Question 412: This question refers to the answer to
Question 26 (b) under ยง20.1003. What is the basis for
using a dose threshold to decide whether a person is
categorized as a member of the public or as occupationally
exposed? The definitions do not specify a dose threshold.
Answer: Question 26 (b) asked whether occupational or
public dose limits apply to individuals, described in three
different scenarios, who are exposed within controlled
areas (outside any restricted areas) at a nuclear power
plant. These scenarios described (1) a fossil plant
worker, (2) a pregnant taxi driver, and (3) construction
workers building a second nuclear power plant and
secretaries in the administrative building. The answer to
Question 26 (a) states that the public dose limits apply to
the individuals in all three scenarios, but the answer also
states that if turbine shine from the nuclear plant is such
that fossil plant workers, construction workers, or
secretaries (but not the pregnant taxi driver) ". . . are
likely to exceed the dose limits for members of the public,
the licensee should consider the individual doses to be
occupational doses and meet the requirements for
individuals who receive occupational doses." The basis for
this answer is the NRC staff's understanding of the intent
of the definition of "occupational dose", specifically,
that portion which states that "occupational dose means the
dose received by an individual . . . in the course of
employment in which the individual's assigned duties
involve exposure to radiation . . . ." This understanding
of the definition is also expressed in more general terms
in the answer to Question 26 (a). (Reference: 10 CFR
20.1003)