b) It is too dangerous to allow untrained personnel to
don SCBA equipment and venture into a known hazardous atmosphere.
For that reason, the Navy has elected not to provide the SCBA,
since there would be no control over who might don the SCBA and
attempt to enter the room.
Radon Mitigation Systems. The following components of
a sub-slab depressurization system should be included in the
design for buildings which will be constructed on sites known or
suspected of being a source of radon gas and which will be
occupied more than 4 hours a day:
a) Piping. Provide one 3-inch diameter polyvinyl
chloride (PVC) pipe (Schedule 20) through the floor slab for
every 1,000 square feet of slab area located as close to the
center of the area as possible. See Figure 1 for floor
penetration detail. Pipe should extend through the building
roof, concealed in partitions, closets, store rooms, etc. An
adequate length of straight vertical piping should be provided in
the ceiling space below the roof for future installation of the
depressurization fan if post construction testing indicates
excessive radon levels. Locating the fan near the roof or
ceiling establishes a negative pressure in the piping system
thereby minimizing potential of leaks in occupied spaces. Crack
between pipe and slab should be sealed with polyurethane caulk.
Evaluate the economic feasibility of combining several PVC pipes
to reduce the number of risers and the number of roof
penetrations, especially for multi-story buildings.
b) Electrical Requirements. Provide a 110 volt, 15
locations near the location for the future depressurization fans
in PVC pipe. Ensure convenient access to locations selected for
future installation of depressurization fans.