fisionarea

Fisionarea is a theoretical concept used in speculative physics and in some fictional settings to describe a region where conditions permit self-sustained fission reactions to occur. The term is not standard in established physics, and its precise definition varies by author or work.

In common speculative usage, a fisionarea would require a high concentration of fissile isotopes, a moderator to slow neutrons, and a geometry that minimizes neutron leakage so that the chain reaction can be sustained. Heat removal and temperature control are crucial, as runaway fission would quickly alter conditions and terminate the reaction.

The concept is often treated as a thought experiment to explore criticality, neutron economy, and containment. Some writers loosely compare fisionareas to natural nuclear reactors such as those inferred at Oklo, though there is no real-world counterpart to the anticipated localized, reactor-like regions described in fiction.

In fiction and theoretical discussions, fisionareas may be depicted as sources of power, as hazards, or as plot devices that require monitoring, shielding, and emergency protocols. As a scientific construct, they help frame discussions about reactor physics, safety margins, and the limits of material design under extreme neutron flux.

See also: natural nuclear reactors, nuclear criticality safety, neutron moderation, Oklo.