Flask (nuclear – transport) meaning

A nuclear transport flask is a heavily shielded shipping cask used to carry radioactive material (for example, spent nuclear fuel or intermediate‑level waste) between nuclear sites, typically by road or rail. “Flask” is an industry description rather than a term defined in legislation; the legal framework regulates “packages”, usually Type B packages for high‑activity materials. Flasks must meet the International Atomic Energy Agency transport regulations (IAEA SSR‑6), as implemented through ADR/RID and domestic carriage of dangerous goods law. In Great Britain, the Office for Nuclear Regulation (ONR) acts as competent authority for land transport and issues package design approvals for Type B/fissile packages; the Civil Aviation Authority and Maritime and Coastguard Agency regulate air and sea modes. Northern Ireland applies equivalent provisions under separate NI regulations with parallel competent‑authority arrangements. In Ireland, the Environmental Protection Agency acts as competent authority for Class 7 transport, with ADR implemented in national regulations. Key legal features include: performance‑tested design (drop, puncture, fire and immersion), package design approval where required, consignor/carrier duties on classification, labelling, radiation protection and emergency arrangements, and (for certain materials) additional civil nuclear security requirements. Usage and expectations are broadly consistent across England & Wales, Scotland, Northern Ireland and Ireland.