Lead equivalent

DOE-HDBK-1109-97

Radiological Safety Training for Radiation-Producing (X-Ray) Devices

Instructor's Guide

Lead equivalent: The thickness of lead affording the same attenuation, under specific conditions, as the

shielding material in use.

Leakage radiation: Any radiation, except the useful beam, coming from the X-ray assembly or sealed

source housing.

Medical X-ray system: An X-ray system for medical use, generally categorized as either diagnostic or

therapeutic. Diagnostic X-ray procedures are used to obtain images of body parts; therapeutic x-ray

procedures are used to manage malignancies.

Normal operation: Operation under conditions as recommended by the manufacturer of an X-ray system

or as specified by a written SOP. Recommended shielding and interlocks shall be in place and operable.

Occupancy factor: The factor by which the workload should be multiplied to correct for the degree or

type of occupancy of the area specified.

Open-beam system: An analytical X-ray system in which one or more X-ray paths (primary as well as

secondary) are not fully enclosed.

Open installation: An industrial X-ray installation that, because of operational requirements or temporary

needs, cannot be provided with the inherent degree of protection specified for other classes of industrial

installations. Generally mobile or portable equipment where fixed shielding cannot be effectively used.

Port: In this context, an opening on the outside surface of the cabinet that is designed to remain open

during X-ray production for the purpose of moving material to be irradiated into and out of the cabinet, or

for partial insertion of an object that will not fit inside the cabinet.

Primary beam: The X-radiation emitted directly from the target and passing through the window of the

X-ray tube.