Abstract: A fast reactor core is submerged in a pool of liquid metal coolant and there is a catchment tray for falling fuel debris disposed beneath the core. The catchment tray comprises a complex of open top collecting vessels arranged on lattice pitches in layers, the lattice pitches of the layers being off-set to provide a complete catchment area.

Abstract: An electrical push-button switch in which the push button has a shank extending through a passage in the switch housing for engaging an electrical contact set. The passage through which the shank extends has a series of notches around the periphery for receiving one end of a pair of springs, the other end of each spring is attached to the shank. The springs have an N-shaped configuration with an extension at one end of the N. A pair of complimentary stationary portions of the switch housing extend in the path of and engage the extended portions of the springs after the push button is depressed. The initial depression of the push button causes the shank to move against the tension of the springs until a changeover point is reached, thereafter the push button movement is assisted by the springs for a further period of travel.

Abstract: A device for the control of light transmission or reflection comprises one or more working electrodes, preferably arranged to form a display and having radiation transmission or reflection properties, an active material comprising an N(p-cyanophenyl) substituted derivative of a compound, usually bicyclic, having two conjugated nitrogen-containing rings in contact with the working electrode surface, a counter electrode, also in contact with the active material and ferrous ammonium sulphate as an auxiliary redox system.