock with each other with the formation of cells.

The basis of the invention is the task of further improvement of this known fuel element of a nuclear reactor and achievements is very small manufacturing tolerances of the cells in the form of bars separator.

To solve this task is about the first hour, forming the wall of the cell between the first and second cell, pinned his first, parallel to the terminals of the side edge parallel to the rods bending edge, which is located in the corner of a regular hexagon the internal racks between two others, formed the second internal counter walls of the cell, of which one wall of the cell is given first, and the other wall of the cell, second cell, the second parallel to the rods of the lateral edge of the first internal rack and both parallel to the rods of the side edges of the second internal rack form a group of three side edges, two of the three side edges of this group are attached in parallel to the terminals, located in the corner of a regular hexagon the internal counters of the side edges of the other two internal counters and the third side edge of this group of attached or parallel to the terminals located in the corner of a regular hexagon the internal racks to the side edges of the other two internal counters or inside the external enclosure.

The second inner strut attached to its bending edge of the first counter is comparatively small, a basic element for the construction having the form of a lattice section is the Number of such pre-manufactured base elements are then joined together in the form of bars separator. Thus the deviation of the base element from its specified dimensions is only locally in a small region having the form of a lattice point and does not continue for the whole having the form of a lattice point. This means that in such a in the form of bars the separator can be very precisely followed a predetermined distance between terminals of the fuel element of a nuclear reactor.

The preferred form of the fuel element of a nuclear reactor is that both the locking of external rack on its inner side formed respectively inner stand wall cells of the outer cells are found inside the external enclosure at an angle of 90o. Due to this facilitated the production of shaped lattice separator.

Another preferred form of execution is that the cell wall has a deflection parallel to the rods forming lines around parallel to the rods of the direction in the direction of rising the deflection of the rigid support for thickening rod. Due to this reduced pressure loss in the cooling medium flowing through the fuel element of a nuclear reactor in use to reduce pressure losses in the cooling medium, flowing through the fuel element of a nuclear reactor in the longitudinal direction of the rods, is that the wall of the cell has a deflection parallel to the rods forming lines around parallel to the terminals of the direction and the deflection towers anchor the spring to the stud.

In Fig. 1 shows in top view contour having the form of a lattice divider in the reference plane orthogonal to the fuel rods corresponding to the invention for a fuel element of a nuclear reactor; Fig. 2 is an enlarged cut - out from Fig. 1; Fig. 3 and 4 shows in top view with the increase of the basic element for a separator according to Fig. 1; Fig. 5 is a side view of a base element according to Fig. 3 and 4 in the direction of the arrow b in Fig. 4; Fig. 6 is a side view of the base element in the direction of arrow c in Fig. 4; Fig. 7 15 shown in top view with the increase of the other basic elements of the III-XI for having the form of a lattice separator according to Fig.1; Fig. 16 shows in top view another form of execution of the base element in the form of bars separator.

Fuel element of a nuclear reactor in the form of bars separator, the contour of which is shown in Fig. 1, sod is surrounding the rod 2, longitudinal axis which penetrates both parallel to each other holding the plate at an angle of 90oattached respectively at each end to one of the two retaining plates. This holds the rod 2 is open at both ends of the metal pipe penetrates the cell having the form of a lattice divider circuit according to Fig. 1. This separator, for example, is held flush between the two sleeves which are rigidly sitting outside on a holding rod 2, this holds the rod 2. Further provided next to each other and spaced with a gap from each other, parallel to each other, and the holding rod 2 containing nuclear fuel in the fuel rods 3. Each of these fuel rods 3 passes through the cell separator circuit according to Fig. 1 and held in this cell with the power circuit by means of a support spring which presses the corresponding fuel rod 3 radially relative to the two fixed reference thickening respectively to the two walls of the cells in the cell.

The fuel rods 3, each of which consists mostly filled with nuclear fuel Trou what to drink on any of the two holding plates, and they have in their longitudinal direction, the gap between the two retaining plates and are therefore free to expand in the direction of the axis, i.e. in the longitudinal direction of the fuel element of a nuclear reactor.

Having the form of a lattice separator having orthogonal to the holding rod 2 and the fuel rods 3 reference plane (the plane of the drawing) of the circuit shown in Fig. 1, is located set on edge external enclosure sheet metal. These external enclosure form the contour in the reference plane have the same side length 4 of a regular hexagon external racks.

