Air-lock for enabling access to interior of nuclear reactor steam generator

摘要

An air lock, which enables maintenance work to be performed in the lower end plenum (4) of a steam generator connected to the primary cooling circuit of a pressurised water nuclear reactor, comprises a closed chamber (20) with a mouth designed to seal against the outside of the generator housing around a manhole therein and a sliding door (23) inside the chamber and able to close the manhole or allow access therethrough. A second door (22) in the chamber roof allows access to the chamber from outside and when closed allows the chamber to be pressurised.