(1) “Access panel” means any barrier or panel which is designed to be removed or opened for maintenance or service purposes, requires tools to open, and permits access to the interior of the cabinet;

(2) “Aperture” means any opening in the outside surface of the cabinet, other than a port, which remains open during generation of X-rays;

(3) “Door” means any barrier which is designed to be movable or opened for routine operation purposes, does not generally require tools to open, and permits access to the interior of the cabinet;

(4) “External surface” means the outside surface of the radiation machine, including the high-voltage generator, doors, access panels, latches, control knobs, and other permanently mounted hardware and including the plane across any aperture or port;

(5) “Ground fault” means an accidental electrical grounding of an electrical conductor;

(6) “Port” means any opening in the outside surface of the radiation machine which is designed to remain open, during generation of X-rays, for the purpose of conveying material to be irradiated into and out of the cabinet, or for partial insertion for irradiation of an object whose dimensions do not permit complete insertion into the cabinet;

(7) “Primary beam” means the radiation emitted directly from the target and passing through the window of the X-ray tube;

(8) “Safety interlock” means a device, which is intended to prevent the generation of radiation when access by any part of the human body to the interior of the detection system through a door or access panel is possible;

(9) X-ray system means an assemblage of components for the controlled generation of X-rays;

(10) “X-ray tube” means any electron tube, which is designed for the conversion of electrical energy into X-ray energy.

(1) Radiation emitted from the system shall not, under any condition of use, exceed an exposure of 0.5 milliroentgen in one hour at any point five centimeters (cm) outside the external surface, or any door or port. The exposure shall be determined by measurements averaged over a cross-sectional area of ten square cm with no linear dimension greater than five cm with doors and access panels fully closed as well as fixed at any position, which will allow the generation of X-rays;

(2) The insertion of any part of the human body through any port into the primary beam shall not be possible. The insertion of any part of the human body through any aperture shall not be possible;

(3) The system shall have a lock-and-key control, which will ensure that X-ray generation is not possible with the key removed. When the system is not in use, the key shall be removed and controlled to prohibit unauthorized use of the system;

(4) The system shall have a control or controls to initiate and terminate the generation of X-rays other than by functioning of a safety interlock or the main power control;

(5) The system shall have two independent means (indicators), which indicate when and only when X-rays are being generated. At least one of the indicators shall be illuminated when X-rays are being generated. One, but not both, of the required indicators may be a milliammeter labeled to indicate X-ray tube current. All other indicators shall be legibly labeled “X-RAY ON.” If the X-ray generation period is less than one-half second, the indicators shall be activated for one-half second and shall be discernible from any point at which initiation of X-ray generation is possible. Failure of a single component of the system shall not cause failure of both indicators to perform their intended function. The system shall have additional means other than milliammeters as needed to insure that at least one indicator is visible from each door, access panel, and port. If the X-ray generation period is less than one-half second, the indicators shall be activated for one-half second and be legibly labeled “X-RAY ON”;

(6) In systems used to inspect objects such as, but not limited to, baggage, boxes, backpacks, purses, and mail, the system shall be designed such that:

(7) There shall be permanently affixed or inscribed:

(8) Each door shall have a minimum of two safety interlocks. One, but not both of the required interlocks shall be such that door opening results in physical disconnection of the energy supply circuit to the high-voltage generator, and such disconnection shall not be dependent upon any moving part other than the door;

(9) Each access panel shall have at least one safety interlock;

(10) Following interruption of X-ray generation by the functioning of any safety interlock, use of a control provided in accordance with subsection (b)(4) shall be necessary for resumption of X-ray generation;

(11) Failure of any single component of the system shall not cause failure of more than one required safety interlock; and

(12) A ground fault shall not result in the generation of X-rays.

(1) Received copies of, instruction in, and demonstrated understanding of, the user's operating and emergency procedures by obtaining a passing grade of at least 80 percent on a written examination covering this material. The written examination shall be at least 50 questions in length; and

(2) Demonstrated competence to use the radiation machines by obtaining a passing grade of at least 80 percent on a practical examination covering this material. The practical examination shall be at least 25 questions in length. An individual operating such a system need not obtain radiographer certification.