United States Nuclear Regulatory Commission - Protecting People and the Environment

U.S. Nuclear Regulatory Commission

Question 74: Dose rates are used to establish posting

requirements for radiation areas, high radiation areas, and

very high radiation areas. 10 CFR 20.1601 (a) (1),

"Control of Access to High Radiation Areas," refers to a

"deep-dose equivalent" in describing when a control device

should be provided to reduce radiation doses below 0.1 rem

in one hour, thus implying that the "dose equivalent" in

the definition of a "high radiation area" is the "deep dose

equivalent" [at a tissue depth of 1 cm (1000 mg/square

cm)]. Are the "dose equivalent" in the definitions of

"radiation area" and "high radiation area" and the "dose"

in the definition of "very high radiation area" all

considered to be at a tissue depth of 1 cm (1000 mg/square


Answer: Yes. In addition see Question 57. (References:

10 CFR 20.1003, 10 CFR 20.1601)

Page Last Reviewed/Updated Thursday, March 29, 2012