In the walls of the cells of the inner cell 9 having the form of a lattice separator these external enclosure do not participate, the walls of these cells inner cell 9 is formed exclusively located set on the edge of the inner enclosures of sheet metal.

These internal racks from sheet metal to form the basic elements with the views from the top, respectively, of Fig. 3 11 and 15. As shown by Fig. 4 6 on the base element II according to Fig. 3, this base element has a first inner rack 6 and the second inner rack 7, which contains pakracka 0 is in the middle between two parallel to the holding rod 2 and the fuel rods 3 lateral edges 7a and 7b of the second inner rack 7. This bending edge 0 the second inner strut 7 forms on one side of the angle 120oand on the other side of the angle 240o. On the side on which the internal hour 7 forms an angle 240othat is the first flat inner strut 6 and captures the second internal rack 7 on the bending edge 0 the two tabs that have a gap from each other and which are made on the first parallel to the terminals 2 and 3, the side edge 6a of the first internal 6 hours. On the side of the second internal rack 7, on which it forms an angle in the 120oboth tabs which are located on the first side edge 6a of the first inner rack 6, rigidly welded with the second internal counter 7 with the formation of the weld 8.

On the side on which the second inner strut 7 forms an angle in the 120oat the upper end and the lower end of the second inner front 7 in the middle between the first parallel to the terminals 2 and 3, the side edge 7a and the bending edge 0 made one reference thickening 7c for fuel rod 3. Two corresponding reference thickening 7c rigid support thickening 7d performed next on the other side of the second internal rack 7, in which the second inner strut 7 forms Demo both of these rigid supporting thickening 7c is at the upper end and the lower end of the second inner rack 7.

Finally, on the side of the first inner rack 6 in the middle between the upper and lower end of this first internal rack 6 is made reed spring 6c as a support spring for fuel rod 3 and is in the angular space between the first internal counter 6 and the second part of the inner front 7 between the bending edge 0 and a lateral edge 7a.

The basic elements of the III VII according to Fig. 7 11 and XI according to Fig. 15 also contain two internal racks 6 and 7, of which one of the inner strut 7 has a bending edge 0, the parallel terminals 2 and 3. This bending edge 0 and also this internal hour 7 forms on one side of the angle 120oand on the other side of the angle 240o. Otherwise, these both internal racks are the same and secured to each other in the same way that the internal rack 6 and 7 of the base element II according to Fig. 3. From this basic element II according to Fig. 3 basic elements of III, VII and XI are different, however, a different distribution of reed springs, respectively reed spring 6c and a rigid supporting thickening, respectively, a rigid supporting the thickening 7c and 7d on both internal racks 6 and 7.

If the underlying element II according to Fig. 3, VI according uma external cells 10, the distance parallel to the rods 2 and 3 the side edges, with which the inner strut rigidly welded on the inner side of the external enclosure, formed from the inner rack 7 bending edges 0 of the corresponding base element, respectively, is greater than the distance of the two other parallel rods 2 and 3, the lateral edges of the base member rigidly welded in the corner of a regular hexagon the internal racks to the two lateral edges of the internal counters of the other two basic elements.

Further welded to the other of the inner rack 7 internal 6 hour basic elements VI and XI has no reference reeds or supporting springs, and is on both sides flat and smooth, while such rigidly welded to the other of the inner rack 7 internal stand 6 in the base element VII according to Fig. 11 contains between the upper end and the lower end vyshtampovanny reed spring as a support spring for fuel rod 3. Internal stand 7 basic elements VI and XI with the bending edge 0 contains between this bending edge 0 and one of the two parallel rods 2 and 3, the lateral edges are not only two speakers in one direction reference thickening, but GU spring as a support spring for fuel rod 3.

The basic elements of the III according to Fig. 7 and the basic elements of IV according to Fig. 8 have internal counters, one of which, as is particularly clearly shown in Fig. 2, has a bend around parallel to the terminals 2 and 3 directions parallel to the rods 2 and 3 forming lines, respectively, in the direction of the two standing on the deflection of the rigid support thickening, one of which rises in the trough respectively on the upper and on the lower end of the base element. These two rigid supporting thickening have thus a lower height than a rigid supporting thickening, for example, the base element II according to Fig. 3 and have a correspondingly lower resistance of the cooling medium flowing through the form of bars separator according to Fig. 1 at right angles to the supporting surface and thus to the plane of the drawing. In the case of a basic element III according to Fig. 7 and the base element IV according to Fig. 8 deflection with both rigid supporting bulges is located between the bending edge 0 and one of the two parallel rods 2 and 3, the lateral edges of the inner front 7 on this internal rack 7.

