A hot particle is a small, highly radioactive object, with significant content of radionuclides. Hot particles are usually released into the environment during a nuclear accident or when high-level radioactive waste is improperly handled, and are the principal hazard of the nuclear fallout from nuclear explosions. They are an important component of radioactive contamination. Radioactive decay is the set of various processes by which unstable atomic nuclei (nuclides) emit subatomic particles. ... Atoms of chemical elements may have many isotopes (different forms) with different atomic numbers and different atomic weights. ... Jump to: navigation, search Pathways from airborne radioactive contamination to man This article covers notable accidents involving nuclear material. ... A Russian fissile material storage facility Underground Radioactive Material Sign Radioactive waste is waste material containing radioactive chemical elements that does not have a practical purpose. ... Jump to: navigation, search Fallout is the residual radiation hazard from a nuclear explosion and is named from the fact that it falls out of the atmosphere in to which it is spread during the explosion. ... Jump to: navigation, search A nuclear test explosion is an experiment involving the detonation of a nuclear weapon. ... The radiation warning symbol (trefoil). ...

The size of hot particles contained in nuclear fallout ranges from 10 nanometers to 20 micrometers for the worldwide fallout; local fallout particles are significantly bigger (100 micrometers to several millimeters).

Hot particles can consist of tiny specks (~10 micrometers sized) of nuclear fuel (so-called fuel fleas due to their tendency to become electrically charged and then jump from surface to surface), or of other material activated by exposition to neutron radiation. Nuclear Fuel is used to generate Nuclear power. ... Neutron activation is the process by which neutron radiation induces radioactivity in materials. ... Neutron radiation consists of free neutrons. ...

Hot particles can be identified by a geiger counter, or by autoradiography. Their age and origin can be determined by their isotopic signature. An antique Victoreen civil defense survey meter model CDV-717 with detachable remote sensing unit (a type of low accuracy geiger counter). ... An autoradiograph is an image produced on a photographic film by the radiation from a radioactive substance. ... Jump to: navigation, search An isotopic signature (also isotopic fingerprint) is a ratio of stable or unstable isotopes of particular elements found in an investigated material. ...

Hot particles present significant health hazard when ingested or entered the body by other means.