Limiting Exposure
Current regulations for both NRC and Agreement States have
established a whole body occupational exposure limit of 5,000
millirem per year. Under normal conditions, a full-time gauge
operator will receive less than 200 millirem per year.
Taking advantage of all available means to limit radiation
exposure is always recommended. The three methods of limiting
exposure are:
♦ Time
♦ Distance
♦ Shielding
These methods are a part of an “ALARA” (As Low as Reasonably
Achievable) program.
TIME
The simplest way to reduce exposure is to keep the time spent
around a radioactive source to a minimum. If time is cut in half,
so is the exposure, with all other factors remaining constant.
DISTANCE
Distance is another effective means to reduce radiation exposure.
A formula known as the “inverse square law” relates the
radiation exposure rate to distance (Figure 13). Doubling the
distance from a radiation source reduces the exposure to one-
fourth its original value. If the distance is tripled, the exposure is
reduced by a factor of nine, etc.
To Next Page
Loading...
Need help?
General
