adj
Meaning 1
In a state where the prompt neutrons produced by a nuclear fission chain reaction are just sufficient to sustain the chain reaction on their own (past which changes in reaction power occur on a timeframe of milliseconds, too rapidly for a human operator to control).
Definition source: English Wiktionary via Wiktextract
Usage: not-comparable
Qualifier: nuclear physics
No example sentence was provided for this meaning.
Meaning relationships
Synonyms: none provided
Antonyms: none provided