Health Physics Questions and Answers - Question 412

Question 412: This question refers to the answer to Question 26 (b) under §20.1003. 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)