A uranium-fired nuclear bomb.

A form of decorative glass with a fluorescent effect, achieved by adding uranium, usually in oxide diuranate form, added to the glass before melting.

(historical) A German project during World War II to research nuclear technology, including nuclear weapons and nuclear reactors.

(nuclear physics) Enriched uranium with at least 2% but less than 20% uranium-235, enough to sustain a nuclear fission chain reaction in a nuclear reactor moderated by light water but not enough to allow a self-sustaining fission chain reaction without a moderator; used as the main nuclear fuel in most commercial nuclear reactors used to generate electricity.

Alternative form of slightly-enriched uranium

(nuclear physics) Enriched uranium with 0.9-2% uranium-235, requiring a special moderator with very low neutron absorption (such as heavy water or high-purity graphite) in order to be able to sustain a nuclear fission chain reaction. Used to increase power output and efficiency in a few types of nuclear reactors capable of running on natural uranium, and for downblending of highly-enriched uranium from decommissioned nuclear weapons into low-enriched uranium suitable for use in commercial power reactors.

(nuclear physics, military) Enriched uranium containing at least 20% uranium-235 (some applications, such as fission weapons and naval reactors, use uranium enriched to as high as 80-95% uranium-235), and therefore capable of sustaining a nuclear fission chain reaction without needing a moderator; used in nuclear weapons and in a few types of nuclear reactors requiring very high power density or high neutron flux.