GB911863A - Improvements in or relating to charge/discharge systems for gas-cooled nuclear reactors - Google Patents

Abstract

911,863. Handling fuel elements. SIMONCARVES Ltd., and GENERAL ELECTRIC CO. Ltd. Nov. 21, 1960 [Nov. 25, 1959], No. 40037/59. Class 39 (4). A fuel element charge/discharge system for a gas-cooled reactor wherein during charging and discharging whilst the reactor is operating fuel elements are at all times in a gas flow path and present a constant impedance to the gas flow. As shown in Fig. 1, the reactor core 1 in a pressure vessel 4 has a number of fuel element channels 2 (only one shown), the coolant gas passing upwardly over the fuel elements 3 through a pipe 5 to a heat exchanger 7 containing a blower, the gas returning through a pipe 6. To refuel a channel whilst the reactor is on load a movable charging vessel 10 is connected to the channel by a charge tube 13, a standpipe (not shown) normally surrounding the tube and being sealed at its ends to the vessels 4, 10. The tube 13 extends through the centre of a magazine 11 having fuel storage tubes 14, a further tube 15 connecting each of the tubes 14 in turn to the vessel 4 as the magazine is rotated. In operation, the coolant gas in the channel 2 being serviced by the grab 12 flows through the tubes 13, 14 and returns to the pipe 5 via tube 15 and the upper part of the vessel 4. Each tube 14 may contain all the elements 3 belonging to one channel 2 whereby a constant impedance is presented to the gas flow. In a modified system, Figs. 4, 5, the gas returns to the vessel 4 through the annular space between the charge tube 13 and a standpipe 18 and the charge tube is outside the magazine 11. A gas circuit 24 connected to that particular tube 14 from or into which fuel elements 3 are being drawn contains a blower 26 and an evaporative cooler 27. The blower 26 may be controlled to compensate for the impedance of the grab 12. A further circuit 19 containing a blower 20 and gas-air heat exchanger 23 is connected through a manifold 22 to the upper ends of certain of the tubes 14 containing discharged fuel elements and serves to cool the magazine. The fuel elements in the tube 14 which is about to be brought into the charging position may be pre-heated or cooled by a circuit 28 containing a blower 29, heater 30 and cooler 31. Specification 789,022 is referred to. Reference has been directed by the Comptroller to Specification 883,901.