Regulations Flashcards
Annual limit on intake (ALI)
ALI is the derived limit for the amount of radioactive material taken into the body of an adult worker by inhalation or ingestion in a year. ALI is the smaller value of intake of a given radionuclide in a year by the “reference man” that would result in a committed effective dose equivalent (CEDE) of 5 rems (0.05 sievert) or a committed dose equivalent (CDE) of 50 rems (0.5 sievert) to any individual organ or tissue.
Deterministic effect
The health effects of radiation, the severity of which varies with the dose and for which a threshold is believed to exist. Radiation-induced cataract formation is an example of a deterministic effect (also called a non-stochastic effect) (see 10 CFR 20.1003).
Radiation area threshold
Any area with radiation levels > 5 millirems (0.05 millisievert) in one hour at 30 centimeters from the source or from any surface through which the radiation penetrates.
Quality Factor
The factor by which the absorbed dose (rad or gray) is to be multiplied to obtain a quantity that expresses, on a common scale for all ionizing radiation, the biological damage (rem or sievert) to an exposed individual. It is used because some types of radiation, such as alpha particles, are more biologically damaging internally than other types.
Controlled area
At a nuclear facility, an area outside a restricted area but within the site boundary, to which the licensee can limit access for any reason.
Restricted area
Any area to which access is controlled for the protection of individuals from exposure to radiation and radioactive materials.
Stochastic Effect
Effects that occur by chance, generally occurring without a threshold level of dose, whose probability is proportional to the dose and whose severity is independent of the dose. In the context of radiation protection, the main stochastic effects are cancer and genetic effects.
Derived Air Concentration (DAC)
The concentration of a given radionuclide in air which, if breathed by the reference man for a working year of 2,000 hours under conditions of light work (with an inhalation rate of 1.2 cubic meters of air per hour), results in an intake of one annual limit on intake (ALI). Established DAC values are given in Table 1, Column 3, of Appendix B to Title 10, Part 20, of the Code of Federal Regulations (10 CFR Part 20), “Standards for Protection Against Radiation.”
Lens dose equivalent
The external exposure dose equivalent to the lens of the eye at a tissue depth of 0.3 centimeters (300 mg/cm2).
Somatic effects
Effects of radiation limited to the exposed individual, as distinguished from genetic effects, that may also affect subsequent unexposed generations.
Very high radiation area
An area accessible to individuals, in which radiation levels exceed 500 rad (5 gray) in one hour at 1 meter from the source or from any surface that the radiation penetrates (see 10 CFR 20.1003).
Annual total effective dose equivalent limit for a radiation worker
5 rem / yr (50 mSv / yr)
Annual deep-dose equivalent or committed dose equivalent limit to any organ or tissue othre than the lens of the eye
50 rem or 500 mSv
Annual limit lens dose
15 rem or 150 mSv
Annual limit shallow-dose to the skin or extremity for radiation worker
50 rem or 500 mSv
