United States Nuclear Regulatory Commission - Protecting People and the Environment

Health Physics Questions and Answers - Question 414

Question 414: This question refers to the answer to Question 6 §20.1201. This answer does not directly answer the implied question, which is, "if a person is assessed a history of 5 rem or more for the current year, is that person permitted to receive any occupational dose?"

Implied in the answer is that if monitoring is not required, that person can receive an occupational dose, presumably up to 500 mrem for an adult. Conceptually, this is not consistent with normal protection standards, i.e., "if you don't measure it, it is not there" is not a normally accepted practice.

The Commission allowance for an explicit 100 mrem (SECY-90-387, November 26, 1990) would seem a much more reasonable approach. Both of these positions appear to conflict with the answer to Question 113 in the third set. Hopefully, a position similar to that taken for the declared pregnant woman with a pre-existing dose history will be taken. That is, an additional small increment of exposure is not biologically significant.

Answer: "If a person is assessed a history of 5 rem or more for the current year", that individual is not permitted to receive any additional occupational dose during that year (except a planned special exposure). The answer to Question 6 does not imply that the individual can receive any additional occupational dose (except in a planned special exposure). As noted in the preamble to revised Part 20 (56 FR 23369, second column), "the allowance of an additional 1 rem per quarter following an exposure in excess of the limits has been deleted" from the final rule published on May 21, 1991. The answer to Question 6 is consistent with the rule and the answer to Question 113, which states that "...if the 5 rem CEDE was received during the current year, this individual would not be allowed any further exposure for the balance of the year."

(Reference: 10 CFR 20.1201, 10 CFR 20.2104)

Page Last Reviewed/Updated Thursday, October 08, 2015