Section He-P 4020.08 - Determination of Internal Exposure(a) For purposes of assessing dose used to determine compliance with occupational dose equivalent limits, the licensee or registrant shall, when required pursuant to He-P 4022.02, take measurements of: (1) Concentrations of radioactive materials in air in work areas;(2) Quantities of radionuclides in the body;(3) Quantities of radionuclides excreted from the body; or(4) Any combinations of these measurements.(b) Unless respiratory protective equipment is used, as provided in He-P 4022.08, or the assessment of intake is based on bioassays, the licensee or registrant 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 of the material in an individual is known, the licensee or registrant may: (1) Use that information to calculate the committed effective dose equivalent;(2) Adjust the DAC or ALI values to reflect the actual physical and chemical characteristics of airborne radioactive material, only if:a. The licensee or registrant submits the proposed adjustments to the DHHS/RHS for review;b. The DHHS/RHS determines upon its review that the proposed adjustments are technically correct, appropriately applied, and consonant with the accepted principles and practices of health physics; andc. The DHHS/RHS has granted its approval; and(3) Separately assess the contribution of fractional intakes of Class D, W, or Y compounds of a given radionuclide to the committed effective dose equivalent in accordance with He-P 4090.(d) If the licensee or registrant uses specific information on the physical and biochemical properties of radionuclides taken into the body or the known behavior of material in an individual to calculate the committed dose equivalent for that individual, then the licensee or registrant shall document such information in the individual's record.(e) If the licensee or registrant chooses to assess intakes of Class Y material using the measurements given in He-P 4020.08(a) (2) or (3) in order to make additional measurements basic to the assessments, the licensee or registrant may delay the recording and reporting of the assessments for periods up to 7 months, unless otherwise required by He-P 4021.13 or 4021.14.(f) If the identity and concentration of each radionuclide in a mixture are known, the fraction of the DAC applicable to the mixture for use in calculating DAC-hours shall be either: (1) The sum of the ratios of the concentration to the appropriate DAC value, that is, D, W, or Y, from He-P 4090 for each radionuclide in the mixture; or(2) The ratio of the total concentration for all radionuclides in the mixture to the most restrictive DAC value for any radionuclide in the mixture.(g) If the identity of each radionuclide in a mixture is known, but the concentration of one or more of the radionuclides in the mixture is not known, the DAC for the mixture shall be the most restrictive DAC of any radionuclide in the mixture.(h) When a mixture of radionuclides in air exists, a licensee or registrant may disregard certain radionuclides in the mixture if: (1) The licensee or registrant uses the total activity of the mixture in demonstrating compliance with the dose limits in He-P 4020.05 and in complying with the monitoring requirements in He-P 4022.02(c) ;(2) The concentration of any radionuclide disregarded is less than 10 percent of its DAC; and(3) The sum of these percentages for all of the radionuclides disregarded in the mixture does not exceed 30 percent.(i) When determining the committed effective dose equivalent, the following information may be considered: (1) In order to calculate the committed effective dose equivalent, the licensee may assume that the inhalation of one ALI, or an exposure of 2,000 DAC-hours, results in a committed effective dose equivalent of 0.05 Sv or "5 rem" for radionuclides that have their ALIs or DACs based on the committed effective dose equivalent;(2) The licensee or registrant may use the stochastic ALI to determine committed effective dose equivalent; and(3) If the licensee or registrant uses the stochastic ALI, the licensee or registrant shall also demonstrate that the limit in He-P 4020.05(a) (1) b. is met.N.H. Admin. Code § He-P 4020.08
#5903, eff 2-1-95; ss by #6827, eff 8-6-98; ss by #8481, eff 11-5-05
Amended byVolume XXXIV Number 24, Filed June 12, 2014, Proposed by #10604, Effective 5/23/2014, Expires 5/23/2024.