Texas Administrative Code
Title 30 - ENVIRONMENTAL QUALITY
Part 1 - TEXAS COMMISSION ON ENVIRONMENTAL QUALITY
Chapter 336 - RADIOACTIVE SUBSTANCE RULES
Subchapter M - LICENSING OF RADIOACTIVE SUBSTANCES PROCESSING AND STORAGE FACILITIES
Section 336.1231 - Radioactive Substances Processing and Storage Categories of Radionuclides

(1) If the identity and respective activity of each radionuclide are known, the permissible activity of each radionuclide shall be such that the sum, for all categories present, of the ratio between the total activity for each category to the permissible activity for each category will not be greater than unity.

(2) If the categories of the radionuclides are known but the amount in each category cannot be reasonably determined, the mixture must be assigned to the most restrictive category present.

(3) If the identity of all or some of the radionuclides cannot be reasonably determined, each of those unidentified radionuclides shall be considered as belonging to the most restrictive category that cannot be positively excluded.

(4) Mixtures consisting of a single radioactive decay chain where the radionuclides are in the naturally occurring proportions must be considered as consisting of a single radionuclide. The category and activity must be that of the first member present in the chain, except that if radionuclide "X" has a half-life longer than that of that first member and an activity greater than that of any other member, including the first, at any time during processing, the waste processing and storage category must be that of nuclide "X" and the activity of the mixture must be the maximum activity of nuclide "X" during processing.