Energy

Nuclear

Nuclear plants

Light water reactors

In light water reactors the fuel is made of cylinders of uranium oxide enriched with uranium 235. The water circulates among the cylinders and acts both as a controlling element and as coolant. The core is hosted in a pressurised steel container provided with the coolant intake and outlet holes. Shields to absorb the nuclear radiation are mounted around the container and the active parts of the reactor: the metal heat shield mainly absorbs gamma radiation, the concrete biological shield absorbs neutrons. Of course the safety and emergency systems necessary to face possible nuclear accidents are paramount.