The basic elements XIII X according to Fig. 12 to 14 are simple separate racks that sodeci reference thickening, how hard reference thickening 7c or 7d basic element II, or do not contain any of the reed spring, nor the supporting bulges. The distance of two parallel to the terminals 2 and 3, the lateral edges of these individual stands apart slightly more than the distance of the respective both side edges of the inner rack 6 of the base element II according to Fig. 3, as these separate rack should also be welded on the inner side of the external enclosure.

For the manufacture of shaped lattice separator according to Fig. 1 first make the basic elements II XI according to Fig. 3 15 and then, as shown in Fig. 1, have inside the path of a regular hexagon external enclosures with sides 4 with the formation of the inner cell 9 with cellular structure of regular hexagons internal racks is equal to g by the length of the sides, as well as the outer cells 10. Adjacent to the inner side of the outer racks internal racks meet with the respective inner side at an angle of 90o. After welding the lateral edges of the internal counters of the basic elements in the corners of the hexagons internal racks and on the inner side of the outer racks is obtained in the form of bars separator, in which the walls forming the edges of the parallel terminals 2 and 3 bending edge 0, which is located in the corner of a regular hexagon the internal racks between the following two formed the second internal counter walls of the cell, of which one wall of the cell is given first, and the other wall of the cell attached to the second cell. In other corners of the hexagon internal racks respectively welded to each other three internal rack on each of the parallel terminals 2 and 3, the side edge.

To put on an edge of the outer racks made rigid support thickening 4a for fuel rods 3 in the direction towards the inner side of the external enclosure. These rigid supporting thickening 4a included in the external cell 10 having the form of a lattice separator, which have at least one formed external rack wall of the cell. Found on the inner sides of the inner rack form related to the external cell 10 wall cells, which are found on the inner side of the respective external at an angle of 90o.

Basic element according to Fig. 16, in which the same parts have the same reference position as in Fig. 3, 4 6, equipped with not only the deflections 7e parallel to the terminals 2 and 3 forming lines around parallel to stamina deflection 6e of this kind can also climb reed spring 6c as a support spring for the rod 3. Thus, not only a rigid supporting thickening 7c and 7d, but reed spring 6c have flowing at right angles to the plane of the drawing of a cooling medium negligible resistance.

1. Fuel element for a nuclear reactor located with a gap, near and parallel to each other by rods, of which at least one is containing nuclear fuel in a fuel rod and which are each respectively through the cell having the form of a grid spacer separator, and with the following characteristics: having the form of a lattice, the separator is placed on the edge of the external enclosure of sheet metal, which is orthogonal to the terminals of the reference plane to form the contour of a regular hexagon external racks; having the form of a lattice, the separator has an internal cell walls formed set on edge inside the contour of the inner enclosures of sheet metal; the angles of the cells of all internal cells having the form of a lattice separator to form a orthogonal to the terminals of the reference plane angles of regular hexagons internal counters, which all have the same length sides; shaped sieves the ku cell and the other two interlocking with external stand on its inner side walls of the cell, educated each inner rack, characterized in that the first inner strut forming the wall of the cell between the first and second cells, pinned his first parallel rods lateral edge parallel to the rods bending edge, which is located in the corner of a regular hexagon the internal racks between the other two formed the second internal counter walls of the cell, of which one wall of the cell is given first, and the other wall of the cell, second cell, the second parallel rods of the lateral edge of the first internal rack and both parallelnye rods, the side edges of the second internal rack form a group of three side edges, two of which is fixed in parallel to these terminals located in the corner of a regular hexagon the internal counters of the side edges of the other two internal counters and the third side edge of this group is attached or to the parallel rods placed in the corner of a regular hexagon the internal racks to the side edges of the other two internal counters or inside the external enclosure.

2. Item under item 1, characterized in that the two adjacent external rack on its inner side formed according to the d 90o.

3. Item under item 1, characterized in that the wall of the cell has a trough with parallel rods forming lines around the parallel rods of the direction in the direction of rising the bending rigid support for thickening rod.

4. Element p. 1, characterized in that the wall of the cell has a trough with parallel rods forming lines around the parallel bars and direction on the deflection towers anchor the spring to the rod.

 

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