Nuclear weapon

The nuclear mushroom cloud seen in the bombing of Nagasaki in World War II.

A nuclear weapon is a type of ordnance using nuclear fission and/or fusion as a source of energy.

An operational idiosyncrasy of nuclear weapons was the result of containing fissile material. Fissile material emitted a readily detectable Cherenkov Radiation signature upon exiting slipspace that negated stealth measures.

The yield of a Nuclear weapon is measured in the amount of tons of "TNT" needed to generate an explosion of similar proportions.

UNSC Nuclear Ordnance

The UNSC employs a range of nuclear ordnance.

FENRIS Nuclear Warhead

The FENRIS is a type of low-yield thermonuclear device. They were slated for decommissioning but munition expenditures during the Human-Covenant War saw the survivors return to service.

Fury Tactical Nuclear Weapon

The Fury is a rugby ball-sized device with a yield slightly less than a megaton. It is extremely clean. It is the "Closest thing the UNSC has to a nuclear grenade."

HAVOK Nuclear Warhead

The HAVOK is a 30 megaton thermonuclear device. Some were delivered by ground forces during the Human-Covenant War.

HORNET Mine

The HORNET is a 30 megaton space mine. The devices are stealthy and carried aboard UNSC Prowlers.

NOVA Bomb

The NOVA is a strategic device. It consists of 9 nuclear warheads encased in a lithium triteride shell, which is compressed during detonation, boosting the yield "a hundred-fold" . A single NOVA has enough power to cause complete devastation on a planetary scale, and can destroy orbiting moons and Naval fleets.

Shiva-class Nuclear Missile

The Shiva is a type of starship ordnance. Its warhead may be removed and carried by a C709 Longsword-class Interceptor.