GB848901A - Improvements in or relating to nuclear reactors - Google Patents

Abstract

848,901. Nuclear reactors. UNITED KING- DOM ATOMIC ENERGY AUTHORITY. April 26, 1948 [May 8, 1947], No. 12529/47. Class 39(4). An element of a core of a nuclear reactor comprises a body of moderator material having fissile material dispersed in it, the proportions of moderator and fissile material preferably being the same as in the core as a whole. The element may be a shaped body or compact made of a mixture of refractory compounds, such as oxides or carbides, of beryllium or aluminium and one of the fissile isotopes of uranium or plutonium sintered or otherwise bonded together. In one arrangement, Fig. 1, the core structure comprises shallow open-ended boxes 1 of moderator material, for example beryllium oxide, with parallel partitions 2 traversing them. Plate elements 4 of moderator material with fissile material dispersed in them are slid into grooves formed in the boxes. Baffle sheets 5 of beryllium are arranged to extend diagonally across the space between the boxes so that coolant gas fed to one side of the row of boxes flows over one face of each baffle and through the adjacent box to the baffle at the other end of the box. In another arrangement, Fig. 4 (not shown), the fuel elements are in the form of hollow slabs. The fuel elements may be in the form of marbles of beryllium oxide containing fissile material and may be used in the reactor shown in Fig. 5. The core vessel 18 is made of beryllium oxide and suspended from a cover plate 16. Fuel elements are fed into the core through a tube 21 and out through a tube 25. The core is surrounded by a reflector comprising marbles of beryllium oxide which may contain thorium and which are fed into the reflector space by a tube 28 and out through a tube 29. Tubes 27 allow control rods to be inserted and a gas coolant may be passed through the reactor from an inlet 13 to an outlet 15.