Radiological Health Support Operations
PART 2 Internal Dosimetry
521 General Provisions
The following individuals shall participate in an internal dosimetry program:
Radiological workers who are likely to receive a committed effective dose equivalent of 100 millirem or more
from all radionuclide intakes in a year [see 835.402(c)(1)]
Declared pregnant workers likely to receive intakes resulting in a dose equivalent to the embryo/fetus of 50
millirem or more during the gestation period [see 835.402(c)(2)]
Occupationally exposed minors likely to receive a committed effective dose equivalent in excess of 50
millirem from all radionuclide intakes in a year [see 835.402(c)(3)].
Members of the public who enter a controlled area and are likely to receive an intake resulting in a committed
effective dose equivalent exceeding 50 millirem in a year [see 835.402(c)(4)].
The estimation of internal dose shall be based on bioassay data rather than air concentration values unless one of
the following conditions exists [see 835.209(b)]:
bioassay data are unavailable
bioassay data are inadequate
internal dose estimates based on representative air concentration values are demonstrated to be as or more
Individuals should participate in follow-up bioassay monitoring when their routine bioassay results indicate an
intake in the current year with a committed effective dose equivalent of 100 millirem or more.
Individuals whose routine duties may involve exposure to surface or airborne contamination or to radionuclides
readily absorbed through the skin, such as tritium, should be considered for participation in the bioassay program.
The bioassay program should establish appropriate frequencies for the collection of bioassay samples, such as urine
or fecal samples, and participation in bioassay monitoring, such as whole body or lung counting. Individuals
should participate at the frequency required by the bioassay program.
Individuals should be notified promptly of positive bioassay results and the results of dose assessments and
subsequent refinements. Dose assessment results shall be provided in terms of rem or millirem [see 835.2(b), dose
term definitions, and 835.4].
522 Technical Provisions for Internal Dosimetry
All bioassay programs implemented to demonstrate compliance with Article 521.1 shall be:
Accredited by the DOE Laboratory Accreditation Program for Bioassay Programs [see 835.402(d)]; or
Excepted from accreditation by the DOELAP Program [see 835.402(d)(1)]; or
Otherwise approved by the Assistant Secretary for Environment, Safety and Health [see 835.402(d)(2)].
A technical basis document should be developed for the internal dosimetry program.
Baseline bioassay monitoring of individuals who are likely to receive intakes resulting in a committed effective
dose equivalent greater than 100 millirem in a year should be conducted before they begin work that may expose
them to internal radiation exposure.