| 摘要 |
<p>1462225 Fuel elements SIEMENS AG 17 April 1974 [19 April 1973] 16871/74 Heading G6C A nuclear reactor, in particular a gas-cooled fast breeder reactor, has a core which includes one or more fuel elements suspended from an upper core part by a primary mounting arrangement and is further provided with a lockable safety mounting arrangement disposed below the primary mounting arrangement, the safety mounting arrangement, when released, enabling the fuel element(s) to be drawn downwards within the reactor core. In one embodiment (Fig. 1) the upper end of a fuel element 1 is provided with a suspension arrangement (not shown) constituting the primary mounting arrangement and consisting of a screwed fastening which transmits the weight of the fuel element to an upper core structure. The safety mounting arrangement comprises a support member 6 through which a rod 4 extends. The support member 6 is connected via a screwed ring 9 and ribs 8 with a nozzle 7 fixed to the lower end of the shell 2 of the fuel element 1. A rotationally symmetrical latch 13 composed of individual pivotal segments has vertical projecting members 14 which engage in grooves 15 in a latch body 16 screwed into the lower end of the support member 6 at 17. In the locking position (c.f. right-hand side) of a locking member 20 the latch 13 is engaged in a recess 12 close to the lower end of the rod 4. However, if the locking member 20 is lifted (c.f. left-hand side), as by means of a charging machine equipped with a special tool (not shown), its lower end frees the latch 13 to such an extent that it no longer engages in the recess 12 and it may be pivoted by means of the above special tool. Thus the rod 4 can be drawn out of the support member 6, or the fuel element 1 itself can be drawn downwards. This permits normal removal of the fuel element 1 when a fuel element change is required. In an alternative embodiment (Fig. 2) a connection between two neighbouring fuel elements 1 is effected in the region of the nozzles 7. In the locked position a latch 26 of one fuel element projects through an aperture 25 in that fuel element and a portion 27 of the latch engages a recess 28 in the neighbouring fuel element. This recess 28 is formed by a part 29 secured to the outside of the nozzle 7 and formed from a particularly resistant material so as to be able to support a fuel element by means of its neighbouring fuel elements. The latch 26 is associated with a locking member 30 which is illustrated in the locking position. When the locking member 30 is lifted out of this position, the latch 26 may be pivoted and the connection with the neighbouring fuel element released. For uniform loading, a latch as shown in Fig. 2 can be provided at several places about the periphery of each fuel element.</p> |
