United States Nuclear Regulatory Commission - Protecting People and the Environment

U.S. Nuclear Regulatory Commission

Question 444: In this example, it has been determined that

an individual will receive less than 100 mrems in a year

while in the controlled area, and the individual has

therefore been classified as a member of the public while

in the controlled area. The individual also accesses and

performs work in the restricted area. In evaluating

whether the individual requires monitoring in the

restricted area, may the evaluation be limited to only the

dose likely to be received in the restricted area, i.e.,

may the potential dose received in the controlled area be

disregarded for the purpose of the evaluation?

Answer: The answer to the question is yes, assuming that

the basis for classifying the individual as a member of the

public while in the controlled area is the type of work the

individual will do in the controlled area.

As emphasized in the answer to Question 26 (a), whether the

dose to an individual outside a restricted area is an

occupational dose or a public dose depends on what the

individual is doing and not on what area (controlled or

unrestricted area) the individual is in when the dose is

received. Furthermore, it is possible, and acceptable (as

indicated in many previous questions and answers), for the

licensee to consider the dose (other than background, etc.)

that individual receives in a controlled area to be an

occupational dose, even though, as stated in the question,

the dose the individual receives in the controlled area is

less than 100 mrem per year. Regardless of the magnitude of

the dose, the dose is an occupational dose if it is

received (in accordance with the definition of occupational

dose) ". . . in the course of employment in which the

individual's assigned duties involve exposure to radiation

and to radioactive material . . ." For example, an

individual who performs a radiation survey, in any area, of

a vehicle loaded with radioactive material prepared for

shipment would be receiving an occupational dose as a

result of exposure to the radiation from the radioactive

material on the vehicle regardless of the magnitude of the

dose. However, the dose (other than background, etc.)

received by a worker performing office work in a controlled

area could be considered to be either an occupational dose

or a public dose; either choice would be considered to be

consistent with the definition of "occupational dose." See

Question 26 and answer for additional information

concerning licensee options with respect to area

designations and dose categories. See Question 126

concerning the use individual monitoring of occupational

doses from effluents. (References: 10 CFR 20.1502, 10 CFR


Page Last Reviewed/Updated Thursday, March 29, 2012