| 摘要 |
<p>1,208,616. Reactors. COMMISSARIAT A L'ENERGIE ATOMIQUE. 15 Feb., 1968 [24 Feb., 1967], No. 7477/68. Heading G6C. An integral nuclear reactor has at least one off-centre extraction opening at one end of its prestressed concrete pressure vessel for the insertion or withdrawal of any one heat exchanger unit, a support for these units being coaxial with the vessel and rotatable about the axis of the vessel so as to bring any one unit into a position opposite to an extraction opening for withdrawal of the unit from the pressure vessel and for substituting another unit in the vacated operating position on the support. In the embodiment shown in Fig. 4, all the heat exchanger units 10 are connected to a single central manifold 44 which is of annular shape and disposed around a passageway 4 provided for a fuel element handling device 5. The manifold 44 extends outwardly through the pressure vessel wall in a series of conduits 46 which are connected to the heat-removal circuit by means of flanges 48. The number of conduits 46 is distinctly smaller than the number of heat exchanger units 10. The assembly of manifold 44 and conduits 46 is fixed inside a tube 50 which is rotatably mounted in the top wall of the pressure vessel. Outside the pressure vessel, the tube 50 is fixed to an annular member 56 supported by jacks 58 either on a stationary annular member 60 or on a ballbearing 62. The annular member 56 is provided with an externally toothed wheel 64 which is rotated by a suitable drive mechanism. By this means, the manifold 44 and the heat exchanger units 10 are rotated. Balls 74 in a channel formed partly in the pressure vessel wall and partly in the tube 50 support the rotary assembly when the annular members 56, 60 are disassembled for the purpose of renewal of the seals 61 placed within the annular member 60. Flanges 70 serve to connect each heat-exchanger unit 10 to the conduit 72 through which hot secondary fluid is discharged to the manifold 44. A biological shield plate 76 which is fixed to the manifold 44 and extends to the heat-exchanger units 10 serves to protect the operator against any residual radioactivity emanating from the reactor core during the replacement of a unit 10. By rotating the tube 50, any damaged heatexchanger unit 10 can be brought into position beneath an opening 2 in the pressure vessel, whereupon it is disconnected from the manifold 44 and replaced.</p> |
