U.S. Nuclear Regulatory Commission
Question 57: The definition of a very high radiation area
(10 CFR 20.1003) and the requirement for control of access
to very high radiation areas specify an absorbed dose of
500 rads in an hour. Is this a deep dose, a shallow dose,
or an eye dose?
Answer: The 500-rad dose is intended to be a deep dose,
evaluated at a tissue depth of 1 cm (1000 mg/square cm).
(References: 10 CFR 20.1003, 10 CFR 20.1602)