DHS 157.03(50)(e)(e) Any discrete source of naturally occurring radioactive material, other than source material, that the NRC, in consultation with the Administrator of the Environmental Protection Agency, the Secretary of Energy, the Secretary of Homeland Security, and the head of any other appropriate federal agency, determines would pose a threat similar to the threat posed by a discrete source of radium-226 to the public health and safety or the common defense and security, and is extracted or converted after extraction for use in a commercial, medical or research activity.

DHS 157.03(51)(51) “Cabinet radiography” means industrial radiography conducted in an enclosure or cabinet so shielded that every location on the exterior meets the dose limits for individual members of the public as specified in s. DHS 157.23 (1).

DHS 157.03(52)(52) “Cabinet x-ray system” means an x-ray system, manufactured under the requirements of 21 CFR 1020.40, with an x-ray tube installed in an enclosure that is independent of existing architectural structures except the floor. The cabinet x-ray system is intended to contain at least that portion of a material being irradiated, provide radiation attenuation and exclude personnel from its interior during generation of radiation. “Cabinet x-ray system” includes x-ray systems designed primarily for the inspection of carry-on baggage at airline, railroad and bus terminals and in similar facilities. An x-ray tube used within a shielded part of a building or x-ray equipment that may temporarily or occasionally incorporate portable shielding is not considered a cabinet x-ray system.

DHS 157.03(53)(53) “Calendar quarter” means a period of time equal to one-fourth of the year observed by the licensee or registrant, providing that the beginning of the first quarter in a year coincides with the starting date of the year and that no day is omitted or duplicated in consecutive quarters.

DHS 157.03(54)(54) “C-arm x-ray system” means an x-ray system in which the image receptor and x-ray tube housing assembly are connected by a common mechanical support system to maintain a desired spatial relationship. The system allows the operator to change the projection of the beam through the patient without changing the position of the patient.

DHS 157.03(55)(55) “Calibration” means determining either of the following:

DHS 157.03(56)(56) “Carrier” means a person engaged in the transportation of passengers or property by land or water as a common, contract or private carrier or by civil aircraft.

DHS 157.03(56g)(56g) “Category 1 quantity of radioactive material” means a quantity of radioactive material meeting or exceeding the category 1 threshold in ch. DHS 157 Appendix U.

DHS 157.03 NoteNote: This is determined by calculating the ratio of the total activity of each radionuclide to the category 1 threshold for that radionuclide and adding the ratios together. If the sum is equal to or exceeds 1, the quantity would be considered a category 1 quantity. Category 1 quantities of radioactive material do not include the radioactive material contained in any fuel assembly, subassembly, fuel rod, or fuel pellet. Chapter DHS 157 Appendix U is used to determine the category 1 threshold for a category 1 quantity of radioactive material. The category 1 and category 2 thresholds in ch. DHS 157 Appendix U and ch. DHS 157 Appendix T are not interchangeable.

DHS 157.03(56r)(56r) “Category 2 quantity of radioactive material” means a quantity of radioactive material meeting or exceeding the category 2 threshold, but less than the category 1 threshold in ch. DHS 157 Appendix U.

DHS 157.03 NoteNote: This is determined by calculating the ratio of the total activity of each radionuclide to the category 2 threshold for that radionuclide and adding the ratios together. If the sum is equal to or exceeds 1, the quantity would be considered a category 2 quantity. Category 2 quantities of radioactive material do not include the radioactive material contained in any fuel assembly, subassembly, fuel rod, or fuel pellet. Chapter DHS 157 Appendix U is used to determine the category 2 threshold for a category 2 quantity of radioactive material. The category 1 and category 2 thresholds in ch. DHS 157 Appendix U and ch. DHS 157 Appendix T are not interchangeable.

DHS 157.03(57)(57) “Cephalometric device” means a device intended for the radiographic visualization and measurement of the dimensions of the human head.

DHS 157.03(57c)(57c) “Certifiable cabinet x-ray system” means an existing uncertified radiation generating device that has been modified to meet the certification requirements specified in 21 CFR 1020.40.

DHS 157.03(57g)(57g) “Certificate holder” means a person who has been issued a certificate of compliance or other package approval by the U.S. nuclear regulatory commission.

DHS 157.03(57r)(57r) “Certificate of Compliance” or “CoC” means the certificate issued by the U.S. nuclear regulatory commission under subpart D of 10 CFR 71 which approves the design of a package for the transportation of radioactive material.

DHS 157.03(57w)(57w) “Certified cabinet x-ray system” means a radiation generating device certified by the manufacturer in accordance with 21 CFR 1010.2 as being manufactured and assembled pursuant to the provisions of applicable federal radiation safety performance standards 21 CFR 1010 and 1020.40.

DHS 157.03(58)(58) “Certified components” means components of x-ray systems subject to 21 CFR 1010.2.

DHS 157.03(59)(59) “Certified system” means any x-ray system that has one or more components certified under 21 CFR 1010.2.

DHS 157.03(60)(60) “Certifying entity” means an independent certifying organization meeting the requirements in 10 CFR 34, Appendix A or an agreement state meeting the requirements in 10 CFR 34, Appendix A, Parts II and III.

DHS 157.03(61)(61) “Changeable filters” means any filter, exclusive of inherent filtration, that may be removed from the useful beam through any electronic, mechanical or physical process.

DHS 157.03(62)(62) “Chelating agent” means a chemical compound used to remove radioactive material from other substances.

DHS 157.03(63)(63) “Chiropractor” means an individual licensed under ch. 446, Stats., to practice chiropractic.

DHS 157.03(64)(64) “Class” means a classification scheme for inhaled material according to the material’s rate of clearance from the pulmonary region of the lung. Materials are classified as D, W or Y, depending on the amount of time half of the material clears from human lungs. Half of class D material clears from lungs in less than 10 days; half of class W material clears from lungs in from 10 to 100 days; and half of class Y material clears from lungs in greater than 100 days.