Determination of internal exposure.

CFR · 2024-01-01 · US · Title 10

(a) For purposes of assessing dose used to determine compliance with occupational dose equivalent limits, the licensee shall, when required under § 20.1502, take suitable and timely measurements of— (1) Concentrations of radioactive materials in air in work areas; or (2) Quantities of radionuclides in the body; or (3) Quantities of radionuclides excreted from the body; or (4) Combinations of these measurements. (b) Unless respiratory protective equipment is used, as provided in § 20.1703, or the assessment of intake is based on bioassays, the licensee shall assume that an individual inhales radioactive material at the airborne concentration in which the individual is present. (c) When specific information on the physical and biochemical properties of the radionuclides taken into the body or the behavior or the material in an individual is known, the licensee may— (1) Use that information to calculate the committed effective dose equivalent, and, if used, the licensee shall document that information in the individual's record; and (2) Upon prior approval of the Commission, adjust the DAC or ALI values to reflect the actual physical and chemical characteristics of airborne radioactive material (e.g., aerosol size distribution or density); and (3) Separately assess the contribution of fractional intakes of Class D, W, or Y compounds of a given radionuclide (see appendix B to part 20) to the committed effective dose equivalent. (d) If the licensee chooses to assess intakes of Cla

official document · source cfr-2024 · id 10:§ 20.1204