SCRAM meaning

SCRAM is the rapid emergency shutdown of a nuclear reactor, achieved by the swift insertion of control rods—usually automatically by the reactor protection system—to stop the fission chain reaction. In UK and Irish legal practice it is an industry/descriptive term (also called a reactor trip or rapid shutdown) rather than one defined in legislation or case law. Its legal significance lies in nuclear safety regulation and contractual risk allocation. In Great Britain (England, Wales and Scotland), a SCRAM can engage duties under the Nuclear Installations Act 1965 regime, Office for Nuclear Regulation (ONR) site licence conditions (for example incident reporting, operating rules and emergency arrangements) and relevant emergency planning regulations (such as REPPIR 2019). Unplanned trips typically prompt internal investigation, regulatory notification, and can affect availability guarantees, outage calculations, force majeure, insurance and compliance warranties. Planned test SCRAMs are usually covered by operating instructions and the facility’s safety case. Usage is broadly consistent across England & Wales, Scotland, Northern Ireland and Ireland. Northern Ireland and Ireland have no operating nuclear power reactors; the term generally appears there in cross-border emergency planning, procurement, financing or insurance documents referring to GB or overseas nuclear installations.