In addition to the requirements specified in NAC 459.341, a licensee or registrant shall institute measures to ensure that a person is not able to gain unauthorized or inadvertent access to areas in which radiation levels could be encountered at 500 rads or more in 1 hour at 1 meter from a source of radiation or any surface through which the radiation penetrates.
Nev. Admin. Code § 459.343
NRS 459.201