Hasadó

Hasadó is an adjective in Hungarian meaning fissile or capable of undergoing fission. In nuclear physics and engineering, it describes materials that can sustain a nuclear chain reaction when irradiated with neutrons, typically thermal neutrons. The corresponding noun is hasadóanyag, usually translated as fissile material. Common fissile isotopes include uranium-235, plutonium-239, and uranium-233; these isotopes can fission upon absorbing a neutron and, in the presence of a moderator and other reactor design features, maintain a self-sustaining chain reaction.

In Hungary and Hungarian-language literature, the distinction is often made between fissile materials (which can sustain chain reactions with slow neutrons) and broader fissionable materials (which can undergo fission with some neutron energies). The English terms "fissile" and "fissionable" are used in similar, but not identical, ways in nuclear science, with "fissile" generally referring to materials that fission readily with thermal neutrons.

Applications include civil nuclear reactors, where fuel composed of fissile isotopes enables energy production. Handling of hasadóanyag is tightly regulated due to radiological hazards and proliferation risks, under national controls and international safeguards by the IAEA and related regimes.

Despite its technical usage, hasadó remains primarily a term in Hungarian-language contexts; in English documentation the concept is normally described using "fissile" or "fissionable" rather than a direct loanword.