Basement Emergency Airlock

The basement emergency airlock at ANSTO HIFAR is a heavy double-doored chamber set into a thick concrete wall, fitted with mechanical interlocks that prevent both doors being opened simultaneously. The doors are steel, each about a hundred and fifty millimetres thick, with circular handwheels and indicator lamps showing position. The interior of the airlock is small, just enough for a person and equipment. Lighting is fluorescent. A radiation monitor is mounted on the inner door, with a hand contamination monitor on a stand at the threshold. The whole arrangement is built and maintained to a precise standard.

Emergency airlocks like this one allow people to enter or leave a containment building under conditions where the routine personnel airlock is unavailable, while preserving the integrity of the containment seal. At HIFAR the basement airlock was a backup access point used during certain maintenance operations and held in reserve for emergency evacuation. After the reactor's 2007 shutdown, the airlock continues to be maintained because the building it serves is decommissioned, not demolished, and the containment requirements have not changed. The doors still close, the interlocks still work, the radiation monitors still read. The system has been kept ready for circumstances that nobody currently expects.