First criticality

Plutonium piles

Pressurized water reactor

Boiling water reactor

VVER

PHWR / CANDU

Magnox

Advanced gas-cooled

RBMK

Liquid-metal fast breeder

Molten salt

High-temperature gas-cooled

Heavy-water hybrids

Sodium-graphite

Aqueous homogeneous

Space & propulsion

SMR / Gen IV