Pool reactor meaning

In nuclear regulation and practice, a pool reactor is a research nuclear reactor in which fuel elements are submerged in an open pool of light water. The water acts as moderator, coolant, neutron reflector and biological shielding. Often called a “swimming‑pool reactor”, it is used for research, materials testing, training and sometimes radioisotope production, not for electricity generation. The expression is descriptive engineering usage, not a defined statutory term. In Great Britain it falls within the general concept of a “nuclear reactor” under the Nuclear Installations Act 1965, so construction, operation and decommissioning require a nuclear site licence from the Office for Nuclear Regulation (ONR), a safety case, liability cover and compliance with ionising radiation protection law and environmental permitting for radioactive substances. Waste management, security and transport controls apply as for other research reactors. Usage is broadly consistent across England & Wales, Scotland and Northern Ireland (though there are presently no nuclear licensed sites in Northern Ireland). In Ireland, electricity generation by nuclear fission is prohibited and no pool reactors operate; the term arises mainly in cross‑border radiological protection, export control and academic or vendor documentation.