GB1480606A - Charging installation for a nuclear reactor - Google Patents

Abstract

1480606 Fuelling reactors HOCHTEMPERATUR-REAKTORBAU GmbH 11 Nov 1974 [17 Nov 1973] 48717/74 Heading G6C A charging installation for a nuclear reactor with spherical operating elements (i.e. fuel, moderator and absorber elements) comprises cylindrical functional units 4 of identical external dimensions for the feeding, discharging and transporting of the operating elements, all the units being removably mounted in blind bores 2 of equal diameter within at least one block 1, e.g. of steel, serving simultaneously as a radiation shield and as a housing and including a plurality of circulation bores 3. The functional units 4 are either "active" or "passive", the former comprising a rotary functional element 5, a bearing plug 6 and a drive shaft 7, and the latter comprising a fixed functional element 8 and a shield plug 9. Discs 18 are secured to the end faces of the blind bores 2 and each may have fitted to it a stop piece 19 co-operating with a counter piece 20 present on each rotary functional element 5 to ensure correct positioning of the latter. The functional elements 5, 8 perform various functions and as shown in Fig. 2, from left to right, they comprise a right-hand diverter 21, a pressure barrier 22, a doser 23, a collector 24 and a ball counter support 25. The order in which these elements are shown is merely illustrative and it is not intended that such a sequence could be used in practice. The diverter 21 has a through channel 28 into which a top channel 29 enters at an angle of 60 degrees. In the position shown, a ball entering from the left is directed at an angle of 120 degrees to the right by impact with a pin 30 arranged in a groove in such a way that it does not obstruct the passage of a ball when the diverter is set straight, i.e. rotated anticlockwise through 60 degrees from the position shown. The functional element 8 of the collector 24 is of similar construction to the element 5 of the director 21, but is however fixed in the position shown. The pressure barrier 22 serves to shut off the transport gas stream whilst dosing spherical operating elements. It comprises two blind bores 32, 33 extending transversely to its rotary axis, each of which serves to accommodate one ball, and is pivotable through 180 degrees. Its outer surface is equipped with labyrinth seals (not shown). The bores 32, 33 are oriented obliquely to a diameter of the element 5 so that after a 180 degree pivoting movement, a ball present in one of the bores experiences an acceleration in the ball circulation bore 3 due to centrifugal force. The doser 23 serves to pass on the spherical operating elements in dosed quantity but without interrupting the transport gas stream. It has a through channel 38 divided into two spaces 36, 37, each to accommodate one ball, by two pins 39, 40 opposite one another in the channel wall. In the region of the channel 38, the functional element 5 has a constricted cross-section 41 which ensures that balls present in the bore 3 in front of the doser 23 are not forced backwards and possibly crushed when the doser is pivoted. To permit the centrifugal force acting on a ball present in the doser to provide an additional acceleration of the ball on leaving the doser, the two pins 39, 40 are not symmetrical to the rotary axis but the one pin, i.e. pin 39, which is placed in front in the direction of rotation of a ball which has entered the channel 38 projects further into the channel cross-section. The ball counter support 25 has an electric ball counter installed for recording the number of operating elements passing through it. A channel 43 extending through the functional element 8 has in its wall a recess 44 to accommodate an annular coil 45. The electric leads to and from the coil 45 are made through a cable 47 laid in a longitudinal groove 46 of the shield plug 9 and in a recess 48 of the support 25.