High Radiation Area

DOE-HDBK-1109-97

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

Instructor's Guide

High Radiation Area: Any area accessible to individuals in which radiation levels could result in an

individual receiving a deep dose equivalent in excess of 0.1 rem (0.001 sievert) in 1 hour at 30 centimeters

from the radiation source or from any surface that the radiation penetrates (10 CFR 835.2(a)).

Incidental X-ray device: A device that emits or produces X-rays in the process of its normal operation, in

which the X-rays are an unwanted byproduct of the device's intended use. Examples include video

display terminals, electron microscopes, high-voltage electron guns, electron beam welders, ion implant

devices, microwave cavities used as beam guides, radio-frequency cavities, microwave generators

(magnetrons/klystrons), and field-emission electron beam diodes.

Installation: A radiation source, with its associated equipment, and the space in which it is located.

Installation enclosure: The portion of an X-ray installation that clearly defines the transition from a

noncontrolled to a controlled area and provides such shielding as may be required to limit the dose rate in

the noncontrolled area during normal operations.

Intentional X-ray device: A device in which electrons undergo acceleration in a vacuum and collide with

a metal anode target designed to produce X-rays for a particular application. Examples include diagnostic

medical/dental X-ray devices, electron LINACs used in radiation therapy applications, portable and fixed

flash X-ray systems, X-ray diffraction and fluorescence analysis equipment, cabinet X-ray systems, some

Van de Graaff generators, and electron LINACs.

Interlock: A device for precluding access to an area of radiation hazard either by preventing entry or by

automatically removing the hazard when the device is actuated.

Ion: An atom, or molecule bearing an electric charge, or an electron that is not associated with a nucleus.

Ionizing radiation: Any electromagnetic or particulate radiation capable of producing ions, directly or

indirectly, by interaction with matter, including gamma and X-rays and alpha, beta, and neutron particles.