Glossary cont'd - DOE-HDBK-1109-97

DOE-HDBK-1109-97

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

Student's Guide

GLOSSARY (continued)

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

receiving a deep dose equivalent in excess of 0.005 rem (0.05 millisievert) in 1 hour at 30 centimeters from

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

Radiation source: A device or a material that is capable of emitting ionizing radiation.

Radiological worker: A general employee whose job assignment involves operation of radiation-

producing devices or working with radioactive materials, or who is likely to be routinely occupationally

exposed above 0.1 rem per year total effective dose equivalent. (10 CFR 835.2(a))

Radiological control technician (RCT): Any person who is actively engaged in or who has completed

facility-specific RCT training and qualification programs.

Rem (roentgen equivalent man): The unit of dose equivalence used for humans, which considers the

biological effects of different types of radiation. The dose equivalent in rem is numerically equal to the

absorbed dose in rad multiplied by the applicable quality factor.

Roentgen (R): The unit of exposure. One roentgen equals 2.58 x 10-4 coulomb per kilogram of air.

Scattered radiation: Radiation that has been deviated in direction as a result of interaction with matter

and has usually been reduced in energy.

Secondary radiation: Radiation (electrons, X-rays, gamma rays, or neutrons) produced by the interaction

of primary radiation with matter.

Shielding: Attenuating material used to reduce the transmission of radiation. The two general types of

shielding are primary and secondary. Primary shielding is material sufficient to attenuate the useful beam

to the required level. Secondary shielding is material sufficient to attenuate stray radiation to the required

level.

Shielded installation: An industrial X-ray installation in which the source of radiation and all objects

exposed to that source are within a permanent enclosure.