Escape from incident routes

Not many readers will handle radioaetive materials, but this incident and the previous one do show how easy it is to overlook some of the routes by which hazardous materials or effects can escape from containment. 

The portion of an exit route that is generally separated from other areas to provide a protected way of travel to the exit discharge from the effects of an incident. An example of an exit is a 2-hour fire-resistance-rated enclosed stairway that leads from the fifth floor of an office building to the outside of the building. Exits include exterior exit doors, exit passageways, horizontal exits, and separated exit stairs or ramps. See also Fire Escape. 

Stage 4 travel is from the foot of the staircase to the outside. The stairs should not all converge into one common area at ground level, otherwise a single incident can block all escape routes. 

Exit 1 on the left is a main exit which leads to the street. Exit 2 in the middle is an entrance to the imdeipass which leads to the main entrance located in platform 1 (not shown). Exit 3 on the right is a secondary exit which also leads to the street. The publicly accessible area forms three circulation/escape routes as indicated by the arrows in Figure 22.7. One hundred and ninety volunteers took part in the normal evacuation trial and 150 in the ADSS trial. The volunteers were instracted and monitored by a number of persons from the GETAWAY project teams. The evacuation scenario was based upon the assumption that an incident has occurred... 

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