The beginnings of nuclear power
Electricity generation by nuclear power plants

The early days of nuclear power saw the emergence of a large number of projects combining different materials:

• fissile materials: uranium (²³⁵U) and plutonium (²³⁵Pu) ;

• moderators: ordinary water (H₂O), heavy water (D₂O) and graphite (C) ;

• fertile materials: uranium (²³⁸U) and thorium (Th) ;

• Heat carriers: ordinary water, heavy water, organic liquids, carbon dioxide (CO₂), helium (He), sodium (Na), lead (Pb), mercury (Hg) ;

• structural materials: prestressed concrete, carbon steels, stainless steels, especially austenitic and ferritic, and alloys used for fuel cladding, based on Mg, Zr or stainless steels;

• absorbent materials: boron, cadmium, hafnium, gadolinium, silver and indium.

Theoretically, this results...