Typical nuclear reactor

The uranium fuel is kept in the reactor’s core. The core is controlled by control rods which can be driven into and out of the core. The core is usually enclosed in a pressure vessel which is surrounded by a biological shield. This is a concrete structure designed to prevent the escape of radiations from the core. The reactor heats the water which is circulated and converted directly or indirectly to steam. The steam drives a turbine generator which produces energy in the ordinary way. Exhaust steam is converted back into water by means of a condenser which uses water from a cooling tower. The cooling tower needs a supply of cool water from a river or sea. The cold water is circulated by a feed water pump back through the hot part of the reactor.