United States Nuclear Regulatory Commission - Protecting People and the Environment

U.S. Nuclear Regulatory Commission

U.S. Nuclear Regulatory Commission

Question 218: 10 CFR 20.1601 (a) (1) says that the control

devices must cause the radiation level to be reduced "upon

entry." (a) Must the devices preclude authorized or

unauthorized entry? (b) At what point must the control

devices activate, when a person passes the final 30 cm

before, or entry itself?

Answer: (a) 10 CFR 20.1601 (a) requires that entrance or

access points to a high radiation area have "one or more"

of the listed features to preclude excessive radiation

exposure to an individual. The control device in

subparagraph (1) stipulates only that it cause the

radiation level to be reduced so that an individual, upon

entry, could not receive 100 mrem in an hour within 30 cm

of an accessible area of the source. This paragraph does

not distinguish between "authorized" or "unauthorized."

(b) The control device must activate "upon entry into the

area" at the "entrance or access point." (Reference: 10

CFR 20.1601)

Page Last Reviewed/Updated Thursday, March 29, 2012