NAC459.325. Limits on occupational doses for adults.

     1. Except as otherwise provided in subsection 5, a licensee or registrant shall control occupational doses, except for planned special exposures, to ensure that no adult receives annually occupational doses in excess of the following limits:

     (a) The lesser of:

          (1) A total effective dose equivalent of 5 rems (50 millisieverts); or

          (2) The sum of the deep-dose equivalent and the committed dose equivalent to any individual organ or tissue, other than the lens of the eye, of 50 rems (500 millisieverts);

     (b) A lens dose equivalent of 15 rems (150 millisieverts); and

     (c) A shallow-dose equivalent to the skin of the whole body or the skin of any extremity of 50 rems (500 millisieverts).

     2. Occupational doses received in excess of the annual limits specified in subsection 1, including doses received during accidents, emergencies and planned special exposures, must be subtracted from the limits for planned special exposures that a person may receive during a current year and during his or her lifetime.

     3. When the external exposure is determined by a measurement with an external personal monitoring device, the deep-dose equivalent must be used in lieu of the effective dose equivalent, unless the effective dose equivalent is determined by a dosimetry method approved by the Division. The assigned deep-dose equivalent must be for the portion of the body receiving the highest exposure. The assigned shallow-dose equivalent must be the dose averaged over the contiguous 10 square centimeters of skin receiving the highest exposure. The deep-dose equivalent, lens dose equivalent and shallow-dose equivalent may be assessed from surveys or other radiation measurements for the purpose of demonstrating compliance with the limits for occupational doses, if the personnel monitoring equipment was not in the region of highest potential exposure, or the results of personnel monitoring are unavailable.

     4. The derived air concentration and annual limit on intake values that are set forth in table I of appendix B may be used to determine the occupational dose of a person and to demonstrate compliance with the limits for occupational doses.

     5. Notwithstanding the annual limits, a licensee shall limit a person’s intake of soluble uranium to 10 milligrams in 1 week.

     6. The licensee or registrant shall reduce the occupational dose that a person is allowed to receive in a current year by the amount of the occupational dose that person received during the year while employed by another person.

     (Added to NAC by Bd. of Health, eff. 1-18-94; A by Dep’t of Human Resources by R137-01, 5-30-2003; A by Bd. of Health by R085-06, 11-13-2006; R185-08, 5-7-2010)