Title 18 . Environmental Conservation

Chapter 85 . Administrative Enforcement

Section 160. Limits of airborne radioactive material in controlled areas

18 AAC 85.160. Limits of airborne radioactive material in controlled areas

(a) No registrant shall possess, use, receive, or transfer radioactive materials in such a manner as to cause an individual in a controlled area to be exposed to airborne radioactive material in an average concentration in excess of the limits specified in Table IV, Part I. "Expose," as used in this section, means that the individual is present in an airborne concentration. No allowance shall be made for the use of protective clothing or equipment or particle size, except as authorized by the department according to paragraph (c) of this section.

(b) The limits in Table IV, Part I are based upon exposure to the concentrations specified for 40 hours in any period of seven consecutive days. In any such period where the number of hours of exposure is less than 40, the limits specified in the table may be increased proportionately. In any such period where the number of hours of exposure is greater than 40, the limits specified in the table shall be decreased proportionately.

(c) Except as authorized by the department in this section, no allowance shall be made for particle size or the use of protective clothing or equipment in determining whether an individual is exposed to an airborne concentration in excess of the limits specified in Table IV, Part I:

(1) the department may authorize a registrant to expose an individual in a controlled area to airborne concentrations in excess of the limits specified in Table IV, Part I upon receipt of an application demonstrating that the concentration is composed in whole or in part of particles of such size that such particles are not respirable and that the individual will not inhale the concentrations, and a description of the methods used in determining the particle size;

(2) the department may authorize a registrant to expose an individual in a controlled area to airborne concentrations in excess of the limits specified in Table IV, Part I upon receipt of an application demonstrating that the individual will wear appropriate protective equipment and that the individual will not inhale, ingest, or absorb quantities of radioactive material in excess of those which might otherwise be permitted under this part for individuals in controlled areas during a 40-hour week. Each application under this subparagraph shall contain the following information:

(A) a description of the protective equipment to be employed, including the efficiency of the equipment for the material involved;

(B) procedures for the fitting, maintenance, and cleaning of the protective equipment; and

(C) procedures governing the use of the protective equipment, including supervisory procedures and length of time the equipment will be used by the individuals in each work week.

TABLE IV CONCENTRATIONS IN AIR AND WATER ABOVE NATURAL BACKGROUND Part I Part II Column 1 Column 2 Column 1 Column 2 Radioactive Air Water Air Water Material Solubility (uc/ml) (uc/ml) (uc/ml) (uc/ml) Bismuth 210 (Bi 210) S 6 x 10 -9 1 x 10 -3 2 x 10 -10 4 x 10 -5 I 6 x 10 -9 1 x 10 -3 2 x 10 -10 4 x 10 -5 Lead 210 (Pb 210) S 1 x 10 -10 4 x 10 -6 4 x 10 -12 1 x 10 -7 I 2 x 10 -10 5 x 10 -3 8 x 10 -12 2 x 10 -4 Polonium 210 (Po 210) S 5 x 10 -10 2 x 10 -5 2 x 10 -11 7 x 10 -7 I 2 x 10 -10 8 x 10 -4 7 x 10 -12 3 x 10 -5 Radium 224 (Ra 224) S 5 x 10 -9 7 x 10 -5 2 x 10 -10 2 x 10 -6 I 7 x 10 -10 2 x 10 -4 2 x 10 -11 5 x 10 -6 Radium 226 (Ra 226) S 3 x 10 -11 4 x 10 -7 3 x 10 -12 3 x 10 -8 I 5 x 10 -11 9 x 10 -4 2 x 10 -12 3 x 10 -5 Radium 228 (Ra 228) S 7 x 10 -11 8 x 10 -7 2 x 10 -12 3 x 10 -8 I 4 x 10 -11 7 x 10 -4 1 x 10 -12 3 x 10 -5 Radon 220 (Rn 220) - 3 x 10 -7 - 1 x 10 -8 - Radon 222 (Rn 222) - 1 x 10 -7 - 3 x 10 -9 - Beta and/or gamma emitters not listed above with half life less than 2 hours - 1 x 10 -6 - 3 x 10 -8 - Beta and/or gamma emitters not listed above with half life greater than 2 hours - 3 x 10 -9 9 x 10 -5 1 x 10 -10 3 x 10 -6 Alpha emitters not listed above - 6 x 10 -13 4 x 10 -7 2 x 10 -14 3 x 10 -8

1 Soluble (S): Insoluble (I)

History: Eff. 9/16/71, Register 39

Authority: AS 46.03.020

AS 46.03.260

Editor's note: In any case where there is a mixture in air or water of more than one radionuclide, the limiting values for purposes of this table should be determined as follows:

(1) If the identity and concentration of each radionuclide in the mixture are known, the limiting value should be derived as follows: Determine, for each radionuclide in the mixture, the ratio between its concentration in the mixture and its limiting concentration established in this table. The sum of such ratios for all radionuclides in the mixture shall not exceed unity.

(2) If either the identity or the concentration of any radionuclide in the mixture is not known the limiting values for purposes of this table shall be the same as those shown at the bottom of the table for "Alpha emitters not listed above."

(3) If the identity of each radionuclide in the mixture is known but the concentration of one or more of the radionuclides in the mixture is not known, the concentration limit for the mixture is the limit specified in this table for the radionuclide in the mixture having the lowest concentration limit.