Current through September 17, 2024
Occupational dose limits for adults are as follows.
005.01
OCCUPATIONAL DOSE
CONTROL. The licensee or registrant must control the occupational
dose to individual adults, except for planned special exposures according to
180 NAC
4-010, to the following dose limits:
(A) An annual limit, which is the more
limiting of:
(i) The total effective dose
equivalent being equal to 0.05 Sv (5 rem); or
(ii) 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 being equal to 0.5 Sv (50 rem).
(B) The annual limits to the lens of the eye,
to the skin of the whole body, and to the skin of the extremities, which are:
(i) A lens dose equivalent of 0.15 Sv (15
rem), and
(ii) A shallow dose
equivalent of 0.5 Sv (50 rem) to the skin of the whole body or to the skin of
any extremity.
005.02
DOSES RECEIVED IN EXCESS
OF THE ANNUAL LIMITS. Doses received in excess of the annual
limits, including doses received during accidents, emergencies, and planned
special exposures, must be subtracted from the limits for planned special
exposures that the individual may receive during the current year and during
the individual's lifetime. See 180 NAC
4-010(E)(i) and
(ii).
005.03
EXTERNAL
EXPOSURE. Licensees and registrants must determine external
exposure so that:
(A) When the external
exposure is determined by measurement with an external personal monitoring
device, the deep-dose equivalent must be used in place of the effective dose
equivalent, unless the effective dose equivalent is determined by a dosimetry
method approved by the U.S. Nuclear Regulatory Commission (NRC). The assigned
deep-dose equivalent must be for the part 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 deepdose 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 occupational dose limits, if the individual
monitoring device was not in the region of highest potential exposure, or the
results of individual monitoring are unavailable.
(B) If an individual is required to be
monitored by 180 NAC
4-022, when a protective apron is worn
while working with medical fluoroscopic equipment and monitoring is conducted
as specified in 180 NAC 4-022.01(E), the effective dose equivalent for external
radiation must be determined as follows:
(i)
When only one individual monitoring device is used and it is located at the
neck (collar) outside the protective apron, the reported deep dose equivalent
must be the effective dose equivalent for external radiation; or
(ii) When only one individual monitoring
device is used and it is located at the neck (collar) outside the protective
apron, and the reported dose exceeds 25% of the limit specified in 180 NAC
4-005.01, the reported deep dose equivalent value multiplied by 0.3 must be the
effective dose equivalent for external radiation; or
(iii) When individual monitoring devices are
worn, both under the protective apron at the waist and outside the protective
apron at the neck, the effective dose equivalent for external radiation must be
assigned the value of the sum of the deep dose equivalent reported for the
individual monitoring device located at the waist under the protective apron
multiplied by 1.5 and the deep dose equivalent reported for the individual
monitoring device located at the neck outside the protective apron multiplied
by 0.04.
005.04
DERIVED AIR CONCENTRATION
(DAC) AND ANNUAL LIMIT ON INTAKE (ALI) VALUES. Derived air
concentration (DAC) and annual limit on intake (ALI) values are presented in
Table I of Appendix 4-B of 180 NAC 4 and may be used to determine the
individual's dose and to demonstrate compliance with the occupational dose
limits. See 180 NAC
4-052.
005.05
SOLUBLE URANIUM
INTAKE. In addition to the annual dose limits, the licensee must
limit the soluble uranium intake by an individual to 10 milligrams in a week in
consideration of chemical toxicity. See Appendix 4-B of 180 NAC 4.
005.06
DOSE
REDUCTION. The licensee or registrant must reduce the dose that an
individual may be allowed to receive in the current year by the amount of
occupational dose received while employed by any other person.
