Health Physics Questions and Answers - Question 94
Question 94: Why was the "controlled area" defined?
Answer: The "controlled area," which is not defined or used in the old Part 20, was defined and used in the revised Part 20 to provide regulatory recognition of the existence of such areas and to clarify their regulatory status within the context of 10 CFR Part 20. In a related change, in revised Part 20, occupational dose limits no longer apply only in restricted areas, and lower (public) dose limits no longer apply to everyone outside a restricted area. Thus, under the old Part 20, an individual who receives an occupational dose in a controlled area is subject to the same (low) dose limit as a member of the public in that same area. Under the revised Part 20, an individual who receives an occupational dose in a controlled area is subject to the occupational dose limits, but a member of the public in the same controlled area is subject to the (lower) dose limits for members of the public.
(Reference: 10 CFR 20.1003).