Glossary cont'd - hdbk110697

DOE-HDBK-1106-97

GLOSSARY (continued)

Characteristic X-ray: X-rays that are characteristic of the element in which they are produced. Their

emission results from the rearrangement of electrons in the shells of excited atoms.

Contamination: Undesired (e.g., radioactive or hazardous) material that is deposited on the surface of, or

internally ingrained into, structures or equipment, or that is mixed with another material.

Radioactive Contamination: A radioactive substance dispersed in materials or places where it is

undesirable.

Fixed Contamination: Radioactivity remaining on a surface after repeated decontamination

attempts fail to significantly reduce the contamination level.

Removable Contamination: That fraction of the radioactive contamination present on a surface that

can be transferred to a swipe tab by rubbing with moderate pressure.

Surface Contamination: The deposition and attachment of radioactive materials to a surface, also

the resulting deposit.

Continuous Air Monitor (CAM): Instrument that continuously samples and measures the levels of

airborne radioactive materials on a "real time" basis and has alarm capabilities at preset levels.

Controlled Area: Any area to which access is managed to protect individuals from exposure to radiation

and/or radioactive materials.

Curie: The unit of activity equal to a rate of 3.7 X 1010 nuclear disintegrations per second.

Decontamination: The reduction or removal of contaminating radioactive material from a structure, area,

object, or person. Decontamination may be accomplished by treating the surface to remove or decrease

the contamination, or by letting the material stand so that the radioactivity is decreased as a result of

natural decay.

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

2400 m3). For the radionuclides listed in Appendix C of 10 CFR 835, the air immersion DACs were