Glossary cont'd - doe-hdbk-1106-97

DOE-HDBK-1106-97

GLOSSARY (Continued)

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 calculated for a continuous, non-shielded exposure via immersion in a

semi-infinite atmospheric cloud. The value is based upon the derived airborne concentration

found in Table 1 of the U.S. Environmental Protection Agency's Federal Guidance Report No. 11,

Limiting Values of Radionuclide Intake and Air