Glossary
The Nuclear Fuel Cycle - General Introduction

Minor actinides

Isotopes formed in a reactor by successive neutron capture from fuel nuclei. These isotopes are mainly neptunium (²³⁷Np), americium (²⁴¹Am, ²⁴³Am) and curium (²⁴³Cm, ²⁴⁴Cm, ²⁴⁵Cm).

Assembly

In the core of a water-cooled reactor, the fuel rods are grouped together in bundles, a structure comprising 264 rods (in the case of French PWRs) and loaded as a single unit into the reactor.

Cigéo

Industrial geological storage center

Nuclear fuel

A nuclide whose consumption by fission in a reactor releases energy. By extension, an assembly of rods containing fissile material, which supplies energy to a reactor core by maintaining the chain reaction. This fuel is periodically renewed in parts.

Spent fuel

Fuel assemblies removed from a nuclear reactor after a period of...