| 摘要 |
1,023,133. Fuel elements. B. T. A. HARGO. March 8, 1963 [March 9, 1962], No. 9421/63. Heading G6C. An elongate nuclear fuel element has several coolant passages extending longitudinally, each over only a portion of the length of the fuel but so that substantially all the fuel is disposed within the coolant passages, a portion of the coolant flowing through each passage parallel to the longitudinal axis of the element. As shown in Fig. 1, a fuel element for a heavy water-moderated pressurized water reactor comprises fuel rods 1 disposed around two circles to form an annular bundle confined between two coaxial guiding tubes 5, 6. The annular space between these tubes is divided into five coolant passages by means of partitions 8, the fuel rods 1 passing through holes in the partitions. Heavy water coolant enters the element at the top end 12 and flows down through the inner guiding tube 5, portions entering the coolant passages through orifices 10 and leaving through orifices 11 after flowing up through the passages, as shown by the arrows 14. The fuel rods 1 and the guiding tubes 5, 6 are suspended in a known manner from the top plate 7 of the reactor. The partitions 8 are carried by tubes or rods disposed between the fuel rods 1 in the annular space between the guiding tubes 5, 6. The arrangement described is also applicable to the fuel elements of graphite-moderated gas-cooled reactors. |
