Other radiation-generating devices - DOE-HDBK-1141-2001

Radiological Assessor Training

DOE-HDBK-1141-2001

Student's Guide

VII. Other radiation-generating devices

Other radiation-generating devices (RGDs) that may

be encountered are small particle accelerators (<10

MeV) used for radiography, ion implantation, or the

production of incidental photons or particles

Some RGDs produce radiation incidental to their

primary purpose. Examples of devices that produce

radiation incidentally are electron beam welders,

electron microscopes, and pulse generators.

VIII. Categorizing RGD installations

The ANSI standards referenced earlier categorize

RGD installations into the following categories for

radiation safety purposes.

A. Exempt shielded installations

The RGD and all objects exposed to the source

of radiation shall be within a permanent

enclosure that, under all circumstances of use,

possesses sufficient inherent shielding and

prevents inadvertent entry to any part of the

body. The exposure at any accessible region 5

cm from the outside surface of the enclosure

shall not exceed 0.5 mrem in any one hour.

B. Shielded installation

The RGD and all objects exposed to the source

are within a permanent enclosure from which

persons are excluded during the irradiation.

Some of the requirements for shielded

installations include mandatory interlocks,

audible and visual warning devices, a "crash"

button, and posting of warning signs.

Skyshine is the term used to describe radiation

emerging more or less vertically from a shielded

enclosure, which then scatters from air

molecules to produce radiation at some distance

from the source.

Module 12 - 8