that provided considerable shielding.
Unshielded participants were
customarily positioned much further away from ground zero.
5.2
PROTECTION AGAINST RESIDUAL RADIATION.
Procedures for protection against residual radiation were more complex
because operations in a contaminated environment involved potential exposure
to radiation sources both external to and inside the body, the latter
resulting primarily from inhalation or ingestion of radioactive material.
The
next sections address these protective measures.
5.2.1
Identification and Control of Radiation Areas.
The fundamental approach for protection against residual radiation was to
control access to contaminated areas.
Obviously, the first step was the
identification of the radiation areas and quantification of the radiation
therein.
In all cases, authorized entry into a radiation area was made
through a control point and preceded by some form of survey by trained
radiation monitors using state-of-the-art radiation detection and measurement
equipment.
In the case of a military maneuver, radiation monitors preceded
the advancing troops to steer them away from radiation areas contaminated
above pre-established limits.
Re-entry into the shot area by scientific
project personnel or military troops visiting a display area normally was
delayed until a "Recovery Hour" was declared after completion of an initial
radiation survey of the area.
The initial survey team used radiation
detectors to locate and mark various radiation intensities approaching the
detonation site.
In some cases, early entry was authorized for certain
scientific project personnel; however, these personnel were accompanied by
their own radiation monitors.
The radiation levels measured by these monitors were used to determine
the amount of time the participants could remain in the area.
"Stay times"
were calculated and observed to ensure that external gamma radiation exposure
limits were not exceeded.
Only gamma radiation was considered for this
purpose since normal clothing provided adequate protection against external
alpha and beta radiation exposure.
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