Glossary cont'd - doe-hdbk-1108-2002

DOE-HDBK-1108-2002

Radiological Training for Accelerator Facilities

Handouts

Glossary - Continued

Decommissioning: The process of closing and securing a nuclear facility, or nuclear

materials storage facility, so as to provide adequate protection from radiation exposure

and to isolate radioactive contamination from the human environment.

Depleted Uranium: Uranium having a percentage of uranium-235 smaller than the 0.7%

found in natural uranium.

Derived Air Concentration (DAC): The airborne concentration that equals the ALI

divided by the volume of air breathed by an average worker for a working year of 2,000

hours (assuming a breathing volume of 2,400 m3).

Detector: Any device that can detect the presence of an energetic electromagnetic

radiation particle or nuclear fragment and measure one or more of its properties.

Electromagnetic Radiation: A traveling wave motion resulting from changing electric or

magnetic fields. Familiar electromagnetic radiations range from X-rays and gamma rays

of short wavelength, through the ultraviolet, visible and infrared regions, radar and radio

waves of relatively long wavelength.

Enclosed Beam: All possible X-ray beam paths are fully contained in protective

enclosures so that no part of the body can intercept the beam during normal operation.

Electron volt: A unit of energy equivalent to the energy gained by an electron in passing

through a potential difference of one volt.

Exclusion Area: Any area to which access is prohibited for the purposes of protection of

individuals.

Fail-Safe: A design feature built into a system or system component so that the most

likely mode of failure causes the production of X-rays to be turned off. If fail-safe design

is not possible or cost-effective, the system or system component should be designed so

that no single failure will cause unsafe operation.

Interlock: A safety device that automatically renders an area safe from prompt radiation

when the device is actuated.

Linear accelerator: A device that accelerates charged particles along a straight line.

Mixed Waste: Waste containing both radioactive and hazardous components as defined

by the Atomic Energy Act and the Resource Conservation and Recovery Act,

respectively.

Muon: An elementary particle apparently identical to the electron except for being 200

times heavier.