The new cell of the stack of vertical channels atomic

摘要

861,800. Nuclear reactors. COMMISSARIAT A L'ENERGIE ATOMIQUE. April 23, 1959 [May 3, 1958], No. 13828/59. Class 39(4). A nuclear reactor fuel assembly for vertical use comprises a tubular casing with an upper support to rest on a fixed member at the top of a reactor and a lower part centred in a recess in the base of the reactor, the support and lower part being connected by an elastic linkage. Fig. 1 shows an assembly in a D 2 O moderated reactor, clamped at 15 on top of the concrete reactor shield and seated by a foot 4 in a hole in a base plate. Fig. 3 shows a spring 31 between a shield plug 14 forming the top ofthe assembly and the main part of the assembly; the spring absorbs changes in length and presses the foot 4 into its hole. Fig. 2 shows the main part, comprising a tube containing fuel cartridges 6 linked by spigots 21 and supported by lugs 19; the tube has internal fins 18 to reduce damage caused by distorted fuel. Coolant flows up over the fuel, through a restriction 23 and a degassing device 24, and out through a deflector 9. A coolant sampling tube 26, a tube 34 to drain the sampling system, and a thermocouple 30 are provided. The reactor has a He atmosphere and pressure-equalising holes 28 are provided. The assembly is of pure Al and the foot is anodically oxidised to prevent adhesion.