1. 1. If multiple sources of the same radionuclide and/or multiple radionuclides are aggregated at a location, the sum of the ratios of the total activity of each of the radionuclides shall be determined to verify whether the activity at the location is less than the category 1 or category 2 thresholds of Table 1, as appropriate. If the calculated sum of the ratios, using the equation below, is greater than or equal to 1.0, then the applicable requirements of this part apply.

2. 2. First determine the total activity for each radionuclide from Table 1. This is done by robadding the activity of each individual source, material in any device, and any loose or bulk material that contains the radionuclide. Then use the equation below to calculate the sum of the ratios by inserting the total activity of the applicable radionuclides from Table 1 in the numerator of the equation and the corresponding threshold activity from Table 1 in the denominator of the equation.

   Calculations shall be performed in metric values (i.e., TBq) and the numerator and denominator values shall be in the same units.

   R1 = total activity for radionuclide 1

   R2 = total activity for radionuclide 2

   Rn = total activity for radionuclide n

   ARi = activity threshold for radionuclide 1

   AR2 = activity threshold for radionuclide 2

   ARn = activity threshold for radionuclide n

Arizona Revised Statutes § 30-673, as amended, provides for criminal sanctions for willful violation of, attempted violation of, or conspiracy to violate, any rule issued under A.A.C. Title 9, Chapter 7. For purposes of this Section, all the rules in this Article are issued under A.R.S. § 30-673 or the rules of the Department.

Appendix A. - Table 1 - Category 1 and Category 2 Threshold

The terabecquerel (TBq) values are the regulatory standard. The curie (Ci) values specified are obtained by converting from the TBq value. The curie values are provided for practical usefulness only.

Note: Calculations Concerning Multiple Sources or Multiple Radionuclides

The “sum of fractions” methodology for evaluating combinations of multiple sources or multiple radionuclides is to be used in determining whether a location meets or exceeds the threshold and is thus subject to the requirements of this part.

Historical Note

New Article 19, Appendix A, Table 1 recodified from 12 A.A.C. 1, Article 19, Appendix A, Table 1 at 24 A.A.R. 813, effective March 22, 2018 (Supp. 18-1).

Amended by final expedited rulemaking at 28 A.A.R. 3533 (November 18, 2022), with an immediate effective date of November 2, 2022 (Supp. 22-4).

Historical Note

New Section R9-7-19109 recodified from R12-1-19109 at 24 A.A.R. 813, effective March 22, 2018 (Supp. 18-1).