| 摘要 |
1324380 Monitoring reactors SIEMENS AG 19 Oct 1970 [24 Oct 1969] 49607/70 Heading G6C A pressurized water reactor has a pressure vessel 11 provided with a removable cover 12 and containing a core comprising fuel elements 2 arranged as shown in Fig. 1. Certain of the fuel elements 2 contain control rods 3 which penetrate the cover 12 through sleeves 21. It is required to measure the neutron flux in numerous ones of the fuel elements 2 by means of guide tubes 6 inserted in those fuel elements. The tubes 6 serve for guiding measuring probes and are diagrammatically shown in Fig. 1 as triangles. As diagrammatically shown in Fig. 1 four tubes 6 are connected by a yoke 5 to a single instrumentation tube 4 penetrating the cover 12 above a peripheral portion of the core which does not contain control rods. Thus the number of cover penetrations for the instrumentation is reduced and these penetrations do not interfere with the control rods. As shown in Fig. 2 the yoke 5 extends radially from the tube 4 and supports a number of guide tubes 6 extending through certain of the fuel elements 2 in the core, the upper ends of the guide tubes terminating in the tube 4. The tube 4 is located by a sleeve 15 upstanding from the core grid 14 and penetrates the cover 12 through a sleeve 13 in which it is sealed by means described with reference to Figs. 7, 8 (not shown). To remove the instrumentation the sealing means is released and the cover 12 and sleeve 13 are removed whereupon the tube 4, yoke 5 and guide tubes 6 may be lifted from the core. To prevent damage to the long slender guide tubes 6 on their insertion in the core s supporting tool is used as described with reference to Figs. 9, 10 (not shown). |
